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Tandy`s Little Wonder - CoCo/OS

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1. rrr page 126 Tandy s Little Wonder page 127 Tandy s Little Wonder page 128 Tandy s Little Wonder mae MICHOCOMPUTADORSSCOLOR There was law in Brazil in the 1980s preventing foreign computer makers from im porting products This was to help the Brazilian electronics industry Proligica teamed up with Sinclair at first to make a ZX 81 clone the CP 200 It then teamed with Tandy to produce the CP 300 and CP 500 TRS 80 Model clones the 500 being aimed at the business market the 300 for the home market This led to a CoCo2 clone the CP 400 Cartridges fit in the front under the hinged lid on the right and the trans former was outside the case This is a true clone licensed from Tandy but with a Brazil ian designed case The ROMS were edited to display Prologica instead of Tandy CoCo cartridges won t fit the CP 400 case but programs are compatible NOTE These photos are from an e bay auction not from Dave Dunfield s page Tandy s Little Wonder page 129 It is unknown whether or not the Sampo Color Computer ever actually hit the marketplace anywhere though it was advertised briefly in the November 1982 issue of BYTE magazine in a special advertising section entitled Computers in Taiwan According to the ad the Sampo Color Computer uses the 6809E CPU and Extended BASIC the same general features fo
2. Level 1 willrunonaCoCo 1 or2 with 64 of memory It willalso run on a 3 but won t access more than 64K Level 2 and Level 3 are exclusively for the CoCo 3 Level 2 is compatible with OS 9 Level 2 which utilizes up 2MB of memory Level 3 is still under development It will contain additional features to manage system memory more efficiently Atthe time of this printing Feb 2006 only four distributions were available NitrOS 9 6809 Level 1 for the CoCo 1 and 2 NitrOS 9 6809 Level 1 for the Dragon 64 NitrOS 9 6809 Level 2 for the CoCo 3 NitrOS 9 6309 Level 2 for the CoCo 3 Few CoCo 1 and 2 users utilize a 6309 so those distributions may not appear All levels should be compatible with lower levels but programs written using higher level features natu rally won t run on lower level systems For more information and to download the available distribu tions in DSK format point your browser to http www nitros9 org DSK files are images of CoCo compatible disks There are instructions on the site for transferring DSK format files to an actual CoCo OS 9 disk NitrOS 9 is distributed as two 40 track double sided disk files and one 80 track double sided file Another source of a simplified DSK file is http nitros9 stg net page 53 Support where to go from here UPDATED FEB 2006 Where does one go for support The local Radio Shack won t be much of much help they ran out of Color Compute
3. o RESO 7 Tim 10088 al Ln _ 1 s Tit Xr A4 ELA Zh page 110 Tandy s Little Wonder HU M MEMETINOI MED ur man mu paii CT A eats ar era uri p rui Wintnoo m 512713 t Diades ares aot agd vsr BD33951 with dame code th e weak at Mag of after da used c n alter date code 8417 mcluda diedes CoCo 2 Korean A B is similar 2 of 2 J T 1 y EOM rmn og id 3 I 3 E itd k E der d Rada p or Jm Tandy s Little Wonder amp CoCo 3 amp 512 RAM Board 1 of 2 page 111 ee HB a Bie 0o SS BETEG ERR OE a EMAL CC LU ee a CoCo 3 amp 512K RAM Board 2 of 2 page 112 Tandy s Little Wonder LLE i k i ds 1 ad Multi Pak Interface large Tandy s Little Wonder page 113 Ss oe oes Th mem Le ee T PT Nu WES Ll mmi r 1 Lo H
4. 3 Ground 0 voltage reference GND 4 Transmit Data from computer TD Baud rate is changed by typing POKE 150 x where x is BAUD Rate Decimal Hexadecimal 120 202 CA 300 180 BE 600 87 57 1200 41 29 2400 18 12 4800 4 9600 1 Tandy s Little Wonder Cassette Interface Suggested input playback level 1 5 V peak to peak witha minimum impedance of 220 Ohms Typical output level to recorder 800mV peak to peak at 1K Ohms Remote switching relay capacity 0 5Aat 6V max Looking at connector from back of the CoCo 3 1 5 4 PIN SIGNAL 2 1 Remote Control 2 Signal Ground 3 Remote Control 4 Input from recorders EARphone jack 5 Output to recorders MIC or AUX jack Radio Shack CTR and CCR recorders use the AUX jack generic recorders use the MIC microphone jack Joystick Interface Looking at connector from back of CoCo 5 1 4 2 PIN SIGNAL 3 1 Right Left comparator input 2 Up Down comparator input 3 Ground 4 Fire button 1 high open low closed 5 5V DC 0 5A 6 Fire button 2 high open low closed A One button Mouse plugged in place of a joystick useful for some applications A white two button mouse was made for the CoCo 3 B Original joystick no self centering one button C The deluxe joystick had slide adjusters and self centering that could be turned on and off for the X and Y axis individually page 101 RGB Interface ASCII Character Codes Looking at the con
5. A dead RS 232 Pak usually has one or two blown chips the RS 232 level converters These are the 1488 and 1489 chips Check each line while sending data over the RS 232 port with aterminal program or diagnostic utility Replace the chip that supports the lines not receiving signals These are really cheap chips each chip and socket under 1 00 so don t hesitate to cut them out and replace with sockets if they are suspect Tests can be conducted at the inputs and outputs of the chip also making sure they follow each other Next check the AZTEC voltage converter This chip converts 5V tothe RS 232 standard 12V 1 and 12V 0 Check for 12V onpin5 and 12V on pin3 of the converter 12V on pin 14 of the 1488 and pin 10 ofthe 1489 on other side of resistor R2 and 12V on pin of the 1488 Don t forget to check the traces and all components between the converter and 1488 1489 chips the 33mf capacitors near the converter and 10K ohm R2 A bad 6551 ACIA is possible but rare as the level converters receive voltage spikes or surges coming in from the source first If replacing the converters fails to cure the problem the 6551 may be suspect It is easiest to check by replacing with Tandy s Little Wonder a known good unit Many Tandy and aftermarket paks have asocketed 6551 but some later Tandy units don t There have been some reports of intermittent failure of the RS 232 Pak under OS 9 Level II If this occurs test the s
6. Imm ap i Multi Pak Interface small page 114 Tandy s Little Wonder FAR sae WED 368 y p me ef 7 88 ae khaswa uou FD 501 Disk Controller FD 502 similar Tandy s Little Wonder FD 501 Disk Drive Tandy s Little Wonder RF M DULATOR POST US MC1372 Ul CARTRIDGE POWER SUPPLY X U7 METAL MC6847 VDG SHIELD U8 TPS U10 6821 6887 PIA A 7415244 12 REGULATOR 021 028 RAM CHIPS Circuit Board Layout CoCo 1 Revisions C Through E OYSTICK JD pon RIAL AS iia CHANNEL TOWER Jl 13 SWITCH 15 RESET ITCH RF MODULATOR SWITCH 09 4 U3 741 IRELAY Q 10 U11 CARTRIDGE 1 MC6809EE CPU CONNECTOR 112 Mq14050 ost POWER SUPPLY 2 020 o sr 19 MC6887 SAMTP9 74LS244 Q METAL GON ETOH U21 U28 RAM CHIPS IKEYBOARD CONNECTOR CoCo 1 TDP 100 Circuit Board Layout Revision NC also called F 285 Tandy s Little Wonder page 117 VDG CARTRIDGE CDNNECTOR U22 4LS783 RAM CHIPS American CoCo2 Korean models similar sub E L RESET MDV8 CHANNEL RF VIDEO C54 VIDEO AUDIO ODULATOR 4464 68 09 512K RAM CHIPS CPU EXPANSION 7 18 BOARD CONNECTORS 512K ls G TP4 9 TP TP9 TP10 C8 IC4 ICS IC6 IC2 e US MdqesB21
7. newer breed of machines write to us Just what do they have in mind here Will have to send a post card and find out The smaller size of OS 9 Underground meant less lead time and overhead and they were able to get the jump on Rainbow with the 6309 story Anissue ofOS 9 Underground was missing this month but the magazine was well repre sented at the October Atlanta CoCoFest What gives Alan JWT let on to what they were up to last month October s Rainbow sported a full page ad for UpTime an advertising newsletter covering all CoCo and 68xxx machines Not a magazine the newsletters function was to provide low cost advertising and product info for the supported products One year subscriptions were available for 15 in two installments of 7 50 each Nine Times OS 9 disk magazine was also continued Burke amp Burke introduced another new product Thexder OS 9 This OS 9 programtook the code from the Tandy Thexder ROM pak and patcheditfor operation under OS 9 similar to the World Class Chess program introduced earlier Gale Force advertised their NitrOS9 software this month It was now available as a kit with a 63B09E and installation instructions Missing this month was PRINT 2 Seems a lot of readers while appreciating the fact that Lonnie was keeping the Rainbow in publication would rather have more info than 1 2 page of editorial Alan Sheltra answered subscriber inquiries about the missing September OS 9 Underground wi
8. or N no go to line 420 If A string is neither the computer will go this far and start over by returning to line 120 Tandy s Little Wonder 140 CLS SOUND 150 4 LOCATE 14 16 PRINT Currently set up for 2400 baud printer and 6ms drive See comments for line 120 150 LOCATE 14 17 INPUT step rate Do you wish to change this Y N A See comments for line 120 160 IF A y OR A Y THEN 190 IF A n OR A N THEN 440 GOTO 150 See comments for line 130 190 CLS LOCATE 6 4 PRINT Select Drive Step Rate PRINT See comments for line 120 The PRINT at the end causes a blank line to be put on the screen 200 PRINTTAB 8 1 6ms 2 12ms 3 20ms PRINT the following beginning 8 spaces over 210 PRINT LOCATE 6 8 INPUT Selected Value D See comments for line 120 220 IF PEEK amp HC004 215 THEN 230 ELSE 270 Check for DECB 1 1 If present go to line 230 otherwise go to line 270 230 IF D 1 THEN POKE amp HD7C0 0 POKE amp HD816 20 GOTO320 240 IF D 2 THEN POKE amp HD7C0 0 POKE amp HD816 21 GOTO320 250 D 3 THEN POKE amp HD7C0 0 POKE amp HD816 22 GOTO320 260 IF D 4 THEN POKE amp HD7C0 0 POKE amp HD816 23 GOTO320 265 amp HD762 2 POKE the values for the specified step rate DECB 1 1 then go to line 320 see line 200 for rates Line 265 sets the number of times the computer will try to read a disk before issuing an I O ERROR in this case 2 tries no
9. 2 Aset of all the connectors on the back of the CoCo both male and female including the RGB connector if you are using an RGB monitor Cable to extend the ports and male cable type connectors will also be needed For the cleanest installation get the female chassis mount connectors that can be mounted toa plate on the back of the case Alternately get female cable type connectors and run the cables out the back of the computer They will have to be labeled in either case 4 A short 4 to 6 inch 40 pin extender cable that will go from the CoCo motherboard to the MPI Slot Pak You can make your own by removing the 40 plug on the motherboard and wiring aribbon cable in its place or get another 40 pin a 44 pin with four positions taped over on one end works nicely and solder the ribbon cable to the back of the original Tandy s Little Wonder 5 A keyboard extender cable See Upgrades for instructions on making one or contact Cloud 9 for a PC keyboard adapter 6 AVOM meter 7 Theability to use a soldering iron 8 GUTS Totakethe plunge PREPARATION 1 Make up the extender cables for the ports and check that they work properly Each cable will need to be long enough to reach through the back of your case 2 Make the extender cable for the RGB plug 3 Make the necessary arrangements for connecting the PC power supply see Power Supply Repairs to the CoCo and MPI INSTALLATION 1 Remove the CoCo motherboard and MPI fro
10. CoCo 4 Tandy should have built RAINBOW VALTER MONTY BASIC was another story the code itself required modifica me TC 9 on the FHL eventually got around most of this though it took about of a year of tinkering The first step was hardware Anemulator Rainbow circuit was devised that would intercept CoCo output and send it to the correct TC9 port Since the TC9 was a bit faster Nov 1991 than the CoCo 3 the hardware didn t slow operation when compared to the original Rather than deal directly with the ROM situation software was supplied that would allow a CoCo 3 owner to copy his ROMs to disk then patch them for page 38 Tandy s Little Wonder Operating Environments and Programming Languages Color BASIC The authors first thought was to make separate sections dealing with these two subjects This wouldn t really be appropriate for the CoCo though It s main operating environ ment Color BASIC is also a programming language Like many of the first generation of home computers the CoCo is ready to go as soon as it is turned on All of these computers Timex Sinclair ZX amp TS series Commodore VIC 20 16 amp 64 Atari 400 amp 800 Adam TI 99 44 etc even the IBM PCjr have a BASIC programming language stored ina ROM chip The ROM is active after power is turned on meaning that nothing has to be loaded before beginning to operate the computer unless working w
11. POKE 52518 78 630 POKE 52917 78 640 POKE 53917 40 650 POKE 54349 78 660 POKE 54580 39 670 POKE 54879 40 See comments for lines 520 590 these for DECB 1 1 1000 CLS PRINT PRINT PRINT FINISHED Clear screen print three blank lines then FINISHED page 42 Miscellaneous Useful PEEKs POKEs amp EXECs 1 POKE 111 254 DIR Prints disk directory on printer 2 308 0 313 0 Disables ALL disk commands 3 POKE 308 19 POKE 313 6 Restores all disk commands DECB 1 0 change 19 to 20 for DECB 1 1 4 POKE 113 0 EXEC 40999 does a cold start Can use POKE then press RESET good for program protection pre vents listing after RESET Mostly used for CoCo 1 2 CoCo 3hasCTRL ALT RESET use EXEC 35867 with POKE 113 0for 5 POKE 234 0 EXEC 55135 parks disk drive heads 6 PRINT PEEK 188 Prints 14 witha disk system 6 with cassette 7 POKE 282 0 Sets lowercase display 8 POKE 282 255 Sets uppercase display 9 POKE 293 0 Disables all BASIC functions 293 20 restores 10 POKE 306 178 POKE 307 119 Disables Extended and Disk BASIC only 306 129 307 104 restores 11 PRINT PEEK 33021 Prints 50if CoCo 3 12 POKE 65281 0 Locks out keyboard RESET to restore POKE 6528 1 4 restores keyboard in a program 14 POKE 383 158 Prevents listing of a BASIC program 383 126 restores 15 POKE H167 amp H39 POKE amp HFF22 21 Enables CoCo 2B lowercase displ
12. TP 10 Thermal Printer 30 cps 4 26 1268 699 00 CGP 220 Ink Jet Printer color 1984 26 3024 179 95 Multi Pak Interface 26 3026 5159 95 16K CoCo2 26 3027 199 95 16K CoCo2 Extended BASIC 26 3128 n a 16K CoCo2 w mono composite video adapter factory installed schools only 26 3134 119 95 16K CoCo2 99 95 12 84 26 3136 159 95 16K CoCo2 Extended BASIC 139 95 12 84 26 3127 259 95 64K CoCo2 Extended BASIC 199 95 12 84 26 3129 399 95 FD 500 Disk Drive 0 Kit 349 95 8 84 on 26 2226 79 95 Deluxe RS 232 Pak 26 1209 49 95 CCR 82 Cassette Recorder SPECIAL 299 95 16K CoCo 2 CGP 115 CCR 82 Joysticks Vocabulary Tutor Cassette 11 84 12 84 1985 26 3008 19 95 Joysticks 26 3012 29 95 Deluxe Joystick 26 3015 29 95 16K Upgrade from 4K 26 3016 24 95 CoCo 2 Keyboard w CoCo 1 adapter 26 3017 59 95 64K Upgrade from 16K 26 3018 39 95 Extended BASIC Upgrade 26 3134 119 95 16K CoCo2 88 00 12 85 26 3127 219 95 64K CoCo 2 Extended BASIC 159 95 12 85 26 3129 349 95 FD 500 Disk Drive 0 Kit 199 95 12 85 26 3143 99 95 Orchestra 90 Stereo Music Pak 79 95 12 85 26 3144 99 95 Sound Speech Pak 79 95 12 85 26 1178 59 95 DCM 3 Modem 300 baud 26 1185 59 95 Graphics Touch Pad 26 1261 99 95 TP 10 Thermal Printer 30 cps 4 79 95 12 85 26 1268 599 00 CGP 220 Ink Jet Printer color page 34 Tandy s Littl
13. 1 0 8040364 If there is an empty socket on a CoCo 1 or 2 next to the Color BASIC ROM then Extended BASIC is not present The catalog number for the required 24 pin ECB ROM kitis 26 3018 includes ROM and new manual part AXX7072 for the ROM only The A and B model CoCo 2s require a single 28 pin ROM that has both Color and Extended BASIC in it A set of five jumpers near the ROM socket are marked 64K and 128K the size of the ROM If the computer came with Color BASIC only the jumper wires will have to be cut and moved to the 128K positions The easiest method is to trim the wires as close to the 64K pads as possible then bend them back to the 128K pads and solder there These CoCo 2s also have a version 1 3 Color BASIC ROM but the only changes are for the SAM setup routine required forthese models the 24 pin Color BASIC 1 3 ROM will also work in older CoCos and the copyright notice The part number for the 128K ROM upgrade is MX 6436 These upgrade ROM kits are likely no longer available but it will only cost 29 cents to write Tandy National Parts and find out Make sure you know the catalog number of the CoCo that will be using the ROM Tandy sorts parts lists by catalog numbers The version number of the highest level BASIC ROM is displayed on screen when a CoCo is turned on Type the following to discover each version of BASIC PRINT PEEK 41302 48 Color BASIC version PRINT PEEK 33023 48 Extended Color BASIC vers
14. 399 00 4K CoCo 1 26 3002 599 00 16K CoCo 1 Extended BASIC 26 3008 24 95 Joysticks pair 26 3010 399 00 TRS 80 Color Video Receiver 13 digitally tuned TV 26 3015 119 00 16K RAM Upgrade 26 3018 99 00 Extended Color BASIC Upgrade 26 1206 59 95 CCR 80A Cassette Recorder 1981 26 3003 n a 32K CoCo 1 26 3004 399 95 16K CoCo 1 26 3017 199 00 32K RAM Upgrade 26 3020 4 95 CoCo printer cable 26 1167 399 00 Line Printer VII 26 1168 799 00 Line Printer VIII 26 1172 149 00 TRS 80 Modem I 300 baud 26 1182 39 95 Plug n Power Controller original uses cassette port 26 1191 1995 00 Multi Pen Plotter use w digitizer 26 1193 199 95 CGP 115 12 cps 4 5 color 26 1195 449 00 Screen Digitizer 1982 26 1196 349 95 Color X Pad 26 1211 499 00 Network 2 Controller software cables included 26 1212 599 00 Network 3 Controller software cables extra 26 1253 399 00 DMP 100 SOcps 26 1254 799 00 DMP 200 120 cps 26 2775 149 00 Network 3 Software floppy drive 1983 26 3005 199 00 64K CoCo 9 83 26 3011 119 95 MC 10 Micro Color Computer 26 3012 39 95 Deluxe Joystick 26 3022 499 00 Disk Drive 0 Kit 26 3024 179 95 Multi Pak Interface 26 3025 49 95 Color Mouse 26 3026 239 95 16K CoCo2 26 3027 319 95 16K CoCo 2 Extended BASIC 26 1208 59 95 81 Cassette Recorder 26 1261 99 95
15. Charles Roslund to name a few April showers included the cross reference index disassembly of 1 1 ROM the firstad for Computerware s 64K Screen Expander word that Bob Rosen was then operating 3 bulletin boards Jake Commander s first installment of the Tandy s Little Wonder most ambitious commenting of the BASIC ROM ever and the appearance of Datasoft s first ZAXXON ads May brought flowers and a cross reference index disassembly of the 1 0 EXTENDED BASIC ROM to TCCM plus aname change for Med Systems to Screen Play What s in a name anyway The Comment Corner column returned to CCN in June authored by Andrew Hubbell and a list of differences for BASIC 1 2 EXTENDED BASIC 1 1 and DISK BASIC 1 1 CoCo s third year ended with two new releases First the long awaited and muchrumored new Color Computer theRadio Shack MC 10 Second another Color Computer magazine HOT CoCo a Wayne Green publication debuted without so much as a word of credit to Dave Lagerquist for coining the name CoCo for the Color Computer oh well we will remember THE FOURTH YEAR Jul 83 Jun 84 CCN definitely seemed to be nearing its end In July there was a full cover photo of the Dragon 32 but nothing on the inside about the computer Rainbow magazine now supporting the MC 10 also celebrated its second anniversary with a 308 page issue containing a two year index a record with some BASIC programs a look at the new MC 1
16. Darien CT 06820 phone 203 656 0756 If the special CoCo adapter is no longer available their RS 232 adapter can be used for serial port connection to the CoCo MIDI Synthesizer Interface Several units were once available but only two are currently produced The first and probably most known is the MusicWare CoCo MIDI 3 and CoCo MIDI Pro systems Both consist of software that func tions like a studio recorder and a MIDI interface adapter that plugs into an MPI or Y cable required Multiple tracks can be recorded and played in real time CoCo MIDI 3 runs on any CoCo with at least 64K A four minute nine voice recording will consume about 95 of memory and require approximately 45K of disk space Disk files can be linked to play in sequence CoCo MIDI Pro requires a 512K CoCo 3 and has additional memory capacity as well as other added features MIDI 3 records 10 tracks MIDI Pro 16 This is an update of the popular Lyra system Tandy s Little Wonder The second MIDI system is the Kala Software UltiMusE III and UltiMusE K systems The first runs under OS 9 Level II the second under OSK Both are virtually the same except for the platforms they run from Actually the only hardware involved is a special cable that connects to the serial port schematics included to build cable or purchase from Kala ready made Records up to 16 tracks May bea little harder for anon OS 9 user to set up OS 9 version uses VDG screen but has the
17. Every computer mentioned so far in this book was discontinued long before the Color Computer Remaining virtually unchanged in its first five years our as it was often called continued to flourish while the others died off one by one Three major events instrumental in paving the way for the Color Computer information explosion occurred in the open ing months of 1981 The Micro Worksand Computerware shared the distinction of being the first folks to offer software for the Color Computer The CBUG monitor program and the 80C disassembler both from The Micro Works Andrew Phelps were released in January Accompanied by documen tation containing information about the Basic ROM these fine programming tools would in the right hands reveal even more information about how the Color Computer worked With the arrival of Radio Shack sDirect Connect Modem in February a feeling of community began spreading among the isolated Color Computerists Using Radio Shack s Video tex the first communications package for the Color Computer users started meeting onCompuServe or more frequently local area bulletin boards to share information and discover les Of less significance but certainly of interest Spectral Asso ciates introduced a 16K upgrade 75 00 an editor assembler plus several other utilities and one of the first games Space Invaders They were alsointhe process of developingMagic Box which would enab
18. McNally were now freshmen in college and unable to spend much time putting a magazine together The magazine had really grown both in quality and size From a few page hand cobbled newsletter to a 34 page magazine these two young men really put forth a memorable effort Though circulation only reached a maximum of about 100 at any given time they had put out a commendable effort for the past four years The only break in publication had been between June 91 and this last issue Good luck boys no men and thanks for the support The September issue ofOSK er was late It actually arrived at most subscribers homes in mid October Aside from that forgivable incident it was a very good issue One reason for the lateness was the Atlanta CoCoFest October 5 6 Scott went to the fest for a look see and covered it nicely in the magazine Ah nothing like Christmas with the CoCo Tandy started their 1990 holiday season sale in November with CoCos going for only 99 95 CM 8 monitors for 179 95 and drive 0 systems for 199 95 Heck I remember when a 4K CoCo costs nearly as muchas all that COMBINED Sundog Systems introduced several new games this month The Quest for Thelda graph ics adventure The Contras military role playing game an early announcement wouldn t actually be ready until 19931 page 26 Crystal City classic space shoot em up andZenix similar tooriginal space invaders but much more action All ofthese ga
19. This capacitor is in the clock circuit and may cause the clock to power up into an abnormal state These problems are most likely to occur when thecomputeris cold and may beless noticeable after warm up There wasaproblem withthe original 1986 GIMEchip Subtle timing differences between the CoCo 1 2 and CoCo 3 created sparklies on some monitor screens caused intermittent problems with hardware that plugged into the cartridge port Tandy s Little Wonder and created a bootlist order bug BLOB problem with OS 9 This can be corrected by either replacing the GIME with a newer one 1987 manufacture or changing the timing signal on the motherboard The timing problem affects the ROM selection circuitry and the CTS and SCS lines of the cartridge connector The motherboard modification requires adding an extra gate so that the ROMs are only read during the E clock portion ofthe read cycle This does require basic electronics skill but isn t overly hard to do 1 Mount a 74LS02 Quad NOR gate somewhere near IC9 74LS 138 and supply power to pin 14 ground pin 7 HINT Mount the 74LS02 piggy back on another nearby 14 pinchip Bend all legs straight out except pins 7 and 14 Solder the two unbent pins to pins 7 and 14 of the board mounted chip supplying power and ground to the 74LS02 2 Solder a jumper wire between pins 14 13 12 10 9 2 and 3 disabling three of the four NOR gates inputs tied high 3 Soldera wire between p
20. and B models and A or B follows the catalog number required the last revision of Color BASIC version 1 3 These computers used a different type RAM chip the 4464 and required different timing rates than previous DRAMs new SAM 741 5285 also had to be used The new SAM supported the 256 cycle RAM refresh rate required by the 4464 chips as well as the 128 cycle refresh of the old style chips so it could be used in any CoCo but the original SAM could not All the 1 3 ROM does istell the SAM to use the 256 cycle refresh rate if jumpers are set for the 4464 chips and change the revision number Color page 39 BASIC and ECB are both burned into a single 28 pin 128K ROM on these CoCo 2 models Standard Color BASIC ROMs will fit but won t work with 44xx series RAM chips The 1 3 ROM willalso workin earlier CoCos The final type Super Extended Color BASIC was introduced in 1986 with the CoCo 3 Like Disk BASIC this was an extension of the existing Extended Color BASIC Due to the copyright agreement with Microsoft Tandy couldn talter the ECB code and didn t want to pay high royalties for MicroSoft to make the necessary changes MicroSoft was much bigger now than they had been when Color and Extended Color BASICs were written In order to add commands to the CoCo 3 anew ROM was made for Tandy by Microware publishers of OS 9 What happens is that the CoCo 3 powers up in an all RAM mode ROM contents copied to RAM a
21. but used a mini tower case a 20 option for the 1990 unit One still needed their CoCo disk drive controller and drive CM 8 or similar RGBA or composite monitor no TV output and a PC AT style keyboard PC XT keyboard not supported 512K CoCo 3s could still be pur chased new for under 350 in 1990 Note that if one purchased the512K upgrade and RAM from Tandy the total price would have been 539 80 Tandy was still stuck with lots of 256K DRAM chips they were forced to purchase during the 1989 DRAM shortage and were STILL trying to pass the high cost to the end user Most purchased the bare board 39 95 and gottheir DRAM elsewhere or purchased third party upgrades for 1500rless In 1991 acomplete TC9 system with one 360K floppy keyboard 20MB hard drive IMB upgrade and Magnavox 1CM135 monitor was priced at 1649 95 Boards could be purchased by those wishing to assemble their own TC9 main board set 349 95 upgrade board 59 95 memory not included The TC9 faded into oblivion after only two years of produc tion Frank Hogg stated The TC9 took far longer to finish than any previous computer I ve done because of the com plexity of marrying an eight bit CoCo toa 16 bit68000 We went through four design stages This work was done by Bob Puppo with the help of just about everybody in the CoCo community offering advice To bad all that work didn t bear more fruit as the TC9 was truly the closest thing ever to the
22. compiler for the CoCo called simply which is very similar to OS 9 C compiler the same reference material is usable with minor differences The best book to get for reference is The C Programming Language by Kernighan and Ritchie The current edition is based on ANSI but the differences between the original language and ANSI are minimal The main advantage of the C language is that it can be transported between different computers and operating systems usually with minimal changes The basic commands are the same for all compilers The compiler is different for each computer operating system Source code the actual list of commands similar toa BASIC program listing is written with an editor or word processor then saved in ASCII format and compiled on the desired computer The differences come in because some computers have added commands that take advantage of differences in the hardware and operating systems One example is the graphics resolution on a CoCo and on an IBM compatible with VGA monitor Any high resolution graphics on the IBM would have to be changed to the lower resolution of the CoCo before the program could be compiled with a CoCo C compiler Some operation systems have more math capabilities than the CoCo also These differences can be overcome but only with more programming Text based programs usually compile with a minimum of changes Many OS 9 commands have been ported ove
23. ended up being liquidated for 54 00 or less some can still be found today Wayne Technology marketed itsCP M for the CoCo actually an add on Z 80 CPU board and Dynamic Electronics marketed the first ever128K upgrade February marked the debut ofGraphicom fromMarty Goodman andElite File fromElite Software plus aname change for the Computer Shack to Michtron A new newsletter Dynamic Color News was launched byBill Chapple owner ofDynamic Electronics The first edition contained comments by the editor a Q amp A column operating hints and several program ming tutorials The newsletter was printed on heavy white paper in an 8 1 2 x 11 format In addition to printing the newsletter Dynamic Electronics also offered soft and hard ware for the Color Computer RainbowFest 3was heldin Long Beach CA February 17 19 Radio station KGON it was reported had its own bulletin board running on a CoCo The firstEast Coast RainbowFest was held March 30 April 1 and featured the first CoCo Hard Disk from Software Support In an attempt to clear its stock TANO reduced the price of the Dragon 64to 149 00 The last Dragon 64 ad in Rainbow appeared this month and rumors started circulating that the computer was about to breath its last flame The OS 9 Users Group founda medium to communicate with members and potential new members theOS 9 Users Group President s Column in the Rainbow The debut article featured general information about the
24. peak to peak monochrome composite video signal The color composite signal is available at pin 1 of the RF modulator or pin 12 unamplified of the video mixer MC1372 If testing of the listed signal gives results other than those shown the tested chip or part of the circuit attached at that point is faulty Check all leads before replacing a chip Other chips even those in peripherals can be easily tested also Take a good working computer disconnect all peripher als excepta TV don tusea monitor interference won t show the same and test each chip witha logic probe or VOM Note any interference on the TV display While not the most accurate testing method TV interference or lack thereof will indicate potential problems Make atesting chart foreach chip Another working computer of the same model should give the same results Many of the 6809 signals can also be checked at the cartridge port so check there also especially if the problem appears to be a peripheral that connects to the port Just because a signal is present at the CPU doesn t mean it is reaching the port or any peripheral plugged in there Ifa MPI is being used check each port for the same signals The following tips should be checked with power ON unless otherwise indicated 1 Ifcomputer is running but experiencing intermittent prob lems or problems in just one area runa diagnostic program and test the area believed to be at fault If all checks go
25. pin 4 pin ofthe 6809 Later ROM Paks and cartridge peripherals have a shorter land on pin 9 reducing the likeli hood of a short but not eliminating it Beforereplacing the 6809 make sure no peripherals are plugged inandtestthe computer again A bad disk controller orjoystick can cause the computer to lock up or appear dead Clean the GIME in a CoCo 3 and check the SAM in a CoCo 1 2 before replacing the CPU Check all other possibilities also MC6821 MC6822 PIA all models Keyboard Cassette Se rial Port Joystick Sound amp Video All Color Computers use two PIAs Peripheral Interface Adapt ers one for the keyboard and one for cassette serial and joystick I O as well as sound and video outputs The CoCo 3 uses a customized PIA LSC81001 for keyboard input It is unclear just what was changed in this chip as a standard 6821 or 6822 will work just fine The 6822 is a more robust version of the 6821 the 6822 will handle higher voltages without damage Itis suggested that a 6822 be used in place of ablown 6821 for durability No letter in the number indicates IMHz operation an 1 5MHz 68A22 and B 2MHz A 1MHz rated part will generally work at 2MHz it just isn t guaranteed by the manufacturer A keyboard problem could indicate a bad address line on the keyboard PIA closest to power supply It could also indicate abadtrace onthe mylarribbon cable Pull the mylar strip out of its socket with a firm tug It isn t as de
26. preter how much longer does it take to get your message through since you have to speak to the interpreter then he she to the other person Converting Between One would think that converting a program between the CoCo 1 2 and the CoCo 3 would be quite simple This is only true if the enhanced capabilities of the CoCo 3 are not to be used The main problem is converting between PRINT and LOCATE statements In cases where only the appearance of the screen needs changing simple replotting of the text locations on screen is in order and relatively simple If a program scans across the screen for input such as a spreadsheet program the programs just aren t easily converted The PRINT function works very different from LOCATE and vice versa when a formula is incorporated into a program to scan or plot locations on the screen One can simply add and subtract from the PRINT value since all screen locations have their own specific value LOCATE must move up and down as well as back and forth making the required formula more difficult to program andentirely different from thatrequired by PRINT The PRINT and LOCATE differences are just some of those encountered between CoCo 1 2 and CoCo 3 BASIC The others can be easily documented by going through the manuals for both computers and comparing Note that the CoCo 3 doesn t support the undocumented semi graphics modes of the CoCo 1 2 Thisis a function ofthe 6847 VDG that was
27. tape will work fine the auto exec land land 8 usually the first one from the left bottom of the card edge of the cartridge thus preventing automatic execution One then types EXEC amp HEO010 to execute the cartridge Note that devices other than game ROM Paks the Tandy RS 232 Pak and Tandy DC Modem Pak that auto execute are ex tremely rare In OS 9 Level I Version 2 0 which will run on a CoCo 3 you areexpected to powerup using the slotin which you have your disk controller CCDisk does NOT set the MPI SCS latch However ACIAPAK assumes the RS 232 pak is in slot one and the disk controller is in slot 4 as it stores a 03 at FF7F CCHDisk when it needs to access the Tandy Hard Disk interface which uses the SCS line changes the MPI selectto 02 CART from slot one SCS to slot three So the HDI must be in slot three In both cases the RS 232 or Modem Pak that you wish to be interrupt driven by ACIAPAK must be in slot one CCHDisk clears D DMAFlg when it s not using slot three soCCDisk knows the SCS is going to slot four when it wants to shut off the motors after a time out That is the disk controller had BETTER bein slot four If CCHDisk 15 using the MPI latch it sets D DMAFlg so CCDisk will reset it s time out counter and try again later Drivers that change slots should use this flag byte Some third party drivers most notably the ones by Brian Lantz for Disto and J amp M don t use this flag In the case of the D
28. the dial on the network controller must be set to the station number that will be saving printing Then the student CSAVEs to the host which is set to CLOAD When the file is received the person at the host can then save or print it All this is a little time consuming especially as the students end the day but the systemis simple and reliable and was cheaper than purchas ing disk drives or cassettes for each station Would you like to deal with 15 tape systems I O errors and all There are ROMPaks for each station but most of these are so old and worn that not all of them work It is actually easier to send the programs the network from disk By using the dial different programs can be sent to each station also Joe and David both went on to college with the goal of pursuing computer related careers Their experiences with the CoCo led them that way as it did for many people They also showed an interest in teaching The author was unable to get in touch with either at the time of printing for an update Frank Hogg and Frank Hogg Labrotories FHL EDITORS NOTE This article was transcribed by myself from atape sent by Mr Hogg I apologize for any misspelled names and possible misinterpretations The first computer I bought was a 6502 based Kim I in 1977 with 1K RAM Tom Spear a friend had a SWTPC South West Technical Products Company 6800 based SS 50 bus computer Well I gota SWTPC in late 77 78 Dale Puckett who was
29. 9 is but hasn t really said anything about what you the user gains Here are a few of my favorite things One thing that can t be emphasized enough any capability of the operating system is usable by any program Some DECB programs support multiple windows or 80 track disk drives but under OS 9 all programs do The big feature is windows I often find myself doing more than one thing time perhaps I m writing a letter and need some information froma disk file or froma spreadsheet Just aclear key away there is a separate screen waiting I also use windows to answer my on line E mail One window displays the mail captured while the other has a text editor running in itfor the replies Even simple things like not having a formatted disk ready are easy to fix with that separate window or two or three as many as needed provided there is memory for them always ready and waiting Since all of OS 9 s commands and utilities are really separate modules the user isn t stuck with any of them In fact new utilities and system patches probably represent half of the software written for OS 9 Don t like the way the copy com page 51 mand works Use a different one Need to read and write MS DOS disks There is a patch to fix the disk driver so it can do that Most of these patches are available free from BBS services or on disk form from several sources If you enjoy programming OS 9 is the key to a whole new wo
30. 91 26 3215 299 95 CM 8 RGB Monitor 149 95 02 91 26 3334 199 95 128K CoCo3 99 95 02 91 26 2228 89 95 DC Modem Pak 300 baud 9 95 02 91 The last appearance of the CoCo in a Tandy catalog was in RSC 22 1991 The last Tandy CoCo ad ran in the May 1991 Rainbow During late 1991 and all of 1992 many software packages were discounted nationwide Users eagerly sought OS 9 software especially Level IL the Level II Develop ment System and the C Compiler Other software was deeply discounted eventually being cleared out for as little as 1 Even today a few game cartridges and more rarely disk software can be found in the back corner of Radio Shack stores Some of the software will not show up on the stores computer meaning that the manager can just about name any price Most cartridges will be found for 3 99 or less The author recently picked up a copy of DynaCalc OS 9 for just 1 so do look page 35 CoCo Clones an attempt to ride Tandy s wake There were only three CoCo clones ever made The most known in the U S is the Dragon Systems Ltd a British company Dragon imported to the U S byTano A second clone was advertised in Byte Magazine the Sampo Color Computer made in Korea but never made it to the sales floor Itis quite possible that the ROMs used were near duplicates Gf not blatantly so of the Tandy code and that Tandy therefore prevented importation Until four to fiv
31. Accessories Disk Doctor fromSuperior Graph ics Spell N Fix fromStar Kits and the firstBASIC Compiler from Aardvark Spectrum Projects debuted as Bob Rosen dropped the name Connection 80 And finally a review of Super Color Writer fromNelson The first national CoCo Users Group was inaugurated in June when CompuServe started it s Color Computer SIG witha membership of 52 and Wayne Day as sysop 80 Micro ran an interesting biography aboutBob Rosen and his Connection 80 BBS Thanks for the plug Bob Newly introduced CoCo support includedMicro Technical Products LCA 47 lower case kit the first kit featuring switch selectable inverse screen and theRainbow Seal of Certification Started by The Rainbow magazine certification insures that the product does in fact exist John Walco s 3 part article on picking winning NFL teams with the CoCo began but unfortunately there would be no winners that year because the NFL went on strike Tandy s Little Wonder Was it my imagination or were both Color Computer maga zines getting stale Due perhaps to the sudden abundance of CoCo information in the second year both appeared to be getting a bit thin THE THIRD YEAR Jul 82 Jun 83 Despite rumors of its demise the COCO celebrated its third birthday in fine health With year 1 shrouded in mystery and year 2 producing tons of information and software what could we expect from yearthree ARCADE GAMES and HARD WARE First s
32. April issue of CCN marking their increased FLEX coverage Clay Abrams article Amateur Radio and the TRS 80 Color Computer dealt with the reception of SSTV pictures Wonderful information for ham operators but it seemed like all the useful utility listings that had come to be expected from CCN were starting to disappear The Rainbow which by April had grown to 52 pages con tained the first part ofDennis Lewandowski s column called The Assembly Corner plusRainbow On Tape Telewriter s disk version was being marketed by this time along with several other new CoCo products such as HUMBUG a machine language monitor program from Star Kits various software fromPrickly Pear Software Auto Run fromSugar Software The Solution the first hi res screen utility fromSnake Moun tain Software andNANOS Systems reference card Wayne Green must have freaked out when in May Tandy opened a 100 000 square foot plant in Fort Worth specifically to build Color Computers Several New Jersey schools also started using the machine at this time Seems like everywhere Wayne Green looks there are CoCos dieing of neglect no doubt CCN celebrated its first year anniversary with apologies from Bill Sias about the double issue but said it was needed to get back on schedule While still a source of valuable information the number of good articles and programs seemed to be declining Some CoCo firsts in May included anEPROM burner from Computer
33. CoCo 3 These mice plug into the joystick port and act just as the joystick does An OS 9 driver fora serial mouse is available on Delphi see Telecommunications or FARNA Systems re quires an RS 232 pak the CoCoPRO DC Modem Pak conver sion won t work Video Digitizer Two companies made popular video digitizers forthe CoCo The Micro Works DS 69 Digisector wasthe most popular A later model the DS 69B is similarto the original sometimes referred to as the A model but faster Neither are currently available An Australian company still produces the Rascan Digitizer updated and renamed DigiSector available from FARNA Systems which is the faster of the listed models These are not frame grabbers they don t pick a moving picture from a video tape or TV set They require a still subject as they take 15 to 30 seconds to fully digitize a picture They don t digitize text either just page 74 pictures These devices are similar to the ones found in malls and amusement parks making computer portraits Plug N Power Appliance Light Controller Two models of this X 10 compatible home controller were made The first plugged into the cassette port 26 1182 of a CoCo or Model VII This came with a cassette program and may be usable on the CoCo 3 but they are extremely rare devices now The second model 226 3142 came out with the CoCo2 It can still bepicked up new butattaches to the serial portand CANNOT be u
34. CoCos After a few hours work we asked if she would like us to come in and show some of the kids how to use the computers She thought that was a wonderful idea Joe and I couldn t believe it We were about to teach Color Logo on the same Color Computers we started with ourselves We went in that week and taught the kids Logo They were amazed at what they could make the machines do and we agreed to come back once a week We even got permission from our high school principal to leave school early on Mondays so we could teach at the elementary school Now that we are out of high school and in college we still find time to go teach Logo and Scripsit to the third grade class on the good old CoCos We even support an after school computer club that meets once a week The children are Tandy s Little Wonder allowed to come in and use the CoCos to play games or create print graphics using CoCoMax or CoCo Graphics Designer during the club meets The CoCos are all connected to aNetwork 2 controller This controller allows up to 15 CoCos to be connected to the host CoCo via the cassette port the host must have a disk drive senda BASIC program to the students one must first load the program into the host Then all the students do a CLOAD The person at the host will do a CSAVE and the program will be sent to all student stations A disk to tape utility is required to send m l programs If a student needs to save or print their work
35. GUI And you don t have to worry about turning your kids loose on the CoCo Cloud 9 Super IDE hard drive controller works with OS 9 and DECB Also has a And last a powerful operating system greatly reduces the number of programs the user has to own For example OS 9 comes with an editor It s not a great text editor but it can do the job of course there are better ones available free from on line services Italso has a list command which can list any file to any hardware device So it s possible to write a short letter and print it without using a program at all just the operating system OS 9 isn t without it s share of problems though Anything with the power and versatility of OS 9 is usually more compli cated also so there is more to learn The syntax for the commands is entirely different from DECB so that has to be learned also one reason many DECB users find it easier to cross over to MS DOS machines is that the command syntax is so familiar Last but not least the system is just adequate as shipped by Tandy There are lots of additional commands that can be added and patches to improve the original com mands Sorting through those can be difficult at best which is why I made a disk of extra commands and patches with an automatic patching program Patch OS 9 which was marketed by FARNA and CoNect The OS 9 manuals from Tandy are not the best to putit mildly The Complete Rainbow Guide to OS 9 printe
36. Micro Learningware and Strawberry Software plus the first detailed instructions on performing the 32K piggyback upgrade By the time CCN s Jul Aug issue arrived on your doorstep two more Color Computer publications had sprung to life The first ever cassette based Color Computer magazine wasDave Lagerquist s Chromasette Magazine Instant software on a monthly basis for a mere 3 50 an issue was quite a deal The magazine s first issue contained 5 Basic programs and a very moving cover Very impressive In addition all tapes were accompanied by a 5 or 6 page news letter explaining the programs The news letter also featured tips the latest rumors Radio Shack disks soon and some of the editor s own colorful insights which brings us to the second publication inaugurated in July Whoever wrote the words From small acorns large oak trees do grow was undoubtedly referring toLonnie Falk and The Rainbow The Rainbow s first issue was all of two pages in length both sides of course and you could tell immediately by the typeset LP VII that no expense was spared in putting together this latest collection of Color Computer information The debut issue was photocopied at the corner drug store and after the first 25 copies sold out 1 00 each another trip to the drugstore was needed for an additional 10 copies Containing the usual assortment of Color Computer articles comments tips and program listings the Rainbow became
37. Program was written for a CoCo 3 Will run a CoCo 1 2 after changing all LOCATE statements to PRINT and running the ROM into RAM program 30 REM by F G Swygert January 1993 1110 1140 by L Todd Knudsen 1992 60 POKE 65497 0 CoCo 3 double speed 65495 0 for CoCo 1 2 65 POKE 150 18 Change printer baud rate to 1200 Will be 2400 double the value with the speed up POKE 70 IF PEEK amp HA282 223 THEN 120 Check for ADOS amp EADOS3 ADOS should already be setup with faster drive access rates If present go to line 120 80 IF PEEK amp HC004 215 THEN 100 Check if DECB 1 0 1 1 If PEEK value is 215 then DECB 1 1 is present Value would be 214 for 1 0 If 1 1 go to line 100 If not therefore 1 0 continue 90 POKE amp HD6CD 0 POKE amp HD723 20 GOTO 140 Set drive to 6ms access time DECB 1 0 2 0 100 POKE amp HD7C0 0 POKE amp HD816 20 GOTO 140 Set drive to 6ms access time DECB 1 1 2 1 120 CLS SOUND 150 4 LOCATE 14 16 PRINT Currently set up for 2400 baud printer LOCATE 14 17 INPUT Doyou wish to change this Y N A Clear the screen Make a sound with tone 150 for a duration of 4 move cursor to column 14 line 16 PRINT statement in quotes move cursor to column 14 line 17 accept INPUT after printing statement in quotes the INPUT will be stored as A string 130 IF 8 OR A Y THEN 320 IF A n OR A N THEN 420 GOTO 120 If A string is y or Y yes go to line 320 if itis
38. Shack stores Computer Centers and participating dealers nationwide See it toda Price Commenter Centers and and reei and motor partem Radie The Technology Store A DIVISION OF CORPORATION CoCo 3 magazine ad circa 1987 0097 Exploded view of a 128K CoCo 3 Other CoCo models are similar Photo Gallery an added bonus pitta 1 pee page 122 Tandy s Little Wonder Tandy s Little Wonder page 123 BAG LE MICROCOMPUTER HANDLE WITH CARE COLOUR gi A complete CoCo 1 system The original keyboard on dust cover in front has been replaced with a later model CoCo 2 keyboard or an aftermarket version Many people didn t like the original chicklet keyboard The original box would have included the CoCol user manual and antenna lead switch box located beside the cassette recorder Of course the recorder was needed to save anything and every CoCo enthusiast had a collection of game cartridges and at least one joystick Cartridges should only be removed or inserted with the power off That s something CoCo owners learned quickly many the hard way Later cartridges had the power land shortened to prevent shorting to ground and blowing the 6809 page 124 Tandy s Little Wonder Tandy s Little Wonder page 125 COLOUR CAD e
39. The Y Box was a fully buffered Y cable more reliable and longer than a Y cable alone A powered version that supplied 12V was available required by Burke amp Burke hard drive systems One other expansion device bears mentioning the simple Y cable This is nothing more than a short piece of ribbon cable with two 40 pin connectors on it Anyone capable of soldering easily make a Y cable Geta 44 pin card 276 154 and cut four of the lands off one edge Trim it down to a comfortable length about one inch Get a 40 conductor ribbon cable no more than six inches long Now get two 40 pin crimp on card edge connectors 44 pin types can be used just tape over the last two positions First separate the wires about one inch on one end Strip enough of each to solder onto the positions on the shortened card Now take a good look at the shortened card lands Notice that they alternate between the top and bottom lands on the board Take a good look at the crimp on connectors One side is offset so that the contacts actually alternate from one side to the other The ribbon cable should alternate also so that the lands top of the card match the top contacts of the connectors and vice versa Once the positions have been lined up solder the cable to the card Plug this into the CoCo Cut the ribbon cable so that it will just touch the surface of the work surface Crimp one connector on the end and the other up just enough so that a second
40. TheAugust OS 9 Underground issue featured acommunica tions theme An insert featuring many OS 9 supporting Bul letin Board Systems BBS was anice touch The cover color page 31 this month was fluorescent orange A short Chicago CoCoFest report to be continued next month and a rather detailed review of several OS 9 BBS software packages was featured Sixteen advertisers and 53 pages not bad for only the third issue Keep up the good work Allen A very interesting feature article instructed one on how to connect multiple terminals toa CoCo creating asmall LAN local areanetwork with no extra software just some cabling and serial port cards TheHitachi 6309 andBurke amp Burke s Powerboost made the headlines in theSeptember Rainbow Marty Goodmande scribed the history of the 6309 and also reviewed the PowerBoost We are told that the new 6309 it had actually been around since 1987 may also increase speed under Disk BASIC by as muchas 15 but the BASIC ROMs would have to be modified or patched in RAM of a CoCo 3 Bill Vergona of Cer Comp reported that he was 95 complete on an assembler 1 1 thatwould take advantage of the 6309 under Disk BASIC One would have to install a 6309 in order to utilize the assembler or any software written for it Bill was also considering modifying some of his software for 6309 opera tion JWT Enterprises had an interesting ad If you are interested in the latest new products for the CoCo and the
41. Wonder All that is needed to upgrade these boards are eight 4164 DRAM chips moving three jumpers from 16K to 64K posi tions and adding another jumper the pegs can be soldered together The jumpers are located near U21 2 U28 1 and U17 the one that needs a jumper added If the computer originally came with 16K clip capacitors C58 C60 C62 C64 C66 C68 C70 and C72 These can just have oneleg cutrather than entirely removed It is not necessary to reinstall the capacitors even if 16K DRAM is put back in American Made CoCo2 IDENTIFICATION White case vents on top CATALOG NUMBERS 26 3026 26 3027 BOARD REVISIONS A There may be only one board revision that was produced The only one the author has seen has REV printed on the board It is possible that an A version was produced or maybe the A was just a prototype like the CoCo 1 A and B revisions The RAM upgrade is the same regardless Remove the eight 4116 chips and replace them with 4164 DRAM Locate the two adjacent solder pads labeled W1 between U6 and U7 nearthe center ofthe board Solderatiny piece of wire between the two pads and the 64K will be activated Many people bend a short piece of wire in a U shape as it is easier to hold with a pair of tweezers or needle nose pliers while soldering KoreanMade CoCo2 IDENTIFICATION Identified by DRAM type and ROM socket and catalog numbers CATALOGNUMBERS 26 3134 26 3136 B
42. a mistake was made EXEC 44539 makes the computer wait for a key to be pressed before continuing the program 430 IF 282 23 THEN 1000 Check for ADOS EADOS If present go to line 1000 440 IF PEEK amp HC004 214 THEN A COEED52AD6 D1D6F1D727D75E ELSE A C101D617D7C4D7E4D 81 0851 Check for DECB 1 0 use first string for data if it is present else use the second string for DECB 1 1 450 FOR V 1TO24 STEP 4 460 A VAL amp H MID A V 4 470 A 189 A 1 240 A 2 157 POKE A 3 18 480 NEXT 490 POKE amp HF09D 52 POKE amp HF09E 127 500 POKE amp HF09F 53 POKE amp HF0A0 255 Lines 450 500 use the data strings in line 440 to POKE values into Disk BASIC to change timing so that double speed can be used reliably 510 IF PEEK amp HC004 214 THEN 520 ELSE 600 Check for DECB 1 0 go to 600 if not present 520 POKE 50952 78 530 POKE 50986 84 POKE 51083 78 540 POKE 51104 78 POKE 51135 78 POKE 52300 78 550 POKE 52697 78 560 POKE 53680 40 570 POKE 54111 78 580 POKE 54342 39 590 POKE 54642 40 POKE 54677 40 Lines 520 590 patch the following in DECB 1 0 for 40 track operation line by line KILL FAT File Allocation Table GAT Granule Allocation Table FREE BACKUP COPY DSKI DSKO and DSKINI Values 40 and 39 are tracks 78 is the maximum number of files 68 for 35 tracks 600 POKE 50997 78 610 POKE 51034 84 POKE 51131 78 620 POKE 51183 78 POKE 51152 78
43. adequate power capacity to drive two half height drives or a half height floppy and hard drive It should adequately power even two 3 5 hard drives The hard drive power requirements are for average 5 25 half height models Older full height models will use more power and newer 3 5 models much less For the 12V line 1 2A is drawn only on start up after which 600mA is drawn to maintain speed Most power supplies are rated at asteady load and will put outovertheirrating for short periods hard drive start up Find the total wattage by multiplying each voltage by the required amperage then adding all to gether A CoCo 3 with two floppy drives would require a minimum of 30 watts 5Vx2 6A 13W 12Vx1 2A 14 4W 13W 14 4W 27 4W rounded up to 30 Always allow atleast 10 over the required capacity for items such as the disk drive controller and RS 232 Pak that aren t included in the calcula tions since they draw very small amounts of power Tandy s Little Wonder Alternate Power Connection Method Rick Ulland The trace cut methods previously described are the neatest way to add an external power supply and are recommended by Marty Goodman There is an equally effective method for those unwilling or unable to cut traces This method is described for a CoCo 3 and has been working reliably for a number of years Review the schematics of other models to apply to them All the components that require removal can simply be cut out on a CoCo
44. advantage of not requiring an MPI Many more items have been available at one time or another for the CoCo The best source for information on unusual finds would be Rainbow and other CoCo magazine back issues especially 1984 to 1986 issues A few will not be compatible with the CoCo 3 but all should work to some degree with the CoCo 1 and 2 unless they require 12V which is not provided by the CoCo 2 unless an MPI is used Hardware Upgrades and Modifications The following upgrades and modifications are the most com mon Note that disk drive Multi Pack and monitor upgrades and modifications are covered under Peripherals Upgrades ROM upgrades aren treally necessary in most cases Replace ment ROMs are still available from some dealers though they may be hard to find There were three versions of Color BASIC 1 0 1 1 and 1 2 The only one that really needs changing is 1 0 1 0 used a seven bit printer driver instead of the more common eight bit Tandy only had a seven bit printer at the time This ROM won t print graphics without a special no longeravailable printer driver program Version 1 1 allowed use of a full 64K and version 1 2 cleared a few minor bugs in 1 1 and the BASIC interpreter was re written to run slightly faster All NC board CoCo 1 and TDP 100 models willhave 1 1 or 1 2 ROMs all CoCo 2s 1 2 or 1 3 Ifanew ROM is desired try to get the 1 3 version 8040364C 1 2 15 8040364B 1 1 8040364A
45. and no start up costs Not getting enough renewals to cover printing and postage expenses would have been dishearten ing to say the least but I think the guy had personal problems like a divorce that caused the sudden drop Instead of packing my CoCos up and keeping them I made the tough decision to sell them I figured that someone willing to pay reasonable amount for them would have to have a keen interest in the CoCo and would continue to put them to good use for a while Isometimes wish I still had one of them but I don tregret that they continued in service at least while longer Being an old car nut I ve always hated seeing a car sitting and rusting away because someone was going to fix it up one day but you just knew it would never happen I didn t want that happening to my CoCos I d rather know someone got a bit more enjoyment from them before they were retired If anyone wants copies of 268 m Tandy s Little Wonder or any of the FARNA publications contact Glenside Color Computer Club see support A couple years after 268 m died I donated all the hard copies to them and made everything public domain FARNA Systems is still in the small publishing business Currently I m printing an AMC Rambler quarterly magazine and working on a couple more AMC Rambler publications I also provide services to others who wish to get their small publishing projects off the ground See the FARNA Systems web site at http farn
46. as higher resolution ply connect the Color Computer 3 to a resolution monitor like the sy de sold separatel Hiis detailed rc Graphs and drawings in vivid colors with most e and accessories designed for the UL AC 26 8994 2 199 95 Monitor Platform 26 1329 19 95 CM 8 RGB Analog Color Monitor T 80 x24 text 540 x 192 graphics 13 diagonal screen Built in speaker with FD 502 Color Thinline Disk 0 Turn any Color Computer with Extended BASIC into a disk system Write your own disk applications or add ready to run software Plugs into the Program Pak port or Multi Pak Interface UL listed AC 26 3133 299 95 Color en Upgrade Kits and Enhancement Options DC Modem Program Pak 8995 Geet and 300 bps Modem Transfer receive ASCII files or access information services by 26 2228 B9 95 High Res Joystick Interface p Lets you address higher c aed modes to 640 x 640 ea 5 o95 67055 16K RAM Upgrade Z 2 eer 95 Low Profile Keyboard Kit gt gt 263008 24 95 64K RAM Kit CD Converts 4K 16K or Color Computer 26 3017 e 5995 Second Drive for 502 Requires in stallation not inciuded RS 232 Interface Deluxe i contro and quicker spring wee Roeting 2 26 3012 95 Deluxe Color Mouse 4995 Simply rol
47. combined input The NOR gate can be piggybacked ontopofIC 15 74LS04 intheCoCo3 where the Hand V signals and 5V and ground for the chip are readily available Moni tors followed by anasterics have both RGB and composite inputs The dot pitch is listed in parentheses when known Commodore 1080 SONY KX 1211HG 39mm SONY CDP 1201 25mm SONY CDP 1302 25mm SONY CDP 1310 37mm SONY KV 1311CRTV monitor 37mm SONY CDP 9000 25mm SONY 20 37mm SONY KV 2011CR 37mm SONY KV25XBR 55mm SONY KV 2511CR 55mm NOTE The Sony K series are TV monitor combinations The first two numbers indicate picture size except for the 9 CDP 9000 Atari ST RGB color monitors are also usable They require separate negative sync signals One would have to run the CoCo 38 positive sync signals through inverter gates 741 504 before connecting to the Atari monitor The second type RGB monitor is theDIGITAL type This is the typeused by IBM for their first color monitor for use with their color graphics adapter hence the common designation CGA The sync signals are correct for the CoCo 3 so just connect all the lines from the CoCo 3 connector to their counterparts on the CGA monitor connector Digital signals are either on 5V or off OV Each of the three signals RGB can only be combined in such a way as to display six colors and two of those colors are black and white RGB all off or all on Another pin on th
48. commands were added to Disk BASIC It would have been nice had Tandy taken the opportunity to support at least 40 track drives possibly even double sided The most likely reason this support was not added was to maintain optimum compatibility with existing systems BASIC is normally an interpreted language This means that thecomputerreads the BASIC code directly through a BASIC interpreter as the CPU can t directly read the code The interpreter converts the BASIC code into machine language the native language of the CPU The interpretation process is page 40 Easy DECB Enhancements There is an easy way to add a few extra to Color BASIC and DECB Changes can be madeto the system by poking different values into specific memory locations This can be done easiest on a CoCo 3 as the ROM code is copied into RAM automatically The CoCo 1 and 2 require being put into an all RAM operating mode ROMs copied to RAM by running the following program 10REM PROGRAM TOCOPY BASICROMSINTORAM 20REMCOURTESY FRANK HOGGLABS 30CLEAR 999 40DATA 26 80 190 128 0 183 255 222 166 128 50DATA 183 255 223 167 31 140 224 0 37 241 57 60FORI 1 TO21 READ A A A CHR A NEXTI 70P VARPTR A 1 80POKEP 126 90EXECP 100 PRINT BASIC NOW INRAM Note that unless the changes are made permanent by burning into an EPROM they will be lost upon reset or power off The first thing one may want from the CoCo is more speed There is a relatively simple w
49. consider a second possibility for where to place the required code From the outset of ADOS I had been aware that a disk controller could accommodate an EPROM with 16K of space rather than 8K The problem was that this could only be done with controllers having a 28 pin ROM socket due to the fact that the only suitable EPROM was the 27128 which had 28 pins All Tandy controllers had 24 pin sockets A solution was to offer a 24 to 28 pin adapter for the Tandy controllers and source of these a fellow by the name of Jim Smith that I had met at a meeting of the Miami CoCo users group who made them by hand These were originally offered to ADOS users simply as a convenience since 28 pin EPROMs were cheaper and easier to obtain than 24 pin ones and since some CoCo EPROM burners were incapable of handling the 24 pin type Since requiring an adapter made the product less attrac tive I had decided to confine ADOS and ADOS 3 to an 8K EPROM even though that limited me to 2K worth of enhance ments With the passage of time though two developments occurred that rendered an adapter unnecessary for many CoCo users to use a28 pin EPROM First third party control lers became considerably more popular especially with the more experienceed CoCo users that ADOS primarily appeals to These third party controllers all had 28 pin ROM sockets Second Tandy came out with the FD 502 controller which contains a28 pin ROM socket although a mino
50. each magazine and earned about 2 00 an hour I d grown in my own computer needs that the CoCo could no longer fill them and there was no affordable OS 9 OSK machine that had the software base to do the things I wanted to do Like most CoCo users I migrated to a PC clone computer instead of a more expensive and ultimitely less capable dueto lack of software OSK machine Not only that butI was getting more involved in my first love AMC cars and Ihadanew wife and family that I needed to spend time with Ijust didn t have time and money for two big hobbies and my Rambler won out But don t think the CoCo was slighted any leven told my new wife celebrated our 10th anniversary in December 2005 that the Rambler had seniority even over her The day came that I finally decided Ino longer had time to print 268 m The last fest I went to had cost me a couple hundred dollars and I had other interests as well I didn t bail because I was no longer making money except for the fest trip I was still making a bit In the end I was working for about 2 00 an hour putting 268 m out My original goal was to do it with no out of pocket costs so as long as it was a break even propo sition I d have continued Time for my family and other interests and a lessening of my interests in the CoCo in general are the reasons I decided to cease publishing Tandy s Little Wonder When I stopped printing 268 m in 1998 I still had a loyal subscriber ba
51. examining the keyboard layout on the schematic Single pole momentary on or keyboard switches mechanical switches most clone keyboards use Hall effect switches that WILL NOT work can easily be wired to the same points that the keyboard number switches are wired to row pin 6 then pins 9 16 for 0 7 row 7 pin 9 amp 10 for 8 amp 9 on keyboard connector Why not add some additional keys also A shift lock key is easily made by wiring a push on push off switch between the two SHIFT keys pin 8 and 16 of the keyboard connector What about those often used shifted keys They can be made single stroke keys on the number jack or alone simply by using a double pole momentary on switch wired to press both keys at once This type switch may be difficult to find in the shape of a key An old keyboard cap may have to be removed modified and glued to the top of the switch Tony DiStefano described using a transistor along witha single pole momentary switch to simultaneously press two keys at once inthe April 1985 Rainbow still available as a back issue at time of printing The ultimate upgrade is to use a PC type keyboard I know I just wrote that the key switches are different and won t work The PC keyboard has a processor in it that sends a signal to the PC itself The only way to use such a keyboard is to purchase an adapter from Cloud 9 see contact info under Support This is an upgraded version of the Puppo
52. from power supply through 100 ohm 1 4W resistor and the other side to ground The Turbo light can be wired to indicate double clock speed by using a 74LS 123 and 74HC74 with the following schematic The Reset switch can easily be wired to the CoCo reset button Remember you can t get to the original one now Simply connectthe wires from the case reset button to the two pins on top of the CoCo reset button 45V E Clock 6809 pin 34 7ALS123 620 ohms E Clock 6809 pin 34 3 D 4 1 74 74 LK D PRE CLR Q 330 ohms T Turbo LED GND NOTE Another LED of a different color can be added to pin 6 of the 74HC74 to indicate normal slow speed page 82 Now if you can remove the plaque from you old CoCo 3 top cover the one that says TANDY 128K COLOR COMPUTER 3 and mount that on the front of the new case for the completed look CAUTIONANDDISCLAIMER This text file reveals how several CoCousers including myself and the author of this book have repackaged their CoCos No responsibility whatsoever is assumed for anyone following the procedure described above If you mess up your CoCo it s your own fault not mine the book author s nor the publisher s Just be careful it has been done many times before and good luck Repairs Most CoCo repairs can be made with only a basic knowledge of electronics and soldering The hardest repair to make will require removing a chip from
53. game and Studio Works a digital audio sampler What was probably the most welcomed new product Ex tended ADOS 3 was announced by Spectro Systems in August Not a new version of ADOS 3 EADOS 3 shared space with ADOS 3 ina 16K ROM EADOS added RAMdisk wild cards clock support and many other features to ADOS 3 EADOS couldn tberun from disk had to be EPROMed and required ADOS 3 Another new item introduction was the RASCAN video digitizer sold byMicrocom CoCo 3 only This was similarto the MicroWorks DS 69 Digisectors but plugged into the joystick ports instead of the expansion port eliminating the need for a Multi Pak or Y cable The RASCAN was developed and made in Australia Bill Chapple decided it was time to call and end to the publication of Dynamic Color News with the August issue Circulation had dropped to just over 100 subscribers The magazine which peaked out with just over 200 subscribers at one time had become to much of a draw on other business activities It had never really made money but hadn t been expected to do so anyway The stated purpose ofthe magazine had been to provide instruction on BASIC amp Machine Language programming computer theory operating tech niques computer expansion plus provide answers to ques tions These goals were certainly carried out Thanks for a wonderful five and a half years of service Bill Though out of the magazine business Dynamic Electronics would continue to
54. graphics screens out of the base 64K area but all of the program code still has to fit there OS 9 Level II doesn tremove this barrier but does work around it nicely by splitting the whole into separate groups A process is up to 64K of code and data The difference is under OS 9 you can have as many processes as you have memory for while under DECB you have one This is the reason some OS 9 programs are split into two parts for example word processors will be divided into a separate editor and print formatter This way the whole package can use 128K 2 processes instead of 64K one process Processes can be connected together from the command line as well When someone speaks of pipes they are talking about con necting one process output directly to another ones input On the commandline a pipe looks like an exclamation 1 page 50 heavy dutyDOS for CoCo proc2 There are two reasons to do this either to get around the memory problem or to make a single utility more useful We ll get into this more later There is still a problem with the total RAM available The practical problem is fitting the operating system into the machine There are 3 ways to do this The DOS can be kept small and simple or simply demand the machine grow larger and larger so the whole thing will fit the disk drives also to get faster and faster so the thing can be loaded the same day and larger so the thing
55. half Make sure enough wire is used so that the shell can be easily separated and the circuit board removed 5 Reinstall disk controller When the switch is in one position the normal side of three double sided drives is active In the other position grounded the back sides are accessed The confusing part is that both the front and back of the same drive will be accessed by the same drive number MODIFYING DRIVEFORDOUBLESIDEDOPERATION This method is a little harder but more rewarding since it operates with no user interaction other than selecting a drive number All that is needed is 741 508 quad two input AND gate and a 16 pin socket all wiring is done to the socket not the chip socket can be eliminated Itis recommended that the number corresponding to the side of the drive be marked on the drive itself for easy recognition 1 On the socket attach a 4 6 inch piece of wire to pin 1 2 3 14 and 15 2 Tie pins 8 9 11 and 12 topin 14 pin 14to 5V position 1 on the drive power connector 3 Tie pins 4 amp 5 to pin 2 4 Solder the wire from pin 1 to land 32 on cable connector DO NOT cut the trace on the drive 5 Connect the wire from pin 6 to the drive select line for the normal side of the drive on jumper pin closest to drive cable connector Connect the wire from pin 2 to the drive select for the back side DSO and DS1 makes the normal side drive 0 back drive 1 The usual method is to use DS 0 amp 1 w
56. legitimate by the third issue with its first ads from The Micro Works and Jarb Software Although initially set up for the Model I amp by July Bob Rosen s BBS was crawling with Color Computer information leftby Wayne Day Syd Kahn Barefoot John Griffen Cal Rasmusen Kent Meyers Lee Blitch and many other gurus including Jorge Mir Radio Shack s cassette based Videotex because it was the first and only terminal program for the Color Computer at this time was used exclusively by anyone calling Bob s BBS with a Color Computer Videotex a very limited piece of software stored incoming information ina puffer but downloading transferring files programs from the BBS to the calling computer saving to tape or printing out the buffer was not supported When off line the only thing you could do with the buffer was look at it and to make matters even worse the only way to exit Videotex and return to BASIC was to shut off the machine Thanks to the efforts of Jorge Mir information started showing up on the BBS about a Videotex modification allowing an exit to BASIC by pressing the reset button thereby preserving the text buffer Download capability was not too far away Tandy s Little Wonder TheSDS80C fromThe Micro Works was the Color Computer s first editor assembler Although marketed in August 82 it had been since June It should be mentioned thatCer Comp of Las Vegas in a letter dated Jun
57. line entry for each virtual floppy Something must be said about the Tandy Hard Disk Interface 26 3145 under circumstances try to use it This has got to be the worst thing Tandy EVER produced for the CoCo No aftermarket hardware or software is usable with the thing Tandy provided drivers for OS 9 but never for DECB The worst problem is that the interface and software will only support old style Tandy hard drives which are no longer available were slow and if found used are not likely to last long Only 10MB 15MB and 35MB hard drives were available for use with this interface These drives had custom built in controller boards and were originally made for the Model I IV computers The most known hard drive system still available is one built around a Burke amp Burke CoCoXT adapter This adapter fits between a Multi Pak Interface Slot Pak or Y cable modified to supply external power the CoCo can t power a hard drive controller anda standard half card PC XT eight bit hard drive controller This system is one of the fastest available for the CoCo page 67 Withnew eight bit PC XT controllers falling in price to the 40 50 range and smaller 20MB 60MB hard drives falling rapidly inprice many CoCousers are now looking at hard drives Used controllers and drives are readily available for 200 or less simply because PC owners no longer need or want them It is getting increasingly difficult if not impossible to find new 2
58. location 150 see appendix Many Tandy Radio Shack printers were made with connect ing to the CoCo in mind These have a four pin serial port as well as a parallel port in most cases Most are switchable between 600 and 2400 bps and serial parallel operation mak ing them usable on all Tandy Radio Shack systems including IBM compatibles In the Tandy Radio Shack numbering system an LP model is a Line Printer early dot matrix DMP a Dot Matrix Printer DWP a Daisy Wheel Printer Tandy s Little Wonder CGP aColor Graphics Plotter or ink jet in the case ofthe CGP 220 and TP a thermal printer which also uses dot matrix technology but with special heat sensitive paper instead of a ribbon Dot matrix types are the most prevalent as they can print graphics as well as text All but the LP series CGP 115 TP 10 and DMP 105 through 120 models are capable of correspond dence quality text printing which is slower but neater than standard draft output The most common printer today is the nine pindot matrix though 24 pin models are quickly becoming the standard Generally the more wires the better the print though the nine pin printer is adequate for most uses A daisy wheel printer is slow but produces typewriter quality output they use the same daisy wheels as typewriters and are essentially typewriters with no keyboard Indeed many high end typewriters have serial ports built in or available as options The f
59. massive EVE Elec tronic Video Exchange which has become the predominant largest and most sophisticated messaging system for the telephone answering service TAS industry EVE has cap tured 70 percent of the TAS market and consists of about 100 000 lines of source code Despite its large size EVE comfortably runs ona single 10 MHz 68000 Motorola micro processor Olaf Meding of Amtelco says FORTH is much more than a computer language FORTH is a complete pro gramming environment and even more itis a philosophy The concept of simplicity is what makes FORTH so effective and powerful Tandy s Little Wonder When you LOAD and RUN a BASIC program the BASIC interpreter analyzes each program line translates it into ma chine code and then executes that code BASIC programming is interactive you can make changes in your program and test those changes immediately This makes program develop ment and debugging comparatively easy But because BA SIC must analyze and translate each program line every time the program is run BASIC programs are also comparatively slow If you use an assembler such as EDTASM or a compiled language such as C PASCAL or a BASIC compiler you write your program in an ASCII source code file and then assemble or compile and link it to a machine language object code file When you want to run the program you simply LOADM and EXEC the machine language object code file The machine language executes dir
60. missed out on lots of material appearing regularly in a publication called68 Micro Journal 68 Micro carried the first information on the MC6883 SAM chip Nov 80 the first Color Computer software ads and a tip on disabling the ROM Pak auto start Jan 81 Mickey Ferguson s letter mentioning plans for starting Colorware Jan 8 1 talk of an expansion interface fromF amp D Associates Mar 81 andaletterfromTallgrass Technologies about their proposed disk system Apr 81 The April issue also miered the first dedicated Color Computer column Bob Nay s 580 Only retrospect Don William s 68 Micro Journal be truly appreciated With a reader base made up of Motorola 6800 users they were among the first to realize the true potential of the 6809 powered Color Computer Names like Star Kits The Micro Works Computerware Mark Data Cer Comp Frank Hogg and others were in the pages of 68 Micro long before there was ever a Color Computer With its support of the Motorola 68xx series 68 Micro attracted some early seekers most however gravitated toward 80 Microcomputing others to 80 U S with still others trying BYTE As more and more interest grew it was inevitable that somebody somewhere would start a publication exclusively for the TRS 80 Color Computer Color Computer News CCN was the first dedicated Color Computer publication to hit news stands Edited by Bill Sias and published by REMarkable Softw
61. new floating point routines to provide them CF83 FORTH is an Extensible Stack Oriented Reverse Polish Threaded Interpreter FORTH is Stack Oriented BASIC and other languages are Variable Oriented In BASIC you store numbers in variables and then use the variable name whenever you want to access the number or pass it to a subroutine FORTH also uses variables when it has to but most of the time it stores numbers on a stack and passes numbers to other words via the stack Tandy s Little Wonder A stack is a simple Last In First Out LIFO storage device Suppose you have a handful of pennies and you stack them one on top of the other on your desk Now if you wanta penny you take it off the top of the stack You don t try to take it from the bottom or the middle of the stack because the entire stack would fall down So the last penny you put on the stack is the first penny you take off the stack i e LIFO The stack orien tation saves memory less memory is devoted to variable storage You might think that the variable memory you save would be offset by the memory needed for the stack But BASIC and other languages also use stacks Programmers just aren t aware of those stacks because programmers aren t allowed to use them directly the stacks are reserved for internal use by the language itself Stack operations are more efficient if you use Reverse Polish Notation RPN RPN should be familiar if you own one of the more e
62. of the VDG will probably cure the problem If not further work to remove heat from the case is necessary See Power Supply Repairs for some suggestions Cooling the SAM can also help same as cooling the VDG The CoCo3 The GIME Graphics Interrupt Memory Enhancement re places the SAM and VDG see in the CoCo 1 2 and also handles the enhanced graphics and memory capabilities as well as interrupts of the CoCo 3 The GIME is suspect of causing problems in several instances including Screen flicker or sparklies Intermittent trash on the screen Intermittent memory loss Missing characters screen shifted 1 2 characters to the left No horizontal synchronization signal at power up Most of these problems can be cleared by cleaning the GIME and socket Use a pair of small screwdrivers to carefully pry the GIME out of it s socket from the corners Note how GIME is oriented in the socket It can be easily rotated and may be damaged if inserted wrong lettering is usually right side up with lettering on the 6821 PIAs and the 68B09 Once out clean the contacts on the chip with a pencil eraser or alcohol The socket should be cleaned with alcohol also It is best to use a foam swab not cotton Tuner or electronic contact cleaner in a spray can may also be used If cleaning the socket doesn t solve the video problems replace C64 a 150pf capacitor with a 220pf 50V or greater 596 tolerance ceramic disc capacitor
63. on priority OS 9 considers each window to bea separate hardware device with it s own keyboard and screen The second possibility is using background tasks DECB users are no doubt familiar with using colons to put more than one command on a line The same thing can be done in OS 9 using semicolons list file gt p dir 40 first lists file to the printer then does a directory of drive 0 But there is another command line separator the ampersand list file gt p amp dir d0 lists the file to the printer and at the same time puts the directory on screen Just want your prompt back List file gt p amp immediately returns OS 9 prompt Free printer buffer There is a third way Although Tandy didn tinclude them with Level II owners of the Level II Development System will find the utilities tsmon and login included These allow other people to log in to your CoCo This can be another computer on the same desk or somebody halfway round the world using a modem The remote user gets his own shell and can run any programs you let him this is why OS 9 files have both public and owner attributes So not only is your CoCo a multi tasking computer it is multi user capable as well All you need is the above commands and acouple serial ports cables and terminals or other computers a good use for an MS DOS machine What OS 9 Does for You The preceding discussion has delved pretty deeply into what OS
64. ones This was followed by our K bus systems At the 1989 Rainbowfest in New Jersey Kevin Darling and some others asked me to stay for a few minutes after the show for a conference Sunday afternoon I was told that Tandy had definitely discontinued the CoCo 3 Kevin anda group of OS 9 programmers had been working on an upgrade to OS 9 Level IL which was sort of in limbo without Tandy support the upgrade was being done for Tandy I suggested that a CoCo 3 upgrade COMPUTER be developed something to get the CoCo OS 9 users into the 68K world There wasn t enough OSK software around and what was out was to expensive for most CoCo users You just couldn t do much with a 68K machine at the time due to lack of software Italked withKevin Pease andKevin Darling about making a 6809 based computer I wanted to use the K bus because it was an existing bus and FHL already had products for it Kevin Pease bowed out because he didn t think the K bus was the page 96 way to go Paul Ward called and wanted to form a committee to developa68K based OS 9 platform FHL had been involved indeveloping many computers and Iknew thatthe committee method wouldn t work well as no one usually agreed on anything and by the time everyone had compromised you hada hobbled system I didn t wantto work with Paul for that reason IMS was formed shortly afterby Kevin Pease andPaul Ward who then started promoting the MM 1 which at the time was non existent The re
65. or so should be safe but do look before continuing Any AC DC portable set will work well color or B amp W IF YOU DON T UNDERSTAND THE SCHEMATICS SEEK HELP FROM SOMEONE WHO DOES OR DO NOT ATTEMPT THIS PROJECT Those warnings given I ll continue Adding the video input directly is incredibly simple All that is required is five components a small piece of PC board and abit of wire Use afemale RCA type phono jack for the input either mounted to the TV cabinet or a short piece of cable 274 346 or 274 338 The shield negative sideis grounded to the chassis hence the shock hazard for hot chassis sets The positive center lead is connected to the chassis through 470 ohm resistor and to the base of the video driver right before the bias circuit through two 13914 1N4148 diodes andasingle 0 1 uF capacitor The hard partis finding the video drivertransistorinthe TV There is usually a schematic inside the case of most TVs Use this to locate the video driver transistor If no schematic one must be located or the project referred toaqualified TV technician TV technicians should be able to get a schematic for a reasonable fee A speaker circuit will have to be used as the sound from the TV signal is no longer available If the TV is to be used solely as a computer monitor wire the circuit in directly Otherwise add a switch between the video input circuit and video driver With a color set this is the limit to the m
66. own the machine only the operating system knows for sure Every process has a priority which tells OS 9 how much time to give it This priority is up to you and it s ahandy power to have Bumping a process priority way down reduces the load on the machine to the point where the user can t tell it s running It will get done eventually and in the meantime you can do other things This helps but there is still a problem Unlike with DECB a program can tjust sit on the hardware For instance a terminal program might be switched out when anew character comes in Since the terminal program doesn t know it s being switched in and out it would miss that character This is where interrupts come in Hardware interrupts inform OS 9 it s time to go take care of the hardware regardless of what else is going on Another concern is wasting time If a process is waiting on keyboard input for instance there is no need to give it CPU time until something is typed So a process can sleep giving up it s CPU time until a signal the software version of an interrupt comes along Tandy s Little Wonder With all this multi tasking ability laying about there has to be some way to use it The first way is by using the CoCo Windowing system This system establishes virtual con soles switching the screen and keyboard between separate processes It doesn t matter which window is visible on the screen they all run full speed depending
67. pack age for the 2 CoCo3 Called simplyCOCO C this wasacomplete C development packagebased on the original Kernighan and Ritchie C standards as was OS 9 C A sad note for the CoCo community appeared in the February 793 issue of UpTime In their usual three page ad CoCoPRO printed a letter stating that they would soon cease operations asa CoCovendor Anunusual offer was made buy atleast 30 of software froma discounted list of products that CoCoPRO owned outright and a license to use ALL 14 of the listed products would be granted The catch to the offer was that at least 33 of the mailing list had to take up on the offer The programs could be obtained via a special password to a database on Jim s CoCo Corner BBS 313 292 4713 E mail on Delphi or by sending 1 per disk to and 3 shipping per order to the CoCoPRO address If 33 didn t respond the programs wouldn t be released but one would still have the software one paid for Not a bad deal The letter was also sent to many CoCo users via direct mail bringingthe total sent to 1966 plus the just under 300 UpTime subscribers who weren t counted in the total 84 were returned as undeliver able leaving 1882 for the group This meant 752 would have to place orders for the offer to succeed As of 19 February Dave reported thatthe original goal was unlikely to be met so the response rate waslowered to 22 and the deadline to 10 March At that time any who partici
68. sold you the computer or from Tandy s customer service Salespeople unless they were also computer people could offer little if any information If you were lucky enough to find a salesper son with computer know how chances are it was Model I Z 80know how Nohelpthere Customer service in Fort Worth on the other hand had plenty of information and was only a toll free call away Unfortunately Raymond Martin and Kathy wouldn t tell you much more than what was in your manual Another dead end One of the first books detailing the internal workings of the 6809 was published in late 1980 Authored by Dr Carl Warren The MC6809 Cookbook contained all the information required for assembly language programming Unfortunately it preceded the first Color Computer editor assemblers by about 8 months and this book was pretty much overlooked Computer magazines at this time were filled with articles and reviews about every computer except the Color Computer When anything did appear it was usually comparing the Color Computer unfavorably to the Atari 800 Reviewers pointed to the chicklet keyboard limited screen display 16 x 32 inverse lower case and small RAM size as areas which make the Color Computer less desirable than even the Atari 400 or Tandy s Little Wonder the VIC 20 Perhaps I m too sensitive but I couldn t help feeling they were laughing at MY computer Did anyone else get that feeling If so realize this
69. speed mode there may be a slight increase in RFI but it shouldn t be noticeable Tandy s Little Wonder The CoCo 3 DOES NOT support the first double speed POKE Tandy actual did something better they decided to support the double speed POKE fully The address at 65497 0 supports true double speed operation of ROM RAM RAM is refreshed properly and video POKE 65496 0 still returns to standard speed Many CoCo 3 programs take advantage of the double speed mode but disk operation is still hindered be cause the Disk BASIC extension was not modified OS 9 Level IIrunsin double speed all the time there is no way to slow the processor down The following program makes several changes to Disk BASIC These changes can be burned into an Intel 2764 ROM to make them permanent The 2764 is a 28 pin chip meaning an adapter available from Spectro Systems is required for all Tandy controllers except the short one Simply run the program and then save a copy of the Disk BASIC ROM code to disk or tape The listing is commented with explanations between program lines don t type in the explanations program lines are in bold Eliminate the lines with unwanted features Programmers may use portions of this listing in commercial products as long as the statement Portions by F G Swygert amp L Todd Knudsen is included in the new BASIC code 10 REM Program for setting printer baud drive step rate and double speed disk access CoCo 3
70. sure pin 1 goes to pin 1 etc Make the cable no longer than necessary a long cable will cause problems This is where the CoNect Xpander or Y Box will help and installation will be easier 5 I cut a piece of sheet metal to mount all those extended connectors on Cut out some of the PC card slot dividers for page 81 additional room and make a plate to mount the connectors on that covers the slot area If using long cables only just leave one of the slot covers out and run all cables through that slot 6 Plug everything together connect to the power supply and double check all the wiring 7 Mount the drives in their slots and hook them up to the power supply 8 Plug your various packs into the MPI 9 Go back and double check ALL connections Make sure EVERYTHING is connected properly Turn on the power supply and test the various peripherals If everything checks out okay you re done If not you know what to do if you got this far AFEWEXTRA GOODIES There are usually three lights a momentary reset button atwo pole on off Turbo button and a two pole key switch on mostall PC type cases If you have a hard drive you can easily useone ofthe lights to indicate drive access by simply finding where the drive access light pins are on your HD and connect ing them to the appropriate light Thisisabig helpif you have used a slot behind the front cover to put your HD in You can wire the power on light by hooking 5 VDC
71. t access One of the first things that captured ones attention in the August issue of Rainbow was a full page ad from Adventure Novel Software In this unique ad players of their newNight of the Living Dead interactive adventure game were offered 500 if they were the first to survive D P Johnson intro duced another programming language for OS 9 users FORTH09 This was FORTH 83 standard implementation specially tailored for OS 9 level I or II even for other OS 9 computers Help for users of fandy s DCM Modem Pakwas offered The Modem Pak s primitive communications software does not allow for downloads or uploads transfer of files from or to the host computer BBS How to overcome this problem was the subject of an article by Delphi CoCo SIG database manager Don Hutchison Even thoughTandy was pushing OS 9 for software develop ers it dropped the RS 232 Pak which was required for telecommunications under OS 9 It wasn t long before some one in this case Orion Technologies introduced a directly compatible clone October 88 Unlike other products such asthe Disto RS 232 Pack Orion s pack had the same hardware address as the Tandy Just plug it in and go A version with external power supply was made for the CoCo 2 and 3 or the standard version could be used with a CoCo 1 or Multi Pack which provided the necessary 12 volts Getting ready for Christmas Diecom released several new games in November Xenion ran on a C
72. that allowed easy fast action and sound Licensing options would be available for programs using Graf Express The February and March 1992 Rainbows were significant in one way February was the last magazine format Rainbow and March thefirst tabloid or newspaper format Thereason for the change was simple economics With fewer advertisers there wasn tas much money flowing to stay with the compara tively expensive slick paper color cover magazine Rather than raise subscription prices 31 for a 50 page magazine isn t cheap the new format was chosen The new Rainbow featuredonly 32 pages but space was actually INCREASED by roughly nine percent due to the increase in size of the pages themselves A four color process was still used for the cover but most of the cover space was used for content rather than just window dressing The ads were bigger and the ad prices were even rolled back to the previous years rates Ad price was a big issue sore spot for many advertisers especially with the cheaper to produce tabloid format The magazine was now the size of many small town newspapers and we all know how much they cost The Rainbow has many more expenses than a small newspaper but many advertisers including some with printing industry connections felt the current subscription price alone should come close to sup page 30 porting the magazine the ad rates were bordering on outra geous still around 300 for 1 4 page
73. that price during the fest also Interestingly Multi Vue continued to carry a 49 price tag These bargains were not advertised but once they were found out things went FAST It was becoming hard to find CoCos and related hard software in Radio Shack stores The end had finally come Many CoCo 3s were made before the Christmas season and there were plenty to many left No more CoCos would ever be pro duced Careful readers should have noticed by now that there has beenno mention of OSK er for five months The reason is that they mysteriously disappeared Thefourth issue finally reached subscribers in May Understandably the editor decided to leave a date off the cover In this case the directory format of the table of contents comes in handy the editorial was last modified on April 23rd 1991 This lapse of coverage with no notice to subscribers was inexcusable and hurt the reputation of both the magazine and editor The editor realized this and wrote an apologetic editorial about missing deadlines It seems that a big reason for the lapse in issues was that the company StG Computers moved locations He also stated that OSK er was back for good To bad that would not prove to bea true statement On the plus side a good article on BASIC09 Introduction to BASICO9 appeared in this issue It didn t take one long to notice that there was no Microcom ad in the June Rainbow Last month it was SD Enterprises distributo
74. the CPU itself These instructions operate on and access data in different ways through addressing modes The 6809 has 59 instructions and ten addressing modes for a total of 1464 different opera tions Variations of these modes bring the total number of modes up to 19 This code must then be assembled into a list of binary data m l code that the CPU can use directly Mnemonic instructions are abbreviations of what the com mand actually does The instruction itself ADDB for ex ample is called the opcode operation code This is fol lowed by a value for the instruction to act on or with called the operand or argument Together the opcode and operand define exactly what the instruction does The mnemonic ADDB 1 means add the contents of register B in the CPU to the number 1 and put the result back in the register The Tandy s Little Wonder ff sign defines a decimal value in EDTASM Other assem blers may use a different designation The above description is a bit simplistic as any A L program mer will readily testify A full discussion on M L and A L programming is beyond the scope of this book Check the Library section for recommended texts As for assemblers several were available for Color BASIC Tandy sown EDTASM EDTASM and Disk EDTASM were naturally popular So was MicroWare s MACRO80C which for a time was even more popular than the Tandy product Used copies of these are likely to show up with used
75. there are a lot of pages with opinions given as facts You can t always assume something is fact because it s repeated on many pages either sometimes one page picked something up from another and it just gets perpetuated So the Internet isn t all it s cracked up to be It takes some digging and a little research to separate fact from fiction and opinion sometimes The Internet is so ubiquitous now that there is no need to explain it Listed below are the addresses to a few of the most active CoCo sites These will naturally have links to others Happy surfing TRS 80 Color Computer Web Ring Links to many Color Computer sites http m webring com hub ring coco Capt s CoCo Hut Many articles but the one that got it on here is the regualraly updated price guide The owner watches E bay and other sites and reports on average prices for hard and software http coco clubltdstudios com index html Tandy s Little Wonder The CoCo Lounge Lots of history monthly articles andanice selection of used hardware and software for sale http www coco 8bit micro com CoCo3 com This is probably the best of all the sites Lots of support and links to just about everything to do with the CoCo The site is very well designed but a bit busy There s a24 hour chatroom and lots of software downloads This is the best site to get one of the free CoCo emulators from If you don t want to download you can order a CD ROM with all the emulators on th
76. they wouldn t be printing due to unexpected problems the authors were having health problems but they would recon sider if another author was found About six months after this about a year ago now finished my AMC book Since I d have the time to write about the CoCo now I gave Falsoft a call I was asked to send in my ideas and a sample of my writing The idea at Falsoft was to make a compendium of recollections from long time CoCo users the pioneers of the CoCo as it were In my opinion what the CoCo community really needed was an all encompassing reference not just a simple history Support was floundering all around us we needed a collec tion of all those valuable tid bits of information that would be helpful to all users Falsoft turned my ideas down by merely saying they were no longer interested in publishing the history At that point I dteremined to go ahead and write this book it should be noted that had Falsoft stated that they were interested in printing a history but not my ideas fora complete reference I would have been willing to go ahead with whatever they wanted In a way I m glad it didn t turn out like that When The Rainbow hit an all time low of 16 pages I was greatly concerned about future CoCo support I wrote Mr Falk a letter expressing an interest in possibly buying out Rainbow About a week later I gotacall from him We talked a while andit was apparent I couldn t come up with the funds needed fo
77. this day to support the CoCo with hard and soft ware products including a large and inexpensive public domain software collection By looking at the Advertisers Index of the September 89 Rainbow one would think that the CoCo market was growing The reverse was true the format of the index was switched to multiple ad entries instead ofasingle entry with multiple pages for each advertiser This gave the first impression that there were more advertisers when there were actually only 52 Page count was down to 130 where it had been since August The Tandy s Little Wonder August 89 advertiser count was the lowest to date 40 The highest advertiser count was in December of 1985 at 142 highest page count was 288 pages in the same issue The Somerset RainbowFest was held October 20 22 This wastheLASTRAINBOWFEST held in New Jersey CoCo 35 were being sold by Computer Plus for just 99 Tandy introduced severalnew ROM Pak games Robocop Rampage Predator and Arkanoid Tony DiStefano of CRC Computers showed off al megabyte upgrade prototype for the CoCo 3 Now OS 9 the only product that could take advantage of the extra memory could REALLY be shown off as soon as it becomes available Zebra Systems introduced their Label Designer a graphics based point and click program that made cassette Rolodex disk file folder and normal address labels and a graphics program similar to CoCo Max Color Paint The new Sundog Systemsadin this mo
78. to share their programming abilities Two things happened in the late eighties which almost saw the death of the CoCo in Australia One was the loss of The CoCo Magazine produced by Graham Morphett and the second was the discontinuing of the CoCo by Tandy These two events caused a large section of the CoCo community to move to other machines or to place their CoCos in the cupboard and forget about them for a while It was also at this time that the majority of the businesses which had been supporting the CoCo decided to go to other machines or leave the computer business Non existent support resulting from these events left the remaining CoCo community in a very precarious position They still used their CoCos and found more uses for them but were slowly being forced to lean towards other machines as parts software hardware and contact became scarce It was at this time that Robbie Dalzell a member ofa CoCoclub in South Australia decided to do something about this state of affairs and began to produce a magazine called CoCo Link CoCo Link again gave some support to the remaining CoCo community It maintained contact gave assistance to those still learning and shared new found knowledge amongst those who subscribed Robbie s magazine again kept the CoCo community together for a further period of four years Notwithstanding the contact and support provided by the CoCo Link magazine software and hardware still became increasingly ha
79. total of 16K New commands included those missing from Color BASIC including a wide range of graphics commands algebraic and trigonometric functions the play command and many new programming statements the most notable being a statement to save machine language programs on tape The Extended ROM could be added to any CoCo for 99 00 plus installation Many of the graphics commands required 16K to use the first CoCo was only 4K the upgrade would add an additional 119 00 plus installa tion to the price The best deal was to purchase a 16K Extended CoCo new it was only 100 more than a 4K non Extended model 599 vs 499 Tandy s Little Wonder There were some minor problems inColor BASIC 1 0 One was the printer driver Tandy used a seven bit code to drive a printer in the CoCo Less than a year after the CoCo s introduction printers including Tandy models standardized on an eight bit code Tandy first rectified this by supplying a new printer eight bit printer driver on tape for free note that some early Tandy printers were seven bit input others were switchable between seven and eight bits This was brought on by the introduction of the Line Printer VII the first with a built in CoCo serial connector four pin and the first capable of dot addressable graphics The seven bit printer driver would print characters but no graphics In November 1981 the new 32K CoCo was introduced With itcame anewrevision ofColor BASIC
80. trs 80 com trs80 cr htm This file came from his 1989 archived catalog page 134 Tandy s Little Wonder REAR COVER DO NOT PRINT THIS PAGE print back side only It was included to even out the PDF file Use a sheet of card stock or heavy colored paper for rear cover Tandy s Little Wonder page 135 Our Versatile Family Color Computer 128K Extended BASIC Color Computer 3 Simply con lo your TV of the high resolution CM 8 color monitor below and you re ready to start computing Use BASIC to create charts and graphs in vivid colors Compatible with most Color Computer 2 accessories Runs instant inading Program Paks see Cat RSC 22S TSP avail 19995 able 26 3334 Low As 15 Per Month Less monitor platicem and floppy drive 1 Color Computer 3 Only CM 8 RGB Analog Culur Monitor 1 25 3215 299 95 FD 502 Color Thinline Floppy Drive 26 3133 299 95 Direct Connect Modem Pak 300 bps 26 2228 8995 Hi Res Joystick Interface 26 3028 9 95 Multi Vue Leve Two interface 3 26 3035 vases 49 95 512K Memory Board with OK RAM 26 3336 39 95 Second Drive for FD 502 26 3135 179 95 Disto Super Controller 2 For FD crives 900 2009 129 95 Ask for Your Free Copy of the Radio Shack Software Buyer s Guide for Great Color Computer Programs aS The Last CoCo 1 4 page spot in 1991 Tandy catalog Tandy s Little Wonder the Color Computer 1980
81. version 1 1 The main reason BASIC was changed was the 32K RAM upgrade itself The old 1 0 ROM would only address up to 16K so it had to be changed While the engineers were making changes any way they decided to add some items to the original ROM code and to fix acouple minor problems though the official stance was that nothing was wrong with the 1 0 ROM The additions included 32K support the eight bit printer driver and display ingan S while searching a cassette fora file and an when a file was found When disk drives became available from Radio Shack in October of 1981 a new BASIC extension came with them Rather than create a disk based operating system Tandy decided to add commands to BASIC that would allow access to the disk drives Disk Extended Color BASIC DECB resided in an 8K ROM contained in the disk controller With the controller plugged in the disk commands loaded into the Program Pak area of Color BASIC This method allowed the CoCo to retain simplicity of use with the speed and conve nience of a disk drive An advantage to BASIC programmers is immediate access to disk information A true disk loaded disk operating system DOS not only has to have BASIC loaded from disk but BASIC has to call the DOS to access most disk information DECB has commands that allow extensive disk data manipulation including directly reading and writing to specifiable portions of the disk new type of CoCo 2 the Korean made A
82. was forged between CoCoists not only in Australia but around the world Letters and articles in the various publications ensured that contact was main tained between CoCoists in Australia America Europe and numerous other countries It was not unusual to see a letter to the editor in an issue of Softgold asking for help with a particular problem from someone in New Zealand or even Holland The advent of the CoCo 3 further advanced the CoCo commu nity in Australia At last there was a comparable memory on board without more expensive add ons and the introduction of OS 9 Level II put the CoCo ahead of the other more expensive machines OS 9 also saw a great number of program page 92 ming gurus come forward and share their abilities with the community atlarge The National OS 9 User Groupin Brisbane Queensland was formed and is still going today The mainstay of the CoCo community in Australia was The CoCo Magazinestarted byGreg Wilsonand then taken over by Graham Morphett on Greg s untimely death In the pages of this magazine was the contact needed by CoCoists from the vast outback of the country with those closer to the cities and the software and hardware vendors world wide The magazine gave hope anda sense of belonging to those who were without telephones and received mail only once a month Content included helpful hints reviews of the latest soft and hard ware and allowed users from the very young to the most experi enced
83. width In general the smaller the dot pitch the sharper the image a CM 8 hada dot pitch of 52mm the popular Magnavox 8 515 and 1CM135 is only 42mm It is not advisable to get a monitor with a dot pitch of more than 52mm for viewing 80 column text An RGB monitor will support all screen modes from 32 to 80 columns Note that RGB monitors do not support artifacting a programming technique used by some CoCo 1 and2 programs to generate additional colors on screen Programs using artifacted colors will display as black and white on an RGB monitor There is no easy way to fix this problem When the CoCo 3 first appeared a few vendors sold patch programs to display artifacted programs in color on an RGB monitor Unfortunately most of these programs are no longer available There are a few patches available from the Delphi CoCo SIG for specific programs Perhaps the best solution is to purchase a monitor that displays both RGB and composite video such as the 1CM135 and 1084 and almost all TV monitor combina tions There are two basic types of RGB monitor that will work with the CoCo 3 The first is an ANALOG type An analog signal varies almost infinitely from 0 9V allowing a large range of colors limited to 64 colors by the CoCo 3 This is the type the computer is really designed to use ala the Tandy CM 8 The most widely available monitors that accept this type signal are the Commodore 1084 for the Amiga and Magnavox 1
84. would deliver true lower case instead of those unsightly inverse characters This was thefirst lower case board for the Color Computer and was also available in kit form from MSB Electronics Marketing began on Soft Sector Marketing s Master Control the first single key entry utility If you ordered immediately you were told some problems have cropped up and we ll be a few weeks late in delivering it Not again Jorge Mir wrote an article describing how Videotex could be modified to return to Basic upon reset thereby giving the Color Computer its first BBS download capability the buffer content could be saved to tape Although there were a few bulletin boards which supported the Color Computer The Ark appears to be the first that actually ran on a Color Computer Barefoot John Griffen the sysop operated the BBS from his houseboat in Portland Oregon Callers includedSteve Den Beste Shawn Jipp Bob Rosen and Ed March Mike Wolf started marketing his Color Computer disk con troller around this time October Unless one had either inquired or ordered his WOLFBUG monitor chances are one didn t hear about it because the controller was marketed only through direct mail With a price tag of around 350 00 the unit included an 80 column card real time clock and parallel printer port In a phone interview Mike said that a Michigan Com puter Club was responsible for the sale of about 10 pieces The name TRS 80 stands
85. 0 anda review of April s RainbowFest Marketing began forUn DiskfromDr Preble Elite Calc fromElite Software andPBJ s 80 Column Card If64K wasn t enough for your CoCo you could always try Dennis Kitsz s 128K bubble memory upgrade which appeared in July s TCCM A new CoCo magazine 68 Color Micro Journal was an nounced in August which brought the number of dedicated magazines for the CoCo up to five Just about all magazines carried articles on the MC 10 New product announcements in August included a new CoCo keyboard from HJL the Multi Pak Interface from Radio Shack Piratector fromSugar Software andChromasette going to disk Soft Sector Mar keting stopped marketing CoCo software Several hundred OS 9 users got together mainly through BBS and E mail systems and formed theOS 9 Users Group Dale L Puckett author of Microware s Official Basic09 Tour Guide and KISSable OS 9 column for Rainbow was elected president and Peter Dibble wrote monthly OS 9 column for 68 Micro Journal vice president The stated purpose of the group was 1 To stimulate and sustain interest in microcomputers in general and in OS 9 in particular 2 To promote the coopera tion and exchange of information between members 3 To conduct programs and activities to promote fraternalism and to advance the general interest and knowledge of members Always on the leading edge Star Kits started its software amnesty program Anyone with pirated Sta
86. 0MB 40MB hard drives The Burke amp Burke interface comes with OS 9 drivers A software package for DECB users Hyper I O is sold separately for 30 A typical Burke amp Burke system would price as CoCoXT Interface 75 New 8 bit controller 50 Refurbished 20MB hard drive 130 Case and power supply surplus 75 Hard Drive Cable Set 5 TOTAL 335 All new equipment would add another 50 to this price Two reasons are apparent that make a CoCo hard drive system so costly the need for an interface converter in this case the CoCoXT and the external case and power supply Together these add up to nearly half the cost of the entire system 150 Today s hard drives don t require a lot of power An old full size floppy drive case will happily power a small half height hard drive especially if it is a 3 5 unit AND a half height floppy without overheating The second best known hard drive set up uses a Disto hard drive adapter eitherin aSuper Controller or MPI adapter The Disto adapter is designed for use with an SASI Shugart Associates System Interface pronounced sassy or an SCSI Small Computer System Interface pronounced scuzzy type controller These controllers are getting hard to find now The following controllers can be used SASI SCSI Western Digital WD1002SHD Adaptec 4000A Xebec 1410A Adaptec 4070 DTC 520 series All but the 4070 use standard MFM type hard drives the 4070 uses an RLL type drive Mos
87. 1 A12 pulse 14 E 6 pulse 21 A13 h p 15 R W 8 h p 22 A14 pulse 16 19 0 25 28 pulse 23 A15 h p 20 GND n a low 24 31 DO D7 pulse 21 4 43 32 R W high 22 5 44 pulse 34 blinking 23 24 A6 A7 45 46 h p 35 Q blinking 25 52 29 low 37 RESET high 26 61 30 high 40 HALT pulse 27 50 31 low 28 31 MAO MA3 n a pulse 32 33 4 5 n a 1 34 35 MA6 MA7 n a pulse 36 15 54 h p 37 14 53 pulse 38 13 52 39 12 51 pulse 40 Vcc n a high n a Vss Vdd 1 35 high n a 1 11 h p n a RESET 9 high NOTE 6809 address signals will read 2 4 4 0V and clock signals 2 4V on a VOM HALT will also read 5V PIAs 6821 6822 VDG 6847 NO DESC READING NO DESC READING 1 GND low 1 GND low 2 DD6 pulse 2 PAO high 3 8 DDO0 DD5 1 3 1 high 11 OA low 10 DD7 1 12 5 h 1 p 4 9 2 7 low high 13 OB low 10 PBO low h p 17 high 11 PBL n c h p 22 DAO h 1 p 12 17 PB2 PB7 high h p 27 GM2 low 18 CB1 high h 1 28 Y low comp video 19 CB2 low 29 30 GM1 GMO low 20 high 31 INT EXT low 21 R W h p 32 INV pulse 22 cso high 34 A S 1 p 23 CS2 high h p 35 A G low 24 CS1 high 37 FS h 1 p 25 ENABLE pulse 38 HS 1 26 33 07 00 pulse 39 CSS low 34 RESET high 35 36 RS1 RS2 pulse 37 381ROB IRQA high h p 29 2 low 40 1 high h p h p high or pulse low or pulse high or low high pulse or low page 84 NOTE Pin 28 Y of the VDGis a source fora weak about 1 V
88. 1 mfd ceramic disk capacitor the VIRQ timer to check regularly called polling for an interrupt register flag in a fully decoded device in slots two three or four So ifadevice fully decodes itself like the Speech Sound Pak itcan goin any slot If it uses the SCS to enable it like the disk controller or needs to use the CART like the RS 232 pak which is fully decoded it must go in the slot that the SOFTWARE decides Note also that you cannot use more than one device that fully decodes itself at the same address since such a device is slot independent in that respect and ALL of them will turn on at the same time a mess So you can t use two RS 232 paks for instance unless they are internally re wired for different addresses Some aftermarket RS 232 paks have jumpers so that an alternate address can be se lected The RS 232 Pak is easy to modify by design to a different address It comes decoded for FF68 6B It is easily changed to be decoded for FF6C 6F though T2 and ACIAPAK can then be used for the original in slot one and M2 and MODPAK for the readdressed one in slot two or three Rewiring is this easy 1 Cut the trace running from pin 8 of the 74LS04 U6 to pin 2 of the 6551 U1 2 Solder a wire from pin 9 of U6 to pin 2 of U1 That s it The use of the A2 address line had to be low before now it has to be high The disk controller address can also be changed see Mass Storage for details Why ar
89. 1991 Second Edition First Edition Copyright 1993 Second Edition Copyright 2006 by F G Swygert All rights reserved Published by FARNA Systems 147 Tom Moore Road Leesville SC 29070 e mail farna att net
90. 20 hours would only be billed an additional 1 20 per hour If one does not belong to Delphi well you don t know what you are missing IMS inabid to win over more users began offering a short lived lease to own option in October For as little as 56 a month with 112 down and approved credit one could get a new MM 1 Owl Ware tried to get into the upgrade game by offering an unusual system a PC AT clone This machine was packaged notonly with MS DOS butalso with a UNIX clone similar to OS 9 in an attempt to sway OS 9 users Gravity Studio introduced something new forthe CoCo PICO CAD a computer aided drafting CAD system 3 D wire frame images could be assembled in full color with this system The only drawback was that a pen plotter that used the DM PL plotting language was necessary for printing NMSA com puter group released a new hardware item CAT This wasa PC AT case modified to contain a CoCo disk drives power supply and a special seven slot bus interface inside Some CoCo users had already mounted their machines in modified or special built cases this package would make such a chore much easier A feature article in Rainbow was Spectra 3 a CoCo Max like graphics editor just for the price of the magazine and afew hours oftyping One could always take the easy way out and purchase Rainbow on tape disk or down load from Delphi though Frank Hogg also had something new to sell this month the Tomcat TC70computer T
91. 3 The CoCo Motherboard 1 Remove QI 5V regulator on heat sink 2 Connect 12V to the unbanded end of D2 and D14 3 Connect 12V to the unbanded end of D4 4 Connect 5V to end of R19 closest to 5 Connect ground to the motherboard one of the key board ground clip lands is a good spot NOTE unbanded end of diodes Dx is the cathode Multi Pak 1 Remove IC9 front left side of board 2 Remove R7 front right near slot switch 3 Connect 5V to circle labeled near slot 1 4 Connect 12V to circle labeled TP2 near slot 2 5 Connect 12V to circle labeled near slot 1 6 Connect ground to any ground point 7 Leave the power switch OFF position or remove 8 Put slot selector to slot four TANDYITRS 30 Color Computer page 91 Tid B Its miscellaneous items of interest to CoCo users The Colour Computer Down Under Seigfred The history of the Colour Computer in Australia has been and continues to be a checkered one The CoCo community here has seen the highs and lows reminiscent of a volatile stock on the worlds stock markets Although Tandy introduced the Colour Computer to Austra lia it could be argued that it was given its real start in this country byGreg Wilson Greg was instrumental in producing the first magazine dedicated to the CoCo in Australia The CoCo Magazine Although it was heavily dependent on material from The Rainbow Magazine in its i
92. 35 note that the Commodore 1084 is made by Magnavox for Commodore itis almost identical toa 1CM135 The Commo dore 1084S also works it is just a 1084 with two speakers for stereo sound hence S All three sold for just under 300 new at the time of publication An analog monitor was used because of the high number of colors for minimal hardware cost Some other monitors that will work are listed below note that these are no longer being manufactured Monitors followed byanasterics have both RGB and composite inputs Both may beconnected to the CoCo3 atthe same time which allows switching between RGB and composite for games that use page 62 artifacted colors acolor TV may also be connected in conjunc tion with an RGB monitor indeed the CoCo 3 will drive all three video devices at once The dot pitch is listed in parentheses when known Commodore 1902 Commodore 1084 and 1084S 42mm Magnavox 8 505 65mm Magnavox 8CM515and 1CM135 42mm Magnavox 8CM643 39mm NEC MultiSync 31 mm TeknikaMJ305 41mm Other RGB Analog monitors are also usable The CoCo 3 uses separate horizontal and vertical up going positive sync signals The below listed monitors differ from these standards but are usable with a little added circuitry MONITORS WITH COMBINED DOWN GOING SYNC Feed both the H and V sync signals from the CoCo 3 into the inputs of a NOR gate 74LS02 and feed the output to the monitor s
93. 40 to amp 5 Note that the entire area isn t used by the disk controller just half of it When Tandy designed the CoCo it intended only one item to be in the expansion port at a time Therefore they allowed whatever was written in this I O area page 65 to completely fill it What happens is that a copy of whatever is in one half ghosts to the second half also This causes problems when a second hardware device such as a hard drive controller attempts to use the I O area from amp HFF50 to amp HFFSF as the signal ghosts up into the area used by the floppy controller The MPI was designed to allow more than one device at a time It fully decodes the SCS I O area so that ghosting is prevented So does the X Port and Slot Pak see Expansion Devices Y cables have no circuitry to do this so will not work with certain devices Naturally CoCo users have found acure for this situation The address area can easily be fully decoded by adding a 74LS32 quad OR gate only one gate is used to intercept the SCS signal and OR it with the A4 address line Connect as follows 1 Bendall EXCEPT pins7 amp 14 ofthe 74LS32 straight out from the sides of the chip 2 Place this chip on the back of any other 14 pin 74xxxx chip in the controller and solder pins 7 amp 14 to same pins of this chip Make sure the notches in the ends of both chips are lined up 3 Solder a jumper between pins 4 5 9 10 12 13 amp 14 This sends pow
94. 4581001 GIME spi9kx Q5 Q6 07 QOO 4 0 TP3 TP2 CoCo 3 Circuit Board page 118 Tandy s Little Wonder REGISTER e E 2 page 119 Tandy s Little Wonder The Tandy Color Computer 3 More colors superb graphics greater power at a low price With Radio Shack s Color Computer 3 26 3334 219 95 you can start com puting right away even if you ve never used a computer before Simply attach it to your TV and you re ready to start Not only does the 128K Color Computer 3 offer twice the memory twice the speed and even better graphics than our popular Color Computer 2 it s also compatible with the Tandy hardware accessories and software designed for the popular Color Computer 2 you may never outgrow it You can choose from a wide selection of educational software including pro grams designed to improve your math skills history spelling vocabulary and typing skills The Color Computer 3 can even be used for writing your own sophisticated programs simply lug in an instant loading Program Pak for fun and games You can even add an optional modem to access educational databases over the phone Enjoy ser vices such as an electronic encycl great for homework and fun to use for the whole family The Color Computer 3 is available at more than 7 000 Radio
95. 5 consecutivly numbered address bits SHIFT 91 D 40 SLENB disables internal device selection nor SHIFT 21 mally low allows decoded but unused sections of ghtArrow 9 RAM to be used by external devices 4 SHIFT 93 96 2 97 122 123 124 125 126 127 Codes 128 159 are mostly European accent marked characters They are not printable with a CoCo 1 or 2 page 102 Tandy s Little Wonder BASIC Extended Disk Error Codes Code SN RG OD FC OV OM UL BS DD 0 ID OS LS ST CN FD AO DN Super Extended BASIC Error Codes CoCo3 ONLY Code HR HP Be e 15 38 39 Description Syntax Error RETURN without GOSUB Out of Data Illegal Function Call Overflow Out of Memory Undefined Line Bad Subscript Redimensioned Array Divide by 0 Illegal Direct Type Mismatch Out of String Space String too Long String Formulatoo Complex Can t Continue Bad File Data File Already Open Device Number Input Output Error Bad File Mode File Not Open Input Past End of File Direct Statement in the File Undefined Function Call File not found Bad Record Disk full Out of buffer space Write protect Bad file name Bad file structure File already exists Field overflow Set to non fielded string Verification error Write or in
96. 600 192 cps 9 pin 9 235 Brother M 1809 360 cps 18 pin 9 340 Brother M 1909 360 cps 18 pin 15 450 C Itoh ProWriter C 510 240 cps 24 pin 9 270 C Itoh ProWriter C 240 240 cps 9 pin 9 300 C Itoh ProWriter C 245 240 cps 9 pin 15 390 Citizen 200 GX 240 cps 9 pin 9 225 Citizen 200 GX15 240cps 9 pin 15 275 Citizen GSX 130 180 cps 24 pin 9 310 Citizen GSX 140 192 cps 24 pin 9 325 Citizen GSX 145 192 cps 24 pin 15 450 Epson LX 810 200 cps 9 pin 9 250 Epson FX 850 220 cps 9 pin 9 265 Seikosha SP 2000S 192 cps 9 pin 9 210 Seikosha SL 230AL 277 cps 24 pin 15 460 Seikosha SP 2415 300 cps 9 pin 15 300 ncludes the cost of an optional serial interface board but not installation Make sure the serial interface is there Somelaser and ink jet printers also had serial interfaces built in If one already has a laser or other serial capable printer by all means connect it Most CoCo software supports the Epson IBM graphics standards so any printer emulating an IBM or Epson model should work nicely Cer Comp s word page 69 processor is the only CoCo program known to have a laser driver Other programs will only work if the laser has Epson IBM emulation built in Few were made that way and none made today have it The same goes for most modern inkjet printers USB interfaces won t work of course Apple printers are usable as is a special cable m
97. 9 10 11 and 12 D amp Eboard possibly the same number for others between the last capaci tor and the power supply If this is atantalum capacitor replace with a50 100mfd ceramic disc type for filtering DO NOT leave atantalum capacitor in the circuit These points were provided for testing the power output of the three regulators The 78M12 U17 TP9 provides 12V 79M12 U18 TP 10 12V 79L05 119 TP 11 and the 723C 5V 013 TP 12 The NC board eliminates the 79L05 and provides unregulated 5V at C82 Apply the corresponding voltages from the external power source CoCo 2 Feed pins 15 and 16 ofthe SALT SC77527inall IC1 in original CoCo 2 IC7 in Korean A amp B models with 12V and 12V respectively WARNING Connecting in reverse order could damage the SALT chip and other components Cut traces and feed 5V as follows 26 313x Cut trace between C5 and C11 and and C11 Supply 5V on positive side of C11 26 313xA or B Cut trace between C34 and C35 Add 5V positive side of C34 Replace C11 and C34 respectively with 50 100mfd ceramic disc capacitors to provide some filtering on the 5 V input DO NOT leave the original tantalum capacitors C11 amp C34 inthe circuit CoCo3 Feed 12V and 12V tothe SALT IC8 as forthe CoCo 2 Cut the trace between C14 and R19 applying 5V to the positive side of C14 Cut the trace between C30 and C31 applying 12V to the positive side of C30 Next cut the trace bet
98. 9 board as a multi function graphics coprocessor This machine ran OS 9 Level II and Disk BASIC support was promised for the future Rainbow losttwo pages this month Now it seems to be losing them one by one THE ELEVENTH YEAR Jul 90 Jun 91 The eleventh year of the CoCo started a new look for the Rainbow which celebrated it s ninth anniversary of CoCo support Saddle stitch stapled binding was introduced In his Wrapping the Rainbow column Cray Augsburg pointed out that there were advantages to this type binding the flat spine binding perfect binding is the proper term made it hard to lay the magazine out flat for typing in listings and pages could come lose with repeated use These were good reasons for switching but the cover up didn t fool a lot of readers Perfect binding didn t look good witha thin magazine only 98 pages and saddle stitch cheaper Like the author most readers were just happy to get the Rainbow Several interesting ads appeared in the anniversary issue of Rainbow A new one was fromP amp M Products Their products were simple keyboard templates with the most used com mands for BASIC CoCo 1 2 amp 3 and Telewriter 64 and 128 They simply laid around the keyboard So simple why didn t someone think of it sooner Hey Kenneth Leigh finally tells us the name of their new computer the MM 1 multi media 1 The company promises to tell more each month This month they tell us that it uses exist
99. 9 word pro cessing software a separate editor and formatter were NOT used Pull down menus were controlled either from the key board or with a mouse joystick Animportantissue in April s Rainbow editorial column Print 2 was the fact that the CoCo was being discontinued in Canada InterTAN an independent subsidiary of Tandy that handles overseas operations had its own officers and stock and also made its own decisions One of those decisions was to discontinue CoCo sales in Canada One reason for this decision was that many Canadians either drove across the borderorordered their CoCo supplies from American distribu tors which lowered actual in Canada sales figures The reason for doing this was the U S Canada monetary exchange rate CoCos were cheaper if bought in the U S Lonnie Falk encour age alarmed Canadian users to write InterTAN and encourage the return of CoCo support Many were afraid the CoCo was being discontinued by Tandy That was still a few years off May was Rainbow s printing issue and desktop publishing was 1989s main feature The three major desktop publishing packages for the CoCo Newspaper Plus Second City Soft ware The Works Colorware and Home Publisher Tandy were reviewed and compared A major enhancement for Rainbow s desktop publisher written by H Allen Curtiss Oct 787 was a high density printer driver written by the original author Printouts were much improved over the origi nal This pr
100. C Since both were derived from UNIX just for different platforms the similarity is natural Just what is NitrOS 9 With the discovery of the additional features of the Hitachi 6309 replacement for the Motorola 6809 processor several members of the CoCo OS 9 community decided that it would be a big boost to incorporate those features into OS 9 To take maximum advantage of the features would require the eventual rewrite of the entire operating system but since OS 9 is modular it could easily be done one command at a time It took several years before the complete system was rewritten butit was eventually accomplished Not only was the 6309 fully supported which led to a 10 20 increase in speed but every module was carefully gone over a tweaked as much as possible resulting in additional code efficiencies which added another 2 5 in speedups and a unique operating system By this time Microware had long dropped support for eight bit OS 9 with the exception of support for a few remaining industrial users at the time and didn t have much concern about the rewrite By the time everything was finished very few remnants of the original Microware code remained anyway The name NitrOS 9 was used to highlight the explosive increase in speed and to pay homage to the system it was based on NitrOS 9 maintains compatibility with OS 9 Level One and OS 9 Level Two by using identical system calls and I O handling It is today s and tomorrow
101. Co 3 graphics CF83 11 Sound Joysticks Timer amp Random NumbersCF83 13 Floating Point Numbers Set CF83 14 Trigonometry Set CF83 15 Complex Numbers Set REFERENCE 1 Medding Olaf FORTH Based Message Service FORTH DIMENSIONS Volume XIV Number 5 January February 1993 FORTH Interest Group P O Box 2154 Oakland CA 94621 FORTHOO is a CF83 FORTH implementaion for the OS 9 operating system It is also available from BDS Software Actual machinelanguage M L and assembly language A L programming is beyond the scope of this book Machine Language refers to the actual code that the MPU reads directly One CAN write directly in this code but most programmers use an Assembler to put the code together thus the term Assembly Language M L and A L are usually used interchangeably Writing directly in M L requires poking the certain values in the correct memory locations This is exactly what is being done when a BASIC program has a routine like the one shown inthe double speed program PEEK POKE EXEC Enhance ments lines 440 480 A data set in this case A contains a list of values that is then poked into memory by a short BASIC program An assembler makes life easier for the programmer The program is written in mnemonic instruction code with an editor usually bundled with the assembler Tandy s EDTASM name comes from EDiTor ASseMbler The instruction code is a set of instructions that are programed into
102. CoCo systems If the manuals are intact they are still good products to have There are many enhancements available for the Tandy product available from Delphi orFARNA Systems FARNA also sells an enhancement thatadds support for the Hitachi 6309 CPU Versions for all CoCo models are shipped on the same patch disk The only currently supported Color BASIC editor assembler isCer Comp s EDT ASM Itis designed to take advantage ofthe added features of the CoCo3 but versions are available for the CoCo 1 2 as well Cer Comp also sells a disassembler which breaks machine language programs down into opcode and operands A skilled A L programmer could use a disassemblerto break down an existing program make modi fications to the code and then reassemble a modified version This takes quite a bit of practice and patience Although A L programs are much faster than BASIC debugging is harder and more time consuming The only OS 9 assembler camewith OS 9 Level I and theOS 9 Level II Developers Pack The assembler was shipped with Level I instead of Basic09 which was sold separately Tandy wised up when Level I came out and included Basic09 instead of the assembler which was relegated to the Developement Pack The Level I assembler works fine with Level Il in fact the Level I and Level II assemblers are virtually the same Binary and Hexadecimal Conversions Wes Ratcliff Regardless of programming language used there will come times whenh
103. CoCo3 199 95 09 87 11 87 129 95 12 87 26 1386 99 95 Modemphone 100 300 baud 26 1394 99 95 DCM 7 Modem 300 baud 26 2812 5399 95 DWP 230 20 cps 1988 26 3018 14 95 Extended BASIC Upgrade 26 3133 299 95 FD 502 Disk Drive 0 Kit 199 95 12 88 26 3334 199 95 128K CoCo3 129 95 12 88 26 1385 199 95 DCM 212 Modem 300 1200 baud 26 1814 379 95 DMP 132 120cps 26 2802 219 95 DMP 106 80cps Tandy s Little Wonder 1989 26 3123 29 95 Pistol Grip Joystick 26 3335 39 95 512K Upgrade board bare 25 1079 149 95 256K RAM Kit 2 required for 512K NOTE This was during the first RAM shortage 26 2815 379 95 DMP 133 160 cps 26 2821 279 95 DMP 107 100 cps 900 2009 129 95 Disto Super Controller 2 no halt 1990 26 3008 19 95 Joysticks 59 95 06 90 26 3123 29 95 Pistol Grip Joystick 21 95 12 90 26 3125 49 95 Two Button Mouse 24 95 06 90 26 3133 299 95 FD 502 Disk Drive 0 Kit 179 95 06 90 199 95 12 90 26 3215 299 95 CM 8 RGB Monitor 199 95 06 90 179 95 12 90 26 3334 199 95 128K CoCo3 129 95 06 90 99 95 12 90 26 1384 59 95 CCR 83 Cassette Recorder 26 2228 89 95 DC Modem Pak 300 baud 59 95 06 90 1991 The Beginning of the End 36 3028 9 95 Hi Res Joystick Interface 4 95 02 91 26 3112 22 95 Deluxe Joystick 11 95 02 91 26 3133 299 95 FD 502 Disk Drive 0 Kit 149 95 02
104. Cos limitations to develop some software The first we developed was the O Pack utilities for Level I The CoCo running Level I was pretty useless only 40K left after loading OS 9 Most people writing about OS 9 and allit s glories were actually using Level II machines usually GIMIX They were really writing about Level II You just couldn tdo much with OS 9 in64K FLEX only used 8K so was abetter fit to the CoCo hardware One could do more software was more capable and had more memory to work with Iwassortofmisunderstoodin the Rainbow columns I wrote pitting FLEX against OS 9 maybe that was my fault for not being clear enough Those articles were really not against OS 9 as I was running a Level II GIMIX system with nine terminals in the dental lab business but simply that OS 9 Level I left much to be desired on a 64K CoCo with 32 column screen One page 95 had to go out and purchase O Pack or an 80 column board to get more than 32 columns and most software required 40 80 columns Multi tasking user capabilities were extremely lim ited in the 40K left ona 64K CoCo FLEX left more resources for programs We weren t running FLEX on the GIMIX be cause it wouldn t do the job as well as OS 9 We weren t running OS 9 on the CoCo due to the same reasoning I took alot of heat about that stance PeopleSTILL remember those articles and assume they are anti OS 9 If FHL wasn tso heavy in OS 9 later they probably woul
105. DECB Disk Extended Color BASIC DOS Disk Operating System DRAM Dynamic RAM EDTASM or EDT ASM Editor Assembler usually the Tandy product EMAIL or E Mail Electronic Mail EPROM Electronicly Programmable Read Only Memory GIME Graphics Interrupt Memory Enhancement chip in CC3 GUI Graphic User Interface IC Integrated Circuit a chip I O Input Output MIL Machine Language MPI Multi Pak Interface MS Milli Seconds millionths of a second MS DOS MicroSoft Disk Operating System NMOS Negative Metal Oxide Silicon chip construction OS Operating System OS 9 Operating System for the 680 9 PIA Peripheral Interface Adapter PCB Perforated Circuit Board P S or PS Power Supply RAM Random Access Memory usually meaning DRAM ROM Read Only Memory RS Rat Shack er Radio Shack division of Tandy Corp SAM Synchronous Address Multiplexer SECB Super Extended Color BASIC SIG Special Interest Group SP Slot Pak also used for Slot Pak IT VDG Video Display Generator VOM Volt and Ohm Meter multimeter WYSIWYG What You See Is What You Get and probably others not listed Tandy s Little Wonder Introduction Alfredo Santos December 1990 While skimming through the pages of a popular Color Computer magazine recently my thoughts traveled back through the 12 years of Color Computer history Back to atime when there was NOTHING I recalled the events leading up to my introduction to this wonderful machi
106. ESCape control C signal when shifted The additional keys were functionally equivalent to the added keys of the aftermarket keyboards mentioned earlier so those boards work well with the CoCo 3 The keys will be laid out different though An interesting side not is that the original CoCo 3 keyboard was laid out just like most of the aftermarket boards with two extra keys on each side of the space bar with a gap between SPACE and the added keys In fact a good number of those keyboards were made for Tandy enough that they were sold through Radio Shack as surplus for 5 each in early 1985 when the final design was decided on All early CoCo keyboards used a ribbon cable and in line pin connector to attach to the motherboard 285 or F board CoCo 1 TDP 100 CoCo 2 and CoCo3 keyboards have amylarfilmconnector The early CoCorequired an adapter no longer available for use of a mylar strip keyboard and vice versa The keyboard connector on a CoCo 2 or 3 can be replaced with an in line pin connector for use of an early type keyboard The female mylar strip connector may still be Tandy s Little Wonder available from Tandy part AJ 7567 This connector was made by Amphenol AMP 193910680A or 19391 1090A and might be found at large supply houses This connector can be installed in a CoCo 1 or used to make an extended keyboard Don t bet on finding one today Tandy made the CoCo and its keyboard all in one case to save mo
107. GND GND GND GND Contrast GND Adjustment CONNECT DIRECT VIDEO HERE LEGEND Female RCA 1N914 Resistor Ceramic E Coil Phono Jack Capacitor 470 ohm 1 4W Resistor GND Direct Video Input Sound Trap Eliminations Combined trap pick off circuits handled the same as similar traps Video lt Video Video Video Drive Drive Output Cut Trace gt Parallel Resonant Trap Series Resonant Trap Tandy s Little Wonder page 61 By far the best video source is an RGB color monitor RGB means that the signals for three colors Red Green and Blue are sent from the computer to the monitor separately where they are then combined in varying degrees to form colors Only the CoCo 3 is made to deliver RGB output There is no simple way to add RGB output to a CoCo or 2 Since an RGB monitor receives the video signal directly and no mixing separating circuitry is required there are no bandwidth limitations other than those imposed by the monitor design itself This allows an increase in resolution again limited only by the monitor design and signal delivered to the monitor The CoCo 3 will deliver a maximum resolution of 640x192 and 640x225 is possible with special machine language programming The monitors used with the CoCo 3 will support a maximum resolution of 640x200 the limiting factor being the bandwidth 15 75KHz compare THAT toa TV s 3 3 5KHz signal and dot pitch
108. Graphics RS William Barden Jr 1982TRS 80 COCO Programs RS Tom Rugg amp Phil Feldman 1982 TRS 80 COCO Quick Reference Guide Radio Shack 1982The Color Computer Songbook Ron Clark 1982Color Computer Graphics Ron Clark 1982TRS 80 COCO Graphics Don Inman with Dymax 1982Programming The 6809 Rodnay Zaks amp William Labiak Motorola see The Motorola Connection 1982COCO Secrets Revealed Disk N Data 1983TRS 80 COCO Interfacing With Experiments Andrew Staugaard Jr 1983 TRS 80 Color Basic Bob Albrecht amp John Wiley 1983 Troubleshooting amp Repairing Personal Computers Art Margolis 2nd edition 1993 also 1983TRS 80 Mod I III amp COCO Interface Projects William Barden Jr 1983TRS 80 Extended Color Basic Richard Haskell 1983Top Down Basic For The COCO Ken Skier 1983Assembly Language Graphics For The COCO Don Inman 1983How It On The TRS 80 William Barden Jr page 56 1984500 POKEs PEEKs EXECs Kishore M Santwani Zebra Systems 1984Color Basic Unraveled Spectral Associates 1984Extended Basic Unraveled Spectral Associates 1984 Disk Basic Unraveled Spectral Associates All three available free as PDF files at http www coco3 com ind unravelled php 1984Things To Do With Your COCO Willis Miller amp Johnson 1984COCO Assembly Language Programming RS William Barden Jr 1984COCOINDEX Dean Norris 1984Your Color Computer Doug Mosher 1985Complete Rainbow Guide To OS 9 Dale Puckett amp Peter Dibble 1985Utilit
109. Group was officially formed in June 92 The new group picked up where the old left off keeping many of the same goals and even the same name for the newsletter Tandy s Little Wonder MOTD Message of the Day what users first see when signing onamulti user OS 9 system Electedpresidentofthe new group was Boisy Pitre vice president Carl Kreider THE THIRTEENTH YEAR Jul 92 Jun 93 Lonnie Falk made an understatement in July s Print 2 col umn it seems I have stirred up something of a hornets nest This statement was made over the mail received after the May column He clarified his stance he WAS NOT advocating thatanyone with a CoCo changetoan MS DOS system nor that MS DOS was a substitute for OS 9 The point was that the new machines were not the ticket for anyone who wanted moreoutoftheir Color Computer If one is looking for another computer though an MS DOS ma chine with its vast software base might be a better choice thanoneofthe new machines with little software support The new machines were basically where the CoCo was when it first appeared on the market The big difference was that most other affordable home computers were not in much better shape than the CoCo and those that had much software weren t far ahead Lonnie also stated that this may bethe last Print 2 column He invited readers to give their opinions use this space for a continued editorial ormore information Sorry Lonnie I will mis
110. Help is readily available on Delphi Leave a forum message to ALL or to MARTYGOODMAN If you don t leave details as de scribed above that is the first thing you will be asked to do Tandy s Little Wonder 2 Before touching any chips on acircuit board make sure you ground yourself by touching something metal or the ground on the board first Some chips are static sensitive meaning that a good static electric jolt could damage them Touch the case of the RFconverter on the CoCo motherboard the metal box the bottom edge connector pins on peripherals that plug into the cartridge port There is usually a wide band that runs around the edge of most circuit boards This is the ground plane and is a good area to touch first also 3 The right tools and supplies are needed to do the job A CoCo repair kit should include the following tools subject to the repairs being attempted Necessary Items Multimeter VOM three range minimum 422 212 Precision Screwdrivers 64 1948 Phillips and Plain Screwdrivers Needle Nose Pliers Soldering Iron 15 30 watt 64 2070 25W De soldering Tool 64 2 120 or 64 2098 Pointed Cutters 64 1833 Silver Solder 64 013 or 64 015 Paste Flux 64 021 Diagnostic Utilities Optional Items Logic Probe with Hi Low LEDs 22 303 IC Inserter Extractor Set 276 1581 IC Pin Straightener 3276 1594 Soldering Heat Sink 276 1567 1 4 Nut Driver a multi tip screwdriver uses 1 4
111. Kevin we need you The August OSK er had a few improvements The most noticeable was a somewhat better font and normal headings for each article though the letters section entries still looked as if they came straight from an electronic mail file Another quirk that appeared on the cover was the volume number It was described as VERO1 02 version 01 02 meaning volume number 2 Interesting articles included specifica tions of the MM 1 and TC70 machines an article on OS 9 In Industry Playing Chess in C the program was being written as the article progressed through multiple install ments and an article explaining just what the term multi media meant Letters were all encouraging The CoCoand OS 9SIGs Special Interest Groups on Delphi have always been great sources of up to the minute informa tion support and software for CoCo users since their creation by Rainbow years ago Price had been a major hurdle for many users of the low cost CoCo though Until September of 1990 connect time cost was 7 20 an hour This barrier was shattered Tandy s Little Wonder whenDelphiannounced the 20 20 Advantage Plan For 20 amonth acallerreceived 20 hours of on line time Itisn t hard to see that this was a bargain For what one would previously have paid for not quite three hours 20 hours were available Ifitcould be considered a catch one had to pay 20 monthly regardless of how little time was used Time over
112. Keyboard Adapter Schematics for the Puppo are still float ing around but a ROM is required for use with the CoCo The Hitachi 6309 CPU There is another processor that will work in place of the 6809 the Hitachi HD6309 HD designates Hitachi as the manufac turer This chip has been around for some time and is pin for pin compatible with the MC6809 At first the only reason to use it was that the computer ran cooler than with the original 6809 The reason is that the 6309 uses CMOS complimentary metal oxide silicon construction which consumes less power than standard NMOS negative metal oxide silicon chips such as the 6809 Don t forget the CoCo uses the 6809E not a standard 6809 and needs the corresponding 6309 When Motorola decided they had a need fora CMOS version of the 6809 they contracted with Hitachi to provide it thus the compatibility between the HD6309 and the MC6809 Hitachi went one step further however and added six registers and anumber of new commands to the 6309 Memory moves could be made four times faster than with the 6809 and a 16 bit multiplication to a 32 bit product was also included plus more When a 6309 is installed in place of a 6809 no difference in processing speed will be noted and there is no access to the added registers or instructions page 79 The 6309 runs 6809 emulation mode when first powered up Native 6309 mode is accessed through a special com mand Some software wr
113. MCGA TYPE PINOUT PIN FUNCTION 1 amp 2 Ground 3 Red LOOKING AT MALE PLUG 4 Green 12345 5 Blue 6 not used 7 Sound pin usually missing 8 Horizontal Sync 9 Vertical Sync Itis possible that some monitors will shift the display one or two characters to the left This is a hardware problem within the CoCo3 notthe monitor Try cleaning the GIME and socket by carefully prying out the chip remember how it is oriented in the socket and cleaning the chip with a pencil eraser the socket with rubbing alcohol If this doesn t cure the problem replace capacitor C 64 150 picofarads the only C 64 a CoCo user should ever be concerned with with a 220 pico farad capacitor ofthe same type The problem rests in timing which is affected by capacitance Note that most of the above monitors are no longer being made Some multi sync monitors will sync down 15 75 KHz but very few will If you re not sure DON T HOOKIT UP No damage to the monitor and or CoCois likely as long as it s connected for only a few seconds Tandy s Little Wonder 2 Mass Storage Systems Mass storage is considered anything that more or less permanently holds a program or data Four major types of storage are available for the CoCo ROM Pak Tape Drives Floppy Disk Drives and Hard Disk Drives Luckily the CoCo was never subjected to punched tape ROMs Read Only Memories are definitely mass storage but only one way AROM can be read anda program executed
114. MPIs slot select circuitry thus preventing normal operation with a CoCo 3 The solution is to buy and install an upgraded PAL chip U8 which is fortunately socketed the ONLY socketed chip and currently available from FARNA Systems and possibly from Tandy National Parts Some of the newer large white MPI and all the small MPI units appear to work fine with the CoCo 3 but there is still a minor problem The reason these MPIs seem to work acceptably is that the address at amp HFF7F is not copied to amp HFF9F so slot select circuitry is not inadvertently changed Problems arise when attempts to read data from ports of the GIME chip between location amp HFF80 and amp HFFBF are made The MPI was designed before the GIME was conceived and thinks these memory addresses are available for general input output operations The data buffers in the MPI are therefore opened when an attempt to read these GIME data ports This means that both the GIME and MPI are trying to access the data bus at the same time which can garble the data being read Tandy s Little Wonder from GIME ports Using an un upgraded MPI with a CoCo 3 WILL NOT damage either device but software may not work correctly at times causing quite a few headaches and uncon trollable results Again the solution for the large MPIs is to replace U8 with an upgraded PAL The newer small MPI requires a different approach due to the custom chip which is soldered in plac
115. Monitor outputs Dimensions 3 10 x 149 4 Power 120VAC 60 Hz 0 894 MHz or 1 788 MHz Keyboard 57 keys inciuding Control uppercasefowercase Color grapfvcs capab ties range formats esolution me same range available t enhanced Extended SPECIFICATIONS FOR COLOR COMPUTER 2 Microprocessor 5809 8 01 Clock Speed 0 894 Megatertz Keyboard 53 keys Video Diplay 16 lines of 32 characters upper case only Color graphics erm 64 32 8 colors to 256 792 1 and Color with three intermediate formats 16K ROM and 64K RAM T cassette recorder optional Two joystick ports RS C seal port Spin oniy Standard TV 300 Ohms output Dimensions 3 x 10s x 143 120VAC 60 Hz 37 REVOLVING CREDIT AVAILABLE See Page 2 Tandy s Little Wonder page 133 VERSATILE COLOR COMPUTER 3 E po e boti 3x 10 x 68B00 8 16 5 Glock Speed 0 094 1500 bauc cassette recorcer joystick ports serial port feu only Standard ware Analog Motor Dimensions iz Certification FOC Class B anc data 5 Ideal for the Whole Family 19995 Low As 15 Per Month l PN ro ae ment spreadsheet Color Computer 3 comes with 128K memory expandable to 512K and gives you the adv oe OH o vorn oe RN MER or 80x 24 With a processing ede enne antage of greater programming rocessing power as well
116. O 3 case 7805 1 5A monolithic regulator which can be mounted in the socket and heat sink ofthe TO 3 case power transistor Study a schematic to locate where traces must be cut or jumpered Add 2 2mfd tantalum capacitors on the input and output lines ofthe 7805 to prevent oscillation MPIs have a similar power supply Another method of power supply replacement is to use a PC style or other surplus external power supply Mounting the power supply can be as elaborate as re packaging the CoCo in a PC style or other case or simply making cables long enough to mount the supply outside the CoCo case on the floor under a desk beside the CoCo etc Any good 5V power supply will work for a 2 or3 The CoCo requires 5V 12V and 12V some of the older chips require the negative voltages to operate If using a MPI remove that power supply also and run both the CoCo and MPI off of the same external power source If aheavy enough supply is used such as a PC type disk drives can be powered from the same also Use sometype of connector between the CoCo MPI and power supply to facilitate easy removal An external power supply gets rid of a lot of heat in the CoCo case by removing the transformer regulators and power transistor page 90 There are several ways to connect an external power supply depending on which CoCo is being connected CoCo 1 Cut the traces on the circuit board on the CoCo power supply side of test points TP
117. OARD REVISIONS A and B revisions noted by RAM locations and catalog numbers There were three different CoCo 2 boards manufactured in Korea Tandy gave each a separate catalog number The first were26 3127 26 3134 and26 3136 26 3127 came with ECB and 64K installed 26 3134 and26 3136came with Color BASIC and ECB respectively These were upgraded by replacing the4116 chips with 4164s In the front left hand corner of the board are two solder pads labeled J1 and 64K between R7 and R27 near IC7 Solder a jumper between these pads just as with the American made CoCo2 The second Korean version added an A to the catalog numbers 26 3134A etc This model uses only two 4416 RAM chips Upgrade by replacing with 4464 RAMS and soldering a jumper between the solder pads labeled J6 RAM SIZE and 64K near IC4 front left corner of board Notice the two white connectors on either side of the RAM chips These were to support a plug in RAM board with eight 4164 chipsifnecessary The availability and cost of 4464 chips was questionable when Tandy first designed the mother board To the best of the authors knowledge no upgrades were ever made using that method Tandy s Little Wonder The final Korean CoCo 2 the B version could be upgraded inthree ways two 4464 chips eight 4164s or via the previously mentioned plug in board with eight 4164s The best and only known to exist method is by using two 4464s To use eight 4164s on t
118. OS 9 article a month Though we had made many changes by the June 92 issue we were in a practiced groove and all was going well we were continuing to get new subscribers and advertisers Then while working on the July issue I received a copy of a new magazine calledOS 9 Underground OS9U It was dedicated to OS 9 with a hint to lean toward OSK In my opinion it appeared to have a more professional flavor than 68xxx I phoned the editor publisher Alan Sheltra Among other things he said such activities as authoring and publishing small periodicals was his profession I told him that I thought there was not enough user advertiser dollars to support two OSK OS 9 magazines With that point in mind we discussed combining the two publications Previous to this discussion I had been trying to get the rights to publish the new OS 9 Users Group magazine When I received the news that Alan was going to do it I thought he might just as well do the whole thing He and I went ahead with the merger buy out idea Our agreement was very simple I would contribute my stock of OSK articles to OS9U at no cost for a few months until Alan developed his own contacts in that world The OS9U action would be to take over the printing and mailing of the combined content magazine under the mast head of OSOU to all current 68xxx subscribers In exchange for this service 68xxx would pay OS9U for the print space its articles and ads used as well as any extra ma
119. Only the fact that the Rainbow was still the only vehicle forreaching the majority of CoCo users kept the few advertisers only 18 this issue in those pages If you were looking for adisk drive system you would be in for a search Computer Plus listed them asSOLD OUT thougha Tandy disk controller was still available They hadlast advertised the CoCo 3 in January 91 foronly 89 Another supplier bit the dust in April 92 sort of CoCoPRO acquired allinventory and rights to the entire Howard Medi cal line CoCoPRO stated that all outstanding warranties would also be picked up in the transfer The last Howard Medicalad hadrunin January 91 With no Rainbow support CoCoPRO again picked up organization of the Chicago CoCoFest first advertised in this issue This festis being billed as the First Annual Last CoCoFest May 30 31 Not that it will be the last but only time will tell unless users keep up support Dave Meyers is starting to show a little strain from organizing these events Glenside will again be supporting Dave as they have always supported Rainbow and may pick up organizing the next Chicago event altogether as ACS will be doing the next Atlanta event The only thing missing from the non Rainbow sponsored events was the Rainbow itself with the exception of the October 90 Atlanta CoCoFest One can understand their inability to organize these affairs out of their home state but itis hard to understand that the m
120. P 130A msmae specs 26 1235 1236 1238 26 2814 DMP 132 9 100 cps 26 2815 DMP 133 9 160 cps ER 26 1254 DMP 200 9 120 cps Tandy graphics only 26 1483 Tandy s Little Wonder 26 1458 3 pack 26 1445 26 1251 DMP 400 15 140 cps Tandy graphics only 26 1418 26 1296 26 2808 26 2809 26 2812 DWP 230 15 20cps 26 1277 DMP 430 15 180cps 18 pin DMP 440 15 300 cps Other printers have add on serial interface boards Virtually any printer or typewriter with a serial interface may be connected to any CoCo A special cable will be needed as the standard for serial devices is a DB 25 25 pin connector Just connect the lines as follows The functions are listed just in case the printer in question does not use a DB 25 such as the PC jr serial printer a once popular surplus item this was a thermal printer that required special paper which is still available at large office supply stores fax roll paper may be used COCOSERIALPRINTER CABLE CoCo DB 25 Pin Function Pin Function 2 Receive Data 20 External Ready 3 Ground 1 or 7 Ground 4 Transmit Data 3 Receive Data Serial printers are difficult to find and few are made today The following printers have serial interfaces built in Prices were average mail order selling as of January 1993 They can occasionally be found used very cheap now but make sure you can obtain ribbons before buying Alps Allegro 500 216 cps 24 pin 9 350 Alps ASP1
121. PC may be a better choice for those people when if they want to upgrade to a faster machine For the OS 9 user the OSK machines are definitely the way to go Anything else with the power of the OSK machines would cost much more It really depends on what a person wants to do with their computer The OSK market is now back to the pre CoCo days where there is more camaraderie with people in the OSK world more appreciative and less demanding Now there is a very powerful 68030 machine rather than the CoCo This is a better market to deal with going into unknown territory Computers more ofa hobby than a business for me Iam very happy with the Kix30 don t know what I would do different if designing it over again The next computer will be a 68040 but not anytime soon as the Kix does all we need it to do and the 68040 processor chip alone is currently 800 I don t think there would be much market for the price we d have to charge Frank Hogg Labs went on to develop an SVGA card and a 68040 processor for the Kix line of computers I couldn t trace down exactly when but by 2000 Frank Hogg Labs was out of the computer business Mr Hogg continues to run a dental lab in Syracuse New York FARNA Systems F G Swygert It seems that some story about the publisher of this book is inorder My father had been working on our family genealogy and asked me if there was a program for the CoCo We tried using one published in Rainb
122. R OUT screen A34B BCE2 SCROLL UP ONE LINE A390 5 6 INPUT FROM KEYBRD A393 5 9 98 5 A42D B663 A444 B67A A46C B6A8 A491 B6CD A502 A095 ASIA B7CC Data mover routine ASEE B820 A619 B84B A629 B85B A635 867 65 B88E 65 891 663 895 701 933 70 B93E BLOCK IN ATIC BDE7 Cass READ out ATE9 BDDC A7D1 B480 703 482 708 BE68 ATF4 B999 BLOCK OUT A928 BA77 Clear Screen A951 BAAO A956 5 974 976 5 sound routine AIDE BD52 AD19 8417 Clear mem NEW 3 B277 89B4 get operand B99C 90 5 PRINT text string Another area of major incompatibility is the keyboard HI TEK 107044 H Although the Dragon has a full stroke keyboard its Tandy s Little Wonder matrix is not wired the same way as the CoCo keyboard For example a CoCo machine language program which you modified of course will produce unexpected keyboard input Typing the following DRAGON COLOR COMPUTER will put this on the screen 4B 17 3 B 3 05 Indications supporting The keyboard matrix incompatibility is the fact that if the Dragon keyboard is installed in the CoCo or vice versa the weird output continues This condition does not affect any CoCo BASIC programs running on the Dragon unless you are PEEKing the keyboard rollover table to check keys pressed A couple more items on keyboard related matters Dragon BASICs routine to poll for entry from the keyboard is
123. S the most compatible with the CoCo ever made now called HDB DOS It partitions the hard drive as 255 single sided floppy drives and patches DECB to recognize additional drive numbers While there are a few pieces of software that won t work on a hard drive most that runs from asingle disk will You can have nearly your entire collection of CoCo software in one place ready to run and small IDE hard drives are pretty cheap The controller for a CoCo is still around 100 but that s still a bargain A list of hardware offered by Cloud Nine as of Feb 2006 Refurbished CoCo 3s 512K Upgrade boards and memory PC keyboard adapter DOS Adapter use 28 pin EPROM in 24 pin socket Pro Tector buffers 6809 lines protects againstblow outs Multi Pak PAL upgrade for CoCo3 use Hitachi 63x09E Processors 6809 replacement with en hanced features TC43 SCSI controller can use with HD and CD ROM Super IDE Interface controls IDE hard drives and has a Compact Flash memory card interface as well CF card can be used to hold any ROM image or program can be used in place of the DECB ROM Refurbished floppy disk drives hard drives and CD ROM drives Cables and misc items supporting the CoCo and Cloud Nine products Drive Wire software for transferring data between a CoCo and a PC through the serial ports Works with DECB and OS 9 NitrOS 9 OS 9 NitrOS 9 software Tandy s Little Wonder Cloud Nine also
124. S 32 2031 or 82771 1008 Get sound output by soldering the center lead of a female RCA phono jack to pin marked on mother board ofthe RF converter the silver box the TV plugs into and the outer lead to ground Almost any audio amp IC can be used to build a simple circuit to drive a small speaker which could be mounted inside the CoCo case Tandy produced anumber of CoCo 1 2 models with composite video but no RF or audio circuitry These were for use in classroom network systems originally sold only to schools Some ofthese have become available as schools upgrade their classroom computer systems Note that the turning off the colorburst signal and changing colors on a CoCo 3 will produce better text just as with a TV set A without composite input can have the input added THIS SHOULD NOT BE PURSUED UNLESS ONE HAS EXPE RIENCE WITH ELECTRONICS There are dangerously page 60 high levels of currentinaTV ESPECIALLY COLORSETS DO NOT attempt this on old tube type sets or sets known to have a hot chassis These sets have one side of the AC power cord connected directly to the metal frame inside the TV the chassis and present a SEVERE SHOCK HAZARD THISIS ESPECIALLY TRUEIN EVEN MODERN COLOR SETS Therefore this modification is only recommended for B amp W sets other reasons are explained in the following text Always use a solid state or transistor TV that has a power transformer Most B amp W TVs made over the last 10 years
125. S ad focussed on software companies with OSK software A phone number forKala Software formerlySecond City was given with the advice to call for a catalog Yes owner Ed Hathaway still supported the CoCo though it wasn t men tioned in the ad Many of the other vendors mentioned as gone were also still in the CoCo business there just wasn t enough of it to pay for Rainbow ads remember around 300 monthly for 1 4 page and make a decent profit in many cases not enough to break even To top the month off actually to START it off the Second Annual Atlanta CoCoFest was deemed a success again There were fewer people than the crowd the year before but still enough to make an effort for next year With the sluggishness of the economy in general the smaller showing was no big surprise Gracing the cover in November was the 6809 based TC9 Tomcat from Frank Hogg Laboratories Until now TC9 design had been subject to several changes The design reviewed was the production model then being shipped The motherboard contained the 68B09 and a genuine GIME to maintain CoCo 3 compatibility The CPU had to be run at just under 2MHz the G IME wouldn t run ata full 2MHz A pair of 256Kx8bit SIMMs single in line memory modules took care of the 512K of memory An additional pair could be added along with a DAT board which handles address translation for a full IMB of RAM The CoCo bus was two row 40 pin header connector A shor
126. SCS amp CART chips Check to see if the slot selection problem is limited to the CTS and CART lines or only the SCS line or if both groups of switchable lines are affected This may help narrow down the problem to a particular chip The big custom IC in the new MPIis unavailable and replacing it with small scale logic chips would mean making up a five chip circuit or designing acomplex PAL chip There is a fuse map posted on Delphi in the CoCo SIG also available from FARNA Systems for burning 14L4 and 16V8 PALs and GALs for replacement ofthat custom IC for anyone with access toa PAL programer On the old MPI all the chips are widely available small scale logic chips except for the factory upgrade PAL chip Information on programming this PAL is also on Delphi Itis easy to check the switching of the SCS line with a logic probe Just put the probe on the line in a given slot select that slot and then try to WRITE a value to the appropriate address range in the SCS line and see if the probe flashes Check the CTS line by plugging a ROM Pak into the slot to be checked If the Pak comes up on screen then the CTS line is good Tandy s Little Wonder Intermittent problems after the MPI has been on for a while usually occur because of a bad buffer IC There are four 74LS367 control functions and address bus and one 741 5245 data bus buffers To find out which is the culprit remove the upper case of the MPI then plug back into th
127. Tandy s Little Wonder The Color Computer 1979 1991 A complete history and reference guide to the CoCo and all related hardware software and support sources by Swygert SECOND EDITION UPDATED FEB 2006 INSIDE FRONT COVER If printing to bind print only page 1 front cover on card stock or heavy colored paper 5 Little Wonder the Color Computer 1980 1991 and still going strong into the next century Second Edition written amp edited by F G Swygert The Original Tandy Color Computer First Edition Copyright 1993 Second Edition Copyright 2006 by F G Swygert All rights reserved Published by FARNA Systems 147 Tom Moore Road Leesville SC 29070 e mail farna att net Tandy s Little Wonder page 3 5 Little Wonder the Color Computer SPECIAL ACKNOWLEDGEMENTS The following individuals have made contributions directly orindirectly to the content of this book Frances Calcraft Lee Duell Thomas Fann Art Flexser MartyGoodman Frank Hogg Alan Huffman Don Hutchison Carmen Izzi Jr M David Johnson Bob Kemper Mark Marlette Cloud 9 Nicholas Marentes Dave Myers Bob Montowski Alfredo Santos Kelly Thompson Jordan Tsvetkoff Rick Ulland Brian Wright Glenside Color Computer Club Mid Iowa amp Country CoCo Club th ANN LAST CHICAGO CoCoFEST Banner for the 15th Last CoCoFest annually hosted by Glenside Co
128. Tools General Trouble Shooting MC6809ECPU MC6821 6822 PIA MC6883 and 74LS783 785 SAM MC6847 and MC6847T 1 VDG The GIME Disk Controller and Drive Repairs RS 232 Pak Repairs Multi Pak Intrface MPI Repairs Power Supply Repairs 6 Tid Bits 7 The Colour Computer Down Under 92 8 The 68xxx Story 93 24 Two Boys and the CoCo 94 36 Frank Hogg and Frank Hogg Labs 95 36 About FARNA Systems 97 38 APPENDIX 39 Color Computer Users Guide 100 4 Serial Interface 101 4 Cassette Interface 101 45 Joystick Interface 101 RGB Interface 102 46 Cartridge Connector 102 46 ASCII Character Codes 102 48 BASIC Extended Disk Error Codes 103 49 Bank Switched ROM Paks Activision 103 50 B SCHEMATICS Typical B amp W TV Circuit 61 54 CoCo 1 D amp E board 104 54 2 American made 107 55 CoCo 2 Korean A B is similar 109 5 57 Multi Pak Interface large 113 58 Multi Pak Interface small 114 FD 501 Disk Controller 115 FD 501 Disk Drive 116 59 Chip Placement Guides 117 6 Block Diagrams GIME and MC6809E 119 68 7 PHOTOS 7 QoCol 3 15th Annual Last CoCoFest 4 B CoCo 1 Magazine Ad 33 76 CoCo 2 Tandy Catalog Page 33 8 TANO Dragon 37 79 FHL TC 9 on cover of Rainbow 38 81 CoCo 2 w accessories 4 Cloud 9 Super IDE HD controller 52 82 Cloud 9 512K SIMM Memory Upgrade 52 83 TRS 80 Color BASIC book cover 56 6 Typical CoCo 3 setup 57 6 Rainbow first mid last issue covers 58 86 CoCo 3 connectors 75 Exploded view
129. WARNING Hardwiring these modes jumperto pin 17 will result in the loss of some graphics modes A no switch modification using a 74LS 157 to automatically switch between text and graphics modes was described in the December 1986 Rainbow The No Switch VDG pp 98 101 After 30 minutes or more of operation intermittent video problems random characters in the second and ninth col umns would start occurring on early models of the CoCo 1 A short time after the video problems started the computer Tandy s Little Wonder would lock up Because the SAM gets hot it was initially thought to be the problem Tandy issued two fixes The first fix didn t do the job soa Final Fix that s what Tandy called it was issued This consisted of a small 1 1 5 circuit board with a logic gate and binary counter on it plus a couple resistors and a capacitor These components formed a pulse generator that cleaned up the horizontal synchronization HS pulse coming from the VDG The pulse would become unstable as the VDG warmed up The Tandy fix restricted the HS pulse to four clock cycles synchronized to the falling edge of the E clock The original pulse was 4 5 cycles long The Tandy Final Fix kit has long since been discontinued IfaCoCo 1 is found without this kit installed it can still be used reliably The culprit is indeed heat but in the VDG Mounting a heat sink pair of 276 1363s with heat sink grease 276 1372 to the top
130. a circuit board but even thatisn t very difficult for the greenest novice to attempt The CoCo is arelatively robust computer and will take lots of abuse that would damage most others Remember the following basics and repairs should be simple and even fun It IS NOT the purpose of this section to cover detailed operation of the CoCo circuitry Simple explanations are given when possible some may seem intentionally vague If you can tfigureit out DON T TRY IT Formore detailed informa tion consult a CoCo Service Manual may still be available from Radio Shack ask a salesperson or call Tandy National Parts to order a service manual for the catalog number of the desired CoCo or the Motorola MC6883 or 74LS785 earlier version was 74LS783 data sheet as well as those for the other major components Schematics are reprinted in the back of this book also 1 Before attempting arepair observe the symptoms carefully It is extremely important to describe what is happening as completely as possible especially when asking for help Try substituting components if possible Also remember to dis connect ALL peripherals before assuming there is a problem with the computer A bad printer joystick disk controller etc could be causing the problem Unplug EVERYTHING then if the computer works right plug items backin ONE AT A TIME and see which causes the failure If asking for additional help outline ALL the steps you have already taken
131. a home att net page 99 Appendix even more useful information Color Computer Users Guide By Lee Deuell EDITORS NOTE The following guide is a quick and dirty run down of using a Color Computer Lee wrote this for the person who will inherited his CoCo 3 system when that time comes It was edited to include CoCo 1 2 information also Feel free to photocopy this article and keep it or send it with a CoCo that finds a new home The CoCo 3 has 57 keys Uppercase and lowercase are toggled by holding down the SHIFT and 0 keys The F1 F2 and ALT keys are not used by most programs The BREAK key is used to halt operation of some programs most programs automatically end The CoCo 1 and 2 do not have F1 F2 ALT or CTRL keys 53 keys Most programs for these use the CLEAR key for a control key when necessary CLEAR will clear the screen under BASIC for all CoCos See the manuals for more information On the rear of the computer are 10 connections and buttons 8 on CoCo 1 amp 2 From left to right as viewed from the rear are the following Reset Audio CC3 only Video CC3 only Channel selector RF out for TV cassette Serial I O input output Right joystick Left joystick and Power Always use care when plugging unplugging cables The Reset button is used to end some programs Also after some machine language ML programs ones that have a BIN after their names on the disk or tape cause strange things to
132. about 2 3 of a disk set up under 300 in 1982 The major drawback was that only Exatron made the thing limiting availability of software though Exatron DID line up some popular products Another drawback was that the operating system had to be loaded from tape before use and some m l programs would write over the operating system making the system useless note that the operating system resided in memory normally reserved from use but clever m l program mers often re mapped CoCo s memory to get a few more bytes of program space The Exatron was pretty popular in the early days enough that it was made for a number of computers and recognized by most knowledgeable computer hobbyist It faded from market around 1983 as competition and demand drove disk drive system prices close to the cost of an ESF system With all the deficiencies of tape itis no wonder that the more expensive floppy drives eventually won out Exatron was responsible forthe first floppy disk systems forthe CoCo The Exatron system was advertisedin July of 1981 foronly 298 and included acontroller with 16K RAM asingle density single sided 35 track drive 80K capacity drive case and power page 64 supply One reason Exatron dropped the disk drive in favor of the ESF was the amount of RFI Radio Frequency Interference generated by their disk system Properly shielding circuit boards and cables drove up the cost of a good disk system RFIproblems were virtua
133. ack issue of the May 1984 Rainbow from Falsoft RAM ROM Upgrade Roundup pp 49 51 Practical RAM up grades are mentioned page 76 Very few C boards were actually sold so few that no attempt to upgrade them should be made these are definite collector items The version was almost a prototype with many wires and a small satellite board inside The D board is quite similar to the C but does not have the satellite board Most 4K and 16K CoCo Is have the D board This board would only work with 4K and 16K DRAM generic number4104 and 4116 Simply replace the 4K chips with 16K units Next find the two jumpers marked 4K and 16K one next to the 6883 SAM the other between the two 6821 PIA chips and move them to the correct position The C board may not even be upgradable to 16K boards were the first to be upgradable to 32K These require simply installing 64K chips in place of the existing 16K units and moving the jumpers one between U8 and U9 three next to the keyboard connector and one just below C44 to the 32K position Hmmm 64K chips but only 32K RAM That s correct 32K was selected as the maximum supported RAM because Color BASIC couldn t use more than 32K anyway and no other operating system was available at the time There never were any 32K DRAM chips made 32K chips were made up by piggy backing 16K DRAMs even commercially Tandy got discount prices on half good 64K chips half bad There is ajumper l
134. agazine won t at least support the fests by having a booth or at least covering them in the magazine These events are of great interest to the CoCo community as many new and old support ers often showed up to display their wares And anything good for the CoCo community would also have been good for the Rainbow Lonnie started quite a controversy in May He stated that Rainbow WOULD NOT besupporting the new 68xxx based computers based mostly on the fact that software was either unavailable hard to come by or to expensive for most home users remember 500 BASIC What REALLY vexed many people was thathe recommended buying an INTEL based PC if one really needed a new computer While this would be a logical choice for most users the OS 9 community really got upset NOTHING on an MS DOS based PC came very close to the power of OS 9 on one of the new machines except maybe Microware s OS 9000 OS 9 for a PC type 386 or higher processor but it was to expensive for real consider ation especially when the amount of investment is consid ered That a special offer for PCM Falsoft s PC magazine followed the above statements made it seem as though he were steering one toward MS DOS because he also published an MS DOS magazine similar to the old Rainbow this was not however the case A feature article by Bill Palmer told how to use a Hewlett Packard Desk Jet printerwith a CoCo These high resolution ink jet printers produce laser quality p
135. ainbow That may very well be true as it is doubtful that Hot CoCo and The Color Computer Magazine combined had as many subscrib ers during the CoCos golden years as did The Rainbow Even so back issues of all are still valuable information sources they were for this book TheRainbow July 81 MAy 08 aiite Falsoft Inc TRS 80 Microcomputer News all Tandy computers September 80 July 84 Tandy 80 Microcomputing 80 Micro all TRS 80 computer October 80 May 83 March 86 Communications 68 Micro Journal November 80 July 83 March 85 1990 Don Williams BYTE Magazine various articles not in every issue October 80 83 The Color Computer News June 81 September 83 REMarkable Software Chromasette cassette mag through July 83 disk after July 81 July 84 Chromasette Tandy s Little Wonder The Programmer s Institute TRC cassette disk mag November 81 March 84 Future House The Color Computer Magazine March 83 October 84 Ziff Davis Publishing HOT CoCo June 83 February 86 CW Communications Dragon User specifically for Tano Dragon August 83 September 86 Business Press International 68 Color Micro Journal September 83 February 85 Don Williams Dynamic Color News February 84 January 89 Dynamic Elect
136. al CF83 3 Block Editor You needa FORTH editorto write your programs in CF83 FORTH Unless you can write your own editor you d better get this one CF83 4 Double Number Set CF83 only handles 16 bit inte gers by itself This set lets you handle 32 bit integers CF83 5 AssemblerSet Integrate machine code routines that have to be real fast with this full featured assembler CF83 6 System Extension Set Helps you define new control words more effectively CF83 7 Controlled Reference Set Words that perform many different functions Includes recursion block control and system maintenance routines CF83 8 Uncontrolled Reference Set Includes case structure string operations printer control and more CF83 9 PMODE Graphics Set Use PMODE graphics in programs CF83 12 Turns your CF83 FORTH programs into binary files that will EXEC directly from BASIC Includes system saving and general disk file handling amp creation The entire set could be purchased for as little as 120 not bad for such ahigh level language Most general users would only need three or four modules though bringing the cost down to under 50 Just recently however the main FORTH module CF83 was placed into the Public Domain making this lan guage even more attractive ContactBDS Software for more info on PD modules page 48 Modules that were under development at the time this was written include CF83 10 HMODE Graphics Set Use high resolution Co
137. ality is that IMS may have done some damage to the market as they were promising complete compatibility with all OSK systems and the CoCo but never delivered The MM 1 actually shipped much later and many users waited months before they had complete systems FHL got many calls from shoppers asking if the FHL system would do all the MM 1 was advertised to do The answer was no and neither would the MM 1 Many people waited to see what would happen instead of buying systems and there was along wait from IMS Part of the problem was lack of business experience within IMS The TC9 was originally designed to bea direct CoCo compat ible machine with the ability to upgrade to a 68K processor at a later date The idea was to get a lot of people into the upgradable TC9 and then into OSK The result would have beenafew thousand more OS 9 users out there Instead FHL had to compete with undelivered promises of CoCo compat ibility from a non existent machine This caused us to change our marketing Mike Smith and I talked in July 90 about using the same chip set of the MM 1 68070 and VSC in the form factor of the original QT This would allow upgrading the QT and provide a low cost board to sell CoCo users directly Design started well after the MM 1 design but came to market well ahead of it This was the TC70 The TC70 was a 16 bit machine while FHL had been working on 32 bit models essentially a step backwards The design was priced to b
138. allgrass and Atomtronics were developing disk systems and Steve Odneal s Color Computer FLEX conversion was reportedly just about com pleted Microsoft s Bill Gates the daddy of Color Basic and Extended Color Basic was interviewed in the May June issue of 80 U S and said there would be a book dealing with the overall structure of both ROMs in the future As the Color Computer s first year came to a close in June third party support was starting to gather momentum but if Fort Worth didn t step up support the TRS 80 Color Computer may die from parental neglect THE SECOND YEAR Jul 80 Jun 82 Following its 1980 debut the CoCo bumped along with virtu ally no Radio Shack support The next 12 months however would witness the biggest outpouring of Color Computer support to date This period produced a flood of upgrades modifications hardware software and most important of all information InJuly of 1981 the Color Computer s first anniversary roared inlikealion Many users celebrated by upgrading to Extended Basic buying various new peripherals and or signing up with CompuServe A word of sympathy here for anyone who ordered Nelson s word processor advertised this month By January of 1982 the software was still nothing more than an ad on the pages of a few magazines This is often referred to as vaporware lots of hotair ads and other publicity but no actual product Another ad appearing that July wa
139. an extra cost AC adapter for items that needed more power The Slot Pack II or whatever was designed by Chris Hawkes a well known hardware designer for the CoCo one reason Chris is so well known is his physical height if one ever meets him at a fest they will never forget Microcom announced yet another improvement for its word processor Word Power 3 3 in January Now 40 and 80 column displays were supported and graphics could also be inserted in documents CoCo Max PMODE 3 4 and HSCREEN for mats Three new games Overlord wargame similar RISK Defendroid similar to the arcade game Defender andThose Darn Marbles roll a marble through mazes not quite that easy were released byOblique Triad Lonnie Falk used the Print 2 column to announce plans for the publication of a book due out in late summer early fall entitled An Affectionate History Of The Tandy Color Com puter The authors of this book were to be Dale and Esther Puckett Unfortunately the book would never be printed An interesting side note is that the book you read now may not have been printed had Rainbow printed their history Rainbow later announced they would be interested in finding a new author This author responded after some thought The prob lem was that the Rainbow book was to be simply a collection of interesting anecdotes and memoirs from various CoCo personalities and a brief history After some thought and before Rainbow was
140. an plugging straight into the motherboard This leaves several extra wires that can be used to mount a remote reset button LED indica tors etc on the keyboard case If using the original keyboard cuta piece of thin plywood or hardboard sheet metal or heavy cardboard to cover the hole left by the removed keyboard This makes an ideal mounting location for the DB 25 connector What to use to house the keyboard Many CoCo hackers use the original CoCo case either as is or cut down in size preferring to mount the motherboard in a separate case with the drives and MPI or other expansion device see Putting It All In One Case A nice looking case can be made from two pieces of plywood Cut a keyboard size hole in the top piece and use a spacer material of suitable thickness around the edges making sure there is enough space for the connector and support for the edges of the keyboard The flat ribbon cable can be laid between the top and spacer sections firmly holding it in place It is suggested that the top be screwed down to facilitate removal if necessary If making a wood case leave two and a half to three inches of blank space below the space bar for wrist support You hands will thank you Room can also be left to either side for a numeric keypad Tandy s Little Wonder Adding an extended keyboard cable is the perfect time to consider a numeric keypad since the CoCo is open anyway HJLused to make a keypad but one can be made by
141. anded memory and a new analog RGB monitor Due to small attendance August brings word of RainbowFest West s possible demise Chicago amp Princeton shows how ever will not be affected Dynamic Color News started a column on Ham Radio amp Computers Dynamic Electronics and their magazine quickly became THE SOURCE for Color Computer HAM software The HAM column became aregular feature after this Could have had something to do with Bill Chapple getting his HAM license W4GQC as of January 1993 page 18 Rainbow s September issue carried the first in depth look at the newCoCo3 the cover states coverage for Color Computer 1 2 and 3 for the first time On power up the 68BO9E gets the 2 byte address at amp HFFFE puts it into the program counter and starts executing code In the case of the CoCo IIL the address found at amp HFFFEis amp H8C1B TheGIME chip Graph ics Interrupt Memory Enhancer a custom job specifically for the CoCo 3 initializes to read the CoCo 3 ROM even if the system has the disk controller Disk BASIC ROM installed so after entry at amp H8CIB the CoCo 3 goes to its internal ROM at amp HC000 Computer Plus sold the new CoCo for 169at the October Princeton RainbowFest where they sold out within minutes Thefirst CoCo3 only programs two graphics demonstration programs were published in the October Rainbow Also introduced this month was a new service Rainbow on disk The disk was a flippy
142. appearance on the cover of the December 91 Rainbow This computer is brained with a Phillips Signetics 68070 Motorola 68020 compatible manufactured for Phillips the licensee by Signetics and 466470 Video System Controller VSC Due to delays in FCC certification the MM 1 was beingdelivered only as a kit The kit included a completed motherboard case power supply keyboard I O board and drives Assem bly took only 30 minutes Anyone who had ever installed a second drive in their CoCo could accomplish this task easily Oneserial RGB analog video keyboard XT type and sound ports were on the motherboard along with IMB of RAM two ROMs and the CPU and VSC chips The I O board had a second serial a parallel stereo sound and joystick ports along with an SCSI interface primarily for hard drives and sockets for two 1MB SIMMs for a total of 3MB RAM The VSC chip supported an interlace mode which allowed crisp 16 or 256 color graphics with up to 720x480 resolution 16 colors in 720x480 mode even on a CM 8 Real time animation se quences were also possible These last two items high resolution graphics and animation were both made possible by the capabilities of the VSC chip Of all the new machines the MM 1 seemed to have left the greatest impression New this month from Sundog was Photon a maze game War Monger war game sort of amodernized version of Risk and Graf Express a graphics and music programming environ ment
143. are compatibility I was also aware that Tandy had left 2K of free space in the 8K chip that Disk BASIC resided in this free space would be ideal for a collection of enhancements to BASIC I do not want to claim that the idea of putting enhancements into the Disk BASIC chip originated with me There was a recently developed product known as JDOS on the market from J amp M Systems that had many of the same features I was thinking about putting into an EPROM But JDOS had the important drawback of being incompatible with quite a lot of software This was not really the fault of the authors who were hampered by copyright restrictions in a way that I debatably was not The folks at J amp M had developed JDOS as an adjunct to the disk controllers they were selling For them to have put a patched version of Tandy s ROM in their controllers would have beenacopyright infringement so they were forced to do Tandy s Little Wonder a complete rewrite ofTandys ROM This changed the ad dresses of all the entry points into various ROM routines resulting in a lot of incompatibility Had Tandy included a full set of documented entry points in Disk BASIC rather than just DSKCON JDOS would have been much more highly compat ible and it is conceivable that I never would have bothered to develop ADOS Unlike the JDOS folks I had no intention of selling disk controllers my market was people who had already bought a disk controller from Tandy and who ha
144. are of Muskegon nois CCN premiered with its May Jun issue a48 page beauty filled with program listings reviews letters from other users and articles Don Inman Ron Krebs Wayne Day Tom Mix Ken Kalish Jorge Mir Gary amp Susan Davis Tony DiStefano D S Lewandowski and Andrew Phelpswere just some of the new users weren t we all back then whose names appeared within the first few issues Another feature of CCN was all those lovely ads Did I say ads As muchas we may sometimes say we hate commercials during the opening months of 1981 many users poured through various computer magazines searching not only for articles butforthatoccasional ad which may have mentioned the Color Computer Lets face it ads ARE an information source espe cially when new software releases were few and far between Although there were only a handful of companies supporting the Color Computer in its first year there was a surprisingly large amount of great software and hardware that was avail able and or under development The Micro Works had its CBUG 80C disassembler and 16K or 32K upgrades Editor assemblers and space invader games were both available from Computerware and Spectral Associates Eigen Systems was putting BASIC programs in ROM Paks The WOLFBUG monitor from Mike Wolf ac cessed 64K of RAM F amp D Associates released a ROM EPROM board and aProto Board while announcing plans for page 9 an Expansion Interface Both T
145. ay have to be made and some features may not be accessible by software but Commodore 64 printers ARE NOT The Commodore uses aunique serial interface not compatible with other computers There is abetter usually cheaper and much more versatile way to connect a printer to your CoCo through a serial parallel converter These devices convert the serial data signals to parallel compatible signals as well as converting the connec tors as well parallel printers normally use a centronics 36 pin connector rather than a DB 25 Radio Shack used to sell a serial parallel converter 26 2889 99 95 thathas a DB 25 on one side a centronics connector on the other A cheaper solution was a converter specially made for the CoCo Several manufacturers made them and they can still be found occasionally Some printers provide 5 V on pin 15 ofthe centronics connector others don t Those that don t will have to be modified to provide this voltage solder a wire from any 5V source inside the printer to pin 15 make SURE this pin IS NOT GROUNDED FIRST if itis grounded disconnect from the circuit board by cutting before adding 5V or an external power supply will have to be purchased Wall wart power supplies are relatively cheap and readily available at Radio Shack By using converter the printer can be used with almost any computer and the converter can be kept if a newer more capable printer comes along later The CoCo serial pa
146. ay mode prevents ASCII saves Try with out first POKE may not prevent ASCII saves then 16 PRINT PEEK 341 ALT key prints 191 pressed PEEK 342 CTRLkey PEEK 343 F1 PEEK 344 F2 these will work on keyboards with four function keys also 17 POKE 65502 0 Disables all CoCo 3 commands reads only ECB portion of ROM directly from ROM justas a CoCo 1 2 would Some programs that won t run on a CoCo3 might after this POKE 65503 0 restores normal CoCo 3 functions More POKE enhancements can be found in the books 500 POKES PEEKS N EXECS Supplementto POKES PEEKS NEXECS and 300 POKES PEEKS N EXECS forthe CoCo III series of books from Zebra Systems These have many programming hints for all CoCos and are highly recommended toall programmers Tandy s Little Wonder ADOS e o o Arts Disk Operating System by Art Flexser A crucial step in the development of ADOS occurred in 1983 when I decided to buy a Lowerkit for my CoCo from Dennis Kitsz s Green Mountain Micro I did this mainly to have lowercase available for telecommunicating which I was doing quite a lot of on CompuServe s CoCo SIG My preferred terminal program at the time was Colorcom E It was able to use a software generated upper lowercase display on the PMODE graphics screen but output to that was a bit sluggish for my tastes In order to have lowercase on the regular 32 column hardware display I needed one of Kitsz s gizmos so off we
147. ay to accomplish this through aPOKE Type POKE65495 0to puta CoCo or2 into double speed mode What this does is address the ROM at twice the normal clock speed 1 79MHz instead of 89MHz of the CPU 65494 0 returns the processor to normal speed Another address POKE 65497 0 addresses the ROM and RAM at double speed but terminates RAM refresh could cause loss of memory and also makes the screen unreadable as it affects the video clock rate also which won t operate at double clock speed If one has lots of math functions to process this may come in handy but the slow down POKE 65496 0 will have to be entered to view the results The computer could also lock up if the RAM drops any bits This seems to work in practice as the author has turned the TV off and let CoCo plot away at Mendlebrot graphics all night the particular program required approximately six hours to plot a single graph at double speed but it is not recommended programming practice and would be unacceptable in a commercial program Some CoCo models required the following minor changes to allow proper double speed 65495 0 operation D amp Eboard clipcapacitors C30 C73 amp C75 also C85 when using a disk controller For NC board clip capacitors C36 C37 and C86 The board letter is in the serial number printed on the booard Noharm will come from removing these 56pf capacitors they are for filtering and distort the clock signal in double
148. be used especially when using high speed mode In general the higher quality the tape the fewer I O errors one is likely to experience whether using double speed or not Note that Radio Shack no longer lists computer cassettes 26 302 10 minute 26 308 20 minute They do have leaderless five and ten minute answering machine cassettes two and a half and five minutes per side 43 437 and 443 4399 that are practically the same as the older computer cassettes These shorter tapes are easier to work with It is good practice to store only one file per tape with three or more copies of that file on the same side one after another If the program is used often put multiple copies on both sides This prevents having to rewind a lot just make sure there is a bit of blank tape between copies Floppy disk systems were rather expensive in the early days of home computers the first Tandy system was 499 A cheaper alternative was therefore a modification of the basic tape drive the Exatron Stringy Floppy ESF system This system used an endless loop tape cartridge called a wafer A typical wafer would store around 70K of data and up to 99 files The good points about the ESF was that random access files were possible it plugged into the standard cassette cable it was fasterthan cassette 7200 bps compared to 1200 bps for cassette a 16K program loaded in less than 20 seconds wait a couple MINUTES for cassette to load and the cost was
149. ble OS 9 25 faster than the CoCo 3 BM PC compatible 101 key keyboard case and power supply Two hardware serial ports no need for RS 232 Paks Support for a PC type serial mouse Parallel printer port mproved joystick ports higher resolution Better sound capabilities CoCo 3 and K bus expansion capabilities Up to IMB of DRAM on the motherboard the original design used a CoCo 512K upgrade and Disto 1MB board the final used four 256K SIMMs and a plug in control or DAT board The TC9 was designed with running Tandy Microsoft Mi croware Super Extended Disk BASIC CoCo3 BASIC in mind There were some problems however The first was that Tandy held the copyright so an agreement would have to be reached with or ROMs purchased directly from them Second was the improved hardware OS 9 could easily cope with the added hardware by supplying the correct software drivers Disk TC9 operation This was used since relatively few TC9 cus tomers insisted on Disk BASIC support most wanted to run OS 9 only This method sort of stepped around copyright infringement since one was expected to own a CoCo 3 Unfortunately the improvements just weren t enough for most OS 9 users who had outgrown their CoCo 3s and the price was a bit high for those just seeking a CoCo 2 or 3 replacement Prices started at 499 95 for a starter system which included a low profile case and 512K 1990 price The second type sold for 549 95
150. bowfest was also covered in detail The Flame ON column featured an article entitled Why the CoCo 4 Will Fail The author Jim Hutchins pointed out various shortcomings of the new machines their targeted market and OSK support in general An example was system cost Any of the three OSK machines would run around 1300 while a comparably equipped AT clone would only have cost 1000 Arebuttal by Paul K Ward IMS was also printed in the same column A big point made about price was that the 1 would be better compared against at least a 386SX based machine and that the MM 1 has a built in network interface which would cost extra for an IBM clone Operating system cost was also mentioned One would really need a version of UNIX or OS 9000 to equal the windowing and multi tasking user capability of a 68xxx based machine The operating system alone would add over 300 to the 386SX price No hint was given that OSK er would expire it just never appeared in a mailbox again The final issue was printed several months later much improved in appearance and even on slick paper It was definitely the last That makes six issues for the 12 subscription price fairenough even though twelve were initially promised Putting out a magazine is a lot of time consuming costly work as this author will soon find out THE TWELFTH YEAR 91 Jun 92 Whew Microcom is back with a one page ad Well at least they are back with us t
151. but NOT write standard 5 25 disks OS 9 and ADOS provide for double stepping OS 9 users will benefit most from these drives especially if a hard drive is not a viable option due to cost or other reasons 1 2MB and 1 44MB floppies can t be used Hard drives were first made available to CoCo users by Software Support in early 1984 These were five megabyte units and sold for 999 95 fora complete system Sure is a good thing that prices have come down dramatically but that is the major reason that hard drives have really been an elite periph eral for most CoCo users Even now complete CoCo hard drive systems cost around 350 for a 20MB system Cost is not the only problem with hard drives for some users Hard drives work very well with OS 9 Tandy even realized that OS 9 needed a hard drive when it introduced it s own hard drive adapter in 1985 Disk BASIC is another story DECB was designed to be a simple floppy disk system period It was never intended to handle the file structure necessary for proper hard drive operation The systems that do work with it partition the drive into as many as 255 virtual 156K floppy drives and patch DECB to recognize as many drive numbers Itis up to the user to keep up with whatis on each virtual drive This isn t as bad as it sounds it can be viewed as having up to 255 directories each directory limited to 156K Most DECB hard drive programs have some type of menu system that allows at least a one
152. but didn t want to publish it under his name to prevent any possible conflict of interest with Bell Labs I published the article under my name entitled 64K for Free in Color Com puter News 68 Micro Journal andThe Rainbow Frank Hogg Labs had licensedFLEX fromTechnical Systems Consultants TSC in NC The 64K upgrade made it easier and better to run FLEX and OS 9 Business picked up overnight We started selling FLEX by the thousands though we had only expected to sell a few Other companies tried to get into the FLEX market Spectro Systems and 68 Micro tried selling versions of FLEX but weren t very successful due to lack of supporting software The CoCo 2 was finally introduced with full 64K capability Tandy came out with a version of OS 9 for the CoCo 2 something before hand Ken Kaplan contacted me long before Tandy came out with OS 9 We made a gentleman s agreement thatFHL would port OS 9 and receive a license to sell without paying up front license fees forthe work My crew started work on the port and we ran ads in 80 Micro I think Suddenly I couldn t contact Ken After a couple months Ken finally called and reported thata deal had been reached with Tandy and MicroWare wouldn t be able to keep the original agreement I could have raised a law suit or made a lot of noise about the deal but decided against it since nothing would really be gained Instead we used our advance knowledge of OS 9 and the Co
153. ce The more reliable the source the more accurate the information is likely to be Although it had been rumored for a while that Tandy was dropping the Color Computer the rumor takes on special significance when in January it appears in Wayne Green s 80 Micro editorial Since the beginning critics had always pointed to the CoCo keyboard and snickered A Dennis Kitsz article put a stop to all that by replacing the chicklet keyboard with a Model I keyboard what would Dennis do next Bob Rosen started his company Connection 80 named after his BBS in January and his first advertised CoCo product was Colorcom E Although Eigen ran his own separate ads Bob s BBS probably accounted for a majority of initial sales With every BBS sign on being accompanied by a little commer cial word spread very quickly as the popularity of both Colorcom E and the BBS grew rapidly Truly a marriage made in computer heaven page 12 1982 marked the start of CCN being published monthly It also witnessed the debut of DSL s ML Rabbit Sugar Software s Silly Syntax Martin Consulting s Smart Term Moses Engineering s Light Pen Tom Mix s Moon Lander and Frank Hogg s CCFORTH In February resumes were being accepted for the sysop of a Color SIG Special Interest Group which would soon be starting up onCompuServe while in New England the CoCo was being used at the University of Vermont Other events taking place at this time include
154. ce and allow an increase in bandwidth TV tuners and RF modulators the metal box inside the CoCo that converts the video signal to a TV signal are great sources of interference The modulator is actually alow power TV transmitter that broadcasts via direct wiring over the channels selected by the switch on the back of the computer 3 or4on U S model CoCos These modulators must comply with strict regulations set by the communications authority in the country of use FCC in the U S and bandwidth signal width is limited to a maximum of 3 5MHz for B amp W sets 3 0MHz for color A composite monitor overcomes all this by eliminating the interference sources modulator and tuner and extending the bandwidth though only to 3 5MHZ for composite color models Due to a wider bandwidth mono chrome and B amp W monitors are capable of a maximum resolu tion of 648x264 dots x lines To use a composite monitor simply plug a video patch cable between the video and audio jacks on a CoCo3 to those on a monitor or TV monitor A CoCo 1 2 will require a video amplifier to add direct video output At one time these were readily available but are not in much demand anymore Dy namic Electronics may still have some Anyone somewhat handy with a soldering iron can build the simple circuit shown This will allow plugging into a color or mono composite monitor If the monitor in question doesn t have sound a stereo or simple audio amplifier can be used R
155. ch as possible into my 2K During theearly phases of development I did notfeel squeezed for space at all after putting in various enhancements to BASIC that had occurred to me early on I still had quite a bit of space left and began to wonder if I would be able to fill it I began casting around for suggestions on CompuServe and in a Miami CoCo users group I was then attending Pretty soon more than enough to fill 2K I found myself poring over already written routines modifying the code to save a few bytes here and there in order to squeeze in this or that additional feature The original Microsoft ROM code pro vided me with an excellent model to imitate it is extremely economically written with regard to accomplishing tasks using a minimal number of bytes The code for the CoCo 3 s Super Extended BASIC written much later at Microware is much less efficient In April 1984 when I hada preliminary version of ADOS ready I sent a copy to Dennis Kitsz hoping that the tie in between his Lowerkit and ADOS support of lowercase commands might lead to some sort of commercial collaboration I heard nothing for months and then got a call from him This was something of a thrill for me since I had in my very early CoCo days been an eager reader of his CoCo articles in 80 Micro We wound up sharing a booth at a number of RainbowFests beginning with the September 1984 Princeton one at which ADOS officially debuted When the CoC
156. ch to upgrading has proven less than impressive resulting in giant expensive programs that each do things their own way OS 9 attempts to put many of the most wanted features of modern computers where they belong in the operating system Of course you only have to learn everything once but sometimes it seems you have to learn everything first The natural tendency is to ask some body what the heck is going on Those fortunate few who know a fellow OS 9 user who lives nearby enjoy a pretty painless introduction The rest of the world has to settle for hurried conversations carried out over telephone or modem andeven though the other person is really trying to help there is just too much information to pass in a few minutes In an attempt to cover as much ground as possible the helper may lapse into that dreaded variant of technobabble know as the buzz word A Very Buzzy Bee OS 9 promises and delivers quite a lot of capability in a very small package watching Level II run on a 6809 is an awesome sight to folks familiar with the chips limitations in memory space and speed You may wellask why worry about memory After all there are 2 megabyte RAM upgrades available Well the rub is the 6809 can only address 64K at atime DECB users are quite familiar with this limitation Evena512K CoCo only shows 24K free the rest of it s 64K ate up by the basic ROMs and some data space BASIC does gain some use of the extra ram by moving the
157. cial programming is required Use the Power button to turn the CoCo on and off Always turn the computer on after all other peripherals and off before them If all peripherals and the computer are connected to a multi outlet surge protector or power strip all may be left on all the time turning all on and off with the surge protector or power strip switch a surge protector is highly recommended The expansion port on the right side of the computer is used for program packs the disk controller a multi pak or one of several available peripherals Always make sure the system is off before inserting or removing anything from this port The computer could be seriously damaged if the item in this port is moved much during operation The Multi Pack Interface or MPI for short allows connecting more than one program pack or peripheral to the expan sion port at once Whenusing the MPIthe disk drive controller must be in Slot 4 Most other items can reside in any slot Slots can be selected by either setting the switch and pressing reset or by typing POKE 65407 x where x is 0 for Slot 1 17 for Slot 2 34 for Slot 3 or 51 for Slot 4 The controller for the disk drives is inserted into the Color Comput ers cartridge slot It contains the Disk BASIC ROM or a ROM for another DOS Disk Operating Systems Disk BASIC is often referred to as RS DOS Radio Shack Disk Operating System but this is a misnomer The Disk BASIC ROM contains addit
158. ciates EPROM board Color Port from Maple Leaf Systems Botek Instruments serial to parallel printer interface amp Shawn McClenahan s article describing the installation of a Model keyboard w numeric keypad inthe CoCo 80 MICRO ranits first annual Reader s Poll to find out the most popular software for Radio Shack machines WithFrank Hogg writing the editorial in the August issue of CCN things were really getting out of hand with all the FLEX material There was the editorial plus several full page ads for his products and of course his 64K Korner Itseemed like CCN had turned into the Frank Hogg magazine Although a bit less technically oriented The Rainbow continued growing and soon surpassed CCN in size page 13 With the addition of his second BBS Bob Rosen s Spectrum Projects was growing too His ads now took up three full pages and in August included Eigen s one key entry utility BASIC Aid Both BASIC Aid and another new single key entry utility Platinum Software s Platinum Worksaver offered much more than the first such utility SSM s Master Control Med System started marketing its software The eyes have it In September Tony DiStefano s Color Clinic column featured the eye saving hardware mod which enabled the CoCo to display green characters on a black screen Whenever I sat at my machine for hours on end usually every night I thanked Tony D Motorola released souped up MC6883 SAM which su
159. comes on and heads move a buzzing sound can be heard from the drives one of three chips need to be replaced The most likely culprit is the 7416 or 7406 on the NMI and HALT lines especially ifthe controller is used ina CoCo or MPI These pins are the second from the left looking in at the cartridge slot end of the controller board on the top and bottom Use the schematics to locate the correct chip or replace both Cut the offending chip out and replace with a socket It is suggested that a 7416 be replaced with a 7406 which will withstand higher voltages than the 7416 Note that there are two 7416s The second likely culprit is 74LS221 which is the second most likely to blow chip On the 12V controllers the 74LS02 and 74LS04 have a nasty habit of blowing Ifthe 7416 in the NMI and HALT lines is blown the 6809 and SAM should also be checked as they usually go down with a 12V short in a CoCo 1 or MPI also Ifreplacing these three two 7416 7406 one 74LS221 doesn t do the trick suspect the main disk controller chip only 40 pin chip aWD1795 MB8877 WD1793 WD1773 orauxiliary disk controller chip WD9216 not used on WD1773 models 12V controllers those with the WD1795 also suspect the WD1691 and WD2143 Unfortunately these disk controller chips are ALL hard to come by as they are no longer manu factured They may still be found in large parts warehouses page 88 however The ROM could be at fault but ra
160. contacted this author had already de cided that more than a simply history was needed With the introduction of Owl Ware s Window Writer 1 2 in February multi lingual word processing arrived on CoCo This slightly updated version alsofeatured a French edition Why French There has always been a relatively strong French Canadian CoCo market segment Also from Canada wasDisto s new 1 megabyte upgrade This was aboard with a small amount of circuitry and 512K in 41256 DRAM chips The existing 512K board plugged into the board A small satellite board also had to be soldered piggy back style over the CPU as several control lines had to be picked up Alter nately the CPU could be socketed and a socket installed on the satellite board to carry the CPU Either way only the page 23 competent hacker could install this memory upgrade Disto also announced another hardware item Tony DiStefano s A Full Turn of the Screw book whichreprintedall hardware articles published in Rainbow from January 1983 to July of 1989 Hardware hackers would be well advised to get the March issue of Rainbow Marty Goodmancoveredfloppy disk drives for the CoCo but the real hacker would be more interested in theComputerized Instruments projects William Barden Jr showed all how to turn CoCo into a dual trace storage oscilloscope with a sampling rate of up to 6000 samples per second Dennis Weide started his series on buildinga digital logic ana
161. corder and a blank tape was just enough equipment to make an attempt to start a small CoCo magazine Shortly after Joe came to school one day in June 1987 with the first issue of TRS 80 Computing He said he had been working on it for a few weeks and asked me if I would like to continue with the venture I loved the idea so we teamed up and started working on improvements That first issue looked like some natives had put it together At the time we had no word processor and still a minimal knowledge of BASIC Everything had to be printed using that nasty old PRINT 2 statement We even cut lettering from newspapers for the logo on the cover Our first few customers were teachers at the junior high school we were attending We had about four or five custom ers for the longest time and printed monthly After six consecu tive months it started to become time consuming and was interfering to much with our school work Besides it wasn t really worth the effort for just a few people As a result we stopped printing for a few months and figured that if we were to continue it would be published annually However with the purchase of many new development programs such as word processors and art programs we figured that with some time effort and alot of planning we could re start the magazine with anew format bi monthly frequency and a raise in price At this time we started promoting the magazine by using flyers Our best customers were
162. ct the hi res interface to a CoCo 3 page 100 The Serial port is used to plug ina printer or modem cable Only one of these can be attached at a time A two position switch or cable which allows connection of both peripherals at the same time can be used Only one of the peripherals may be actually used at once though A parallel printer must use a serial to parallel interface another interface to be connected to the CoCo These interfaces can run at a variety of baud rates The CoCo must of course be set at the same rate as the convertor or serial printer This is accomplished with a POKE 150 x either entered from the keyboard or put in a program where x is 180 for 300 87 for 600 the rate normally used on power up 41 for 1200 18 for 2400 4 for 4800 or 1 for 9600 baud Consult your serial printer manual for the correct baud rate most run at 2400 Parallel interfaces can usually be run at the highest speed though not much difference will be noticed over 2400 baud Com mands to print to the printer are issued like this PRINT 2 THIS WILL PRINT ON SCREEN Some games and other programs use the joysticks ora mouse They plug into the left and right joystick ports Some CoCo 3 specific programs require the hi res joystick interface This plugs into the right joystick port and the cassette port with the joystick then plugging into the hi res interface The hi res interface cannot be used unless specified by the program as spe
163. cur over the next several months as the program was almost totally re written to take advantage of CoCo 3 features and for higher resolution printing April 26 28 was the time for the last Rainbowfest held in Chicago Radio Shack took up almost a fifth of the floor space They were sellingCoCo 3s for 80 OS 9 Level for 40 and lots of OS 9 based software for 5 and 10 The final hours of the last day saw Tandy sellingCoCo 3s for only 60 guess they didn t want to load them back in the truck Many page 27 vendors were there showing their wares including the three OSK machines Delmar andFHL displayed actual production models while IMS still had aprototype Developmental delays including FCC certification problems had delayed produc tion Many people were upset but they were continually reassured that the computer WOULD eventually come and the fact that the company was showing up at the fests at least let everyone know they still existed Lonnie Falk moderated a question and answer seminarbetweenEd Gresick Delmar Paul Ward IMS and Frank Hogg FHL concerning the three OSK machines Seems that interest in these new machines is pretty high Wonder if I should consider making the switch Guess I should try learning OS 9 on my CoCo first Soon after this fest Tandy started selling most OS 9 soft ware including Level II the Development System assem bler and compiler for 5 10 nationwide they were let go at
164. d DSx where x is the position desired note that some drives are marked 0 3 others A D Shunts had metal jumpers that were initially all connected the drive desired would be broken Changing configuration meant replacing the shunt There are two simple hardware modifications that allow ac cessing the back of a double sided drive one to the controller another to the drive only one or the other is necessary The modifications are fully reversible This is not recommended unless itis known that OS 9 will not be used as OS 9 can use the drives as single 360K units If one owns a set of full height drives by all means keep using them provided they are reliable and meet ones needs If any problems replace them with double sided 40 track drives Tandy s Little Wonder MODIFYING CONTROLLER FOR DOUBLE SIDED DRIVES This is perhaps the easiest of the two modifications to accomplish All that is needed is a SPDT toggle switch 1 Cut the trace on the disk controller circuit board between land 32 of the drive cable connector end and the rest of the circuit board use a sharp razor knife to cut the trace 2 Solder a wire to the land 32 and another to the other side of the land Solder another wire to ground all of the bottom drive cable connector lands are grounded 3 The wire on land 32 should be connected to the center pole of the switch the other two to either side 4 The switch can be mounted in a hole drilled in the top shell
165. d bought use of a Tandy ROM Thus there was a strong argument that there was no copyright infringement involved in my selling such people a means of improving the ROM they had bought from Tandy I realized that this argument was not entirely airtight so I was always just a tiny bit worried that Tandy might some day come after me But I gauged that a I was too small for them to bother with and b if they did notice me they would probably just tell me to knock it off rather than sue Still it was the copyright worries that caused me later to farm out the EPROM burning to others rather than handle that myself In addition to the compatibility advantage of being built around the Tandy ROM there was also another important way in which I felt ADOS would be a significant advance over JDOS configurability I saw itas an enormous advantage that users of ADOS yes it stands for Arts DOS would be able to configure the default printer baud rate the drive step rates and keystroke macros prior to having an EPROM burned Throughout the development of ADOS software compatibil ity was always uppermostin my mind I saw the biggest hazard to compatibility as arising from 64K software that used the area immediately above Disk BASIC where I intended to put my enhancements The DISABLE command in ADOS was my attempt to solve this problem In shutting off most of the ADOS enhanced features DISABLE also freed up the memory above Disk BASIC for other u
166. d by Falsoft willbe very helpful as well as acopy of Start OS 9 ifitcan be found or borrowed The Complete Rainbow Guide to OS 9 Level II Vol I A Beginners Guide to Windows Falsoft will help Level II users with windows but assumes a basic under standing of OS 9 All this makes it hard for the long time DECB user to make the jump to OS 9 Be patient and get help from an on line service local BBS user group or local OS 9 user OS 9 will seem difficult at first but like anything else you will gain confidence and skill with practice You may even find in time that you actuallylike OS 9 Cloud 9 also makes this 512K upgrade flash memory card socket Boot from that uses two 256K SIMMS flash super quick page 52 Tandy s Little Wonder NitrOS 9 NOTE This article is unashamedly plagiarized from the official NitrOS 9 web site http www nitros9 org NitrOS 9 is arguably the biggest most intensive software project ever undertaken for the Color Computer It been in existence since 1994 having been created by a number of dedicated individuals within the Color Computer OS 9 com munity Much ofthe code was written by the original NitrOS 9 team Wes Gale Bill Noble and Curtis Boyle Later Alan DeKok made even furtherimprovements NitrOS 9 is an oper ating system created by the Color Computer Community for the Color Computer Community NitrOS 9 and the original OS 9 forthat matter is very much like Linux on aP
167. d increases in program operation The only modification required to the CoCo itself is the addition of a socket for the processor Two editor assembler packages were available to allow using 6309 functions with DECB a patch from CoCoPRO to Tandy s EDTASM and anew editor assembler byCer Comp NitrOS 9 was written specifically to take advantage of the 6309 There is hope for Disk BASIC users also The following program written by Rick Ulland of CoNect with the assis tance of Art Flexser Spectro Systems puts the 6309 in native modeand patches Disk BASIC 1 1 2 1 andthe PLAY SOUND and TIMER commands for proper operation 5 REM 6309 Patch by Rick Ulland and Art Flexser 10 POKE amp H0300 amp H11 20 POKE amp H0301 amp H3D 30POKE amp H0302 amp H01 40POKE amp H0303 amp H39 50POKE amp HD8AA amp H6C 60 POKE amp H9CS55 amp H69 amp H0300 Change line 50 to amp HD7B7 amp H6C for Disk BASIC 1 0 2 0 or ADOS There will only be a slight speedup maybe 10 in BASIC programs Machine language programs could be sped up 30 or more using the extended 6309 instructions page 80 There are still few problems for BASIC users One is that the baud rate is thrown off This can be adjusted by using different values for setting the printer baud rate POKE 150 xx values other than those listed for BASIC Experimentation will deter mine the proper values A manual describing the 6309 extended machine lang
168. d many more specialized at tachments The primary CoCo peripherals will be discussed individually with other less common items grouped together L Video Display Devi One of the most important peripherals for any computer is a video display device In the early days of personal computing when a non extended basic CoCo 1 sold for 399 most personal computers even the original IBM PC relied on a standard television set for a display No wonder even the relatively low resolution TRS 80 Model monitor sold for 199 and it was only capable of adequately displaying 16 lines of 64 characters in black and white Note that this and other monitors of the day were really nothing more than TVs modified for direct video input and increased bandwidth This was comparable to most other monochrome monitors which were inferior in many ways B amp W resolves graphics with more shades than monochrome how many shades of green or amber are easily separated by sight Composite color moni tors were selling for as muchas 349 and were no more capable than lower cost B amp W models all prices circa 1982 The CoCo was designed as a low cost color capable computer and most people already had color TVs so TV was the only officially supported display device until the 1986 release ofthe CoCo3 which supported TV composite video and RGB Analog video Support for these devices was long overdue as prices had come down to under 100 for monochrom
169. d with small square keys It was functional but didn t look or feel like a real keyboard Professional keyboards made their appearance onthe CoCo marketin 1983 toreplace the chicklet model These plugged right into the CoCo in place of the normal keyboard The first was re wired Model 1 keyboard provided by Spectrum Projects in 1983 This was closely followed the same year by KeyTronic Micronix Mark Data and HJL the later being the most known Looking at the CoCo keyboard sche matic itis easy to see that there is room for four additional keys All ofthe replacement keyboards had these keys on them The keys could be programmed for special uses but no programs for the CoCo 1 or2 were written to take full advantage of them The next CoCo keyboard appeared from Tandy late in 1983 Did Fort Worth take notice of all the replacement keyboards Maybe not but the CoCo 2 and 64K CoCo 1 were introduced with anew full travel low profile typewriter like keyboard The keys were only about 1 4 inch tall thus low profile but typing was much easier and faster This keyboard was later supplanted 1985 by a deluxe keyboard with 1 2 tall keys slightly angled to make typing even easier and faster yet The CoCo 3 was introduced with a keyboard similar to the CoCo 2 deluxe model but with four additional keys CTRL ALT F1 F2 added The arrow keys were also moved to the right in a diamond pattern and the BREAK key was coded to provide an
170. dCharlie s Machine a column written by Charles J Roslund author of War Kings Dragon LTD a British company started makingthe Dragon a CoCo clone It used a similar BASIC and software but featured some major hardware differences like full travel keyboard parallel printer port and composite monitor output An American version would be available sometime in 1983 Messages on CompuServe s Color SIG rumored that a new CoCo magazine would debut in March of 1983 MSB the folks who marketed the Kitsz lowerkit folded Radio Shack an nounced that they would market a 64K upgrade and aMulti Pak Interfacein early 1983 Basic Technology marketedthe first CoCo expansion interface with a real time clock page 14 Justintime for Christmas November releases includedColor LOGO and afour color graphics printer fromRadio Shack Frank Hogg s five slot expansion unit called The Solution andTelewriter 64 Other marketings wereDunkey Munkey fromIntellitronics andMonkey Kong by Ken Kalish ofMed Systems Software Although these are the first two monkey programs actually Donkey Kong arcade game clones the best is yet to come A premature ad for the Sampo Color Computer ran in November s BYTE magazine but this CoCo clone never saw the light of day in the U S It was supposedly sold in Korea the next year A reasonable assumption would be that the manu facturer couldn t get around U S copyright laws the ROMs were probably near duplicates
171. device will rest on top of the first The cable should be only three to fourinches in length the shorter the better Y cables usually work well witha disk controller and RS 232 Pak Using two devices that containa ROM oruse the SCS and CTS lines requires changing the address location of one of the devices see Mass Stor age for modifying the disk controller address Expansion Devices for modifying the RS 232 Pak A good way to disable a ROM is to cut the leg from the chip across from pin number one cut the power pin Note also that some devices require 12V power which would have to be supplied from an external source for CoCo 2 and 3 models make sure the 12V DOES NOT go into the CoCo cartridge connector page 73 5 Miscellaneous Devices Many more items have been made over the years that allow the CoCo to do many specialized jobs The most prevalent are listed below Two items not listed are modems and RS 232 paks These are discussed in detail under Telecommunica tions elsewhere in this book Only one modem the 300bps DC Modem Pak 26 2228 was made specifically for the CoCo Joysticks Three different joystick designs were made for the CoCo by Tandy The first was a very simple one button stick 26 3008 They were housed in a black case and sold in pairs for 19 95 All can be said is that they are better than nothing The second design was much better the Deluxe Joystick 26 3012 This stick was switchable betw
172. difference in cost between the TC70 and Kix30 Kixisacouple hundred more foracomplete system but is 52 5 times faster than a TC70 The Kix was so good that the other QT products were dropped also The Kix could be configured for any system so there was no need for any other boards CoCo sales had degraded so much by January 1993 that support was more trouble than it was worth Sales averaged only 1 2 per month The remaining CoCo people seem to be in two categories 1 happy with what they have and love the CoCo and appreciate anything that you do to help them and 2 those just looking for a bargain who don t want to pay fair prices for expensive hardware Current plans are to put the FHL 6809 material out as unsupported shareware This is sort of on the back burner will be done eventually There isstill TC70 support as some industrial users still have requirements for the cards but this is dwindling Many industrial customers are converting to the more powerful Tandy s Little Wonder Kix30 is market driven we build and sell what custom ers want Some of the larger companies Apple IBM etc will do surveys then build what they think the customers want If they make mistake they dump the products at a lowered price and start over We can t afford those tactics What should CoCo users go to Well many bought the CoCo because of low cost The OSK machines the better ones are rather expensive 1500 2000 A
173. dn t though With 128 512K the CoCo 3 was much better suited for OS 9 and support for CoCo FLEX dropped I first got involved in 68000 computers in 1984 Mike Spit at Hazelwood Computer had designed a 68008 single board computer with 128K RAM upgradable to 512K that ran OS 9 This board sold for just under 1000 That was a good price for the time The only other 68000 based computers were from Hazelwood on a SS 64 bus extended SS 50 and sold for 4 000 5 000 The new board was calledUni Quad Since FHL was selling hardware for the CoCo and OSK software Mike thought we might be interested in selling the 68008 computers He sent one and we called it the QT Quad Terminal for four serial ports I was advertising in 16 17 magazines full page ads The cover of the QT brochure was used for a single page Rainbow ad We sold 3 4 QTs the FIRST DAY the Rainbow ad came out The QT sold for 3 000 3 500 with a hard drive and I was surprised at how many sold We followed with the QT which had a68000 processor instead of a 68008 68008 has 8 bit bus 68000 16 bit andup to IMB Then came the QT20 from GIMIX The QT20 didn t sell well due to the high price like all GIMIX systems GIMIX had intended to take some of Hazelwoods business with the QT20 The QT20X was the first 68000 board designed to fitin a PC case before the PT68K sold by Delmar This form factor allowed the use of low cost readily available enclosures not custom made
174. ds find the icons directory look in icons find the file myicon Lets take an example that uses both redirection and pipes DSave looks at a disk and outputs all the copy commands it would take to copy the disk one file at a time Dsave d0 d1 would just print this list of copy commands to the screen standard path Not terribly useful Dsave d0 d1 gt d0 file would send these to a disk file on drive 0 which you could run later A little better Dsave d0 d1 shell pipes this list of commands directly to a shell Since shell s job is to run commands and dsave outputs commands the disk gets copied immediately So far we have been talking about space the pile of actual things modules that make up an OS 9 system Now we have to address time Theprimary design goal of OS 9 is thatis bea real time multi tasking operating system This causes some unique prob lems Since computers can only do one thing ata time all multi tasking systems have to switch the CPU between each pro cess that s waiting in line for CPU time asystem knownas time slicing There are two options The first is cooperative multi tasking where the individual programs decide when orif they are going to give up the CPU This idea has some problems you have to buy special programs written to cooperate and any program can hog the machine Definitely not real time OS 9 uses pre emptive multi tasking The individual programs all think they
175. ds who had discovered the Color Computer just a few years before The name of the newsletter magazine was TRS 80 Computing and the publishers were Joseph Ahernand David McNally The first few would be delivered monthly but the boys soon found that a bi monthly schedule worked around their school work better Good work guys shows just what a couple imaginative teenagers and a computer can do Disto finally started delivering the long promisedhard drive interface in February of 1987 Since it fits inside the Super Controller there is no need for a MPI and it makes for a neat installation Good thing J amp M stopped advertising their neat hard drive system a few months back maybe Disto came around just in time THE EIGHTH YEAR Jul 87 Jun 88 The new CoCo year started with the introduction of a much needed book The Complete Rainbow Guide to OS 9 Level Vol I A Beginners Guide to Windows As the title suggests the main subject of this volume was the new windowing system of OS 9 Level II Very little was mentioned about the operating system in general necessitating the need for the originalRainbow Guide to OS 9 also Still this book provided much needed information to the beginner and experienced OS 9 user alike The Vol I inthe title led readers to believe that other volumes were forth coming Itis unknown whether more were planned but there were no further volumes published or advertised The book was advertised for Aug
176. dware combo included a Hitachi 63B09E pro cessorchip anddrivers for OS 9 Level II The Hitachi proces sor was a68BO9E clone in CMOS architecture but with some advanced features These advanced features were taken advantage of by the new OS 9 modules and patches provid ing an average 40 increase in speed while maintaining direct compatibility A 6809 could be directly replaced with a 6309 without the user knowing any difference The new software and the enhanced mode of the 6309 was the secret A book describing the newly found secrets of this CPU was alsoavailable from B amp B What s this 7A NEW MAGAZINE The firstissue OS 9 Underground Magazine Dedicated to OS 9 OSK Users Everywhere was sent out in June The cover featured a 6309 chip on wheels being driven by a CoCo driver The 40 page magazine featured advertisements from eight companies most notable being Delmar System IV computer It was printed in a5 1 2 x 8 1 2 format saddle stitched stapled Although the print was a little small it was exceptionally well laid out and professional looking with multiple fonts No wonder The editor Alan Sheltra was a graphics artist by trade Articles included Test Driving the 6309 and BASIC Training A classified section was also carried The cover was abright yellow which certainly added to the magazines visual impact Subscription price US wasonly 18for a year cover price 2 per issue Thenew OS 9 Users
177. e and unalterable The data buffer enable circuit must be modi fied to prevent the MPI from opening its data buffers when the GIME addresses are in use The fix involves mounting a 74LS 10 gate chip on a small piece of circuit board a 14 socket may also be used Wire as shown below Make sure the circuit board is mounted so that it cannot move about inside the MPI possibly causing a short circuit if using a socket place a piece of double backed foam tape on the chip then stick upside down on top of another chip or the circuit board 1K ohm 1 4W resistor GND GND from pin 8 of any 16 pin IC To pin 19 of ICI 7418245 ENBUS TCC1001 ENBS To pin 11 of IC4 1 4 741 5367 7 9 of IC4 3 of 5 SLENB OS 9 poses a few additional constraints on MPI use Place ment of devices in particular slots is mandated by OS 9 device driver software device decoding and if the device needs to send a CART interrupt back to the CoCo The RS 232 or Modem paks need to get an interrupt line back to the 6809 inside the CoCo Therefore they must be in a slot selected for the CTS CART lines before the interrupt can get through Since only one slot can do so at a time you have two different drivers and MODPAK sets up for an interrupt from slot one and MODPAK instead uses page 71 5V from pin 16 of any 16 pin 0
178. e 1 1982 stated the availability of their editor assembler which may make it actu ally the first The Micro Works however did get theirs to market first Other notable releases in August includedMark Data s first two adventure games Calixto Island and Black Sanctum Tallgrass Technologies disk system and 64K RAM adapter board and THE FACTS a Color Computer technical manual fromSpectral Associates Barry Thompson Tandy s Product Line Manager in his column for Radio Shack s TRS 80 Microcomputer News replied to Mark Grangers PCLEAR 0 inquiry with this explanation THERE 15 NO WAY TO RELEASE THAT LAST PAGE OF GRAPHIC MEMORY Had Mr Thomp son read The Rainbow 5 second issue he not only would have found out about the PCLEAR 0 trick but he would have heard from a very high placed source that a Radio Shack disk system would be out within 2 months along with a 32K upgrade Hadn t we heard those stories before September is a time to return back to school A time for learning and learn we did We learned from Radio Shack that the much rumored 32K upgrade was finally a reality Although not mentioned the upgrade included both the new E board and 1 1 Basic ROM One discovered that the first Color Computer word processor C C Writer was available from Transfor mation Technologies We were taught by C J Roslundthat the PCLEAR bug could be fixed with a simple reverse reference and our homework assignment was
179. e CGA type monitor doesn t have a counterpart on the CoCo 3 This is the intensity pin which leads to the designation of RGBI for a digital monitor By using Tandy s Little Wonder this signal even an IBM type computer can display only 16 colors The limited resolution 640x200 and color set led to development of higher resolution analog monitors for IBM type computers While these higher resolution monitors are not normally usable with the CoCo 3 it does mean that used CGA monitors are readily available at electronic and amateur radio HAM swap meets at reasonable prices around 100 or less around 200 new While some game screens may be hard to read due to the limited color selections 80 column text will be easily readable NEVER CONNECT AN EGA OR VGA MONITORTOA COCO 3 These monitors sync at faster rates than the CoCo 3 and damage to the monitor and or computer WILL result Only monitors known to be compatible with CGA or that are known to sync at 15 75KHz should be connected to a CoCo 3 Note that many expensive Multi Sync monitors support 15 75KHz but not all Check with the owners manual or manufacturer to find out Even today multi sync monitors are somewhat expensive The only reason they are mentioned here is that they can be used with higher resolution IBM type machines as well as a CoCo3 soif one has both machines one monitor may suffice though both computers obviously can t be used at the same time RGBI IB
180. e Wonder 1985 continued 26 1275 299 00 TRP 100 Thermal Ribbon Printer battery or AC powered 26 1276 199 95 DMP 105 80 cps 26 1277 899 00 DMP 430 180 cps 15 18 pin 26 1278 599 00 DWP 220 20 cps 15 26 1280 349 95 DMP 130 100cps 26 2226 79 95 Deluxe RS 232 59 95 12 85 26 2228 89 95 DCM Modem Pak 300 baud 1986 26 3124 99 95 Multi Pak Interface 26 3127 199 95 64K CoCo2 Extended BASIC 159 95 08 86 on 99 95 12 86 26 3131 299 95 FD 501 Disk Drive 0 Kit 199 95 12 86 26 3132 179 95 FD 501 Drive 1 Kit 26 3141 24 95 Electronic Book 26 3145 129 95 Hard Disk Interface works only with OS 9 Tandy 10 15 35 MB drives 26 3215 299 95 CM 8 RGB Monitor 26 3334 219 95 128K CoCo3 26 3335 149 95 512K Upgrade 25 1025 699 00 10MB External Hard Disk 26 1277 699 00 DMP 430 180 cps 15 18 pin 26 1393 59 95 DCM 6 Modem 300 baud 26 4172 2695 00 35MB External Hard Disk 1987 26 3028 9 95 Hi Res Joystick Interface 26 3030 69 95 OS 9 Level I 26 3031 79 95 OS 9 Level II 26 3032 99 95 OS 9 Level Development System 26 3125 49 95 Two button Mouse 26 3133 299 95 FD 502 Disk Drive 0 Kit 219 95 12 87 26 3135 179 95 FD 502 Drive 1 26 3142 99 95 Appliance Light Controller serial 26 3143 79 95 90 Stereo Music Pak 26 3144 79 95 Sound Speech Pak 26 3334 219 95 128K
181. e competitive with the MM 1 I was going to go with Kevin Darling s K Windows but Steve Adams J Windows was a more mature product so I went with it instead In July 1992 we started with the concept of a new computer Mike had 268030 32 bit machines on the market the PC 30 QT 30 and PC 30 16 QT 30 16 These were somewhat successful the QT 30 was made for Washington University and had aPC XT 8 bit bus similar to the PT68K sold by Delmar This taught us that interfacing to all those PC type cards wasn t very easy Documentation was difficult sometimes impossible to get making it hard to write proper drivers that would work with the low cost cards on the market We ended up like Delmar with support for only a few cards software support was horrendous OSK is a bit more fussy about what is connected to it the drivers have to know EXACTLY what is there Each card had to be reverse engineered individually to create proper drivers Tandy s Little Wonder The new machine was originally going to use the PC AT 16 bit bus We started working on the design with that in mind At this time the local bus was being talked about in the PC market which was a 32 bit bus Mike dida study on supporting the AT bus Supporting it would take a LOT of board space Not supporting the AT bus would bring the cost of the motherboard down enough to provide serial SCSI floppy parallel etc ports The AT bus was only 16 bits and only operates a
182. e composite monitors and to around 300 for RGB monitors The following paragraphs explain in detail the various aspects of each of the main types of video displays available to CoCo owners There are certain advantages and disadvantages for each Choose carefully and use whatever fits your needs and budget The first video device most people consider for the Color Computeris astandard television set This is usually adequate for games the low resolution text screens 32 and 40 columns and CoCo3 medium resolution screen 64 columns Some CoCo 1 2 software generates a 51 and or 64 column screen which also resolve adequately on a TV When choosing a TV set stick with a 10 to 16 inch screen A color TV only has a maximum usable resolution of 256x256 which means 256 dots leftto right 256 lines fromtop to bottom This means that there are a total of 65 536 dots on the entire screen The smaller the screen the closer those dots are and the better the picture will appear to be Tandy s Little Wonder A black and white TV will give a superior text display There is less signal data to decode in a B amp W signal Color will look better with games the difference between color and B amp W will basically be the same as watching color versus B amp W TV shows Text displayed on a color set will have a fuzzy colored edge around the letters caused by the color burst signal This can be reduced by turning the color all the way out on se
183. e computer and commence operations When the computer locks up deter mine which chip is warmest One method is to turn the computer and MPI off then unplug the MPI and physically touch each chip One should be warmer to the touch than the others maybe even hot A better method is to spray each chip being careful notto get much overspray on nearby chips with component cooler 464 3321 The computer should reset itself and or resume operation as soon as the offending buffer is cooled down Replace the defective chip Ifan individual slot is causing problems the connector or cold solder joints could be the problem Inspect the connector first making sure all contacts are visible and protruding enough to connect with a circuit board Nexttry cleaning the socket with tuner cleaner or cleaner degreaser Clean the device being inserted into the suspect slot also Check the solder joints on the underside of the board If some of the joints appear dull re melt the solder with an iron Test the unit to see if the problem persists after each check if a problem is found If the connector needs to be replaced order a new one from Tandy National Parts This connector cannot be destructively re moved proceed with removal with extreme caution if not experienced with a de soldering tool DO NOT attempt re moval with solder wick Irreparable damage to the circuit board will result Go through the checks for slot selection circuitry before determining i
184. e feature ascratch nsniff adventure game The issue also contained a complete index of articles and reviews which have appeared in the magazine since its begin ning Rumors appeared about a new Radio Shack CoCo keyboard and the folding of Chromasette A new product calledTele Form was first marketed byCIGNA The software enabled mail merge withTelewriter In August TCCM was the subject of going out of business rumors Bob Rosen put BBS 5 air in San Jose and rumors circulated in England thatTandy was interested in the flounderingDragon Data Ltd company At the SeptemberRainbowFest held in Princeton NJ 28 30 Dennis Lewandowski debuted his128K upgrade Other first timers includeNOMAD therobot fromF rank Hogg Graphicom II from Whitesmith and agraphics program and digitizer fromGRAFX The rumored takeover by a Spanish company EUROHARD gave BritishDragon users something to roar about Dragon production was moved to Spain when the takeover was finalized in October Soon after TANO Micro computer Products Corp sold their remaining stock toCali fornia Digital Included in the deal was anumber of joysticks and software The number of computers was undisclosed but CD was still selling them in March of 1993 for only 39 At this time there were under 1000 left Many had reportedly gone to South American companies and schools The Dragon ended up having a long life after all TCCM s rumored demise proved correct as th
185. e last issue appeared in October This was the third CoCo magazine to fold within the past year including Chromasette s Disk Maga zine Dennis Kitsz also announced the start of Under Color UCL for short which hit newsstands in November An auto answer modem too expensive Check out the Novem ber issue of Rainbow and find out how to teach your Modem I to auto answer Bill amp Sara Nolan sold Prickly Pear Software toMike amp Joanne Chinitis Rumors rumors every where Radio Shack has CoCos withtrue lowercase using the new Motorola 6847 TI VDG chip which won t be released until after the holidays Better late than never a 26 page Under Color magazine premiered in December with information about two new Korean manufactured for Tandy CoCo 2s featuring a 1 3 BASIC ROM Other new December arrivals included The Wizard fromNEXUS which modified Telewriter s character set Dennis Lewandowski s 128K upgrade the Calindex appointment scheduler from Grantham Software a video digitizer fromThe Micro Works andNOVASOFT aTom Mix company started marketing its CoCo goodies 7000 Tandy s Little Wonder people attend Britain s first 6809 Colour Show for Dragon and Tandy CoCo users 1985 started with abang and a whimper The bang came from the debut of another CoCo milestone CoCoMax from Colorware Like Telewriter nearly every CoCo user has seen or used this graphics program which was patterned after MacPaint for the Apple Macinto
186. e single CD http www coco3 com index php CoCo Friends Disk Magazine Web Archives CoCo Friends Disk Magazine CFDM was published ona floppy disk from February 1992 through December of 2000 It was one of the first electronic publishing ventures It is now available free on the Internet at this site Articles programs etc Download it while you can and burn on a CD ROM An emulator is required to transfer the downloaded file to a CoCo compatible disk or file Only DECB was supported no OS 9 http 142 179 110 134 jeffv cocodisk index html Alan DeKok one of the primary supporters of OS 9 onthe CoCo maintains a site with a lot of NitrOS 9 and OS 9 infor mation and links http www sandelman ottawa on ca People Alan_DeKok in terests SockMaster s Tandy Color Computer 3 Page One of the more interesting pages out there It s full of programming info and some hardware info as well The SockMaster is John Kowalski best known for his amazing graphics demos for the CoCo3 He probably knows more about graphics programming on the CoCo3 than anyone else ever has http www axess com twilight sock index html CoCo Wiki Alan Huffman along time CoCo addict and former Microware employee also maintains a great site This site like this book is mainly an historical archive of the CoCo and people that made it come and stay alive http www coco25 com wiki index php Main_Page The original 1981 Tandy Technical Reference Manual is on l
187. e to mount three cartridge connectors A support is glued under the shell for stability The original SPII was powered by the CoCo itself or an external wall transformer which was necessary for devices which required 12V The 5 has an integrated power supply as the CoCo 3 does not have sufficient capacity to power more than one external device without over heating It also has a switch which allows use of a ROM Pak game cartridge in the center slot without unplugging all cartridges Some ROM Paks do not seem to work properly though it would be best to unplug all devices except the disk controller and ROM Pak then transfer the ROM to disk if possible or unplug the SP for ROM Pak use Due to the possibility of dislodging the SP from the CoCo and subsequently blowing the 6809 it is best used with a key board extension cable of some sort Slots one and two of the SP function similarly to the MPI slots Slot one uses the bits for MPI slots one AND three slot two for MPI slots two and four Only one of the bits is necessary to set the slot value though This was done so that if software was hard coded to use slot four the three slot SP would still function correctly The CART line IS NOT switched by the SP at all it is strapped between all three slots similar to the modification described earlier the diode still needs to be installed inside the CoCo 3 though The third slot DOES NOT have the CTS or SCS connected at all This means tha
188. e years ago U S copyrights weren t protected in most Asian countries including Japan and Korea One could walk into a Korean computer store and find hundreds of copies of commercial software for share ware prices averaging 5 per disk plus 5 10 for a manual The third clone was not really a clone at all but an attempt to make an improved but downwardly compatible computer The FHL TC9 used a 68B09 and GIME just like the CoCo 3 but had some improved hardware design It was intended to primarily be an OS 9 platform TheDragon Data Tano Dragon The following article was originally written for the October issue of Color Computer News by Alfredo Santos but never appeared due to the magazines discontinuance Enter The Dragon 64 Alfredo Santos September 30 1983 TheDragon 64 computer which is enjoying great success in England is now available in America What makes the Dragon worthy of mention in this magazine is the fact that it uses a 6809E microprocessor and Microsoft BASIC just like our friend the TRS 80 Color Computer When I first heard about the Dragon 64 and little brother Dragon 32 my first question was Will Color Computer programs run on the Dragon The answer is YES and NO The incompatibility of BASIC word tokens between the 2 machines prevent CoCo programs from working on the Dragon directly If you save a CoCo program using the ASCII format CSAVE filename A it will CLOAD and RUN on Dragon with l
189. east another decade It was with this in mind that this book was written to keep your CoCo alive and well for many more years to come LEFT Magazine ad for the CoCo 1 circa 1981 pz um be Mis 11909 PE E x 1 wu da accru sua iam Cram eee ee i zm Compe at t L posna irm com hegua Brh Teu ie arean pares Bn Wai a ume ia mg eres Pd ATE Fr n uma dur Program ica X n acm ip ad mmd ILL EE ULL Locali Je L eee ORO nmi page 33 CoCo Hardware Prices The following prices were obtained from Radio Shack adver tisements and catalogs This list is far from all inclusive my personal RS catalog collection dates back to 1987 but does give an idea as to what early CoCo enthusiasts gave for their equipment If anitem is not priced fora given year that usually means that earlier prices were carried over no change Note that CoCo specific items use 3xxx catalog numbers These will be shown first with remaining numbers in numerical order Listed printers have the 4 pin CoCo style serial connector and all have 9 1 2 wide carriages and 9 pin print heads unless otherwise noted 1980 Introduction 26 3001
190. ectly it doesn t have to be analyzed and translated each time the program is run There fore machine language is comparatively fast But assemblers and compilers are not interactive if you make any changes in the program you have to re assemble orre compile and re link it before you can test the changes This makes program development and debugging difficult A threaded interpreter builds fully analyzed and translated machine language code by compiling new words as you write them into the program A FORTH program consists of a list of word definitions where each word definition is simply a list of previously defined words Once it has been defined a FORTH word is BASIC subroutine it can be called over and over and it can be called from other subroutines which themselves can be called over and over etc etc Aha The best of both worlds So Where s the catch First of all you have to learn a whole new way of thinking Forget everything you ve ever learned about computer program ming Start from scratch CF83 FORTH does not use floating point numbers it only uses integers 5is alegal number in CF83 FORTH but 5 0is not This is both an advantage and a disadvantage Integer arithmetic is MUCH faster than floating point arithmetic so anything that can use integer arithmetic e g screen graphics will make BASIC really look like a turtle And if your application really needs floating point results you can write
191. ectors on each end RS 15 1536isa 6 cable Plug one end into a cable ready TV or cable TV adapter and plug the other end into the CoCo An F connector to phono plug adapter will be required to connect the 75 ohm cable to the phono plug on the back of the CoCo old RS 278 252 All this willresultin about a 100 improve ment in video quality at a cost of under 10 well worth the investment The next video type to consider is composite video This is basically a without a tuner butis much clearer Composite monitors are readily available as combination color T V moni tors usually for use with high quality VCRs Harder to find nowadays are monochrome single color usually green or amber composite monitors which are really needed for 80 page 59 column text display for the same reason that B amp W TV is superior to color As good as monochrome are B amp W compos ite monitors These are usually available at security dealers as they are frequently used for surveillance systems Check with surplus electronics dealers for composite monitors of all types Timeline Inc 1490 W Artesia Blvd Gardena CA 90247 213 217 8912 http www timeline inc com and California Digi tal 17700 Figueroa Street Gardena Calif 90248 310 217 0500 http www cadigital com cadigtl htm forexample If TV and composite are virtually the same then how is composite better Composite video monitors reduce the sources of possible interferen
192. ed to 1000 The 12 indicates the speed ofthe chip in hundreds of nanoseconds ns one billionth of a second in this case 120ns Therefore a 164 10 isa64Kx1bit 100ns DRAM If the second digitis a 4 the chip is a four bit chip Remember that it takes eight bits to make up one byte so two 4464 10 chips makeup a complete 64K whereas it takes eight4164 10 chips 120 150ns DRAM should be usedin all RAM upgrades Less than 120ns faster DRAM chips will be slightly higher priced but will also work just fine Slower chips will overheat and eventually fail causing intermittent problems as the computer heats up Do note that the early CoCo 15 did use 200ns DRAM These were never intended to run at double speed however so the slower access time wouldn t normally cause a problem At any rate it is difficult to find chips rated at less than 150ns anymore and the smaller chips 4K amp 16K are difficult to find at all The Original CoCo CoCo 1 IDENTIFICATION Gray Case w vents one the sides Chicklet keyboard CATALOG NUMBERS 26 3001 26 3002 BOARD REVISIONS C D It IS NOT practical to upgrade these boards to 64K though it is possible A description of each board and reason for not upgrading follows Many early CoCoist DID upgrade these boards but with CoCo 2 computers selling for under 25 in most areas it is not advisable nor cost effective to make such upgrades If one must upgrade one of these machines order a b
193. een self centering and free floating action the first are free only Two fire buttons are used though only one works on the CoCo 1 2 both on the CoCo 3 These sticks were made by Kraft and also connect to the 1000 series of IBM compatibles note that the similar appearing IBM sticks are wired different they WILL NOT work with the CoCo or 1000 series They may still be available in some stores but are not listed in the 1993 catalogs Only the last stick design the 26 3 123 Pistol Grip model was listed in 1993 This stick features two buttons on the base plus a trigger and thumb button on the stick The stick buttons work the same as the two base buttons only two active inputs Like the Deluxe stick these also work with the 1000 series A Hi Res Joystick Interface 26 3028 was also available for the CoCo 3 This gadget plugged into the cassette and one joystick port and increased the resolution of the joystick making for smoother action Unfortunately special software was required and little of this was made The last versions of CoCo Max3 a popular paint program and 10 a graphic Mac MSWindows type word processor require the Hi Res Interface Mouse Tandy came out with a CoCo mouse not long after the CoCo 2 was introduced The original mouse 26 3025 featured only one button since the CoCo 2 supported no more on the joystick port A two button mouse the Deluxe Color Mouse 26 3125 was introduced along with the
194. effort to update in many cases entirely re write programs to take advantage of the many CoCo 3 features Others like Computerware who ran their last CoCo ad this month ex panded into more profitable computer fields Paul Searby ownerof Computerware redirected his programming efforts Tandy s Little Wonder toward the popular IBM PC and compatibles Computerware had been one of the largest CoCo suppliers Fortunately many small newcomers were joining the programming ranks which accounts partially for the large number of ads Microcom became the largest advertiser with five entire pages Several other interesting things happened in July of 1988 Windows came to Disk BASIC users through Cer Comp s Window Master software Up to 31 windows even overlap ping with pull down menus could be controlled via a mouse joystick or the keyboard on a 512K CoCo 3 Burke amp Burke introduced R S B Radio Shack BASIC for OS 9 which allowed pure Disk BASIC programs to run in a window under Level II Lastly Rainbow reviewed another desktop publish ing package for the CoCo 3 this one from Tandy and operating under OS 9 Level II Tandy s Home Publisher was abit slow but did do the job The main gripe with this program was that it only supported Tandy DMP and Epson RX 80 printers While most printers would operate with the RX 80 drivers the RX 80 was getting a bit dated and newer printers were much better and had features the RX 80 driver wouldn
195. eliminates having to specify an EXECution address after you CLOADM a program Power up initializa tion puts the value amp HBF49 at amp H009D Dragons 64K mode ROM entry pointis amp HBF49 If you wish to enter the 64K mode AFTER having loadedina machine language program amp H009D will then contain then EXEC address of that program so typing EXEC amp HBF49 will be required to access the 64K Another nice thing about the Dragons use of its 64K is that it frees user RAM from amp H0600 amp HBFFF s by moving the ROMs up to amp HCO000 amp HFFFO0 The CoCo doesn tmove its ROMs so you endup with 2 blocks ofRAM amp H0600 amp H7FFF and amp HC000 amp HFFFO with memory locations amp HA000 amp HBFFF amp H8000 amp HBFFF for Extended BASIC CoCos off limits because CoCo s ROMS are there With 64K of RAM Dragon 64 full stroke keyboard parallel printer port and color composite monitor output this com puter should be a very serious consideration for anyone in the Tandy s Little Wonder market for an inexpensive yet powerful machine with high resolution graphics capabilities In addition to the above mentioned ports the Dragon has the standard CoCo type connections for 2 joysticks a cassette recorder 40 pin ROM cartridge expansion slot and TV hook up The power transformeris externally mounted making the computerrun a good bit cooler than a CoCo no fan needed The Dragon has all the power and versatility of the very p
196. en t all devices fully decoded Cost is why It s cheaper to make a disk controller that uses the already de coded SCS line from the CoCo than to include the one or two extra chips needed to decide it s own address Theoretically it also meant you could have a disk controller in each slot and pick between them but that isn t really practical Many OS 9 Level II users CoCo 3 ONLY have found it necessary to strap the CART line between all four slots This is done by soldering ajumper wire under the MPI circuit board between the CART pins pin 8 of all four slots This keeps the RS 232 pak from locking up or loosing characters during operation and allows more than one device to send an interrupt to the CPU without switching slots The RS 232 will sometimes loose characters or lock up CoCo 3 due to the way the GIME chip detects the CART signal The GIME detects a CART on transition from high to low of the interrupt line Ifone interrupt occurs directly after another the GIME never sees the second one This situation can easily occur when using RS 232 Pak under OS 9 as an interrupt is generated each time a character comes into the RS 232 At the same time the GIME is generating 60 interrupts per second Sooner or later one interrupt follows another to close and a character is lost or the RS 232 Pak locks up page 72 A Schottky barrier diode 276 1165 must also be added inside the CoCo 3 to complete the fix The anode o
197. er Comp had software that took full advan tage of the power in the new CoCo still in the works In February Rainbow reprinted an old article the first and only time this was done The article was a utility to transfer tape programs to disk The reprint is due to the programs popularity it successfully transfers machine language as well as BASIC programs and the popularity of Rainbow on Disk Tandy s Little Wonder June marked the arrival of the first CoCo 3 only graphics program Computize s Color Max 3 Picture convertors to allow use of pictures in Atari ST ST NEO and TNY Graphicom and CoCo Max formats as well as several support ing utility programs are also offered Cer Comp started adver tising their first CoCo 3 only products A communications terminal disk editor assembler and screen enhancing pro grams were described A word processor disassembler and BASIC enhancer were promised even by the time the ad was out Speaking of BASIC enhancements Art Flexser Spectro Systems introduced ADOS 3 for 34 95 this month AI though it was for the CoCo 3 it had a disable feature so that itcould be burned into an EPROM and the disk controller could be used with a CoCo 1 or 2 also Double speed disk I O command line editing and support of 35 40 or 80 track as well as double sided drives were some of the new features A new magazine was introduced this month also This newsletter was created by two seventh grade frien
198. er to the unused inputs forcing them high and preventing possible problems later pins 6 8 amp 11 canremain unconnected 4 Locate land 36 SCS line on the edge of the controller that plugs into the CoCo Cut the trace from this pin with arazor knife just after the wide land stops Solder a short piece of wire to the land being careful to leave enough room for the controller to push in the CoCos connector The other end of this wire should be soldered to pin 1 of the 74L S32 5 Find out where the trace that was cut from land 36 goes on the controller it will be slightly different depending on the controller part number Solder another piece of wire from this point to pin 3 of the 74LS32 6 Locate land 23 A4 address line on the same end of the controller Solder a short piece of wire to that land also DO NOT cut the trace The other end of this wire goes to pin 2 of the 741 532 The controller should now work properly with a Y cable All other CoCo floppy controllers will require this operation also Even the Disto Super Controllers need this modification to work witha Y cable On the Super Controller and possibly the J amp M controllers with built in parallel port this modifica tion renders the mini buss expansions unusable as they are decoded in amp HFF50 to amp HFFSF area To use the mini buss a Slot Pak X Port or MPI MUST be used as they re supply the necessary decoding Nowa word about floppy disk drives themsel
199. ere was an example of all three new CoCos in the hands of the Rainbow technical staff Coverage of the new machines was planned but only as we see evidence of upward migration to these systems The CoCo would still be covered of course Marty Goodman authored an article explaining exactlywhy the Tandy Multi Pak Interface MPI required updating for the CoCo3 Older models grey case had to be upgraded to use the disk controller because the GIME chip in the CoCo 3 used an address which would cause an unmodified MPI to switch away from slot 4 which contains the disk controller The newer models large and small white cased appeared to work just fine in most cases Intermittent problems resulted from the 6809 trying to read data from certain GIME port addresses main problem was thatthe MPI was designed before the CoCo 3 and the data buffer is activated whenever a read was performed in that overlapping address range The GIME and buffer would then try to give the 6809 data at the same time Tandy s Little Wonder garbling theread data This would happen even if nothing was in the MPI Upgrading the large MPIs was easy order a replacement PAL chip from Tandy Upgrade instructions were given forthe newest 26 3 124 small white MPI which required the addition ofa single chip and afew jumper wires Tips were also given for modifying the MPI for OS 9 use not required but some modifications enhance operations under OS 9 The IM
200. erial ports and options for hard drive controllers a PS 2 keyboard adapter and even a LAN port It will be the biggest most complete upgrade for the CoCo 3 ever devised or made available Beyond 64K in the 1 62 There were several 128K CoCo amp 2 upgrades introduced in 1984 All suffered the same fate not enough support or utility to really be used The main problem with these upgrades was that they had to move large chunks of memory either 32K or 64K to maintain compatibility with existing software this was also due to the memory map of the CoCo All of these upgrades actually banked or paged through the large memory chunks Some had the 32K ROM area stationary and the 32K RAM area was switched others the more useful with existing software actually switched the entire 64K memory block in and out ROM and all A machine language program was usually required so that a POKE switched between memory banks The one exception was the Dynamic Electronics upgrade which had a toggle switch to page between two banks of 64K This proved to be a bit more useful as two m l programs that changed the ROM code could be loaded and switched between This setup was designed so that two documents could be edited at once using Telewriter 64 by switching the two banks There was no way to copy text between the two banks however The POKE method worked well with BASIC programs but m l programs couldn t be switched without crashing T
201. esson when he released his 6809E Instructional Kit which came complete with text and audio and program cas settes In November atColor EXPO 83 Marty Goodmandebuted his state of the art graphics program Graphicom Other new releases were Elite Word from Elite Software Super Screen fromMark Data PASCAL fromDEFT Software the BASIC Unravelled books from Spectral Associates and Computerware s first BASIC Compiler Nelson Software changed its management and name toSoftlaw Corporation Super Color Library programs became VIP Library pro grams With Christmas only days away TANO started including 8 FREE programs with its Dragon 64 home finance word processing and games Things did not look good for the only CoCo clone Reviews for the Dragon 32 and Dragon 64 ap peared in a couple of publications along with the announce ment of Time Bandit from the Computer Shack Magigraph from The Micro Works and POKES PEEKS amp EXECS books fromMicrocom Software In January aBarcode Reader calledOSCAR was advertised in several computer magazines for different machines includ ing the CoCo Programs could be printed in magazines normal printing presses using barcodes no need for expensive companion disk or tape subscriptions just a one time pur chase of an Oscar by the user And Oscar was independent page 16 with a software change he was ready to connect to virtually any computer with an RS 232 port This 178 ill fated project
202. et another odd disk system marketed forthe CoCo the Amdek Amdisk III This was the first small floppy disk system the disks were only three inches in diameter The disks were also more protected as they were in a hard plastic case The Amdek disk resembled the newer 3 5 inch disks available today but there was no metal shutter over the case slot a jacket was still required The only problem with the Amdisk was the disk size Amdek wisely used the standard Radio Shack disk controller but one still needed a standard 5 25 inch drive The Amdisks biggest feature was price itcame with two drives two blank disks and a controller for only 599 intro duced in 1983 A key feature ofthe system was that both sides of the two drives were accessible giving 624K of storage capacity These weren t very popular with CoCo owners due to the non availability of software on the small disks The Amdisk was only advertised in Rainbow in 1983 it didn ttake them long to realize CoCo owners weren t biting A side note is that Amdek DID findaniche market for their three inch disks many typewriters and dedicated word processors used the Amdek instead 3 5 inch drives When OS 9 came out a flaw was quickly discovered in the Tandy disk controller and all others made at that time Although OS 9 was a multi user multi tasking true DOS the CoCo disk controller was not The controller used a simple design that interrupted the 6809 during disk access This was
203. exadecimaland binary numbers will be needed The following method works well and is rather simple Most other methods require tables of numbers These work but require looking up each nibble 4 bit half of an 8 bit byte separately Wes method is a bit easier especially if one needs to do conversions without tables Asan oldassembly language programmer hexadecimal hex is second nature But anyone can calculate hex in their head without resorting to tables Just break a number into nibbles That is each hex character represents a value from 0 to 16 If Tandy s Little Wonder you have the number amp HF2 for instance think ofitas and 2 Each character in hex is represented by 4 digits in binary in binary is 1111 and 2 represented in binary is 0010 So that amp HF2 hex is the same as 11110010 binary A little practice and it will come naturally All you have to remember is the values from 0 to 15 16 bit values are interpreted the same way as four nibbles DECIMAL HEX BINARY 0 0 0000 1 1 0001 2 2 0010 3 3 0011 4 4 0100 5 5 0101 6 6 0110 7 7 0111 8 8 1000 9 9 1001 10 A 1010 11 B 1011 12 1100 13 D 1101 14 1110 15 1111 If you want to convert a decimal number you can start at the left If you re working with an 8 bitnumber bit 7 represents 128 decimal bits numbered 0 7 right to left So if your number is greater than 128 write a 1 If not write a 0 If you wrote a 1 subtract 128 fr
204. f a connector is bad Also try different devices in the suspect connector there could be a device problem Finally if the entire MPI is dead suspect the power supply See the next section for repair details Power Supply Repairs The power supply in all CoCo models MPIs and disk drives are pretty simple and easy to repair Remember that live 110V AC current is at the transformer so be extremely careful when attempting repairs especially if the computer is still plugged in for testing On older D board CoCo 1s loss of 5 V poweris usually caused by the 6 2V zener diode This diode will fuse if overloading occurs sacrificing itself and grounding 5V power out to save the rest of the power supply Check the zener diode with power off Current should only pass through any diode in one direction only If it passes from both ends the diode is fused and will need to be replaced On the D and E board CoCo the zener is a 1N4735 CR17 Another popular reason for loss of 5V is a burned out 33 ohm 2 watt power resistor R66 page 89 The CoCo 2 uses acustom Tandy IC for much of the regulator circuitry This chip the Supply And Level Translator SALT handles 5V power regulation RS 232 level translation and cassette input This chip is was only available from Tandy Early CoCo 2s used a SALT that required 3 9V zener diodes on the incoming RS 232 lines for protection Later model CoCo 2s used a newer SALT that was internally pr
205. f the diode lead opposite the stripe should be connected with a length of wire 24 or 26 gauge to resistor R2 4 7K ohms the part reference numbers are printed on the circuit board This resistor is located near the reset button Solder the wire on the end of the resistor farthest away from the reset button The other end of the diode the cathode end nearest the stripe should be connected with a length of wire to resistor R7 which is located near the PIA 40 pin chip near the opposite corner of the board as the reset button kitty corner from reset Solder the wire to the end of R7 nearest the PIA Insulate the diode and all bare areas of the wire well to prevent shorts on the circuit board This modification bypasses the GIME inter ruptand connects the CART line directly to the IRQ interrupt request pin of the 6809 The diode prevents interrupt signals from feeding back to the CART line Ifa Schottky barrier diode isnotavailable amore common N34 germanium diode can be used Silicon diodes CANNOT be used they could cause logic problems The only DECB program known to use interrupts when using RS 232 Pak is Ultimaterm a popular share ware terminal program Otherwise only OS 9 users need to con sider this modification The only problem with strapping the CART line is that auto execute ROM cartridges and expansion devices would cause acrash of the system The solution is to either cut the trace to or tape over scotch
206. fects both signals Anything other than the above video frequency renders the video output useless which is why the crystal can t be changed to speed the computer up The CPU frequency is altered by the speed up poke which reduces the divide value to eight 14 31818 divided by 16 0 8948862MHz by 8 1 7897725MHz justunder or2 MHz This was necessary to produce the required video signal which must be exact the CPU signal can vary a good deal from the rated speed The second job of the SAM is device selection The portion of computer circuitry looked at by the CPU is controlled through the address lines of the CPU Internal registers of the SAM can be addressed or up to eight external devices can be addressed For external device selection the SAM has three chip select lines which are connected to a three to eight decoder chip Devices are selected by a combination of on and off settings of the three select lines there are only eight possible combinations The final job of the SAM 15 address multiplexing Insummary this means that the address and video signals are used in different combinations to form a larger number of addresses than otherwise possible These addresses activate different portions of RAM There are only two versions of the SAM The MC6883 and 74LS783 are the same except for designation A slightly improved version 74LS785 was introduced in late Korean made model CoCo 2s andis inall Korean
207. for Tandy Radio Shack and the 80 was a result of the Z 80 cpu in Tandy s first computer the Modell Because the CoCo uses a 6809 cpu maybe it should have been called eithera TRS 68 ora TRS 09 Color Computer but what s inaname Some nicknamed it the TRS 80CC other the TRS 80C still others the 80C It wasDave Lagerquist who first used the name COCO in October sChromasette Maga zine This innocent enough action set off a name calling debate lasting for several months throughout the ever grow ing CoCo community Some things in the November winds included a tip to reduce internal heat produced by the 32K piggyback upgrades by painting the inside of the CoCo s top cover flat black arumor that Radio Shack was using half good 64K chips in its 32K upgrade and an interesting article about CoCos being used to controlMr Bolden s solar heated home in Washington state The computers were set up by Home Computer Sys tems Inc of Seattle November also brought the first review ofthe Exatron disk system theProgrammers Institute stape magazine TRC but still no Super Color Writer Nelson Software may have been dragging its feet but not Cognitec Withinacouple of months ofits Novemberrelease page 11 Telewriter was the talk of the CoCo community Telewriter was the first world class CoCo word processor To this day Telewriter is probably the most used CoCo word processor nearly every Color Computer owner has used Telewr
208. from it but it can t store new information Therefore ROM Paks have to be used in conjunction with tape or in some rare exceptions disk if any information is to be stored A program stored ina ROM for the CoCois normally a machine language program BASIC programscanbe stored ina ROM but must include a m l loader to move them into an area where BASIC can run them The computer detects the presence of a ROM Pak through the CTS cartridge select signal on the expansion port or MPI The CART cartridge detect interrupt line senses the presence of aROM Pak also and auto executes it Auto execution can therefore be deterred in all but a very few ROM Paks by taping over pin eight on the cartridge itself The ROM can then be executed by typing EXEC 49152 CoCo 1 2 ONLY or EXEC 57360 CoCo 3 ONLY or the information can be saved to tape with CSAVEM name 49152 65279 49152 This will save a standard 16K ROM Pak all CoCo 1 2 Paks are only 16K to tape A special program or patch has to be used to save and run the larger ROM Paks from RAM Patches for some are available from Delphi or FARNA Sys tems The first mass storage system time CoCo users were intro duced to was the cassette recorder Tandy made several recorders with computers in mind CTR and CCR series Computer Tape Recorder and Computer Cassette Recorder but any portable cassette recorder with aremote microphone and earphone jack will work on the CTR CCR series the AUX
209. game made especially for the fest was available from CoCoPRO also In Marty s Nightmare starring Marty Goodman well at least a good caricature of him had to search through a maze for a lost seminar This neat software tribute to the good doctor was programmed by none other than Steve Bjork Highlights of the fest included seminars by Steve Bjork history and development of the CoCo Cray Augsburg Rainbow managing editor on happenings at Falsoft concern ing the Rainbow anda Q amp A type meeting withKevin Darling that lasted four hours Good thing it was the last one The manufacturers of the three new OSK machines were actually grouped together at a single seminar Sunday After giving a brief introduction questions flew concerning all three ma chines and their differences Several notes of interest came from Crays seminar 1 Rainbow WOULD NOT be folded into PCM 2 there would be a Chicago Fest sponsored by Rainbow next year 3 the new computers WOULD be covered as they became available to the general public and 4 the planned CoCo history book project was being cancelled due to lack of time by the author The Atlanta Computer Society took care of door prizes and assisted CoCoPRO with running the operation Good work guys can t wait until next year October must end with a sad note Color Computingmagazine changed in June from TRS 80 Computing sent out what would be its last issue Editors Joseph Ahern and David
210. h all the others Run diagnostics for further checks 6 If ground is high replace chip internal short Ifno low logic probe on ground chip should be replaced 7 The address lines of the SAM GIME 0 15 should indicate an address in the BASIC ROM Check each with a logic probe A pulse only or pulse low indicate a low 0 pulse high a high 1 The combination should indicate a binary number 10100111110100000in early CoCo 1 A7D0 whichis a location in the BASIC ROM Convert to hex or decimal and check the memory map for location Ifitisn tin BASIC ROM there is a problem between the CPU and SAM GIME 8 Ifthe pattern on SAM pins 25 27 GIME 29 3 1 are other than indicated replace the SAM GIME The pattern shown selects the BASICROM 9 If SAM pins 28 35 and pins 11 amp 12 are other than shown replace the SAM These are used by the multiplexer 10 SAM pins9 amp 10 are frequency driven Check by presence of a logic pulse and interference on a TV screen SAM pin 7 must also show a pulse If these tests fail replace the SAM Test only pin 10 of the GIME 11 Ifany but the data pins ona PIA read differently than noted suspect a bad PIA The PIA may not be initialized properly though whichindicates a problem in the CPU or ROM circuits SAM 74LS138 3 8 decoder or GIME Check these before replacing the PIA 12 If there is a signal other than a pulse on the data lines of a PIA the trouble is somewhere along the da
211. h to the Present HOW THE COCO WAS BORN The initial Tandy Motorola connection occurred sometime in the mid 70s when the two were invited by the U S National Weather Service to assist in developing a weather radio system In 1977 a year after starting talks with Motorola about the possibility of designing a low cost home computer that could be hooked up to a regular TV set Tandy was invited to participate inanagricultural experiment Project Green Thumb as it was called would employ information retrieval to give farmers data updated hourly by computer Terminals used in this project were developed by and sold by Radio Shack in conjunction with Motorola Terminals were distributed to 200 farms in Shelby and Todd counties Kentucky The Green Thumb network was sponsored by the National Weather Service U S Department of Agriculture and the University of Kentucky By late 1977 Motorolas MC6847 Video Display Generator chip was developed Althoughit was unclearifthe VDG came about because of project Green Thumb or Tandys search forthe low cost home computer in 1978 when it was married to the MC6808 CPU the Color Computer was born This prehistoric Color Computer however contained to many chips to make it affordable for Tandy s anticipated target market Motorola solved this problem late in the year by replacing the network of chips which made up the memory management circuits with its newly developed MC6883 Syn chron
212. happen to CoCo when you exit them Pressing reset should remove the pro gram completely from memory If not powerdown the computer for a few seconds For a CoCo3 hold ALT and CTRL down then press reset Let go of all the keys A screen with three people on it will appear These men helped design the CoCo 3 Finally press reset again and you will get the start up message and RAM will be cleared The CoCo 3 Audio and Video ports are used to connect the CoCo to a composite monitor An RGB monitor port is located underneath the computer Be careful when moving the CoCo 3 if the RGB cable is still connected It s fragile so don t plug unplug it often The Channel Selector switch is used to select either Channel 3 or Channel 4 when using a TV with the computer The RF Out port is used to connect the CoCo to a television set Some games written for a CoCo 1 or 2 use colors not displayable on an RGB monitor due to the way the colors are derived by the programmer he actually cheated with some fancy programming to get more colors The Cassette port allows one to connect a cassette drive tape recorder to the CoCo Disk drives are much faster for storage and retrieval plus files programs are easier to find on disks A regular audio tape recorder with facilities for an external microphone and remote control will work nicely The volume setting may have to be played with a bit to get it exactly right The cassette port is also used to conne
213. hat one missed issue was a scare Lonnie recognized a special person which hardly anyone will even know inhis column in this 1 1th anniversary Rainbows CoCo is 12 issue Steve Ostrom Who is this One who had continually subscribed to the Rainbow for the entire eleven years can one be more loyal Remember the CoCoPRO modem pak RS 232 serial conversion Marty Goodman showed how it was donein this issue Advertisers are down to only 21 Weare slowly but surely losing support Don t worry to much a lot of the old ones are still out there ready to sell The problem was that it a quarter page ad in Rainbow cost around 300 Sales were falling to a level that could not support these rates for many suppliers And pages were down to only 66 Tandy s Little Wonder A full page ad appeared in the August 91 Rainbow for the CoCoPRO sponsored Atlanta Computer Society hosted Second Annual Atlanta CoCoFest It would be heldin October 5 6 Hmmm must make plans to be there AnewCoCoPRO product isNewspaper 09 adesktop publishing package for OS 9 Level II Itis based on Newspaper Plus Lonnie used his PRINT 2 column toreview the Chicago fest of last April no pages taken up by a real Rainbowfest Report as before He states thatcoverage may be coming for the new 68xxx based machines and thatreview machines were expected soon The Delmar System IV was even included in the Received and Certified section The verylast Microcom ad ran this mon
214. hat tells the computer where to find them while the disk controller and others that rely on SCS CTS slot switching doesn t Slots can be selected by software also This is done by POKEing a value in location amp HFF7F Once memory location has been written to the hardware switch is deacti vated until the MPI is reset or turned on after being turned off It is best to leave the hardware switch on the slot the disk controller normally slot 4 is in when the computer is first turned on The hardware switch must be used to selecta ROM Pak in a slot when a disk controller is left in the MPI The following values are used to determine which slots the CTS CART and SCS lines are switched to SLOT CTS CART SCS dot matrix printers still made will but lasers and inkjets made 1 amp HO amp HO over the last 10 years most likely won t Many businesses 2 amp HOl continue using dor matrix printers but new ones are back up 3 amp H20 amp H02 to 1980s prices 4 amp H30 amp H03 page 70 Tandy s Little Wonder To change all three signals to a slot add the two values together For all three in slot one POKE amp HFF7F amp H00 for all three in slottwo POKE amp HFF7F amp H11 etc To place CTS and CARTinslottwo SCS in slot four POKE amp HFF7F H 13 value H10 amp H03 Note that there are enough bits in the control byte to allow up to 16 slots The most ever used in one device was six by PBJ Slot Pak and J NOR I
215. he CoCo 2 or3 This useful program came onSIX diskettes complete with storage box Like other Zebra software First Prize operated in an easy to use point and click graphics environment CoCoPRO came through the fest with some leftover Japan scenery disks Flight Sim II OS 9 Level 2 and Marty s Nightmare games Those who didn t attend the fest were now able to purchase these bargains The IMS ads featured an interesting twist anMM 1 could now be purchased as a kit add your own case keyboard monitor and drives for 659 a savings of 120 One reason for the kit wasdelays in meeting FCC requirements for full systems which was causing serious delivery delays Many people who had made down payments were wondering if they would ever get anything Kits could be sold without FCC certification Delphi users would notice lower rates in their ad 6 hour and also discover thatMarty Goodman is the CoCo SIG manager And whatis that on page 33 A System IV computer fromDelmar Company Iremember This was aTHIRD 68xxx based OSK computer system which first came to light at the Atlanta CoCoFest which was only fitting sincePeripheral Technolo gies of Atlanta builds the boards These machines used a 16MHz 68000 chip anda PC XT 8 bit expansion bus The PC XT bus was used due to the availability of cheap expansion cards A base model with four serial ports a parallel port 1 4MB 3 5 floppy drive 40MB hard drive case keyboard OSK operating syste
216. he TC70 was based on 155MHz Signetics 68070 processor Motorola 68020 clone and also came with BASIC C compiler OSK and various software and utilities A floppy based system 1 4MB 3 5 drive 101 key keyboard color monitor 1 5MB RAM 2 serial and 1 parallel port SCSIhard drive port and builtin DMA cost 1499 95 A similarly equipped MM 1 would cost 1495 The TC70 board can beused to upgrade the Tomcat system to a 68xxx processor ifthe TC9 is already owned or buy the TC9 and upgrade when the money comes along 999 95 for board and software only The TC9 board was upgraded to use two 512K SIMMs rather than DRAM chips and a CoCo type 512K board The main board was also divided into two boards a main processor board and a DAT board The main board held all memory but the DAT board was required to use the second 512K This was done to decrease the cost of a basic system which could also be used as a low cost terminal for more expensive multi user computers Almost forgot thefirst ever Atlanta CoCoFest was held in October I was there The show turned out to be a big success with many vendors and lookers alike CoCoPRO had a LARGEbooth in the center of the main show floor with floods page 25 of used and old stock Tandy software They even had some rare scenery disks for Flight Sim II Japan scenery which was selling for only 9 95 the scenery disk was selling for more at 24 95 and OS 9 Level 2 for only 34 95 A new
217. he desire andthatPeter Stark the authorof SK DOS mightbe willing to lend a hand by giving me his magazine and a mailing list It took a week to talk with people in the industry line up a printer and getRandy Keippner to agree to do the layout The 68xxx Machines was now in business The aim was to satisfy the higher level user programmer quality not quantity Despite our lack of experience the first issue was mailed Feb 91 all of sixteen pages long The format was small 5 1 2 X 8 1 2 pages with small print The result was Tandy s Little Wonder full size information within a package that reduced production and mailing costs By the end of the first year the subscriber base had grown m a n y times over and the number of advertisers had more than doubled The number of pages was held at 24 to keep costs and quality under control All bills had been paid on time since day one including advertising inThe Rainbow It soon became apparent however that the traditional user base for OSK was not going to number into the thousands not even one thousand Trying to increase the number of potential subscribers several out of the main stream operating systems had been featured These articles didn t increase the sub scriber numbers very much Requests to include OS 9 kept coming in I had reasoned that since Rainbow hadn t done much with it it wouldn t do a lot for 68xxx But to leave no stone un turned I began to include one
218. he main problem with these upgrades was that they never caught on Drivers were never written for OS 9 to take advan tage of the extra memory indeed it may not have even been possible Due to the programming restrictions of these up grades another reason they weren t very popular they are notrecommended If one is interested articles on how to build them were printed in the following magazines Rainbow DEC 1984 128K The Easy Way pp 162 168 HOT CoCo SEP 1985 The Fat CoCo 256K pp 28 31 program listing pp 46 49 The Rainbow issue is still available from Falsoft as a back issue order the Hot CoCo article may still be available from the publisher See Library for addresses The only practical way to use memory over 64K in these machines is by using a RAM disk This uses RAM memory to emulate a disk drive A RAM disk is very fast but one must remember to copy or backup anything in the RAM disk to a page 78 physical floppy before turning off or resetting the computer Most RAM disk software can set the RAM drive as any number making it useful for games that load different parts as needed Several were made at one time though none accept possibly a Disto unit are available today A project to build aRAM disk appeared in the SEP OCT and DEC 1989 issues of Rainbow in three parts all three needed which are available as back issues from the publisher Upgradingthe Keyboard Theoriginal CoCohada chicklet keyboar
219. he motherboard sockets would have to be added to the blank spaces marked off for them on the motherboard or the chips could be soldered in directly NOTE The 4464 chips removed from a CoCo 3 when upgrading to 512K can be used inan A or B model CoCo 2 CoCo3 IDENTIFICATION Has different arrow key location F1 F2 CTRL and ALT keys CATALOG NUMBERS 26 3334 BOARD REVISIONS Only one board made The CoCo 3 comes with 128K installed This is made up by four 4464 DRAM chips There are two white connectors near the four RAM chips These are fora 512K upgrade board Before installing the board pull the four 4464 chips out and clip capacitor C65 Several 512K upgrades were made all using 41256 256 1 DRAMs Cloud 9 currently offers 512K upgrades that use 256K SIMMs Disto made a 1MB upgrade that plugged into the 512K upgrade sockets required a bit of soldering to the CPU had 1641256 chips on board and had sockets for an existing 512K board This took up quite a bit of room inside the computer made itrun hotter and wasn t exactly easy to install Many OS 9 users loved the extra memory regardless of the difficult installation In 1993 Disto announced a2MB upgrade This board uses two IMBx8bit SIMMs Single In line Memory Modules the three chip variety and plugs right in The only soldering required is replacing the CPU with a socket which the 2MB board plugs into there is a socket for the CPU on the 2MB board Thi
220. he tape circuitry could be affected also In that case the only alternative is to find a Tandy Diagnostic ROM Pak Good luck finding one They only tested up to 16K of RAM but checked all other circuitry All but the RAM test is usable on the CoCo 3 also 4 The destructive removal method of IC removal should be used by all but accomplished hobbyists Use pointed cutters to cut the legs off of a chip close to the chip body removing the body after all legs are cut Now grasp each leg individually with needle nose pliers and heat the solder joint pulling out the leg Go back and clean each hole Hold the de soldering tool ready then heat the solder quickly placing the de soldering tool and triggering it as soon as the solder becomes liquid This method destroys the chip being removed but greatly reduces the chance of damaging an irreplaceable circuit board The de soldering tools listed can be used to remove a chip without cutting in much the same way just be CERTAIN that all solder is removed before pulling the chip out It is best to practice on an old circuit board before trying this on anything else Chips are cheap and usually suspected bad before removal The exception might be when replacing the 6809 with a 6309 The 6309 or another 6809 is replaceable the CoCo motherboard is not 5 The only way to learn to solder is by practice Get an old circuit board and practice soldering wires and chips to it Remove some ICs also destr
221. hex bits doubles as a nut driver TV Tuner Cleaner 64 33 15 or Cleaner Degreaser 64 3322 A multimeter can be used for some logic probe applications Find a good circuit board ground then test for a voltage for ahigh signal usually 5V OV for low Some tests REQUIRE a logic probe One might want to consider Radio Shack s compact 14 piece PC tool kit 64 1972 which contains screwdrivers chip extrac tor inserter nut driver tweezers and carry case in lieu of some of the listed items The necessary items could be purchased at the time of writing for under 40 with the optional items an additional amount under 20 plus another 20 for the logic probe Almost any repair the average hobbyist is capable of making can be done with the necessary tool list the optional list makes the job a bit easier especially when working with ICs chips Solder wickis NOT recommended for the novice The vacuum type solderremovers are more efficient and easier to use If one is practiced and comfortable with wick by all means go ahead and use it otherwise get a vacuum remover the purchase won t be regretted Tandy s Little Wonder Diagnostic utilities on disk are available The only problem with disk based diagnostics is the disk drives could be the problem It might be a good idea to transfer some of the diagnostic programs to tape I can hear long time users who have used tape storage before groaning already Of course t
222. hics with music and sound effects using simple one line commands Pow erful programming features include PEEK POKE and USR com mands multi character variable names two significant string arrays up to 255 characters full featured editing tracing and 9 digit accuracy Includes tutorial manuals on both Standard and Extended BASIC 26 3027 459 00 Specifications Color Computer Upgrade Kits Add More Memory and Better Graphics YT W 16K RAM Upgrade Kit Converts a 4K Color Computer to 26995 27 69 00 64K RAM Upgrade Kit Converts 4K 16K or 32K Color NEW Multi Pak interface Connect Computer to 64K 26 3017 199 00 upto four Paks to your New Low Price Extended Color BASIC ROM Upgrade puter at Play with Kit Upgrades a Color Computer for advanced graphics changing setup capabilities Requires minimum of 16K Was 149 00 26 3024 1983 Catalogue 26 3018 110 00 NEW Deluxe m Program New Keyboard Upgrade Kit 26 3016 Pak Communicate informa Upgrade kit prices do not include required installation tion services 26 2226 119 95 Under development Price and availability to be announced 178 Items Shown Are Available Through Selected Radio Shack Stores Computer Centers and Participating Dealers From 1984 Tandy Catalog page 132 Tandy s Little Wonder POWERFUL COLOR COMPUTER 3 S
223. hown at the West Coast Computer Fair in February George Associates CoCo CP M expansion unit hit the market inJuly Although it looked impressive who was going to drop 1200 00 to upgrade a CoCo Did anyone out there buy one of these In July in the best get better department The Micro Works unveiled its disk based editor assembler MA CRO 80C Tony DiStefano s first Color Clinic column in 68 Micro ex plained why some CoCos would not accept the double speed poke andDonald J Sommerof Seattle Washington detailed the steps required to upgrade a pre E board CoCo to 64K CCN continued putting more emphasis on FLEX OS 9 and other CoCo operating systems but featuresDarrel Wright s utility to convert Telewriter text files from binary to ASCII and vice versa and some pictures taken at a Cincinnati TRS 80 users meeting Plans were disclosed to offer CCN on Tape and winners of the first CCN programming contest were an nounced They were J Ventling for the George C Scott portrait Garry Howard for the William Tell Overture and Regena s Cookie File program The Rainbow s first anniver sary issue was a beauty Featuring its first full color cover and typeset copy throughout it s hard to believe that it started out in a drugstore a year ago Rumors circulate that the 4K CoCo will be discontinued and a 64K version will be intro duced in the near future The first CoCo hardware to reach the market in August includedF amp D Asso
224. id bring tothe CoCocommunity the information required to double the computer s effective memory and in so doing created a base for his FLEX operating system In March Kraft s new joystick available within 2 months Type N Talk fromVOTRAX andGeorge Associates 7 80 based CP M interface were three new CoCo products pre viewed at the West Coast Computer Fair in San Francisco Data Comp debuted their FLEX operating system by marketingSteve Odneal s conversion which at the time utilized the Exatron disk system In an attempt to pacify software reviewers who had been waiting for the long overdue Super Color Writer Nelson shipped their Super Color Ter minal Magazine articles at this time include Shawn McClenahan s detailed instruction on various 64K upgrades anon Kitsz hardware project for those of us who were tired of constantly switching the modem and printer cables from the back of the CoCo and Frank Hogg s article on moving ROM to RAMin your new 64K CoCo Perhaps in light of February s Tandy s Little Wonder information flood both CoCo publications seemed to have had lack luster March issue If I hear about the double speed With 2 FLEX operating systems available for the CoCo Microware started looking into the possibility of porting its OS 9 operating system Meanwhile Dale Puckett s article FLEX Comes To The Color Computer along with the first installation of Frank Hogg s column 64K Korner appeared in the
225. iling cost To sweeten the deal OS9U would keep all proceeds from subscription renewals new subscrib ers and new advertisements In exchange forthe 68xxx no cost mailing list OS9U would pay the postage costofthe OS 9 part ofthe magazines sent to 68xxx subscribers We both deemed it to be a fair exchange and the deal went through EDITORS NOTE AlthoughThe 68xxx Machines was dedi cated to 68xxx based computers this story is included here because many CoCo OS 9 users benefitted from the OS 9 articles The OS 9 Underground was short lived quietly disappearing after less than one years existance page 93 Two Boysanda CoCo Joseph Ahern and David McNally by Joseph Ahern former editor TRS 80 Computing It all began in the fifth grade when we were introduced to the Radio Shack Color Computer Once a week our class was allowed to go to the computer room and use Color Logo We soon learned how to master all those impossible shapes they had us draw We had such a good time using these computers that both of us talked out parents into getting one It was hard learning BASIC because up to now we had only used Color Logo Both of us tried learning to program by spending hours reading through and typing the sample pro grams from the Color BASIC manuals After sharing each others knowledge we could do some simple programming Within a years time Joe had saved enough money to buy a DMP 105 printer This along with a computer cassette re
226. in3 of IC9 to pin5 or6ofthe 74LS02 GIME line 52 Solder a wire from the other pin 5 or 6 to the intersection of R9 and C10 E clock signal from the GIME 4 Cut pin 4 or 5 not both of IC9 as near the circuit board as possible Bend the remaining portion out and solder a short wire to it Solder the other end to pin 4 of the 74L S02 Unless intermittent hardware problems or sparklies on the screen appear regularly this modification is unnecessary It should not be required with 1987 and later GIME chips as the problem was addressed inside the GIME Disk Controller and Drive Repairs The first step in repairing a disk controller is to make sure the controller is the problem 1 Unplug the controller and make sure the computer operates normally 2 A faulty disk drive or cable could also cause problems Test the suspected controller cable and drives on another system if possible Check the cable for continuity 3 If another known good disk system is available see if it works correctly on the problem computer 4 A software problem could be the culprit Make sure a cold startis effected if a problem occurs after running a m l program Turn the computer off for afew seconds then back on CTRL ALT RESET may not clear everything up on a CoCo 3 page 87 5 Check all the cartridge port lines using the logic probe readings for the 6809 previously listed The CPU could be at fault Note that the 12V controller requ
227. ine at http homepage ntlworld com kryten_droid coco coco_tm htm I suggest copying this 10 CD ROM before it goes away page 55 The Color Computer Library The first section contains a list of books which will help you aquire a better understanding of the TRS 80 Color Computer programming it and its various systems The word COCO all capitol letters is used to replace the words Color Com puter in some titles If the title uses CoCo it will appear in that form Watch yard sales flea markets used book stores classified ads on Internat sites and E bay for them The past magazine section lists all defunct magazines and the approximate dates of publication Many useful programs and much information can still be found in these publications Again about the only place these will be found is through yard sales classifieds etc Books 1978MC6809 Macro Assembler Ref Manual Motorola 1979MC6809 Preliminary Programming Manual Motorola 1980The MC6809 Cookbook Carl D Warren 198 1MC6809 MC6809E Microprocessor Program ming Manual Motorola 1980The MC6809 Cookbook Dr Carl Warren 1981101 COCO Programming Tips amp Tricks Ron Clark 198155 COCO Programs For Home amp School amp Office Ron Clark 198155 MORE COCO Programs For Home School amp Office Ron Clark 19816809 Assembly Language Programming Lance Leventhal 19816809 Microcomputer Prog amp Interfacing Andrew Staugaard Jr 1981 The Facts Spectral Associates 1982COCO
228. ing CoCo disk drives and analog RGB monitor saving some of our investment when if we decide to upgrade the 15 68020 based system Anew magazine hit the scene in July Entitled The OSK er the publication proclaimed to have news and views in the world of OS9 68000 and 6809 The premiere issue contained 24 pages including both sides of the cover in an 8 1 2 x 11 two column format on a high quality white not slick paper saddle stitched stapled There were some highly unusual formatting standards used The table of contents looked like a disk directory the title of each article like a file description and the pages were numbered as sectors The entire maga zine read like an on line conference The most interesting articles were a Q amp A session about the TC9 TC70 and MM and arather lengthy interview with Kevin Darling which described when Kevin first got interested in OS 9 among Tandy s Little Wonder other things The magazine was published byStG Comput ers Inc and edited by StG owner Scott Griepentrogg In the August Print 2 column Lonnie discussed the arrival of the new computers He predicted that they would be natural extensions of the present CoCo possibly an acceptable upgrade path for many users He also alludes to the possibility of there being several regional CoCoFests sponsored by local groups not Rainbow This allusion is to theAtlanta CoCoFest sponsored by CoCoPRO and the Atlanta Com
229. ion Tandy s Little Wonder The back of a CoCo 3 The RGB connector right was underneath and required a special cable Only the CoCo3 had the RESET button andAudio Video out connectors Other CoCos looked the same across the back except for those three things RAM Upgrades fashion All original model gray case CoCos can be upgraded to 64K though the earliest models only supported upgrades to 16K officially It just took some enterprising CoCo enthu siasts to figure out how to access additional memory once it was learned that the 6809 could actually address 64K Each model is discussed separately along with its identification characteristics Revision numbers are found on the right front side of the circuit board on the CoCo 1 models All CoCo 2 boards are easily identifiable by the DRAM configurations Each revi sion of these boards is only slightly different from the others CoCos are most easily identified by their catalog numbers thoughitis possible that a later board was installed in an older case when upgrading or repairing by a Tandy Radio Shack service center In such a case there should be a sticker on the bottom ofthe case stating which board was installed and what upgrade was done Generic numbers have become common for DRAM In the number 4116 12 the 4 indicates Dynamic RAM the first 1 a one bit chip and 16 the capacity in bytes is actually 1024 bytes though this figure is usually round
230. ional BASIC commands that simply allow BASIC itself to access infor mation on the disk drive OS 9 is example of a true DOS as is MS DOS Micro Soft DOS for IBM compatibles Even A DOS a popular Disk BASIC enhancement is not a true DOS Disk BASIC is available immediately upon starting the computer whereas most DOSes have to be loaded from disk The CoCo is capable of using up to four single sided disk drives though most people only use two Up to three double sided disk Tandy s Little Wonder drives may be used Tandy used the side select line for the fourth single sided drive though only OS 9 is really capable of fully utilizing double sided drives Several programs and disk BASIC enhancers notably A DOS will allow accessing the back sides of double sided drives as if they were additional single sided drives therefore two double sided drives could be treated as four single sided drives The Tandy disk controller is capable of handling drives with a capacity of up to 720K both 5 25 and 3 5 types Disk BASIC enhancers or OS 9 must be used to access the larger drives Under disk BASIC drives are numbered from 0 to 3 instead of 1 to 4 or A to D Always make sure there are no disks in the drives when the computer is turned on or off A stray signal over the cable sometimes erases or changes the data directly under the drive head s Torun programs under BASIC type RUN filename disk to load and automatically run or ty
231. ires an MPI for 12V power if used with a CoCo 2 or 3 12V may have been run to the controller from the disk drive power supply by an enterprising user such was common when the CoCo 2 first came out This type setup may be used ona CoCo 3 also Problems will occur whenrunning a 12V controller with OS 9 Level IL and possibly under DECB ifrunning the CPU at double speed OS 9 Level runs at double speed all the time This is due to the design of the 12V controller and cannot be fixed Ifthe disk controller is still suspect clean the contacts on each end of the controller The case will have to be snapped apart to properly clean the contacts On long approx 6 control lers a single phillips head screw is located under the label on top On short controllers approx 4 the screw is located under a seal that reads WARRANTY VOID IF LABEL REMOVED or something similar Remove the screw and snap the case halves apart Clean the contacts with a pencil eraser until they are bright and shiny Re assemble and test the system This cures most unexpected errors Incidentally any peripheral plugging into the cartridge port or MPI can be affected by slightly corroded dirty contacts Clean in the manner noted The sockets themselves can be cleaned by spraying with TV tuner cleaner or degreaser cleaner see tool list Ifthe normal Disk Extended BASIC copyright notice appears on screen but reading and writing to the disk fails the drive light
232. isto paks since they are slot dependent these drivers shut off interrupts while accessing the hard disk or RAMdisk while the SCS slot is changed This is probably in the mistaken belief that drivers can be time sliced acommon Tandy s Little Wonder misconception and some other might change slots There s no reason to do this unless there is an IRQ driven device that will change slots on you None are known to do that Most third party hard drive interfaces except the Disto as noted above also need to reside in slot three when using OS 9 The mentioned slot assignments are usually used by convention even on Level II systems CCHDisk and ACIAPAK can be easily patched to use a specific slot for the RS 232 pak The bytes to change are at offsets 80 in ACIAPAK and offsets 4D7 and 4E9 in CCHDisk if you use it Currently these bytes are set to 03 02 03 Change the zero 0x to whichever slot code you desire for the RS 232 pak re verify the modules and you re done For the RS 232 pak using ACIAPAK driver in slot three change them to 23 22 23 forexample Tandy discontinued the MPI in 1989 This left the market open for vendors to come up with a way to allow more than one cartridge to be plugged in at one time Howard Medical introduced the Slot Pak December of 1989 This device is packaged in the equivalent of an old long disk controller shell about six inches long leaving enough room outside the CoCo cas
233. ite power hungry when compared to newer models so two half height drives will work nicely in one of the old full height cases Was 360K mentioned in the previous paragraph as the drive capacity DECB only supports 35 track single sided operation 156K but the drive mechanicals are otherwise identical to the double sided 360K units There are several DECB enhance ments that allow accessing the full 40 tracks and the back sides of these drives All configure the front normal single side as drives O and 1 and the back as drives 2 and 3 If only one double sided drive is used it can be configured as drive 0 and 1 The back sides can also be accessed by using some memory location POKEs see Color BASIC The connec tors on the drive cable will have to be replaced with new ones 4276 1564 if there are teeth missing as the contact for position 32 missing from pulled teeth cables is necessary to switch to the back side Only three physical double sided drives can be connected to a CoCo controller because all follow the Tandy convention of using position 32 as drive select3 necessary to maintain software compatibility Drive number selection is made with a shunt on the oldest drives is NOT likely to find a drive with a shunt in use today by the more common jumper block one newer ones Once the connectors have all their teeth the drives must be configured for position This is done by placing a jumper over the pins marke
234. iter in one of it s variations Although it was possible to do primitive Videotex download ing Colorcom Efrom Eigen Systems was light years ahead It supported on line off line scrolling cassette file transfer automatic or manual data capturing off line print outs and selectable RS 232 options WhenMark Davidsaver sColorcom E was ready for shipping he mailed flyers to those who had responded to his put your Basic program on a ROM ad June 81 Bob Rosen upon receiving his flyer immediately phoned Mark Colorcom E became the first major software sold by Bob s Connection 80 BBS The rest as they say is history for both Bob and Colorcom E December saw not only the release of Computerware s Pac Attack the first of many PAC MAN clones but a review of the Tallgrass Technologies disk system This was probably the only disk system ever which would run in As 1981 drew to aclose reviews and comparisons were being made between the new Radio Shack disk system and the Exatron system The consensus of opinion seemed to be that Exatron s single density format was its biggest drawback as it stored less information on a single diskette than the Tandy double density format With third party support growing dramatically and even Radio Shack waking up the CoCo s future seemed secure but into each life a little rain must fall THE COLOR COMPUTER IS DEAD Now when most of us hear rumors we usually consider the sour
235. ith a pre recorded program This was done to make the computers seem less intimidating Cartridge slots were also a part of most early home computers A cartridge containing a different ROM chip Tandy ROM Pak could be inserted before turning the sys tem on and when powered up whatever was in the cartridge ROM would be ready to go What could be simpler There are four types of BASIC for the CoCo in three versions Color BASIC Extended Color BASIC Disk BASIC and Super Extended Color BASIC Color BASIC is the simplest form of BASIC for the CoCo It came in an 8K ROM and was the first BASIC available There were no definition commands DEFUSR DEF FN etc only one trigonometric function SINe no error trapping and few graphics commands only POINT SET and RESET Ifa line was typed in wrong it would have to be retyped there was no editing capability This BASIC was very similar to TRS 80 Model I Level I BASIC CoCos with only this BASIC installed would display COLOR BASIC VERSION 1 0 on screen when turned on It didn t take Tandy long to realize that programmers wanted more Extended Color BASIC ECB similarto TRS 80 Model I Level was announced when the CoCo was introduced in September 1980 with an expected introduction of late No vember It actually arrived in mid January 1981 Extended BASIC contained many new commands in another 8K ROM that plugged into a socket next to the existing Color BASIC for a combined
236. ithasingle drive 0 amp 2 and 1 amp 3 with two double sided drives 6 Connect the wire from pin 3 to any drive select on the jumper side across from the drive cable connector 7 Connect pin 7 to ground anywhere on the drive frame 8 Once all connections are made to the socket firmly press the 741 508 into it Mount the chip upside down to the drive frame with double backed foam tape picture hanging tape being sure to place it where it won t touch the case sides or interfere with other drives 9 Install drive in case and plug into disk controller It should now operate as ifit were two single sided drives Ifnot go back and check your work Although the standard CoCo drive is the 156K or 360K 5 25 35 40 track unit the disk controller will also support 5 25 or 3 5 720K 80 track drives Simply plug the drive into the cable along with the other drives Unless a modified DECB Tandy s Little Wonder such as ADOS is used only the first 35 tracks and one side will be available the previous modifications will work on these also OS 9 comes with drivers that allow full use of these drives The 5 25 units were made obsolete when IBM skipped over them in favor of the 3 5 720K drives The ill fated Tandy 2000 several other non IBM type systems adopted the 5 25 drives before IBM started using an 80 track drive The best thing about these drives is they can be double stepped the head moved two tracks instead of one to read
237. itten for the 6809 times itself by the IRQ interrupt request and NMI non maskable interrupt instructions In native mode the 6309 reduces the number of clock cycles required by IRQ and NMI causing these pro grams to crash Changing stack pointers directly also causes asystem crash Anything indexed from the stack pointer goes to a different location due to the added registers of the 6309 In DECB disk drive functions the PLAY and SOUND com mands and the TIMER function all use the interrupts for timing Any use of the drives or these commands causes Disk BASIC to crash There was a slight problem however Motorola did not authorize any improvements Motorola wanted a work alike in CMOS packaging and that was all it authorized Hitachi to make This led to no documentation for the advanced native mode of the 6309 being officially available When a group of CoCo users started discussing possible faster processors to replace the 6809 on Internet see Networks a Japanese student volunteered the 6309 due to the added functions When asked for additional information he transcribed a detailed article from a Japanese trade journal describing the added registers and instructions Details of the native mode were apparently leaked or discovered in Japan With this new information in hand Burke amp Burkeand Gale Force Enterprises developed packages for OS 9 Level II that took advantage of the new registers and commands to provide 10 30 spee
238. ittle or no problem Problems may occur if any memory locationsinlow RAM are PEEKed or POKEd and problems will occur for sure if any CoCo ROM routines are called Here s why Dragons Color BASIC and Extended Color BA SIC are identical to CoCos in many ways with some major exceptions Both are burned into asingle HN4827128G 3028 pin EPROM Whilethe Dragons BASIC chip IC 18 occupies memory locations amp H8000 amp HBFFF like the CoCo ROM entry points are different CoCo s POLLCAT routine for instance is at while on the Dragon it sat amp HBBES This fact prevents Color Computer machine language pro grams from running on the Dragon unmodified page 36 Dragon ROM entry points and CoCo BASIC equivalents CoCo Dragon Address Address Comment A000 A000 8006 POLL KEY A002 A282 A002 54 CHAR OUT cass A004 ATIC 4004 8021 CASS READ A006 A70B A006 B93E BLOCK IN A008 A7F4 A008 B999 BLOCK OUT 00 9 A00A 8012 READ IN JOYSTK VAL A00C A7D8 00 801B HEADER OUT Both the CoCo and Dragon have indirect addresses at amp HAO000 amp HAOOC Dragon s bid at CoCo compatibility 894C 903 95 A95D 00 B39B SECONDARY RESET A027 B3B4 MAIN RESET A02A B3B7 06 HARD START 0 8 B44F SOFT START A176 50 CHAR IN A186 51 1 1 B538 1 1 5 CHECK KEYBRD A282 54 CHAR OUT cass A290 B560 A2A8 578 A2BF BDIA A30A BCAB CHA
239. jack is used instead of the earphone jack The first problem with cassettes is that they are SLOW It takes a few seconds to load or save even a short program The second major drawback is that files cannot be randomly accessed the entire file must be read into memory before use in most cases limiting the amount of data that can be worked with When using tape one must be careful to start loading only at the beginning of a file An I O error will occur if a load is attempted in the middle of a file An easy way to locate a file is to type MOTOR ON AUDIO ON This turns the monitor speaker and tape motor on allowing one to listen for the beginning of a file Another method is to pull the remote and earphone jacks and listen through the recorder speaker The Tandy recorders come in handy for either method as they have and review feature which allows rewind and fast forward operations while still listening to the tape the buttons must be held half depressed page 63 Tape I O for the CoCo normally occurs at 1500 bps Tape operations can be sped to approximately 2700 bps by using the double speed POKE POKE 65495 0 for CoCo 1 2 POKE 65497 0 for CoCo 3 to save Load by typing POKE 143 14 POKE 144 24 POKE 145 6 CLOAD name or CLOADM whileindouble speed mode POKE 143 8 POKE 144 24 POKE 145 4 at normal speed POKE 143 18 POKE 144 24 POKE 145 10restorestothe normal rate 1500 bps Only high quality tapes should
240. ke amp Burke prices A good source for small inexpensive hard drives isAAA Disc Drive Repair 1464 Madera Road Simi Valley CA 93065 phone 805 523 9495 At the time of this writing they had ST125N SCSI drives 20 refurbished 15 month warranty for 125 and floppy drives for as little as 25 same warranty Call or write for current pricing As of February 2006 the only source to consider for a hard drive controller is Cloud 9 See their contact info under Sup port Cloud 9 makes an IDE and SCSI hard drive interface The IDE is probably the best bet as small used IDE drives are cheap and plentiful Small SCSI drives are still relatively easy to find though andit can be used witha CD ROM drive as well Unfortunately there is no new floppy controller 3 Printers more common parallel type Serial devices transmit data one bit at atime over as few as three wires for a printer Parallel devices transmit data over a minimum of ten lines one byte eight bits at a time Though the speed of parallel transfer is fixed it is usually faster than serial transfers Parallel rates depend upon the speed of the computer and printer Serial transfer speed varies from as little as 120 bps bits per second to as fast as 19 200 bps on the CoCo With no alterations serial data is transferred at 600 bps Note that bps and the term baud are usually used interchangeably The serial transfer rate can be changed by poking a different value in memory
241. l across tabletop to position the cursor Two buttons for Tandy 1000 compatible software 26 3125 49 95 Operating Systems Disk atom tgs Level Two 69 95 CD Supports 512K RAM and dual speed d 26 309 79 95 5 9 CO Com plete editor and assembler with full Screen editing Requires OS 9 Level om 99 95 Multi Vue User friendly graphics Joysticks 1995 Our lowest priced joysticks Now two players can experience the fun Fast 2 Ie 26 3008 2 19 95 Hard Disk Interface Utilize Primary Drives 12995 Requires 64K Multi Pak Interface fioppy disk with controller and OS 9 2 0 or later 26 3145 129 95 Save 40 on an FD 502 Disk Drive and a Level One or Two OS 9 Operating System FD 502 and OS 9 Level One Reg Separate Items 369 90 26 3133 26 3030 FD 502 and OS 9 Level Two Reg 26 3135 179 95 interface for 24 Two programs Separate Items 379 90 512 RAM Kit 1 26 3335 149 95 2059098 ra es 26 3133 26 3031 339 90 hems Shown Are For Use With the Color Compute 2 or 3 except as indicated D Color Computer 3 only GD Computer 2 orty a4 installation Required Not Included Some installations May Require Additional Cost Hardware OS 9 TM Microware and Motorola 1989 Tandy catalog CoCo3 page Tandy catalogs from 1977 1991 can be downloaded from Ira Goldklang s site http www
242. le Model I amp III tapes to be loaded directly into the Color Computer Magic Box enabled many to easily port transfer then re write BASIC games and utilities from the popular Models I amp III to the CoCo The Connection 80 BBS Bulletin Board System of Woodhaven New York which went on line March 22nd was like hundreds of other Model I boards providing information for the Model I amp Model with one exception The sysop system operator having just purchased a Color Computer started putting things on the BBS about the Color Computer and at 300 baud news spread quickly about Bob Rosen s BBS One of the main topics of BBS conversation at this time was an article inB YTE Magazine s March issue entitled What s Inside Radio Shack s Color Computer Authored byTim Ahrens Jack Brown and Hunter Scales the article con tained the most comprehensive information ever assembled including an in depth look at the 6809E architecture the job description of all the major chips the expansion port pin out the famous POKE 65495 0 speed poke plus a tricky way to get 32K bytes of memory Although occasional Color Computer tid bits were printed in various computer publi cations they were usually in the form of reviews with no more information than found in the Getting Started With Color Basic manual Tandy s Little Wonder If in those early days you looked for information in Wayne Green s 80 Microcomputing you
243. lf height disk drives A full or half height Hard Drive The CoCo motherboard main circuit board An MPI small large may fit Four Paks fit in four slots of the MPI This is what Ihave installed in my ATCoCo If I can figure out how to get the modem in there I ll put itin too My system has been running this way since Dec 1988 with problems at all NEEDEDPARTS Before you can get started you will need 1 Suitable Caseand Power Supply This article assumes a full size atleastsix inches tall inside PC AT clone case and power supply Other cases such as the more common PC XT size be used but the actual installation will differ as there is not sufficient room in a PC XT case to put an MPI or Slot Pak on it s edge as described The CoNect Xpander however doesn t require as much height and will easily fitinside an XT size case or any case as little as four inches tall inside Tower cases usually have enough room to mount the MPI on the bottom and the motherboard running up one side 90 degrees to each other Check the size of your MPI before purchasing a tower case as some mini tower cases may not have enough room for the MPI In many cases a Slot Pak or Y cable can be used where an MPI can t Power supply connectors may differ If in doubt use a VOM to check voltages before connecting toa CoCo A floppy only CoCo system needs about 40 watts a hard drive adds another 15 W 20W 65W 100W would be sufficient
244. licate as it looks pull it out Now would be a good time to spray a bit of cleaner in the socket Check continuity of the traces with a VOM Bend the mylar strip as itis being checked the break may be small and only show when the strip is flexed If one is found to be bad look carefully for the break A break can be fixed with a rear window defogger grid repair kit such as Loctite 15067 usually available in auto parts stores The other PIA a 6821 is used for cassette joystick and video videoin CoCo 1 2 only Checkitif experiencing problems in these areas especially if an input device has been used in the joystick port other than a joystick video digitizer tempera ture sensor home built project etc page 85 MC6883 and 74LS783 785 SAM Chip CoCo1 2 SAM stands for Synchronous Address Multiplexer This chip replaces a good deal of circuitry normally required for output from the CPU The main job of the SAM MC6883 or74LS783 in early models 74LS785 in later CoCo 2s is to produce the various clock frequencies required by the CPU and video A few capacitors resistors anda 14 31818MHz crystal make up the master clock frequency The SAM divides this value by four to generate the RF color video frequency of 3 579554MHz The CPU E and Q frequencies which must be 90 degrees out of phase with each other a job also handled by the SAM are created by dividing the master clock by 16 Any change in the master clock af
245. limited OSK coverage In May the announcement came through that the magazine the world of 68 micros all in micro letters was a go The first issue would be delivered in August get those subscriptions in RADIO SHACKS AFFORDABLE TRS 80 COLOR COMPUTER ATTACHES ANY FOR FAMILY FUN AND EDUCATION RIGHT Radio Shack catalog page for the CoCo 2 1984 Tandy s Little Wonder Really sad news started trickling down in March Falsoft started calling advertisers and letting them know thatthe May issue would be the last of The Rainbow The decission at Falsoft couldn t have been easy The Rainbow made Falsoft into what it is today From a business standpoint however The Rainbow couldn t continue Subscriptions were down to a point that the publishing capacity could be put to better use printing almost anything else That The Rainbow sur vivedaslong as it did was due to the good will of Lonnie Falk Thanks Lonnie you kept us all informed and helped us to learn one heck of alot about Tandy s little wonder much more than Tandy ever did On a personal note without The Rainbow this book would have been next to impossible to write What does the future hold for the CoCo Who could have imagined that the CoCo almost ignored to death by Tandy inthe beginning would be around today to enjoy its thirteenth birthday With continued support from YOU the current users the Color Computer will be around for at l
246. lished the first data sheets for the new MC6883 SAM chip in November but there were few Color Computer owners out there to read it Radio Shack at the same time released the first Color Computer software ThisROM Pak cartridge software included Chess Checkers Quasar Commander Personal Finance and a Diagnostic Pack By the time Decemberrolled around there was a 16K upgrade avail able from Radio Shack Which would be required for the delayed Extended Color Basic ROM which was only a month away from introduction Ifthe Color Computer you gotas a Christmas gift was your first ever computer you were probably unaware that the Getting Started with COLOR BASIC manual accompanying the early machines contained only 13 of the scheduled 24 chapters Radio Shack explained in the December issue of its TRS 80 Microcomputer News that when the machines were ready to ship the manuals weren t Rather than keep the Color Com puter from customers they sent what was available It was probably more a case of not wanting to lose out on Christmas sales that prompted the decision to ship with incomplete documentation With the only available information being found between the covers of the unfinished Getting Started with COLOR BASIC manual the first year was like being in the Dark Ages for the small but hardy band of early Color Computer owners The place to look for information was either from your local Radio Shack store probably the person who
247. lly non existent with tape drives The early Exatron disk system generated so much RFI that the TV screen was unreadable during disk access Within months after delivering these systems Exatron was taking them back The FCC finally had to step in and lay ground rules for the amountof RFI ahome computer could generate Exatron finally got the RFI problems straightened out late in 1982 Tandyreleased it s owndisk system for the CoCo in October of 1982 The retail price for this system was 499 but the drives were single sided 35 track double density units capable of storing176K An Exatron system required two drives at about the same total cost to come close to this storage capacity The Tandy drive quickly drove the Exatron system out of the market simply because software developers naturally chose the Tandy for compatibility Had the Exatron used double density drives there may have been a way to make the systems compatible The first Tandy controller drive 0 kit 26 3022 required 12V tooperate Later models were 5V only The 12V controller be used with a CoCo 2 or3 only through an MPI which supplies the necessary voltage It is not reliable at double speed disk operation even if DECB has been modified for double speed OS 9 Level II operates at double speed only There were several other early disk systems made but all failed to gain support as they were not fully compatible with the Tandy system The operating system was usuall
248. lor Computer Club true stalwarts of the CoCo Community This edition is dedicated to all those who continue to collect use and enjoy the Tandy Color Computer All brand trade names copyright their respective owners No part of this publication may be reproduced or quoted without written permission from the publisher Alldesign and editing performed by F G Swygert First Edition Printedin U S by CopyMasters Warner Robins GA 20 April 1993 Second Edition Published via PDF by FARNA Systems Leesville SC 29 April 2006 Copyright 1993 amp 2006 by F G Swygert page 4 Tandy s Little Wonder Table of Contents Writting Conventions Introduction History CoCo Hardware Prices 1980 1991 CoCo Clones Dragon Systems Tano Dragon FHLTC 9 Operating Enviroments amp Programming Languages Color Basic ADOS Compiled BASIC Converting Between BASICs Other DECB Programming Languages CoCo C CF 83 FORTH Machine Assembly Language Binary amp Hexadecimal Conversions Microwares OS 9 NitrOS 9 Support Glenside Color Computer Club Cloud 9 Internet Resources The CoCo Library Past Magazines A Tribute to The Rainbow Magazine Technical Reference Peripherals Video Display Devices Mass Storage Printers Expansion Devices Miscellaneous Devices Hardware Upgrades amp Modifications ROM Upgrades RAM Upgrades Upgrading the Keyboard The Hitachi 6309 CPU Putting It All In One Case Repairs General Procedures
249. ls would be practical as the Commodore and Apple BASICs have many unique commands PEEK POKE and EXEC locations are different for all the previously listed computers One must find out exactly what the original program expected to find at the specified memory location and write a routine or find a similar operation on the target machine to emulate the PEEK POKE or EXEC opera tion Itcan be extremely difficult sometimes virtually impos sible to rewrite a program that contains a lot of these state ments When converting from the IBM to CoCo it is much easier to convert to the CoCo 3 because the LOCATE commands are similar The format for the CoCo 3 is LOCATE x y column row while the IBM is the opposite LOCATE y x row column The CoCo 3 numbers rows and columns beginning with 0 0 79 0 24 and the IBM numbers beginning with 1 1 80 1 25 If going from the IBM to CoCo many routines will have to be totally rewritten Going from the CoCo to IBM is easier as CoCo BASIC is simpler than the IBM version Converting to from the CoCo 1 2 has the same major problem as converting to the CoCo 3 the PRINT and LOCATE command disparities page 45 Other DECB Programming Languages Other programming languages were written to operate in conjunction with DECB over the years These include FORTH PASCAL and LOGO Only the firsttwo are currently available Anew company Infinitum Technologies recently released anew C
250. lyzer for testing and checking DIP type integrated circuits An unusual ad promising a new computer in 1990 CoCo users dream computer was run by Kenneth Leigh Enterprises this month Just what would this dream ma chine be No details were given just encouragement to write for details Rainbowfest Report covered the Oct Rainbowfest in New Jersey and a tentative date Oct 20 22 forthe next New Jersey Fest was set The Chicago Rainbow fest would be next month Chicago Rainbowfest was held April 06 09 Two new com puters were shown Kenneth Leigh Enterprises was show ingtheir yet to be named 68020 based machine whileFrank Hogg had a 6809 based computer on display These were basically prototypes more to come on them later Lee Veal turned up with an old grey original CoCo serial number 000001 was engraved on the bottom Not to be completely overshadowed by Rainbowfest was a small quarter page ad in this months Rainbow by a new company called CoCoPRO They offered good prices on hardware and also something new in the CoCo market gently used software with original documentation of course no pirating here Another item of interest was that Danosoft had acquired the Simply Better word processor One last thing for this month Oblique Triad upgraded their Studio Works program to createStudio Works Professional New features include 35 KHz 8 bit wide sampling MIDI slave mode and support for up to of memo
251. m and monochrome monitor sold for 1399 Delmar sold complete systems kits were available directly from Peripheral Technologies This computer had been in existence for several years It actually started as a build it yourself project in an electronics magazine several years before sort of like the original hobbyists computer the Altair anyone reading this even remember one of those Tandy s Little Wonder The ads were interesting in Februarys Rainbow The first thing one will notice was that longtime advertiser Microcom only had two pages Didn t they ALWAYS have six before Arethey fading away also Thelast Howard Medical and last Dr Preble s Programs ads appeared this month Thanks go to Ross Litton Howard Medical and Dr Preble he was actually a Dentist for the many years of good service The had only two quarter page ads this time Maybe the new CoCo isn t doing so well after all previous ads were one and two pagers But here to save us from all this gloom is the rising star of the CoCo community CoCoPRO New this month was an OS 9 version of Kyum Gai to be Ninja Though many critics thought OS 9 was not a good environ ment for action graphic games they were proven wrong as the two versions of Kyum Gai were nearly indistinguishable There were only 30 copies of Marty s Nightmare left now better hurry Last but not least Tandy announced a CoCo blow out sale on the back cover CoCo 3s could be pur cha
252. m their cases 2 Lay your CoCo motherboard in the AT case with the ROMPak slot facing away from the drives and the plugs facing the front of the AT case as far back in the case as possible 3 Mark where the four mounting holes on the coco are on the case Drill out the holes in the case You can either mount the coco with the plastic legs supplied with the case or build your own mounts using small blocks of wood or plastic under each hole Keep the CoCo OFF the bottom of the case about 1 8 to 1 4 inch This will give you enough room to run the port extension cables under the board prevent shorts and allow the power supply fan to cool the motherboard It would be a good idea to place a piece of cardboard between the case bottom and CoCo as further protection from shorts 4 Put the MPI in the left hand front corner of the case with the slots pointing in and the card edge that connects to the CoCo towards the back Put electrical tape over the components that may be easily shorted to ground on the bottom edge of the MPI such as D1 Again a piece of cardboard between the MPI SlotPak and case would be prudent If you have a short extender ribbon connector for the 40 pin ROM Pak slot on the coco you can see how easily you can connect the MPI to the CoCo If you want to make up your own you will have to de solder the slot connector and remove it Solder a ribbon cable where the connector was and the other end to the removed connector Be
253. mes featured superior graphics sound and animation especially when viewed on an RGB monitor Burke amp Burke had something new for OS 9 users a speech synthesizer called Cyber Voice which used a SC 02 synthesizer chip TheDecember Rainbow has Lonniesquelching rumors ofthe Rainbows demise He states that Thereis nointention plan idea concept or anything of the kind to cease publication of the Rainbow I don t know how these rumors get started Well one way is the shrinking size and number of advertisers still 98 pages 47 advertisers He reassured readers that there would be a Rainbow for some time and that there would be a spring fest in Chicago Some time was still two and a half years away Many readers complained about no rack seller availability This was due to cutting back the number of rack sellers Why Rainbow actually took a LOSS on many single issue sales due to support of many locations that only sold a few copies monthly Only those outlets with good sales would besupported from then on Perfecttime to save money and get a subscription A new version of the Slot Pack Slot Pack was introduced byHoward Medical A hardware switch was added to allow use of most ROM packs in slot 1 a leg added to support the pack faster buffer chips used and an external power supply became necessary as the draw from the CoCo was just to much If you have ever consideredrecording CoCoscreens on video tapeor using some of the CoC
254. models The 785 willreplace MC6883 and 783 buta 783 MC6883 WILL NOT function in place of a 785 The SAM runs quite a bit hotter than most of the other chips Over heating can cause failure and intermittent problems Many users stuck heat sinks a pair of TO 220 types 276 1363 or similar longer type on top of the SAM with heat sink grease 276 1372 This will definitely increase the life of the SAM especially if the computer is on for long hours or in a particularly warm environment page 86 Itis hard to pin point particular problems that could be caused by the SAM because this chip is the lungs of the system if the CPU is considered the heart The SAM affects total operation of the computer Commence with eliminating all other possible problems then proceed to the checks outlined under General Troubleshooting If the problems start only after the computer has been on a while add a heat sink as described in the previous paragraph before replacing the SAM MC6847 MC6847T1 or XC80652P VDG The 6847T1 or XC80652P is an enhanced version of the original 6847 In order to make it perfectly software compatible with the older 6847 the enhancements aren t readily acces sible This chip is used in all CoCo 2s with a B in the catalog number It cannot be used as a direct replacement for the older 6847 as the pin assignments are slightly different To use the T1 older CoCo one chip has to be removed and some
255. mpers The HDS controller could support two 24 pin ROMs by setting jumpers inside the controller The second 24 pin ROM was then placed in the 28 pin socket The DECB ROM supplied by HDS was usually enhanced for faster disk access times as only the oldest Tandy drives required the DECB default of 30ms HDS sold CoCo disk controllers from 1985 1989 About the most well known aftermarket supplier of CoCo hardware is Disto They introduced a disk controller the Super Controller as their first product in 1985 This control ler had four 28 pin ROM sockets and came with C DOS which was DECB compatible The ROMs could be selected via a software switch If one wanted DECB it had to be copied into a 2764 EPROM The Super Controller had a unique Mini Expansion Buss MEB where several add ons could be attached without the need for a MPI This is probably the feature that sold more Super Controllers than any other aftermarket controller A full range of add ons including areal time clock EPROM programmer 80 column card for CoCo 1 2 aparallel port an RS 232 port and a hard drive adapter were eventually made with most still available today A Super Controller described later in this section and a Mini Controller introduced in 1989 were also made by Disto The later contained only two ROM sockets with provisions for a 24 pin ROM and no MEB It was shorter than the SC or SCH like Tandy FD 502 Tandy s Little Wonder There was y
256. ms CoCo 1 2 amp 3 were supported by this update of CoCo Graphics Designer This was the closest thing to Print Shop available for the CoCo Cards signs and banners could be printed Start OS 9 Kenneth Leigh Enterprises A book that stepped one through the process of setting up and getting started with OS 9 Level II A disk with several extra utilities was also included This was the easiest to use guide to OS 9 ever Eliminator Frank Hogg Labs A multi I O card for the CoCo 3 and OS 9 Featured two serial ports 1 parallel port real time clock plus a high speed floppy and hard disk interface No more multi pak cluttering up the desk if one were OS 9 user only Colorware started advertising THE WORKS in the Janu ary 88 issue of Rainbow Your CoCo 3 will think it s a Mac in their words The Ultimate in Desktop Publishing THE WORKS included Max 10 with a spell checker added CoCo Max III and additional font sets for both SD Enter prises introduced VIP Calc III this same month As in other VIP products 32 80 columns were supported VIP Calc also offered up to 16 windows which allowed easy comparisons and a spreadsheet size of 512 columns by 1024 rows Owl Ware purchased the rights to all CoCo products from J amp M Systems and began advertising an improved disk controller based on the J amp M design The parallel port was missing as was JDOS OWLDOS or Disk BASIC are offered Owl also introduced a
257. n screen widths Other features included a built in spell checker no longer an extra cost item and print spooling Unfortu nately only a48K textbuffer was allowed though the 48K print spooler buffer did allow editing one document while printing another This would be rectified in a future release page 20 February s Spectrum Projects ad was the last to grace the pages of a CoCo magazine Orders were still filled for several months and some advertising done by direct mail to repeat customers Spectrum was sorely missed by many the author included To end the month on an upbeat note Dynamic Color News started anew series on OS 9 and Basic09 The 18th installmentoftheregular HAM Radio amp Computers column was also printed Good work Bill Lonnie Falk s editorial column in the March Rainbow was written to quell rumors that Tandy was considering dropping the CoCo 3 Many of the rumors started due to large price reductions of CoCo products Mr Falk sought to put the rumors to rest by stating that the CoCo was outselling all other Tandy computers combined and the lower pricing was due to lower costs incurred in production May 20 22 1988 brought forth the Chicago RainbowFest Many vendors attended this annual gathering of CoCo enthu siasts Host for the show was Chicago s very own Glenside CoCo Club who had assisted with many RainbowFests Colorware maker ofCoCo Max announced the arrival 10 with atwo page ad in J
258. nIBM keyboard adapter for 119 more than a CoCo 3 Computer Plus had them on sale for only 115 in the same issue and without the keyboard Zebra Systems had a cache of 500 64K CoCo 2s to sale for only 49 95 hurry while supplies last If you hadn t upgraded your CoCo yet or were thinking of buying a hard drive the March issue of Rainbow was issue not to miss Marty Goodman went through RAM and ROM upgrades for all CoCos ever made He also went on in another page 21 article to explain the ins and outs of adding a hard drive to a Color Computer system not an easy task Simply Better fromSimply Better Software was introduced in an ad and review in the April issue of Rainbow This word processor for the CoCo made quite an impact being preferred over other word processors by the likes of Cray Augsburg a Rainbow Technical Editor who also wrote the review for this product after using it only a short time At a price of only 29 95 the review heading of the most bang for your buck was definitely true The author even prepared this text using Simply Better which was purchased largely due to the review and a comparison article in the same months Rainbow TheChicago RainbowFest was held April 14 16in 1989 WT Enterprises introducedNine Times a bi monthly magazine on disk for OS 9 This would prove to be very popular for Level II users Another new OS 9 item was Owl Ware s Window Writer word processor Unlike most other OS
259. nbow Guide to OS 9 authored byDale Puckett and Peter Dibble president and vice president of the OS 9 Users Group respectively plus from our Canadian friends atDragonfly Writing cassette magazine calledDIGInews For CoCo Spectral Associates withdrew their support for CoCo after four years of very good products and service In May voice recognitionfor the CoCo becomes areality when Speech Systems started marketing itsElectronic Audio Rec ognition System EARS for short RainbowFest celebrated the third anniversary of CoCo shows with three fun filled days amp nights 17 19 in Chicago Causing quite a stir was Steve Odneal s fully portable CoCo complete with disk drive and monitor built in Although only a prototype Steve used the show to judge user interest It may have made production had a good low cost screen been available Unfortunately the three inch LCD TV was just to small to be practical page 17 In June as the curtain descended on the CoCo s fourth year so too does it fall on yet another Color Computer publication This time it sDennis Kitsz s Under Color whichfolded after just seven months of publication THE SIXTH YEAR Jul 85 Jun 86 Subscribers toUnder Color magazine were informed in July that any unfullfilled subscriptions would be taken up by Rainbow magazine celebrating its fourth anniversary Rain bow was now the only widely circulated printed publication exclusively for the TRS 80 Col
260. nd the new ROM patches the ECB code in RAM much as one would alter the code with POKE statements avoiding copyright problems with Microsoft Twenty six new commands were added to take advantage of the CoCo 3s enhanced graphics text and memory capabilities as well as error handling The three people who designed the code also did something else with some extra space in the single 32K ROM Color and Extended BASIC are in the lower 16K with minor changes CoCo 3 BASIC in the upper they puta portrait of themselves To see them hold down the CTRL and ALT keys while pressing the RESET button on the back of the computer This does a cold start also the RAM is reset and most cases the computer behaves as if it has been turned off then back on which is the only way to cold start a CoCo 1 or 2 pause at least 15 seconds before turning back on There are times when this may have to be done with a CoCo 3 also suchas after running some machine language programs To return the CoCo 3 screen to normal and complete the cold start press RESET once more holding no keys down this time Note what the screen says when a CoCo 3 is powered up It should read Extended Color BASIC 2 1 or Disk Extended Color BASIC 2 1 or 2 0 depending on version in disk controller No there isn t really a third and fourth version of BASIC nor anew version of Disk BASIC The ECB code was changed to replace the 1 with a 2 to indicate a CoCo 3 No new
261. ndustries User 80C IMPORTANTMPIRELATEDSIGNALS CoCotoMPI SCS secondary chip select signal FF40 5F CTS cartridge enable 8000 000 32K 16K ROM pak used for device selection under OS 9 MPIto CoCo CART cartridge interrupt connected to FIRQ via PIA or FIRQ IRQ via GIME Enabled from slot which also has CTS selected There were two different versions of the MPI made The large MPI 10 25 x8 5 26 3024 was the first It was initially marketedin a Mercedes Grey case to match the CoCo 1 With the introduction of the CoCo 2 later in 1983 a matching white cased unit was made available The second version a smaller unit approximately 8 5 x 7 5 26 3124 due to areduction in circuit board size was introduced late in 1985 A custom 64 pin chip in the small unit took the place of nine separate chips in the large The coming of the CoCo 3 late in 1986 caused a few problems for the MPI The oldest grey MPI stored a copy of the slot select address amp HFF7F at another address amp HFF9F the address older MPI manuals recommend POKEing to for slot selection This was not a problem on older CoCos because they did not use amp HFF9F for anything the CoCo 3 uses it as part of its video horizontal offset register Any time this address was written to by the CoCo 3 the older MPI switches away from slot 4 where the disk controller normally resides Subsequent writes to this address would further confuse the
262. ne It seems like only yesterday Christmas morning 1980 my wife must have known that I was very interested in getting a computer because there under the tree was the new Mattell Intellevision Pam bought that machine due in part to the computer capabilities the unit would have with a keyboard console scheduled for release in the spring After several days of gunning down waves of aliens we both suffered from blurred eye sight blistered fingers lack of sleep and video game burn out Spring seemed so far away A couple weeks after Christmas I came across an ad in New York Daily News for anew Radio Shack computer which like the Intellevision had game cartridge capabilities an important feature because if I didn t like computing I could always go back to cleaning up the galaxy For the refund price of the Intellevision sorry Pam plus another 150 I had enough money to purchase the new TRS 80 Color Computer I celebrated the arrival of an early spring It was January 9th 1981 It seems like only yesterday This project was to say the least a labor of love Every attempt was made to ensure an accurate account of the Color Computer s evolution Extensive use of various computer magazine articles and ads were used as the basis for dating events This dating method was used because most of us probably heard about various developments through these sources Keep in mind however that sometimes ads can precede
263. nector under the CoCo cable exits from inden DOO puer at pin tive is the decimal code 32 column screen CoCo 1 2 only displays 9 75 3 1 codes through 122 Character Decimal Code Display characters by typing PRINT CHR xx where 108 642 BREAK 3 CLEAR 12 ENTER 13 PIN SIGNAL SPACE 32 1 Ground 33 2 Ground 34 3 Red 35 4 Green 36 5 Blue 37 6 Polarity no pin amp 38 7 Sound 39 8 Horizontal Synchronization ag 9 Vertical Synchronization 2 10 NOTCONNECTED 43 44 Cartridge Port Expansion Connector s 45 Looking in at the connector on the CoCo odd numbered 46 pins are on top from right to left even numbered pins 47 bottom from right to left 39 amp 40 on left 1 amp 2 on right B 2 50 PIN DESCRIPTION 3 51 1 12V 100mA CoCo 1 only 4 52 2 12V 300mA CoCo 1 only 5 53 3 HALT input to CPU normally low 6 54 4 NMI non maskable interrupt normally low 7 55 5 RESET to CPU normally low 8 56 6 Eclock signal main 9 57 7 Q clock signal leads E 58 8 CART cartridge detect interrupt normally low 9 5 300 all models M 61 10 7 10 017 consecutivly numbered data bits 62 18 R W read write signal to from port high on write 9 63 19 31 0 12 consecutivly numbered address bits 64 32 CTS cartridge select normally low A Z 65 90 33 34 Signal ground Up Arrow 94 35 Sound output SHIFT 95 36 SCS spare cartridge select normally low DownArrow 10 37 39 A13 AI
264. ney The CoCo can t always be putin most comfortable position for typing though especially with an MPI attached and there is the possibility of moving the MPI enough to blow the 6809 The simple solution to this problem is to extend the keyboard away from the CoCo This can be easily done with up to six feet of 16 conductor ribbon cable and a suitable connector on each end 16 conductors will probably have to be removed from a 25 or more conductor cable 278 772 is five foot 25 conductor cable A single row PCB mount male in line pin connector can be inserted into the mylar strip connector A matching connector can be purchased for earlier model CoCos The connector for the mylar strip is a little more difficult One could de solder the keyboard connector from the CoCo motherboard and replace witha singlerow PCB mount male in line pin connector using a matching female connector on the ribbon cable An easier approach is to use a 34 position card edge connector a disk drive cable connector 276 1564 This works well but re quires aheavy piece of cardboard behind the mylar strip Also note that the mylar strip only makes contact on one side If using a crimp on type connector remember that every other pin goes to the opposite side of the connector Simply place the strip in the connector with the two unused pins on one end Most people use a DB 25 connector mounted on the CoCo case and cable to connect to the CoCo rather th
265. nfant days it quickly became an almost totally Australian content maga zine Greg also brought into Australia the first non Tandy software from the USA a move that Tandy was reluctant to make in the early years The early to mid eighties could be recorded as the hey day of the CoCo in Australia During this time a plethora of companies sprang into existence supporting what at the time was consid ered the ultimate home computer and arival to the Commodore as a games machine Also during this time a great number of user groups and CoCo clubs came into existence all over the country some of these are still in existence today years later These user groups and CoCo clubs seemed to be made up of a different sort of computer enthusiast Unlike those using other machines the CoCoists seemed to genuinely want to help each other and were more interested in learning about the computer than pirating the latest software That is not to say that an amount of pirating did not go on to say other wise would be a travesty but compared to those clubs dedicated to the other machines it was insignificant Support for the colour computer in the eighties was phenom enal There were the user groups and CoCo clubs The CoCo Magazine Softgold magazine The Australian Rainbow American Rainbow Tandy and hundreds of businesses ranging from chemists drug stores in the USA to dedicated computer stores Australia wide During this time a strong bond
266. nnected to 741 5 175 pin 15 but is not used on the Activision ROM Paks It would only be used with larger ROMs page 103 im CoCo 1 D amp E Boards 1 of 3 page 104 Tandy s Little Wonder CoCo 1 D amp E Boards 2 of 3 page 105 Little Wonder Tandy s eT T sl StH 41 ett aud s egy M INL LI ru CoCo 1 D amp E Boards 3 of 3 page 106 5 Little Wonder En Ber 11011111 dL E 11 1 232554 i 1 M aa ML idis B i dz CoCo 2 American 1 of 2 page 107 Tandy s Little Wonder M Hu ii 1 T H eis f nr eee HIE Bi 2 De TIED i mum e Bi 1 Il Mi CoCo 2 American 2 of 2 Tandy s Little Wonder page 108 Ma _ Mie tr T7 oa imin dd om TEE 2 A T E S EXTEND VERSION ICH HCHEAIAGP 0 Aa Lr VEREEON ICE TECHOOT 4 30 CoCo 2 Korean is similar 1 of 2 Tandy s Little Wonder page 109 p 3232
267. not officially supported by Tandy Only one commercial program is known to have used this mode the Plug N Power ROM Pak Converting is probably NOT the correct term when IBM BASIC BASIC A or GW BASIC is concerned The author has done this before and it isn t quite that easy There are many differences between the two to many to even begin to list here Manuals for both BASICs can be gone through and the differences compared possibly during a program conver Tandy s Little Wonder There are two BASIC compilers available for the CoCo now WasatchWare s MLBASIC andCer Comp s CBASIC Itis important to note that compilers don t normally accept as is BASIC code they have certain formats the code must be written in before compiling These differences are minor if one is already familiar with BASIC though The Cer Comp compiler requires much fewer changes reportedly up to 99 compat ible with BASIC than WasatchWare s but is more expensive BASICs not an easy task sion exercise One can also visit the local library and see if BASIC Program Conversions HP Books 1984 ISBN 0 89586 297 2 is available This book lists all the commands and equivalents of IBM compatibles Commodore 64 Apple H TRS 80 Model and CoCo 1 2 BASICs There is room for notes to be made on the CoCo 3 commands but they aren t included in the book These other computers could theoreti cally be converted to from but only the TRS 80 mode
268. nt my check in the mail But soon it began to bother me that whenever I would type a BASIC command in lowercase all I got for my trouble was the familiar SN ERROR I wrote alittle ML patch for BASIC to make it understand lowercase commands This exercise was intellectually satisfying to some degree but was not of much practical value to me LOADMing it was more botherthan just switching to uppercase Meanwhile on CompuServe ID had run across a bunch of small utilities by various people to remedy assorted shortcomings ofthe CoCo s stock BASIC There were patches for automatic line numbering 40 tracks fast step rates and a few others including a particularly nice one for editing the last direct mode command contributed by Bill Dickhaus who later gave permission for me to use itin ADOS After the 64K upgrade became available several people on the CompuServe SIG put anumberofthese patches into a64K programcalled DOS64 CC Icontributed my lowercase patch anda RUNM command But even having a number of extra features collected into one utility struck me as limited in usefulness it was a bother having to boot up the utility and there was quite a bit of software that DOS64 CC was incompatible with It seemed to methatacollection of BASIC enhancements would be a great deal more useful if they were burned into an EPROM this would not only avoid the hassle of having to boot it up from disk but would also enable a much greater degree of softw
269. nths Rainbow introduced three new games Sinistarr Kyum Gai to be Ninja and Paladins Legacy and a sound editing sequenc ing program Soundtrax In the November issue Rainbow decided to run a reader survey All readers were encouraged to reply The survey coincided with the promotion of Cray Augsburg a former Rainbow technical editor to the position of Managing Editor Questions were asked about the reader him her self and their system configuration Readers were also asked to rank in order of importance certain topics and Rainbow columns Congratulations Cray The Print 2 column in Decembers Rainbow was very inter esting Mr Falk was visited byEd Juge Tandy s Director of Market Planning Readers were reassured that Tandy would continue the CoCo as long as it sold well and reminded that it ALWAYS sold well during the Christmas holidays A note about the InterTAN decision to drop the CoCo from Canadian distribution was also included It seems that enough CoCo users wrote InterTAN that they decided to reintroduce the CoCo Unfortunately the production run for the season had ended and InterTANs order was not large enough for another run Readers were urged to write AGAIN this time to encour age InterTAN to order as soon as the next run started Something different appeared in this months Rainbow an article by Tandy itself Surprisingly this article appeared due toaletter by a Rainbow reader Back in May 89 a reader from A
270. o The direct mail advertising method was the most effective as it brought in many more subscribers and contributors In June of 1991 we decided to change the name of the magazine toColor Computing because TRS 80 was aregistered trademark of Tandy Corporation By this time we were able to get access to a Macintosh and a laser printer to give some of our pages a more professional look After five long years of supporting the CoCo we were in our senior year of high school and both realized that it would be impossible to continue the magazine once we graduated We were both planning on going to college and there was just no way we could go on Publication ended in October 1991 Around the same time as the demise of the magazine we were informed by one of our former teachers that a couple of elementary schools still had theCoCo lab When the actual lab was dismantled the TVs were given to the teachers and the CoCos stuffed into a closet The teacher decided she wanted to use them in her class She went around an collected all the TVs and got the keyboards out of the closet Having no idea what to do with them she asked around for assistance She ended up contacting one of the junior high teachers who had subscribed to our magazine He told her how to get in touch with us It so happens that the teacher wanting to use the CoCos was our former first grade teacher She contacted us and we agreed to go down to the school and show her how to use the
271. o 3 appeared I wanted to have a version of ADOS that supported its features and so began work on ADOS 3 There was very little room to add any features beyond those present in ADOS since the ADOS enhance ments entirely filled my available 2K But I managed to make a little room by taking advantage of the fact that BASIC runs out of RAM on the CoCo 3 which allowed certain routines to be rewritten Also ADOS ON ERROR GOTO and RAM commands were no longer needed so that gave me some extra bytes to work with I was particularly interested that BASIC should support the CoCo 3 s double speed mode and modi fied disk and printer routines while adding FAST and SLOW commands I also allowed ADOS 3 to be configured to boot up in 80 column mode ADOS 3 was introduced in January 1987 at the Color Expo in Anaheim California page 44 One thing that disappointed me about the CoCo 3 was that its internal ROM was soldered in Had it been socketed I would have strongly considered having ADOS 3 reside there since the internal ROM contains plenty of free space 6K of which is taken up by the infamous Three Stooges graphic To remove that ROM and install a socket would require some delicate soldering which struck me as a highly undesirable requirement for a commercial product Still after releasing ADOS 3 I was itching to include quite a number of additional enhancements I had a backlog of ideas and suggestions this time and so began to
272. oCo 1 2 or3 and was similar to the arcade game Xevious Medieval Madness was another CoCo 3 only light phaser game If one already had a Sega light phaser and interface from Iron Forest the disk could be purchased alone Microcom added a spelling checker pop up calculator split screen editing andtwo column print ing to Word Power release 3 2 Colorware started advertising their Max products CoCo Max III and Max 10 as the ideal Tandy s Little Wonder desktop publishing package for the CoCo 3 Release 2 0 of SD Enterprises VIP Writer III supports up to 495K of text space ona512K CoCo3 106K ona 128K model more than any other word processor to date It was hard not to notice that Microcom had become the biggest CoCo advertiser ever their ads were up to 6 pages in the December 88 Rainbow They offered a wide variety of CoCo products from many different companies as well as their own software A new offering was512K BASIC for the CoCo 3 When Tandy updated the CoCo s BASIC they didn t allow easy access to more than 32K for BASIC programs This product patched BASIC to allow access to 64K on a 128K machine and 384K with 512K RAM The only problem was that one musthave 512K BASIC in order to run a program that took advantage of the extra memory What better time to advertise new products than the Christmas issue Notable items were Warrior King Sundog Systems a CoCo 3 fantasy game CoCo Graphics Designer Plus Zebra Syste
273. ocated near U29 marked HIGH and LOW This selected either the upper 32K or lower 32K halves of the 64K chips all the chips had to have the same half bad Tandy just sorted them before installing If new chips were purchased it won t matter which half is selected Later versions have all good 64K DRAM as the supply of half good chips dwindled Why were there half good chips to begin with Manufactur ing achip onasilicon wafer is tricky business Even now 10 20 of chips made are defective and must be thrown away because there is no way to repair them The larger scale the chip integration more components single chip the higher the rejection rate The supply of half good chips dried up as manufacturing techniques improved 64K CoCo 1 TDP 100 IDENTIFICATION Beige Case Low profile keyboard vents on sides some early models came with CoCo 1 style cases and keyboards CATALOG NUMBERS 26 3002A 26 3003A 26 3004A 26 3005 BOARD REVISIONS NC also called F or 285 This board either had NC or no revision marking at all Many people refer to it as the F board because it cam after the D revision why not the then who knows or the 285 due to those numbers being the first in the number silk screened on the board It is unclear what NC actually meant The keyboard on these machines had full size square keys but they were only about 1 4 inch tall leading to the low profile designation Tandy s Little
274. od run complete test cycle 2 Unplug ALL devices except TV or monitor and see if computer works correctly first Ifit does plug each peripheral back in one at a time checking operation after each Repair replace faulty peripheral 3 Noor higher lower than 5V on Vcc check power supply Also check bypass capacitor between Vcc and ground 4 Noclock signal check for signal at SAM pins 13 amp 14 or GIME pins 6 amp 7 outputs Ifnothing check at crystal inputs SAM pins 5 amp 6 GIME2 amp 3 Touching a logic probe to either of these pins will produce a good bit of TV interference TV only not monitor indicating the crystal is working Ifstill no signal check capacitor and resistor in clock circuit If they are good replace crystal If the crystal amp circuit are good replace SAM orGIME Ifasignal is at the SAM GIME outputs check traces between there and CPU 5 With power OFF check address and data lines for continuity first VOM on one end on the other end of the trace or a section of Then check for resistance between trace and ground All should be very near the same If not look the circuit over and see if there is a reason for the difference If none found there could be a possible short between that trace and ground Check resistance from one trace to another There Tandy s Little Wonder should be a high resistance If not suspect a short between traces with low resistance check each line wit
275. odifications that will improve the display as there is an essential 3 58MHzcolorburst signal It is therefore best to use a B amp W TV as the signal can be further improved enough to adequately display 80 col umn text The easiest additional modification fora B amp W is elimination of the 4 5MHz sound trap This is done either by cutting the circuit board trace connecting a series wired trap or adding a jumper around a parallel wired trap A switch will have to be used to cut the trap out or bypass it if the set is to be used for normal TV reception Eliminating the sound trap widens the bandwidth to 4 5MHz enabling 80 column dis plays to be viewed without undue eye strain The above are the extent of practical TV modifications for the average hobbyist to accomplish For further information consultTV Typewriter Cookbook by Don Lancaster chapter 8 lastknownprinting 1981 Howard W Sams amp Co 4300 West 62nd Street Indianapolis IN 46268 available in many public libraries the publisher or directly from the author Synergetics Box 809 Thatcher AZ 85552 phone 602 428 4073 Tandy s Little Wonder Typical Black and White B amp W TV Circuit leow Brightness Sync Adjustment 12V NI Sound sov NI 4 5MHZ Sound Pick Off Last Video IF GND Transformer Video d KI 00000 0000 GND NS Video Output eS 424N 7 RES 150V QO0Q0000 E 4 5 MHZ Sound Trap GND
276. of CoCo 3 121 8 oto Gallery 89 14 pages of bonus photos added just before publishing in 89 April 2006 122 Back Cover Tandy s Little Wonder page 5 writing conventions used in this book In the course of writing some standards were set so as not to confuse the reader Hardware modifications upgrades and repairs are referred to throughout this book At times the references given may not seem clear They are written in such a way that a person with some understanding of electronics and the CoCo can easily figure out what to do f you do not understand the directions you probably should not attempt the operation alone get help THE AUTHOR PUBLISHER NOR PRINTER ARE RESPONSIBLEIN ANY FASHION FOR THERESULTS OF ANY PROJECTS OR REPAIRS MEN TIONED INTHIS BOOK TO INCLUDEBODILY HARM LOSS OF EQUIPMENT OR LOSS OF DATA All references to hexadecimal addresses are written as amp Hxxxx The amp H is used to precede the actual hexadeci mal value when poking into memory to let the computer know the value will bein hexadecimal Some other texts use a dollar sign in front of a value to mark it as being hexadecimal others use an asterics or don t mark it at all as eight bit hexadecimal values usually contain numbers and letters When Radio Shack lists an item mentioned in their catalog especially parts the part number will be listed in parentheses This is not to encourage patronage of Radio Shack bu
277. of the CoCo s which were not legally protected in Korea and most other Asian countries With various disk systems available for the CoCo the poor timing award went toJPC Products Co for their high speed cassette system One can only wonder how many systems were sold at the 129 95 price Lonnie Falk announced plans for a big CoCo show for the Spring of 1983 in Chicago It will be called RainbowFest Lonnie also hinted at an electronic Rainbow in conjunction with Bob Rosen s BBS November also gave us the first look inside the new TDP 100 computer and the first review of Eigen s disk ColorCom E When CCN first came out it contained a lot of basic CoCo information but with the magazine stalled at the 90 100 page size and Bill Sias devoting more ad and column space to FLEX OS 9 GIMIX and ham radio operations much of the basic information was being squeezed out The opening item in the December issue was a tour of the GIMIX plant Rainbowannounced support for the Dragon 32 in December its first perfect bound issue square back with glued in pages just like a paperback book Tom Mix s king of the Donkey Kong clones Donkey King was released just in time for Christmas This is one of the best game ever done for the CoCo Thanks Tom DON TBUGME 1982 closed out with a tip of the hat to the very inventive folks in Natick Massachusetts for coming up with a very imagina tive idea DEBUG The concept worked like
278. offers repair and modification services for all CoCos This can be anything from socketing the 6809 re quired for some upgrades and replacing the 6809 itself to burning a custom ROM chip for DECB Cloud 9 3749 County Road 30 Delano MN 55328 Internet http www cloud9tech com e mail info cloud9tech com Internet Resources The Internet is a nationwide computer network originally established or perhaps a better term is cultivated by the National Science Foundation NSF Itis actually acollection of many regional networks all interconnected using acommon communication protocol called the Internet Protocol or IP The original intent was to enhance research and education projects through open communication and exchange of data Development of the telecommunications backbone was sub sidized by the U S government Up until about fifteen years ago as of 2006 use of the Internet was restricted to people or organizations involved in research and education The guide lines governing acceptable use were change in the late 80s to allow commercial companies and online services like Delphi to use Internet mail for many purposes Internet use exploded with the introduction of web pages in the early 90s Now it s almost possible to find anything on the Internet As long as there s an interest someone will have a page up about it The only problem is those pages may not have all the facts One can only put what they know on a page and
279. ogram was almost as good if not AS good as Tandy s Home Publisher And speaking of bargains Colorware put CoCo Max Max 10 0n sale for only 79 95 for BOTH if bought at the same time Individual prices were 49 95 and 39 95 respectively The Micro Works makers of the video digitizer Digisector DS 69 amp DS 69B for the CoCo ran its last ad in the Rainbow this month The digitizers were still available from Colorware Another product allowing the BASIC programmer access to more memory was introduced in June Danosoft announced its BIG BASIC which allowed access of up to 472K witha512K page 22 CoCo 92K with a 128K machine Only three new BASIC commands were required One wonders why Tandy didn t do something like this Like 512K BASIC from Microcom a program written to take advantage of these new features meant that one had to also own a copy of BIG BASIC That was the primary reason neither product was a real big seller THE TENTH YEAR Jul 88 Jun 90 July markedthe tenth anniversary ofthe Color Computer This wasamilestone inthe small computer industry Only the Apple Commodore 64 remained alive along with CoCo in what wasonceateeming competitive field A new arrival this month wasCIII Pages fromMicrocom Asthe name may suggest CIII Pages wasa yetanotherdesktop publishing package for the CoCo3 A new advertiser wasOblique Triad Their premier products wereTheSeventh Link a three disk graphic adven ture
280. ollowing list of Tandy Radio Shack printers have the four pin connector built in All are nine pin and support the IBM graphics character set unless otherwise noted A couple of the printers were made to use with the CoCo only The ribbons for some of these may be next to impossible to find in stock note that the DMP 107 was the last advertised to work directly with the CoCo in 1991 Radio Shack will order ribbons for you no extra charge or minimum order for many of their printers Catalog numbers for ribbons were listed in the 1993 catalog thermal paper for TP 10 Cat Printer Notes Ribbon 26 3020 all 6 CoCo MC 10 Printer Cable 4 pin n a 26 1167 9 30cps 7 pin Tandy graphics 26 1424 26 1168 LPVIII 9 80 cps 26 1418 26 1261 10 4 thermal paper 8 pin CoCo only 26 1332 26 1275 TRP 1009 thermalribbon battery 110V 26 1297 26 1193 CGP 1154 5 12cps inkjet 3 black 26 1480 color set ea red green blue 26 1481 26 1268 CGP 220 9 37cps inkjet 26 1281 color set 1 ea red green blue 26 1281 26 1253 DMP 100 9 50 cps 7 pin Tandy graphics only 26 1424 26 1276 DMP 105 9 80 cps 7 pin Tandy graphics only 26 1288 26 2802 DMP 106 9 80 cps 26 1288 26 2821 DMP 107 9 100 cps 26 1236 3 pack 26 1238 color set 1 ea red green blue 26 1235 26 DMP 110 9 50 cps 8 pin 26 1283 26 1255 DMP 120 9 120 cps Tandy graphics only 26 1483 26 1280 DMP 130 9 100 cps Tandy graphics only DM
281. olor Computer When connected to a TV the Color Computer 3 will display text in a 32 character by 16 line format Get a 40 character by 24 or 80 character by 24 line display with a monitor Best of all the new Color Computer 3 is com patible with software and accessories designed for the Color Computer 2 in the Color Computer 2 mode Expands easily with disk drives printer telephone modem and more UL listed SERRE ERECT SST Oe ER AMA SE SALE 219 95 Color Computer 3 512K Upgrade Kit Installation required not included 26 3335 4 149 95 New High Resolution Color Monitor CM 8 RGB Analog Color Monitor for use with the pone Displays up to 80 x 24 text and 640 x 192 graphics It is the perfect complement to the superb graphics capabilities of the Color Computer 3 The CM 8 features a 13 diagonal screen and a built in speaker with volume control Includes cable UL listed AC 26 3215 299 95 SPECIFICATIONS FOR COLOR COMPUTER 3 Alternate FI and F Video from 64 x 32 8 colors to 640 x 192 Colors and background color with 6 intermediate d spkay BASIC or Paks 128K RAM internally expandable to 12K commands serial port 4 pin onty Standard TY 300 ohms composite monitor and machine Extended tt cassette recorder Microprocessor 68809 8 01 Clock S V6 ines of 32 characters uppercase to 24 lines of 80 characters optional Two joystick ports AS 232C Analog
282. om your decimal number Move to bit 6 Here a bit represents 64 Repeat the above exercise writing a 1 if the number is greater than 64 then subtract 64 from the number and go on to the next bit which represents 32 Each lesser bit represents half the bit before it Continue until you re at bit 0 The opposite is also true In the binary representation above we 128 64 32 16 no 8 no 4 a2 and no 1 Add em up and you ve got your decimal number To convert a decimal number to hexadecimal convert it to binary first then break it down into nibbles Write the values of the nibbles down in binary from the sixteen values above For an eight bit number add the values together For a 16 bit number add the first two and the last two nibbles two eight bitbytes and write those values down Multiply the first byte on the left by 256 then add to the value of the second page 49 Microware s OS 9 An Introduction to OS 9 Rick Ulland Do you need OS 9 Maybe not Many users view their computer as an appliance Any good appliance should per form it s job as easily as possible without much muss or fuss For this type of use DECB cannot be equalled You cram is a disk type run and away it goes The only problem with computer as appliance is they just aren t that good yet Making it simple usually means leaving things out Individual programmers can write any capability into any program and sometimes do but this approa
283. ommands can t be easily changed or new commands easily added unless you are intimately knowledgeable concerning every internal idiosyn crasy of the CoCo and an adept assembly language and machine language programmer to boot It takes hours of development and debugging time also So you can choose slow easy BASIC or fast difficult Assembly Language But what if you want fast and easy both CF83 FORTH is not a perfect solution but it comes close CF83 FORTH is almost as fast as Assembly Language and almost as easy to use as BASIC once you get past the initial learning phase which is admittedly not trivial The first FORTH was written by Charles Moore in 1971 to be a data acquisition system for the National Radio Astronomy Observatory at Kitt Peak in Arizona FORTH has since grown into a major control language for the entire astronomical community But FORTHis no longer limited to astronomy FORTH 15 also currently used in image processing robotics servomotion controls electrophoretic separation of biological materials on the space shuttle and many small scale imbedded systems These systems all require very compact code in small pack ages and that is just what FORTH was designed for But FORTH also does well in truly huge systems A FORTH system currently controls almost all the operations of the main airport in Saudi Arabia The game STARFLIGHT for the PC is written entirely in FORTH Another FORTH system is Amtelco s
284. opular TRS 80 Color Computer plus features which make the Dragona more professional machine with greater capabilities If you ve held off buying the TRS 80 Color Computer because of some above mentioned limitation then now is the time to stop Dragon your feet and check out this very great Briton You liked the Beatles didn t you Even today there is continued support for the Dragon in the United Kingdom England There is an active user group that continues to provide limited support for the machines through the Internet http www dragon archive co uk The M E S S emulator also supports the Dragon EUROHARD a Spanish company bought Dragon Data and all rights to the computer in 1984 and attempted to revive it as an educational computer The attempt was not successful and the factory closed in 1987 New in the box Tano Dragon 64s are still available from California Digital 17700 Figueroa Street Gardena CA 90248 phone 800 421 5041 orders or 310 217 1945 tech support information As of February 2006 California Digital still had asmall supply of new in the box Tano Dragons Their web site address is http www cadigital com computer htm Tano Technical Associates of New Orleans was the U S company licensed to sell and manufacture Dragon Data computers in North American and the Caribbean Basin As far as could be determined only Dragon 64s were made by Tano Tano worked closely with Dragon Data on a new Dragon 128 tha
285. or Computer which itself turned five years old in July Though somewhat overshadowed by Rainbow Dynamic Color News had become a small magazine by this time and started printing product reviews this month While Rainbow had a circulation in the tens of thousands Dynamic only had just over 200 In November a little over four years after their debut on the CoCo scene the absence of the Nelson Softlaw VIP take your pick ads were keenly felt They were one of the first but sadly not the last large advertisers to start dropping CoCo support This did not spell the end of availability of Softlaw VIP products however as other vendors still advertised them It seemed that 1986 would be the year of the hard drive with Owl Wareadvertising afive megabyte hard drive system for 495 in November 85 and J amp M Systems advertising a five megabyte system for 495 in December The Owl system used an SCSI interface made by L R Tech and required a MPI or Y cable The J amp M system was operated through the parallel port on their floppy disk controller no external controller or MPI was needed THE SEVENTH YEAR 86 Jun 87 On July 30th 1986 6 years and 1 day after the debut of the original TRS 80 Color Computer Tandy unveiled the long awaited and muchrumored CoCo3 The basic unit 219 95 came with 128K upgradable to 512K anda Super Extended BASIC Also announced were OS 9 Level II operating system which allowed use of the exp
286. os abilities in yourhome movies then do get a copy of the December 90 issue An article by Mark Haverstock and Bill Wills shows how An article by Andrew T Boudreaux Jr tells howthe New Orleans CoCo Users Group made a show on the CoCo through a local cable community access channel The group even used their CoCos for several required functions such as headers title screens and prompters It s here CoCo TV Anew CoCo book was reviewed this month Connecting CoCo to the Real World was written by William Barden Jr a Rainbow contributing editor The focus was connecting the CoCo mainly through the joystick ports to many items Projects included a burglar alarm and weather station If one can find the book it is very interesting and the projects pretty easy to build Unfortu nately Mr Barden left the CoCo community shortly after releasing the book Worse he seems to have left on a sour note or at least left some CoCo users who ordered his book that way The author was one of several who ordered the book and never received it yet had their check cashed Inquiries were left unanswered Luckily few CoCo vendors whorely on mail order leave us in this manner most are VERY reliable Who would have thought this of Bill If there was extenuating circumstances unknown to us I apologize in advance for including this here but we who ordered were at least due an explanation and a refund And sadly yet another advertiser falls ou
287. otected The later SALT can be substituted for the early and vice versa Just either eliminate or add the protective 3 9V zeners The zeners are located near the power supply 5 and CR6 A problem common to all CoCo and MPI power supplies is cold solder joints The joints expand and contract with heating and cooling When they expand intermittent loss of power can result due to cracks in the joint This usually occurs after the computer has been ona while progressively getting worse A cold joint won t be as shiny as a good one so may be visible The cure is to re melt the solder at the joint Heat can also cause problems Most of the heat generated in aCoCo 1 2 is from the large TO 3 cased power transistor It is hard to miss large round and in a heat sink There are many cures for this ranging from replacing the power supply as described in the next paragraph to installing afan Some users merely added vents directly over the power transistor by drilling holes in the case Others just used a small desktop fan blowing over the computer Larger heat sinks were also used I have even seen the transformer removed from the case via longer wires to the motherboard The CoCo 3 power supply is less likely to cause heat related problems The old style 5 V power supply is somewhat complicated and runs a bit hot With a basic knowledge of power supply circuitry and a schematic of the board the old power supply can be replaced with a T
288. ould be a CoCo BASIC content of around 70 with the remaining 30 coverage for OS 9 and OSK combined In all fairness articles that pertained equally to all operating systems would be included in the CoCos 7096 such as Bill Sgambatis C Programming series which is based on the CoCo C com piler butcan be used with ANY compiler Also the percent ages would have to change with the subscriber base As long asahigh percentage were CoCo BASIC users the content for those would remain high As people moved away from the CoCo something that was inevitable then a higher percent age would be devoted to OS 9 and OSK I expected the CoCo BASIC users to keep atleast 5096 ofthe magazine forthe next five years Imyself was primarily a DECB user I had intended to base percentages on reader surveys which would be done yearly and when one sent in a subscription form Unfortunately there just weren t enough responses to base anything on The problem is the old chicken and egg routine You have to have achicken to get an egg but you have to have egg to get a chicken I had DECB users so I had to support them In order to attract OS 9 OSK users I had to show some support but I needed articles from some of those users to print And I didn t want to allienate the DECB users either So instead of growing in to a new market I just ended up supporting the old until it just got to be more trouble than it was worth to me I spent 40 hours on
289. ous Address Multiplexer SAM chip In December of 1979 about a year after production began on the MC6809 microprocessor reports circulated that it would be Microsoft and not Motorola that would write the Basic interpreter for the new TRS 90 The name TRS 90 was eventually dropped in favor of a much more colorful name THE FIRST YEAR Jul 80 Jun 81 On July 31st 1980 two months after unveiling their TRS 80 Videotex terminal Tandy publicly displayed its three new computers for 1981 the TRS 80 Model III the TRS 80 Pocket Computer and the TRS 80 Color Computer In September the Color Computer started appearing in Radio Shack stores It sold for 399 00 and came with 4K RAM 8K Microsoft Color Basic 1 0 a 53 key calculator type keyboard built in video modulator to allow connecting to any television RS 232 interface a 1500 baud cassette interface joystick connectors and a slot where Program Paks could be inserted In BYTE magazine s October issue an article speculated that of the 3 new Radio Shack machines the TRS 80 Color Computer would probably create the most interest in consumer markets Steve Odneal andWayne Day the market for machines at this time purchased Color Computers and yes Virginia some jumpered page 8 C boards were sold Tandy meanwhile was rumored to have aquality control hold on the Color Computer following several reported failures after only a few hours of operation 68 Micro Journal pub
290. ow but it wasn t powerful enough I then searched the PC SIG database on Delphi for a BASIC genealogy program for the IBM PC I found one by the name of Genealogy ON DISPLAY Equipped witha general knowledge of BASIC on both the CoCo and IBM PC GW BASICor BASIC A and BASIC Program Conversions HP Books I proceeded to convert the program to the CoCo There is a good reason convert is in quotes it isn t the correct word GW BASIC has several keywords unavailable to the CoCo variable names can be up to eight characters long and the memory limit is around 60K not the CoCo s 32K Genealogy ON DISPLAY was made up of twelve individual modules Each one had to be totally re written to work on the CoCo 3 It wasn tan easy job finally completed the work after page 97 ayear of on and off laboring My father would start using each module as it was finished so the programs were thoroughly debugged Few bugs found their way into the commercial version which was ready for the public in early 1991 Thad thought of uploading the program to Delphi but wasn t about to give away that much work I started selling the genealogy program early in 1992 I ran my first ad in The Rainbow that May Up until then I had been involved with installing point of sell and other programs for small busi nesses There wasn t much work for a small part time operation in this field so I turned my attention to my real love the CoCo I got my fi
291. pated would be able to get copies of all the software for 1 per disk plus shipping provided the lowered goal was met CoCoPRO granted licenses to the software to other vendors to guarantee contin ued availability Evenif the goal wasn t met Dave promised something extra for those who supported him in the last days Sorry to see you go Dave but glad you madean effort to pass everything on rather than just leaving asso many others have The offer ended up netting only 18 total response Tandy s Little Wonder Why did CoCoPRO fail The CoCo community is small and naturally getting smaller Dave Myers attempted to run CoCoPRO asa full time business while most other vendors run their businesses as part time or sideline endeavors There simply is not enough business to keep a full time operation going and growing Most vendors make a small amount from their efforts but a lot of the energy is pure enjoyment and support of the CoCo There isn t enough money in the CoCo community any more to supporta thriving full time operation This shouldn t discourage users from marketing their soft ware just don t expect to make a fortune in a shrinking tight market CoCoPRO did well their first couple years andDave must be applauded for his efforts and support of the CoCo community Talk of a possible new magazine hit the FIDO network and Delphi in February This new magazine would be supporting primarily Disk BASIC but also CoCo OS 9 and
292. pe LOAD filename disk R Use LOADM filename disk followed by EXEC after load is finished to execute run machine language programs If no disk number isspecified drive number 0 is assumed by Disk BASIC Cassette systems are similar except with C appended to the front of the command CLOAD CLOADM and device number is needed there is only one cassette recorder Most programs include a way for them to automatically end One way to stop a program that is running is to press the BREAK key As a last resort you can press the reset button on the back Be careful when using reset however as it can erase a program that is in memory or on a disk in the drive If a program asks you on the screen if you wish to quit or end the program you may need to press SHIFT and y yes or n no as some programs only recognize capital letters I think this is enough information to get you started using the Color Computer I don t want to tell you everything If you have any problems or questions get in touch with one of the computer clubs listed elsewhere in this book Also don t forget to read any manuals or books you may have with your system The Library listing and past magazines should help also Good luck and happy Color Computing Serial Interface Specifications Looking at the connector from the back of the CoCo 4 3 2 PIN RS 232C SIGNAL CODE Carrier Detect status input CD 2 Recieve Data to computer
293. position 6 which was used by all other manufacturers The problem with this was that position 32 is the side select line Position 6 is unused on Tandy cables To use four single sided drives position 32 must be jumpered back over to position 6 There is good reason NOT to do this use of double sided drives explained later The first fully compatible aftermarket disk controller was manufactured byJ amp M Systems introduced in April of 1983 This controller was quite popular due to its compatibility with the Tandy system The controller was shipped with JDOS a J amp M version of DECB but a standard Tandy DECB ROM could be used as well Later models had two external switch controlled ROM sockets and a parallel printer port accessed through JDOS or modified DECB ROM One of the ROM sockets supported a24 pin ROM such as the DECB ROM and the other a 28 pin such as popular low cost Intel EPROMs required A smaller controller was released in 1987 that contained no parallel port J amp M sold production rights of the small controller to Owl Ware who still produces it late in 1988 A full drive 0 kit from J amp M was priced just 50 less than Tandy s but used higher quality TEAC drives Another controller worthy of mention was the Hard Drive Specialist floppy disk controller This controller had two ROM sockets one 24 and one 28 pin also but no external switch for selecting which one was active this was done by a set of internal ju
294. pposedly allowed double speed operation in the all RAM 64K mode but it was never marketed New arrivals for the CoCo includedStar Kits STAR DOS The Toolkit fromArzin joysticks fromEndicott Spectrum Projects gloom stick Game Writer fromWash ington Computer Services a 129 00 program that helped write super action video games and software from a new company calledANTICO September s CCN issue no date on the cover featured a look at the CoCo s INTERPRET routine in Andy Phelps Comment Corner column CCXREF from Mike Donahue a fine debug ging utility used to locate variables in BASIC programs and the first review of Eigen s The Stripper a utility which removed spaces and comments and packs program lines The Rainbow s 106 page September issue made it the BIG GEST CoCo magazine in publication Besides being their first official theme issue education and containing a readers survey the Rainbow s cover mentions support for the TDP 100 computer The TDP was Tandy s first venture at marketing outside Radio Shack stores The TDP 100 which wasreally a CoCoina white case was marketed by RCA distributors and would later be found to contain the F or 285 board which would soon start showing up in the CoCo Speculation was that the TDP venture would be successful it wasn t In October 68 Micro went on line with its BBS and Andy Phelps lastComment Corner appeared in CCN The Rain bow meanwhile starte
295. product availability by as much as a month or more Those of you who ordered the very first Super Color Writer program from Nelson Software know what I mean Other information sources included printouts and files from old bulletin board sessions telephone interviews and correspondence with various users Before starting let me just say that while looking through the numerous back issues for Color Computer information a strange thing started happening Remember that frustrated feeling of the early years when YOU looked for Color Computer information and none could be found It all started coming back to me Francis G Swygert March 1993 Al graciously allowed me to use his existing text which was written for submission to The Rainbow Magazine Rainbow decided not to print it so Al released it to the public over Delphi a major computer database Als format and style were used pretty much intact for the history portion of this book though heavily edited and added to in places by myself The original text only wentup to June of 1986 history text after that date and all additional information was written by myself except where noted Many thanks goes to Al and the other contributors I can also echo Als opening statement this project was definitely borne out of a love for the little computer we affectionately call CoCo It is also important to remember just how this text is written This was not intended to be a definitive hi
296. put past end of record Description Hi Res Graphic Error Hi Res Screen Print Error Tandy s Little Wonder Bank Switched ROM Pak Activision Some of the CoCo 3 ROM Paks contain more than 32K of data which the CoCo 3 can select directly from the cartridge port the CoCo 1 2 could only use 16K Paks This is accomplished by switching banks of 16K in and out of the memory map This switching is accomplished totally within the ROM Pak by two ICs a 74LS 10 triple input NAND gate and a 74LS175 edge triggered quad flip flop Up to 16 banks could be selected by this hardware allowing ROM Paks to contain up to 256K of data Switching is accomplished by writing to the first four bits of location amp HFF40 This sets the outputs ofthe 741 5 175 These outputs control the high order address lines of the ROM At power up or reset the outputs are all set to zero so that the first bank is always selected first This is done by tieing the ROM master reset to the CoCos reset Writes to any address in the amp HFF40 through amp HFFSF range will set the bank select latch as no further decoding was done Note that since bank selection is done in 16K increments this same technique could be used with a 2 74LS10 E clock Pin 9 of 74LS175 ROM A16 128K Pin 12 of 74LS10 74LS175 The remaining ROM lines are wired as anormal 16K ROM Pak DO D7 of the CoCo is wired to the same on the ROM and likewise with A0 A12 A13 would be co
297. puter Society ACS a CoCo club in Atlanta Georgia being planned for October 6 amp 7 Stated right out is that there would bbNO NEW JERSEY COCOFEST sponsored by Rainbow There would be a single RainbowFest in Chicago during the spring The Atlanta show held at the Lakewood Holiday Inn was adver tised by CoCoPRO the primary sponsor and also mentioned in the ad Hey What s this Not only do we now have a picture of the MM 1 but prices as well A single floppy 1 4MB 3 5 system without monitor use your CM 8 or compatible but with OSK BASIC C compiler and several other programs and utilities cost 779 They would even be GIVING ONE AWAY at Atlanta Anew company name appeared inthe MM 1 ad for the first time also Interactive Media Systems IMS Nottobe passed up Frank Hoggbills his machine as the CoCo 4 that Tandy should have made With the 6809 processor and genuine GIME chip Frank is close to the truth in calling his machine aCoCo4 The only thing missing is the promised Disk BASIC compatibility Mr Hogg also introduceda reference book for OS 9 written by none other than Kevin Darling Inside OS 9 Level was not areplacement for the manual nor atutorial buta programming reference that really gets into OS 9 like no other A disk full of patches and utilities was included Kevin continues to support OS 9 and OSK OS 9 for 68xxx processors with his amazing programming prowess to this day Keep up the good work
298. r Kits software could send in a registration fee and receive a valid copy Who but Peter Stark would be bold enough to give software pirates a chance to cleanse their souls Star Kits also marketed the page 15 first MC 10 software HUMBUG a machine language moni tor If you needed a new computer to take back to school with you September you might trythe newly released CoCo 2 Don t bother subscribing toCCN because unknown to its subscrib ers the September issue was the last Reports circulated thatThe Color Computer Magazine would holdCOLOR EXPO 83 in Pasadena CA November 4 6 Not to be outdone Rainbow would also hold more RainbowFests in the future New products released in September included Color Micro Journals 32 page debut issue Pooyan fromDatasoft akey board from Keytronics Pro Color Forms from Derringer Software and the Dragon 64 from Tano Microcomputer Products Corp of New Orleans Louisiana the American distributor for the previously mentioned British CoCo clone Nelson announced that Super Color Writer was the official word processor for the Dragon The highlight ofthe second RainbowFest held in Fort Worth on October 14 16 was a walking tour of Tandy s new CoCo Plant The same monthRadio Shack released the Walt Disney and Sesame Street educational software Multi Pak Inter face the Color Mouse the Deluxe Kraft joystick and the OS 9 operating system Dennis Kitsz said I m gonna teach you a l
299. r The Rainbow About two weeks passed and I received another call from Mr Falk They were getting ready to cease publication of the Rainbow this was in February of 1993 and would consider a sum much lower than he had originally mentioned This lower amount was somewhat attainable so I discussed the idea with several potential investors The outcome of these discussions was that they didn t think it was a reason able risk 90 100 000 would be invested in all but they would be interested in helping to support a new magazine I gave the idea of starting a magazine from scratch some thought With the support of several influential CoCo people Idecideditcould be done I contacted several people who had publiched small CoCo publications in the past All had ceased publication but were willing to give much helpful information With my research in pricing and pulishing in mind I formulated plans to startanew magazine In order to survive the magazine would have to leave the door open for OS 9 and OSK support but for the present and near future CoCo Disk BASIC support would be the priority The tittle was finalized as the world of Tandy s Little Wonder 68 micros all lower case micro letters with a sub heading spelling out Tandy Color Computer OS 9 OSK This would prevent the necessity of a future name change As stated the primary goal of 68 micros would be support of the Color Computer To begin with the target w
300. r also The word processor supported 512K by adding two RAM disks Mail merge and even laser printers were supported The ad was even edited and printed usingTextpro IV and an Okidata laser printer With desktop publishing so popular itis no wonderthat CoCo users would be very interested in publishing programs Rain bow started a very ambitious series which resulted in a com plete desktop publishing program for the CoCo Separate versions were available for the CoCo 1 2 and CoCo 3 The programs were written by H Allen Curtiss and did indeed prove to be very popular Several upgrades would come later Sundog Systems made their debut in the October issue of Rainbow with a half page ad Their premier game was Kung Fu Dude thefirst full graphic martial arts game for the CoCo 1 2 and 3 Also advertised was Champion previously from Mark Data and White Fire of Eternity previously from Saguaro The14th RainbowFest was held inPrinceton New Jersey 9 11 October A new arrival to the CoCo market made their debut at this show witha hard disk adapter for the CoCo that allowed use of a standard PC type eight bit hard drive controller Burke amp Burke also had a version with a built in real time clock Tandy gave away 500 64K upgrade kits the 16 RAM chip variety and 4600 Plug n Power controllers 16K CoCo 2s were sold for a mere 9 95 while64K versions sold for only 29 95 CoCo 3s were onsale for 100 Friday night but back up to 115 for Saturda
301. r drug store the four pages included the cover Who would have thought that little newsletter would have grown into Falsoft whichis nw apublishing firm of some size note the premier issue is still available page 58 Unfortunatly the size of Falsoft along with the dwin dling number of CoCo users is why The Rainbow ceased publication with the May 1993 issue Sub scriptions had fallen to under 4 000 by that time Fora company of Falsofts size it was difficult to justify allocating resources and personnel to continue publica tion resources that could be put to more profitable use It was not an easy decision for Lonnie Falk to let the Rainbow go It must have been like losing a dear friend We all feel that way Lonnie but at least some of us understand the economics of the situation and I hope others do after reading this A limited number of back issues are still available from Falsoft Prices range from 5 50 Check the list out on the Internet at http www the e mall net netcat htm Left to right First issue of The Rainbow September 86 issue Last issue 2 1 um pem oe seem 1 _ The Time Has Come Tandy s Little Wonder Technical Reference Section COvers all the hardware aspects of the CoCo Peripherals A peripheral is any hardware item attached to the computer These include Video Display Devices Mass Storage Systems Printers Expansion Devices an
302. r from UNIX computers through C C wasn tas popular with CoCo BASIC it was available forthe CoCo early on but only as a subset of the full C language as it has been for the OS 9 crowd but renewed popularity of C across all computers should change that It will also mean converting a program from one computer to another won trequire as much work as it has in the past as a program written on a CoCo in C should easily transport to a more powerful machine The package from Infinitum is more than just a compiler it contains all one needs to start programming in C exceptatext book Included in the software package is a text editor for creating editing source code any word processor may also be used the compiler an assembler for creating assembly language files library linker to create stand alone binary files and acommand coordinator to integrate the above into auser friendly enviroment page 46 CF83 FORTHis available fromBDS Software The following description was written byM David Johnson BASIC has 157 commands in a CoCo 2 and 185 commands in aCoCo 3 This is quite alot and when you combine commands to make a program the number of things you can accomplish with your CoCo becomes very large indeed But there ARE limits Because there are only so many commands there are some things that you just can t do in BASIC And because BASIC has to interpret every command as it is encountered BASIC tends to be rather slow C
303. r items a long time ago and many had little knowledge of the CoCo anyway There is not likely to be anyone in your area with a CoCo or any more knowledge of the beast than you have It s almost as it was when Radio Shack first introduced the Color Computer only at least then they had a little software and a few peripherals available Butall is not lost The Color Computer has always been arobust machine It s hard to blow up and not difficult to make most repairs if you re not scared of a soldering iron In fact most of the info to repair the machine is contained in this book Even if you don t know how to solder there are several enthusiasts still working with the CoCo that can help you out Glenside Color Computer Club Atone time there were Tandy Color Computer user groups or clubs in nearly every large city I don t have to tell you that those times are gone There was only one well known groups still active as of February 2006 theGlenside Color Computer Clubnear Chicago Illinois Glenside has been in existence almost as long as the CoCo itself 1981 They have members from across the US and Canada and from around the world Regular meetings are still held at the Schaumburg Township District Library A news letter CoCo 123 is printed quarterly publication Glenside hosts theAnnual Last Chicago CoCoFest yearly usually in May as it had done when Rainbow magazine promoted the fest This year the 15th Annual Last CoCo Fe
304. r modification is required to use a 27128 EPROM Therefore I began to develop Extended ADOS 3 to fit together with ADOS 3 ina 16K EPROM After having had to squeeze everything into 2K watching every last byte having another 8K to work in seemed like the lap of luxury sort of like moving from a closet to a mansion When I began I never felt I would come anywhere near to using the whole extra 8K even though I had quite a few things I wanted to add These included a RAMdisk which Marty Goodman had been begging me to putin for some time menu driven utility for selecting files to execute kill load copy etc fast BACKUP and DSKINI wild card copy file dating that supported real time clocks block move and copy of BASIC program lines and various other miscellaneous goodies As things turned out I came a lot closer than I expected less than 1K was left unused and included pretty much everything on my wish list Extended ADOS 3 debuted at the Chicago RainbowFestin April 1989 Tandy s Little Wonder Compiled BASIC ABASIC compiler takes the BASIC code converts it to M L then saves the M L code in a form that the computer can run directly bypassing the built in interpreter This speeds the program up from 10 20 times over interpreted BASIC The interpreation from BASIC to native 6809 machine language is part of what makes BASIC slow compared to other languages A good analogy is speaking to someone through an inter
305. r of the VIP series Is one of the largest CoCo suppliers leaving Lonnie lets us all know notto expect to find Rainbow on many newsstands These sales were never high but many were kept up because one could walk out of anearby Radio Shack with a CoCo and pick up a magazine this was now next to impossible Only those stands with historic high demand would from now on be supported Frank Hogg who had a few troubles with the slow moving TC9 came out with the Tiger 10MHz 68000 based processor board This was basicallya coprocessor for the TC9 that would speed execu tion of OS 9 Level II by a factor of two or three OSK could be purchased and run later with the addition of other K bus boards A low price of 129 95 made this an affordable alter native to the much more expensive TC70 Burke amp Burke page 28 introduced anupdateto the Tandy Cyrus chesscartridge The update allowed transferring the cartridge to disk and running under OS 9 Mouse disk and windows support was also added The Cyrus program is still considered the best ever chess for the CoCo Anissue of OSK erappeared well it either appeared in June or July or was it August This time the table of contents didn t even reflect a date that little item was probably overlooked in the last issue not this one The MM 1 was finally reviewed and promises of reviews for the Tom Cat computers were made for next month no one was going to hold their breath for that The Rain
306. r was a real innovator both in software and advertising In February 68 Micro eluded that they may be starting aCoCo publication to meet the explosion of new subscribers Absent for the first time since many issues of 68 Micro areThe Micro Works ads Was something happening Most of the other February news included reports of CoCo products on display at last fall sCOMDEX show in Las Vegas The products included AMDEK s new 3 inch disk drives WICO s joysticks and trackball and the long awaited ZAXXON fromDatasoft a licensed version of the arcade hit not aclone The February rumors were obviously true because in March the third CoCo magazine hit the news stands Edited by Kerry Leichtman The Color Computer Magazine TCCM for short premiered with articles fromJake Commander Bob Rosen William Barden Jr and Dennis Kitsz March s nuclear issue of Rainbow featured the first Rain bow Scoreboard and an ad forElite Software s ZAKSUND the first ZAXXON clone TheMark Data replacement keyboard was also reviewed Inlate April of 1983 users from across the United States and Canada not to mention Great Britain Germany Hawaii and the Yukon descended upon Chicago to take part in the first ever CoCo convention RainbowFest Estimated attendance for this day bash was around 10 000 On the sales floor J amp M unveiled itsJFD disk controller while seminars were held by Don Inman Fred Scerbo Tom Nelson Steve Bjork and
307. rallel converters can also be used with other computers by making aspecial cable as the CoCo type converters use the CoCo four pin serial input instead of a DB 25 Some manufacturers made parallel port cards for the CoCo All suffered from the fact that BASIC had to be patched in order to use them Both J amp M and Disto disk controllers supported parallel ports with their modified DECB ROMs Disto also supplied drivers usable under OS 9 The Disto parallel ports require either a Disto Super Controller or a MPI and adapter One thing to remember most modern printers are dumb devices The printer itself has little software inside What used to require a chip in the printer is now done in the printer driver of most printers designed for Windows 95 and later and even Linux This makes it difficult to know ifa printer can be made to work with a CoCo even if it has a parallel interface The few 4 Expansion Devices When Tandy first came out with the CoCo they envisioned it as a beginner game machine If one got serious about computing they should buy a more serious Tandy com puter Only oneexpansion port the game cartridge connector was included Needless to say Tandy under estimated the market and the CoCo and users soon wanted to install a disk drive RS 232 Pak and still be able to plug in the latest game cartridge without tearing the system apart first Tandy introduced the four slotMulti Pak Interface MPI in 1983 to cure
308. rder to obtain Those few who still carried products in Australia charged inflated prices which the com munity could not afford and those who were producing their own software had no way of marketing the products When it seemed that the CoCo was again about to die a natural death Fred Remin a CoCo user decided to approach a number of companies in the USA with a view of obtaining software and hardware for the ailing CoCo community in Australia Success was slow but it was forthcoming with FARNA Systems Rick s Enterprises Sundog Cer Comp and JWT Enterprises being some of the first to recognize an Tandy s Little Wonder untapped market and responding to Freds request With software and hardware again being available a large number of ex CoCoists retrieved their CoCos from the cupboards and dusted them off to relearn and once more enjoy the pleasures that come from using the CoCo By the end of 1992 Robbie Dalzell had been producing the CoCo Link magazine for four years and had decided that it was time for him to have arest CoCo Link however has not ceased it is now being produced by Fred Remin and is continuing to maintain contact between the CoCo users throughout Australia In conclusion the Colour Computer has in Australia had a checkered life span similar to 15 evolution in other countries It has however maintained pace with its more expensive counterparts and continues to grow and surprise not only those who use it but al
309. re wiring done This was described in the October 1986 issue of Rainbow on the Video Display Generator pp 88 92 The most important change was true lower case on the 32 column screen something Tandy chose not to support for backwards compatibility purposes This mode can be tempo rarily invoked by typing POKE amp HFF22 PEEK amp HF22 or 16 To enable lower case mode all the time bend VDG pin 30 up and solder a wire from it to pin VDG pin 1 An SPDT switch may be used to make the change temporary Bend pin 30 up and wire to the center pole of the switch Solder a wire from pin 1 to one of the other switch poles from the other pole to the socket hole or cut leg of pin 30 The second change involves the screen border Normal text mode is black letters green screen with a black border The border be changed to green by typing POKE amp HFE22 PEEK amp HFF22 or 64 Change to lowercase AND green border with POKE amp HFF22 PEEK amp HFF22 or 80 The green border can be made permanent by bending pin 27 up and soldering a wire to pin 17 or wiring a switch exactly as for lowercase only substituting pin 27 for pin 30 The third change provided inverse video a black screen with green characters POKE amp HFF22 PEEK amp HFF22 or 32 invokesthis mode with POKE amp HFF22 PEEK amp HFF22 or48 invoking inverse and lowercase This can also be made permanent by wiring pin 29 the same as pin 27 and 30
310. rectory Mdir module directory lists all the modules is memory and keeps track how many times each one is being used The link count starts at one if a module is loaded or 0 if it s just called and goes up one each time it is executed then down by one when it s finished If it hits 0 that module is dropped and you getthe RAM back Soamodule that was run from the command line and not loaded first disappears when it s finished There are two special commands to deal with this link bumps the number up one so a module will never be dropped while unlink reduces it one Enough unlinks and it disappears With all these modules and processes lurking around things could get a little skitzoid The input and output can t be left to each process else running your OS 9 system would resemble abad adventure game Theunified I O system helps keep the Tandy s Little Wonder data organized There is a path leading to and from each process the standard path being keyboard to process to screen Butit s negotiable Redirection can be used to connect a process to any hardware device using the greater less than arrows So list file goes to the screen but list file gt p goes to the printer and list file 2 t2 sends it out the RS 232 port The slash letter part of these commands is called a pathlist and can get quite long sometimes d0 cmds icons myicon 15 a pathlist meaning look in drive 0 find the cmds directory look in cm
311. relatively new group Membership would be 25 per year and new users would receive one free disk from the library additional disks were 3 formembers A condensed library directory was also published Disks would be sent on standard OS 9 5 1 4 or 8 floppies as well as CoCo 5 1 4 single sided 35 track format Bob RosenmovedSpectrum Projects to San Jose California in May Word was out about the future release of the C Compiler fromRadio Shack and VIP CALC fromSoftlaw New productreleases came fromPrickly Pear Software with their Disk Trivia and the Tom Mix milestone Worlds of Flight thefirst real flight simulator for the CoCo This was the lastissue of Rainbow that the OS 9 Users Group President s Column appeared in A short note asking for assistance with group activities and new members appeared Dale Puckett would print highlights from the user group in his KISSable OS 9 column from then on By the time the June 22 24 RainbowFest touched down in Chicago Dragon 64 ads had vanished from all CoCo maga zines as Dragon Data Ltd British parent company went under receivership It seemed that The Color Computer You ve Been Waiting For wasn t fairing as well as expected Tandy s Little Wonder THE FIFTH YEAR Jul 84 Jun 85 The CoCo turned 4 years old in July at the same time Radio Shack s TRS 80 Microcomputer News published its last issue The Rainbow celebrated itsthird anniversary with yet another innovativ
312. rely gives any problems If the problem is determined to be a disk drive unit replace it with another drive Floppy drives especially the 360K 5 25 double sided units used with the CoCo are not economical to repair A simple alignment would cost more than a used replacement drive Remember that standard 360K IBM type drives work with the CoCo and will read write 35 track single sided disks This is the perfect time to upgrade those single sided drives see the Upgrades section A less common problem is a worn cartridge port connector on the motherboard This can be identified as the problem when VERY mild wiggling or tilting of the controller causes the system to crash or give intermittent results If this occurs clean the controller and connector first If this doesn t solve the problem the connector must be replaced First remove the mother board then the ground plane foil covered cardboard backing held in place with push in clips Then clip each leg on the connector close to the connector housing Remove each wire individually by heating with a soldering iron and pulling out with needle nose pliers Carefully clean all holes with a solder sucker Put a new connector in position and solder Connectors can be purchased from Tandy National Parts RS 232 Pak Repairs There are afew commonrepairs for the Tandy RS 232 Pak Note that most other RS 232 adapters are similar in design meaning these tips may be used for them also
313. rint and graphics with out sophisticated software features at half the price or less Tandy s Little Wonder of an expensive laser H Allen Curtiss was at his Ultralace desktop publishingsystem again correcting some problems and adding some new features His desktop publisher ap peared to be one of the most popular Rainbow programs yet A new Zebra Systems ad they had been absent for two months was starting to be concerned indicated that they had gained rights to the POKES PEEKS N EXECS books previously from Microcom ad for anew magazine 68XXX Machines couldn t have been better timed consid ering Lonnies editorial At only 14 75 fora one year subscrip tion it was worth looking into if one was considering a 68000 based computer A new ad from FARNA Systems appeared that not only advertised software but also advertised space Since Rain bow ads were so costly why notsublet advertising space at amore reasonable rate The idea was to purchase a large block of space at a better rate than a small ad then spread the cost over many small advertisers The idea was sound in principal but not enough advertisers were interested to continue for long CoCoPRO had a full page ad for the Second Annual Last Chicago CoCoFest held this month May 30 31 that included directions for getting to the Inland Meeting Center where the fest was held Burke amp Burke introduced their PowerBoost in June This software har
314. rld Microware BASIC aka Basic09 can be used to write everything from old fashioned line number oriented programs to structured modular code your computer science professor would be proud of try to get a copy of The Official Basic09 Tour Guide from Microware iteven has some general OS 9 hints There are plenty of languages to work with besides Basic09 there are C and Pascal compilers FORTHO0O9 and two assemblers were produced And you don t just have two or three documented ROM calls but literally hundreds of systemcallsto make things easy The unfortunate thing is that unless a new or used copy of the Tandy version of these languages is found they are pretty much unavailable The exceptionis FORTHOO from BDS Software see the article on FORTH under Other DECB Programming Languages Shell scripts can automate a complex set up process Lets assume a program runs best with a RAMdisk but you don t usually have one running Make a text file containing the commands to start and format a RAMdisk and run the program Typing the name of the text file as acommand will run each line just as if it had been typed at the OS 9 prompt Then there isMulti Vue Guru types don t like to use Multi Vue since it s a little slow Not many commercial programs come with the iconandaiffile included either Butif you have the patience to set it up and get the icons and aifs from an on line service or make your own it does make a pretty neat
315. rmally 5 270 IF D 1 THEN POKE amp HD6CD 0 POKE amp HD723 20 GOTO320 280 IF D 2 THEN POKE amp HD6CD 0 POKE amp HD723 21 GOTO320 290 IF D 3 THEN POKE amp HD6CD 0 POKE amp HD723 22 GOTO320 300 IF 0 4 THEN POKE amp HD6CD 0 POKE amp HD723 23 GOTO320 305 POKE amp HD66F 2 Same as 230 265 except for DECB 1 0 310 GOTO 190 If none of the above go back to line 190 320 LOCATE 6 10 PRINT Select Printer Baud Rate PRINT See comments for line 190 330 8 1 600 221200 322400 14 4800 5 9600 See comments for line 200 340 LOCATE 8 14 AZPEEK 65314 B INT A 2 C A 2 IF C B 0 THEN PRINT PRINTER IS ON ELSE PRINT PRINTER IS OFF Move cursor to column 8 line 14 the next four statements check the printer port for activity PRINT whether the printer is on or not 350 PRINT LOCATE 6 18 INPUT Selected Value R See comments for line 120 4 30ms page 41 360 IF 1 THEN POKE 150 180 GOTO 420 370 IF R 2 THEN POKE 150 87 GOTO 420 380 IF R z 3 THEN POKE 150 41 GOTO 420 390 IF R 4 THEN POKE 150 18 GOTO 420 400 IF R 5 THEN POKE 150 4 GOTO 420 410 GOTO 320 POKE the values for the specified baud rate then go to line 420 Note that the value is actually HALF the specified rate because the double speed POKE is used 420 LOCATE 20 23 PRINT PRESS ANY KEY TO ACCEPT BREAK TO STOP EXEC 44539 This line allows a chance to stop if
316. ronics Undercolor December 84 June 85 Green Mountain Micro DIGInews cassette magazine April 85 April 86 Dragonfly Writing CoCo Time disk magazine October 85 July 86 Microcom Software Spectrogram November 86 June 87 Spectrogram Magazine TRS 80 Computing Color Computing bi monthly June 87 October 91 Color Computing the world of 68 micros October 93 March 98 FARNA Systems CoCo Friends Disk Magazine February 92 January 00 Rick s Computer Enterprises The Upgrade Disk Newsletter from Mid Iowa and Country CoCo Club 1984 2001 Terry Simons Editor page 57 A Tribute to The Rainbow 1981 1993 Itis possible that The Rainbow is responsible for the CoCo being as mucha success as it was When Tandy wouldn t tell us what we wanted to know Rainbow did At one time the Rainbow published over 200 pages per issue It was far from that when it finally ceased publication down to 16 pages in a tabloid format Yet it was still packed with good CoCo information It willbe sorely missed by all CoCousers The Rainbow started life on a CoCo and Tandy Line Printer VII dot matrix without lowercase descenders even typed in witha little three line editor written by Lonnie Falk just for that purpose The premier issue consisted of four pages copied at the corne
317. rst CoCo thanks to my first hobby and a Timex Sinclair 1500 My first hobby is old cars specifically sixties AMC Ramblers my personal driver being a 1963 Rambler Classic I wrote and published a book on the history of the AMC Rambler using a typewriter This lead me to realize a computer would be much easier for that type work Due to limited funds an IBM PC was out of the question PCs were still priced over 1000 with dual floppy drives and a mono chrome monitorin 1985 I first purchased a Timex Sinclair T S 1500 from a pawn shop for 50 I also purchased a couple books on the little beast I wasn t much of a typist so the small calulator type keys wouldn t present much of a problem The entire unit was only 8 1 2 wide 5 1 2 deep and 1 1 2 thick with allof 16K RAM Isoon found one fatal flaw in the 1500 Itused abit by bit printer port that was designed for the little 40 column T S printer ONLY No full size printer could use that port and a serial printer interface would cost 100 Well determined I could get another small computer for that price as the bottom had fallen out of the home computer market TI99 4A computers were being sold in department stores for 49 95 around 1985 I did some research this time around and decided that of all the small computers the Tandy Color Computer 2 was the best Not only did it have a serial port that many printers would connect to but the disk drives were standard units except for
318. ry It seems that Orion Technologies had faded out of the CoCo market Their last ad was run this month This is the first May 1990 of the 100 page Rainbows There are only 46 advertisers Sure is getting thin Will the Rainbow fade away In his editorial Print 2 Lonnie Falk is encour aging those who also have MS DOS machines to try PCM PCM was started two years after the Rainbow to support Tandy laptops and MS DOS based computers Is this a subtle hint Maybe not What s that on page 33 Another one of those odd Kenneth Leigh Enterprises ads This one prom ises MS DOS based applications multi tasking alongside MIDI programs in 256 colors and sound that surpasses CD quality If you want to know the computers name and price you still have to write Budding astronomers could take page 24 advantage of their CoCos power to map the sky withGravity Studios Planet Engine Maps could be made for any time date even with proper shadowing for phases If you want to know how Tandy managed to squeeze up to 1MB of data into a ROM Pak then get the June issue of Rainbow Frank Hogg Laboratories announced theTomcat 9 a 6809 based computer that was 25 faster than the CoCo used a PC AT 101 key keyboard up to 1MB of RAM high resolution joystick parallel port two REAL serial ports ACIA controlled K bus and CoCo bus expandability and fit intoaPC type case With the K bus one could later add a 68xxx processor and use the TC
319. s for the Exatron disk system 32K PLUS DISKS 298 00 read the ad One could call the listed toll free number and be placed on a list After about a month and a half the systems were finally delivered Soon after most were ready for a return trip back to Exatron s Sunnyvale plant The amount of generated RFI Radio Fre quency Interference made the screen unreadable This was in the early computer days before the FCC Federal Communi cations Commission stepped in to regulate the amount of interference a computer system could generate Many small computers had little or no shielding This was especially hard on apartment dwellers as just turning a system on could interfere with a neighbor s TV and radio reception Model I users would remember this well Steve Odneal at about this same time was having a little bit better luck With a home built disk system hooked up to his 32K machine and 8K of RAM on the disk controller board Steve completed the first ever conversion of the FLEX oper ating system for the Color Computer While Mark Data was rushing to convert their Model I adventure games to run on the Color Computer IMB Illus trated Memory Banks released its first offering Although page 10 written in Basic Meteor Storm was the first software to take advantage of the CoCo s graphics capabilities Thanks to Fred Scerbo who authored Meteor Storm July also wit nessed the introduction of the first educational software from
320. s is amuch neater installation One should note that these boards were designed with the OS 9 user in mind Programs for DECB can be written to take advantage of the added memory but only ADOS is known to use any memory over the standard 512K and then only for RAM disk use The 1MB and 2MB boards will also function as if they were 512K upgrades under DECB The MMU Memory Management Unit inside the GIME chip is capable of addressing up to 2MB but is two control bits short to access that much RAM Tony DiStefano the designer of the boards added one bit on the 1MB board and two on the 2MB board with external circuitry The problem with DECB use of the additional RAM is that the GIME doesn t track the contents of these added bits and therefore can t read them Any DECB applications must store the contents of these two bits sothatthe GIME can move around the extra RAM without crashing the computer OS 9 handles memory differently and does not require the GIME to track the two added bits page 77 There are no other commercially available upgrades but for the avid electronics hobbyist up to 8MB can be added Take a look at the CoCoZilla website http home wwdb org irgroup frontpage html for details Cloud 9 is currently as of FEB 2006 working on completing their SuperBoard upgrade for the CoCo3 that is similar to the NoCan projects on the CoCoZillasite The SuperBoard will feature 2MB via two 1MB SIMMs a parallel port two s
321. s operating system for all Color Computers It is constantly being improved and enhanced is freely available and is also faster and more optimized than Tandy s OS 9 operating systems There are two issues with using OS 9 Level One or OS 9 Level Two today first there is no upgrade path for the products second neither operating system has been sold in Radio Shack stores for years denying new users the ability to purchase valid licenses As long as thereiscommunity interestin NitrOS 9 it will remain available Support is limited only by those who use it and their willing ness to share their work with the community Around the turn ofthe century 2000 NitrOS 9 users decided Tandy s Little Wonder UPDATED FEB 2006 the newest OS for the CoCo written by CoCo users that OS 9 had been dead long enough and the new OS was different enough from the original OS 9 that they should support the original 6809 and CoCos as well as the 6309 While the speed improvements wouldn t be as dramatic without a 6309 NitrOS 9 would still run 10 15 fasterthan OS 9 This led to the current support scheme of three levels and two proces sors yielding seven possible distributions NitrOS 9 6809 Level 1 for the CoCo 1 and 2 NitrOS 9 6309 Level 1 for the CoCo 1 and 2 NitrOS 9 6809 Level 1 forthe Dragon 64 NitrOS 9 6809 Level 2 for the CoCo3 NitrOS 9 6309 Level 2 for the CoCo3 NitrOS 9 6809 Level3 for the CoCo3 NitrOS 9 6309 Level3 for the CoCo3
322. s you some but d rather see more formy CoCo TheOS 9 Underground had a few changes for the better in just the second issue The magazine was noticeably thicker this time sporting 50 pages wrapped in a fluorescent green cover The colored covers did add a bit to the magazines overall appearance On the title page of this second issue appears a little box exclaiming Now incorporates 68xxx Machines Rather than fold The 68xxx Machines editor publisher Jim DeStafeno decided that there was no need to fragment the OSK market with two magazines A merger agreement was reached between 68xxx Machines and OS 9 Underground whereby Underground would absorb the sub scription base and writers of the former Several columns were carried over also Acomplementary disk with program list ings was first offered this month The disk would be pub lished on a quarterly basis the first being available in mid August for 35 yearly or 10 per issue There werefourteen advertisers in this issue notably Delmar Peripheral Tech nologies makers of System IV kits and boards and Frank Hogg Labs TC70 The only OSK system missing is the MM 1 IMS The subscription rates stayed the same but cover price increased to 3 due to the increase in size Gale Force picked up on the extra 6309 power by introducing NitrOS9 This was a set of patches for OS 9 Level II thatallowed native mode operation of the Hitachi 6309 similar to the B amp B PowerBoost
323. se that had an interest in the CoCo I tried to find someone to take the publication over at no cost by announc ing that fact in the magazine and letting subscribers know that I wouldn t just stop printing without warning After about six months I founda taker We made an arrangement where I paid for the printing and mailing of the next two issues and forwarded all renewal funds from the take over date on I usually received enough renewals to cover printing and mailing costs between issues even at that late stage of the game so that plan should have given a little extra to start off We did discuss all business aspects and that the magazine alone would be little more than a break even proposition I didn t want anyone having a false hope of making much money off the deal Unfortunately that person ran into problems and only printed another issue or two after the printing money ran out and around 100 subscribers lost a little money some the entire 520 subscription price but most half that or less I never could get in touch with the person again and forgot who it was a long time ago It s possible that after the announcement that I was personally getting out of publishing that alot of people simply didn t renew The two issues printed after I left off were as nicely done as I had printed my opinion the deal included a copy of PageMaker software and templates to ensure reasonable quality and little change in appearance at first
324. sed for 99 95 CM 8 monitors and single disk drive systems for 149 95 Marty Goodman told all about monitors for the CoCo in March This was alsothe thinnest Rainbow yet only 82 pages CoCoPRO ads grew to 1 2 page They offered Tandy Orches tra 90 paks for only 17 95 was 79 95 and Where in the World is Carmen Sandiago for only 15 95 was 34 95 Sadly another supplier is lost asDanosoft runs their last ad Rainbow stopped shipping the magazine in plastic bags this month Cray Augsburg said it didn t significantly reduce complaints about mangled magazines in the mail but most subscribers realizeit was mainly a costcutting measure Better the bag than more pages Anewserial pack was introduced in AprilCoCoPRO ad It was aconversion of the Tandy 300 baud DC Modem Pak which contained most of the circuitry fora true serial port The modification wasdesigned by Marty Goodman A completed pack or kit was offered The company ad was up to a full page in May Soft and hard ware from several companies was brought on line There were only 23 other advertisers A new piece of hardware came to light in May also the Delta Pro sound device by Lucas Industries 2000 The Delta Pro used the delta or change method of recording sound Digitized sound was now possible with minimum memory usage H Allen Curtiss desktop publishing program was updated beginning this month into Ultralace which would run on the CoCo 3 only The updates would oc
325. sed with a CoCo 3 The reason is that it comes with ROM Pak software that won t load on the CoCo 3 because a semi graphics mode of the CoCo 2 is used This mode is not supported on the CoCo 3 due to limited use the Plug N Power is nearly the ONLY thing to use that mode It might be possible to use the IBM compatible Plug N Power or X 10 controller serial version but software would have to be written for it Orchestra 90 CC This was a six octave five voice stereo music composing cartridge with built in ROM software 26 3143 Itcould be connected to a stereo for output Some music files can be downloaded from Delphi see Telecommunica tions Created music can be stored on tape or disk with a MPI Sound Speech Cartridge This thing would actually make your CoCo talk 26 3144 A few games supported this cartridge very few It came with instructions for easily programming speech A Bus This is a general purpose control system for the CoCo and anumber of other computers as well Each computer had a special adapter that connected to a special five slot A BUS board Up to five of these could be interconnected making 25 slots available A full range of devices for process control robotics data acquisition monitoring and sensing and motion control were available Software was not supplied this was experimenter s system This item is still available from the manufacturer Alpha Products 242 W West Avenue
326. ses allowing problem programs to be made compatible In the early days of ADOS I made quite a few minor changes to achieve compatibility with one program or another with the result that there soon remained practically nothing that wouldn t run under ADOS at all and very few that required DISABLE The compatibility issue also guided my choice of features to include in ADOS Notably absent from ADOS are commands like DPOKE double byte poke While such a command is convenient in some situations the use of it within a program renders that program unusable by CoCo owners with standard Disk BASIC My aim was to create a more powerful but also compatiblecomputing ENVIRONMENT Hence the extracom mands of ADOS are those that would mainly be used from direct mode rather than from within programs page 43 As I began to develop ADOS I was faced with the problem of what features to include I knew I had a limit of 2K of space to work in Two K does not sound like very much a modest sized BASIC program takes up more space than this but I rapidly discovered that many BASIC enhancements could be accomplished using surprisingly few bytes My addition of RUNM to the command set required only 18 bytes allowing COPY filename to drive number took 37 bytes This economy was made possible by the fact that many pre existing ROM routines could be called to accomplish parts of the task andImade maximum use of such routines to squeeze as mu
327. sh The whimper was pro vided by rumors that Color Micro Journal was about to go belly up The February RainbowFest in Irvine California 15 17 at tracted 8 000 visitors for a first hand look at CoCoMax 250 sold Product debuts included the P 51 Mustang Attack FlightSimulator fromTom Mix the68008 expansion card fromRGS Micro Electronics and a15 key numeric keypad from Moreton Bay Tandy sold 16K CoCos for a mere 50 a drop in the proverbial bit bucket Back to where it all started CoCo information will start re appearing in68 Micro Journal as rumors of 68 Color Micro Journal s demise prove true With this month s issue CMJ joinedColor Computer News Chromasette and The Color Computer Magazine as the fourth major CoCo publication to fold within the past 17 months March brought word that new CoCo would be exclusive OS 9 machine no BASIC ROM and would be in Radio Shack stores sometime between September 85 and March 86 Callers to any ofBob Rosen s 4 bulletin boards in Woodhaven New York were greeted not by the usual high pitched carrier tone but by a disconnected message Bob signed off the east coast boards On March 30 31 Londonis the scene of the second 6809 Colour Show for Dragon and CoCo users Looks like the Dragon lives on R G S Micro Electronics Montreal Canada who had just debuted their 68008 expansion folded April saw the release of two library offerings the long awaited Complete Rai
328. so those who were under the impression that it was dead and gone or just a kids games machine The advent of the Hitachi 63BO9E coupled with the advances in both OS 9 and Disk BASIC will undoubtedly ensure that the CoCo will survive for many years to come Australian CoCoists like their American counterparts have recognized the poten tial ofthe Colour Computer While contact can be maintained and software and hardware is available these users will ensure that this amazing computer system will outlive its strongest rivals The 68xxx Story by Jim DeStafeno former editor The idea to start a monthly publication centered around the revitalized OSK community that was brought on by the newly released OSK KMA computers The idea became more than a dream at the 1990 CoCoFest held in Atlanta Georgia spon sored by Dave Myers of CoCoPRO As I was told later Fredrick Brown manufacturer of the PT 68K2 4 computer boards Ed Gresick owner of Delmar Corp and soon to become vendor ofthe System IV Dan Farnsworth author of REX DOS and many application programs forit and SK DOS Jack Crenshaw and Ron Anderson both nationally known writers of computer related books and magazine articles and GilShattuck of Granite Computer Systems pulled two tables together at the hotel restaurant After dinner the conversation turned to their perceived need for a magazine to unite the anticipated growth of the OSK community After the fest I was contacted told of t
329. some what less efficient than CoCo s I m not a speed typist but in the two years ve been computing I ve gotten pretty profi cientattyping the word LIST The word is typed so fast that before the L key is released the I key is being pressed then S and T The Dragon turns my lightning LIST into LST This occurs because the Dragons keyboard polling routine will not recognize the I key stroke until the L key is released because they are apparently on the same row of the keyboard matrix This also effects the method used to pause scrolling during a LIST with a SHIFT The inability to accept a double keystroke happens only while Dragon is in the 32K mode on power up While in the 64K mode not only is the problem eliminated but ifa key is held down for more than a few tenths of a second it starts repeating By the way you ll know ata glance whether you re in the 32K or 64K mode simply by the cursor color In the 32K mode the cursor will be a blinking solid black graphics character while a blinking solid blue cursor indicates 64K mode Dragons 64K mode is entered by typing EXEC and pressing ENTER Easy hey When the machine is turned on part of its initialization process includes moving data into low RAM amp H0000 amp HO3FF for the BASIC interpreters to use For instance the system uses location amp H009D to hold the EXEC address of the last machine language which was loaded into the computer This
330. st is being held April 29th and 30th at the Holiday Inn Hotel amp Suites Elgin IL aboutan hour westof Chicago Willitbethe reallast CoCo Fest As long asthere s a Glenside to put on the show and enough people to come so that the associated bills get paid there will be a fest So says Glenside Contact information as of FEB 2006 Glenside Color Computer Club c o Bob Swoger 613 Parkside Circle Streamwood 1L 60107 1647 Internet http members aol com clubbbs index html e mail rswoger aol com Bob Swoger Cloud Nine Aboutthe only real vendorleft forthe CoCois Cloud Nine run by Mark Marlette and Boisy Pitre two long time CoCo enthu siasts It s a hobby business for them nothing full time but there hasn t been a full time CoCo vendor in at least 20 years The partnership works perfectly Mark is mostly a hardware guy and Boisy is mainly a software type Of course both have a good knowledge of both hardware and software when it comes to the CoCo page 54 Mostof their work 15 OS 9 related or more specifically NitrOS 9 They do however carry hard drive controllers and the software necessary to operate a hard drive with the CoCo s Disc BASIC and many of the hardware items work with DECB and OS 9 equally well Some does require OS 9 due to the way the DECB works OS 9 will work with any hardware DECB is hard coded to expect specific hardware to work with The DECB hard drive software is an updated version of RGB DO
331. still our teachers and some relatives We still didn t give up though and eventually by sending out severalletters to CoCoists across the U S and Canada we got our first contributing editors There were also some who were willing to occasionally submit programs and articles which helped out a lot and allowed us more time to work on giving the magazine a better look We got away from using markers and relied heavily on the word processors while still trying to build our knowledge of BASIC You can actually tell by looking at our first issues that we didn t know BASIC all that well akeen eye would be able to spot our improvements as the years progressed page 94 In an attempt to improve business by covering a broader market westarted toinclude Commodore and Apple material we didn t yet have enough money to advertise much further thanthelocal area This did help some but we eventually gave thatup andwent back to an all CoCo publication During this time we were able to place a small classified ad in November 1989 issue of Computer Shopper In about two weeks the ad paid off with the addition of about 25 more subscribers A few months later we placed another ad and got another 20 sub scribers Many more people had heard about us and as far as we were concernedbusiness was booming Ournextad went into the March April 1990 last issue of CoCo Clipboard Atthe end of 1990 we sent out 1000 flyers direct mail in conjunction with CoCoPr
332. story Indeed it is the authors belief that the CoCo is far from being relegated to history as of yet Instead the history portion is more of an overview of what has happened in the life of the CoCo over the years almost a time line type of chronology The entire book itself is acomplete CoCo reference book the CoCo bible so to speak Francis G Swygert February 2006 This was not intended to be a definitive history but it has pretty much become so When the first edition came out there was still a lot of life left in the CoCo I used one myself until 1997 for all my on line needs and a few other tasks until the graphics intensive World Wide Web took over The CoCo just doesn t have the graphics capability of newer computers Nevertheless itis still a favorite of experimenters and has a retro computing following as well As powerful as modern computers are they are also daunting for the average person to learn to program or to experiment with Those are both areas the CoCo is well suited for There may not be any more made but there are still thousands out there I never intended to print a second edition especially not this far after the first but an active though small CoCo community has inspired me to do so It is my sincere hope that this volume this CoCo survival guide helps keep those computers alive in the hands of hobbyists for another decade and beyond Tandy s Little Wonder page 7 CoCo History From Birt
333. t featured dual 6809 processors and 128K but it never got beyond the prototype stage It was designed from the start to run OS 9 and featured four serial ports for terminals It s truly to bad that machine didn t get off the ground TANO Dragon 64 page 37 Tomcat ee Frank Hogg Labrotories bid to build a better CoCo FHL introduced the Tomcat TC9 in June of 1990 Unlike other OS 9 OSK computers the TC9 was designed to use existing CoCo hard and software reducing the initial investment required To maintain this compatibility it used a68BO9E and original Tandy GIMEchip A CoCotype 40 pin expansion bus was also included via a 40 pin header connector A one ortwo 40 pin card edge connector ribbon cable attached to the header Even the MPI could be attached Since the bus was fully buffered unlike the CoCo s the cable presented no problems and a cable with a couple more connectors would probably work just as well as long as it was kept to a minimal length A 68xxx type K bus was also used on the TC9 This allowed adding numerous FHL K bus cards and even a 68xxx processor card The processor card could be used as a coprocessor for 6809 OS 9 or vice versa A special 10 gt 68000 based card the Tiger was designed specifically forthat purpose though one ofthe faster more expensive 68xxx based cards such as the 15MHz 68070 based TC70 could also be used Features of the TC9 included CoCo3 soft hard ware compati
334. t 8MHz editor Some AT class 386 486 machines did use faster bus speeds but the ISA standard is 8MHz to maintain backwards compat ibility with original AT cards The ports built into the motherboard wouldn t be limited to 8MHz operation We therefore decided to scrap the PC AT bus support idea Thevideo cardsfrom FHL were32 bit ran up to 33MHz had mouse port serial keyboard port high quality sound and video for around 300 similarto the price of high performance 32 bit PC cards Since these cards were stand alone meant that more than one could be installed Each card could support a separate user with full 32 bit video and multiple windows The computer design finalized in August the Kix 30 The design fell into place very easily The board fit into a PC case easily using standard cables and connectors The first boards cameinat 10 00a m ona Friday early in October and acomputer was running that same day this was a prototype board The prototype board actually only needed six jumper wires to correct minorerrors From conception to finished product only took four months No committee could have agreed on any thing by that time The fewer people involved in designs like this the better Keeps cost down compromises to a minumum After theKix the TC70lost interest TC70 was slower than the Kix30 and cost more to expand Since our supply of boards was low as wellas interest the TC70 was dropped There was actually very little
335. t Y cable was connected to this Unlike the CoCo this bus was fully buffered so running with a Y cable would not strain the bus nor the 200 watt power supply Composite video and RGB was available but no TV output Two serial and one parallel port the CoCo bus and joystick ports were on an I O board mounted above the motherboard The only real incompatibility with CoCo OS 9 hardware was thata different address had to be used for the sound port Three bytes had to be changed in Kyum Gai in order to here the sound effects OS 9 Level II had to be purchased separately from Tandy or another source New boot disks with the correct FHL 9 drivers had to be made with a CoCo 3 or the original OS 9 disks sent to FHL so they could make a new boot for the TC9 purchaser Disk BASIC was not yet supported but FHL did release a utility within a year that allowed saving ones CoCo 3 ROMs to disk and patched them for TC9 use thus gaining Disk BASIC compatibility but only ifone had access to a CoCo 3 note it would be considered piracy if one did not own a CoCo 3 page 29 Rainbowshrank yet again down to 50 pages and 20 advertis ers Two letters were printed from readers who had trouble with support from Microcom They were still shipping orders for Word Power 3 3 butwere NOT returning letters asking for supporteven after repeated queries A sad way to end what was once a well respected company And finally areview ofthe IMS with an
336. t only devices NOT decoded in the range of amp HFF40 amp HFFSF and WITHOUT on board ROMs can be used there This slot was intended for an RS 232 Pak though others meeting the previ ous criteria work also Tandy Speech amp Sound Pak most MIDI adapters etc Inthe same issue of Rainbow December 89 Orion Technolo gies introduced their XPort also a three slot MPI replace ment This device worked identically as the Slot Pak with two Tandy s Little Wonder switchable slots and one fixed The main difference was that the XPort had a fifteen inch ribbon cable between it and the CoCo This allowed moving the XPort away from the CoCo the keyboard could easily be pulled closer to the user greatly reducing the possibility of blowing the 6809 and the need for an extended keyboard The XPort also had its own power supply builtin from the start Unfortunately Orion is no longer in business In 1992 anew company appeared to support the CoCo with hardware CoNect They provided two expansion devices XPander a Y Box The XPander plugs into cartridge connector and provides two SCS driven ports as well as a third port for fully decoded cards The third port can also be used for ROM cartridges with the flip of a switch The XPander was designed to fit modified CoCo case or used for repackaging in a PC type case Another feature of the XPander is a builtin RS 232 port whichis compatible with the Tandy RS 232 Pak
337. t there is a Radio Shack in or near almost every town across the U S One would be better served to find an electronics parts store with a better small parts stock then RS or mail order parts from one of the following All Electronics Corp P O Box 567 Van Nuys CA 91408 Order phone 1 800 826 5432 call for catalog Minimum order is 10 plus 3 50 shipping and handling Mouser Electronics 2401 Hwy 287 North Mansfield TX 76063 Phone 817 483 4422 call or write for catalog Digi Key Corp P O Box 677 Thief River Falls MN 56701 0677 Order phone 1 800 344 4539 No minimum order minimum shipping charge of 5 no shipping if order over 25 No Motorola chips listed but will supply non listed items if available Volume discounts for orders over 100 Jameco Electronics 1355Shoreway Road Belmont CA 94002 page 6 Orderphone415 592 8097 call forcatalog 20 minimum order plus 5 shipping and handling Catalog usually has some IC pin out information and RAM EPROM cross reference good reference source The following abbreviations are used Assembly Language ANSI American National Standards Institute ASCII American Standard for Computer Information Inter change BASIC Beginners All purpose Symbolic Instruction Code BPS Bits Per Second CCx Color Computer x 1 2 0r3 CMOS Complimentary Metal Oxide Silicon chip construc tion CoCo Color Computer CPU Central Processing Unit actual processor chip
338. ta bus not in the PIA 13 Any of the signals coming into the VDG could be bad producing bad output Check the inputs first If they are all correct check outputs Bad outputs require replacement of the VDG If inputs are bad check circuitry going into them The previously listed tips are just that tips not complete trouble shooting procedures They should be enough to get arepair started on the right track Unless the repairer has alot of patience and trouble shooting experience repairs are usu ally limited to replacing one of the major chips These chips provide so many functions of the CoCo that one of them usually is the problem more often than not the CPU Tandy s Little Wonder MC6809ECPU also HD6309E in emulation mode The CPU usually needs replacing when garbage is displayed on the screen especially vertical columns and ampersands signs Other random garbage could be caused by other components though the CPU is still suspect Most totally dead CoCos are due to a blown 6809 There are no buffers between the 6809 and the cartridge port Pin 9 on all CoCos has 15V 300mA onit The original CoCo also has 12V 300mA on pin 2 and 12V 100mA on pin 1 Anything removed or inserted from the cartridge port at a slight angle while the computer is on can blow the processor by crossing one of these powered pin with an adjacent pin This would apply power to the Q clock pin 7 data bit 1 pin 11 HALT pin 3 or NMI
339. taking a post graduate course at Syracuse Univer sity was also in Syracuse NY area We were the only ones in the area with 6800 based home computers We exchanged software and developed the systems and communicated with others around the country with similar systems This lasted until about 1980 Irun a dental laboratory and bought computers then just for the business We had heard rumors of a Tandy 6809 computer coming in late 79 I felt that there would be a major market for a Tandy 6809 computer with a lot of users This was discussed with Dale Tom Al Jost who wrote DynaStar and some others It was decided that I would expand into selling software the others wrote This would provide all with added income Tandy s Little Wonder and tax deductions for new equipment helping to justify hobby expenses My first ad was a full page in the July 1980 issue of 68 Micro Journal selling Dale Pucketts Spell Test Dyna Spell and Tom Spears Remote terminal program The Tandy 6809 machine the original CoCo was a disappoint ment only 4K of RAM and noreal expansion just a cartridge port We all had more powerful and expandable SS 50 bus 6809 machines running FLEX and OS 9 Well went out and bought one anyway Richard Hogg anephew had graduated college and was working for Bell Labs He took the CoCo and found that a 32K model could easily be converted to 64K by adding a few wires Richard wrote an article describing the conver sion
340. tas the lastSecond City Software ad appears Buttake heart They aren t leaving the CoCo market just moving operations and changing name to Kala Software Unfortu Tandy s Little Wonder nately Rainbow ads won t be in the new companies future any time soon Hardly anyone noticed that the last Computer Island ad appeared in the October 90 issue of Rainbow Nor thatthe last article written by Steve Blyn a contributing editor since July 1982 with hisEducation Notes column appeared in November This was brought to their attention by Lonnie Falk in the January 1991 issue Steve wrote a very good letter explaining that orders were slow and the operation was winding down Lonnie publicly thanked Steve and his wife Cheryl for the many contributions to the CoCo community and wished them luck from ALL of us In this case Lonnie definitely spoke for at least most longtime Rainbow readers Well at least there is some good news as the first ad from Rick s Computer Enterprises appears Several programs are offered but the most interesting is The Rainbow Indexes a database of all Rainbows since the original and promised to be updated annually Now if one needed to refer to an old article simply boot the program and search No more thumbing through the anniversary index issues Thanks Rick we needed something like this Not all was doom and gloom in January Zebra Systems introduced First Prize an award certificate making program for t
341. tcurrently available SCSIdrives have builtin embedded controller boards meaning they do not require an external controller between the Disto interface and hard drive The only problem with this arrangementis that most newer SCSI drives only support the PC standard of 512 byte sectors The driver software that comes with CoCo adapters requires 256 byte sectors Only Seagate N numbered as STI57N and Rodime 650 series drives are known to support 256 byte sectors all have embedded controllers Cloud 9 offers an OS 9 driver that supports 512 byte sectors meaning almost any SCSI drive can be used and software for DECB page 68 Other hard drive systems include Owl Ware This system supports almost any SASI and SCSI controller or embedded drive with 256 byte sectors The 5200 controller which also supports high speed no halt floppy drives under OS 9 is fully supported Hard drive works under DECB with drivers from Owl Hard Drive BASIC 3 and Burke amp Burke Hyper I O for Owl The floppy system works ONLY under OS 9 A Tandy type floppy disk controlleris still required for DECB support with the Omti 5200 floppy system The Ken Ton interface is the best true SCSI interface available for the CoCo It also supports SASI control lers RGB DOS is available for DECB users as well as drivers forOS 9 Prices vary depending on the size drive and type of controller but should be similar to new equipment Bur
342. th They will be missed but not for long they go out by creating a small stir in the next few months Gracing thefront cover of Septembers Rainbow was none other than the Delmar System IV received last month cause of high interest this review item was given a high priority Readers found that thePT68K 4 motherboard used 8 bit PC XT compatible cards though drivers may not be available for some and a16MHz 68000 processor all neatly packaged in a PC type case A CoCo 3 was connected to one of the four serial ports as a terminal It was remarked that this would be an excellent way to continue using existing software until OSK software could be purchased The PT68K 4does not come with BASIC so the reviewing staff contactedMicroware and received a copy for review along with an integrated package word processor spreadsheet and database called SMART Both hadhigh price tags 500 for BASIC and 895 for SMART It was discovered that terminals running from the serial portsrequired VT 100 emulation A prototype 8086 based card was shown This would allow running MS DOS software but not simultaneously with OSK A new era of computing was coming at least for OS 9 enthusiasts With the passing of Danosoft CoCoPRO picked up the rights of Simply Better They advertised it on sale for 29 95 the BEST CC3 word processor ever I have to admit some bias here SB was used to write this book In October Lonnie tells us that th
343. th the news that adouble issue would come out this month The double issue was finally delivered in November At the time this book went through final editing March 93 the next issue was nowhere to be seen and inquiries weren t being answered It seems we have lost yet another support source page 32 Although Lonnie Falk said he would not be covering the 68xxx machines just a few months ago it seems a truce had been called between the Rainbow and hard core OS 9 users John Donaldson authored the first of a series of articles on his experiences with his new MM 1 in November Mail from worried CoCo users had alot to do with Lonnie 5 first decision mail from angered OS 9 users and even advertisers the three producers of the 68xxx machines had pumped a LOT of money into Rainbow advertising prompted this repositioning Cray Augsburg stated that although Rainbow wasn t going to put a lot into support of the new machines just yet they would consider articles on them for publication programming language compilerhad been available for the Disk BASIC CoCo user in the early days but had not been available for some time last advertised in Dec 84 Rainbow This prevented many users from learning that language as they had no interest in learning the intricacies of OS 9 Well Infinitum Technology changed all thatin Decem ber 92 Theyintroduced a complete C compiler assembler library linker command coordinator and text editor
344. the BASIC program line PRINT This Phrase then you can use ptf anywhere and it will print the phrase at that point 1 ptf ptf ptf You have just added a completely new keyword you have EXTENDED the CF83 FORTH language This is one of the page 47 most important features of FORTH you can extend and customize it to meet your own particular needs And youcan do so almost without limit Except of course that you can t use the word until after you have defined it CF83 FORTH is modular Unlike other languages where you have to buy the entire package whether you need it or not CF83 FORTH is organized onto individual disks that you can buy one or more at a time You only buy what you need and only when you need it As an additional savings each module s instruction manual is stored on the module s disk printed manuals are available though Prices are significantly lower without the printed manuals You can view the stored manual on the screen and if you need one you can print a hardcopy on your own printer CF83 FORTH is a 1983 Standard FORTH for the 64K CoCo 2 128K CoCo 3 and 512K CoCo 3 with at least one standard single sided 35 track floppy disk drive As of January 1993 the CF83 FORTH system included the following modules CF83 FORTH 83 Standard Required Words This module is the foundation you must have this one for any of the others to work CF83 1 Technical Reference Manual CF83 2 FORTH Tutori
345. the cheapest and easiest way to build the controllers but it prevented OS 9 from doing anything until disk access was completed To alleviate this problem Sardis Technologies introduced a no halt controller late in 1987 This smart controller used a RAM cache to speed up disk operation and limithalting ofthe 6809 while retaining full compatibility with the Tandy controller Under DECB halt mode was used while under OS 9 no halt operation was allowed This controller sold forabout 50 more than comparable disk controllers Why solate before one ofthese became available OS 9 wasn t very usable for multi tasking user operations with just 64K in the CoCo 1 amp 2 With the 512K CoCo3 faster operation became desirable to increase productivity Sardis had dropped out of the CoCo market by the next year Disto also introduced a no halt controller theSuper Control ler IT justa month or two behind Sardis The SCH was priced about the same as the Sardis controller but had the features of the original Super Controller as well four ROMs one could now be a 24 pin and mini expansion buss which made it more attractive than the Sardis model not to mention the respect which Disto products had earned There is something strange about the disk controller s I O address in the CoCo s memory map The disk controller is addressed from amp HFF40 to amp HFF4F This means that the SCS line activates the controller as the SCS line areais amp HFF
346. the controller I soon located a used CoCo2 for 100 about half the cost of a new one I started out with a cassette recorder and Scripsit cartridge The problem with the cartridge was the lack of an ASCII save feature I purchased a copy of Telewriter 64 on tape and was in heaven I then ordered a surplus IBM PC jr thermal printer and made a special cable to adapt it to my CoCo I only paid 49 for that printer It required thermal paper but was full size I eagerly sought all the information I could on my new computer In many ways it was just like my Rambler simple durable and efficient doing its required job with few prob lems I got a subscription to Rainbow and bought a couple boxes of older magazines from a friend who was switching to an IBM compatible I saw no reason my CoCo by now a CoCo 3 and RGB monitor did all I needed page 98 Icompleted my second book a complete history of all AMC products on the CoCo 3 in 1992 ASCII files were transferred from the CoCo written with Simply Better to a Macintosh at a local copy shop The book was then assembled using PageMaker and printed ona laser printer The text quality was exceptional especially when compared to that first work It was this book which kept the ads in Rainbow going as the ads were expensive and software sales weren t up to justify the cost though the software was moderatly successful Falsoft had announced a history of the CoCo but then told us
347. the disk version of Telewriter undergoing final testing Steve Blyn soon to startComputer Island marketing his first educational software and violently negative reactions to Wayne Green s editorial started surfac ing Wayne sure didn t make too many friends that month CCN s February issue was probably the best issue of any Color Computer magazine ever published The issue was special for several reasons If you were looking for a method of transferring your tape files to disk there wasTPTDSK from Jack L Aker Tony DiStefano s article on running machine language programs from disk and C J Roslund s article on disabling the BREAK key What really marked this issue worth its weightin gold however was the article appearing on page 23 32K RAM FOR FREEW byFrank Hogg see FHL story for more on this After Radio Shack s 32K upgrade became available rumor had itthatthe 32K chips used were in fact half bad 64K chips Frank Hogg s article detailed the steps required to enable your Radio Shack 32K CoCo not piggyback 32K to go into the allRAM mode thereby giving the CoCo effective 64K of RAM Frank speculated correctly that although very early 32K Radio Shack upgrades may have contained the half bad 64K chips most 32K upgraded CoCos contained prime 64K chips Radio Shack s 32K upgrade also included the E board and 1 1 Basic ROM Although Frank Hogg didn t perform or even make available the first 64K upgrade his article d
348. the limited expansion offered with only one port Just before the MPI was released in October of 1982 Basic Technology introduced it s own answer to the expansion problem a five slot expansion buss on a cable At one time there were three to five expansion bus devices available forthe CoCo Itis not advisable to use any of these with a CoCo 3 as addressing may conflict with memory areas used by the GIME All were discontinued by 1986 Any MPI slot could contain a ROM Pak game To choose between them one merely turned the MPI off and then moved the numbered switch on the front of the MPI to the desired pak The disk drive controlleris normally used in slot 2 or 4 and the RS 232 Pakin slot 1 or3 A hard drive controller would reside in slot 2 or 4 also whichever the disk controller was not occupying location depends on particular setup Only the CTS cartridge select SCS spare cartridge select and CART cartridge select interrupt are switched between the pairs of slots all other lines are always connected to all four CART and CTS are switched together The reason for this is that the CTS and SCS lines are used to activate devices with ROM in them Only two such devices can be used in the MPI at any one time The other pair of slots must contain a device such as the RS 232 Pak that doesn t use the SCS or CTS lines for port decoding The Speech Sound Pak Modem Pak and RS 232 Pak and a few others contain internal circuitry t
349. this You sent these folks a program you wrote that may have bugs If the program is interesting enough they send your program to people who like to stomp on other people s bugs The understanding was that the program is sold by them if debugged and everybody shares in the profits The ad asked for 5 00 to accompany your bugged program or 9 00 for a cassette containing 20 or so bugged programs from other people or 12 00 for both The idea of buying someone elses problems was and still is a bit bizarre however and ads soon disappeared Tandy s Little Wonder In January Jake Commander CCM predicted the arrival of the British made Dragon computer early in 1983 CCN started the year with a new cosmetic look including a new cover The Color Computer Magazine for 6809 users and newspaper quality pages Cosmetic changes also appeared in the Rainbow s January Adventure issue with the first Fred Crawford cover art work Fred brought a Norman Rockwell feel to the pages of The Rainbow and many looked forward to Fred s covers This issue probably had the first centerfold ever in a computer magazine Other January events included Micronix Systems marketing the first keyboard for the CoCo Dennis Lewandowski writing the Rainbow Check and dates confirmed for the first RainbowFest It was held in Chicago April 22 24th Peter Stark one of the pioneer CoCo supporters started including little tips in his ads Pete
350. to read Clay Abrams documentation for another Color Computer first his RTTY CW communications software The Sep Oct issue of CCN debuted a column which quickly became one of the most popular Comment Corner Written by Andrew Phelps author of The Micro Works CBUG 80C Disassembler and SDS80C each column took an in depth look at one of the Color Basic ROM routines A first this month September from Computerware was the Color Computer s first alternate language PASCAL Computerware also started marketing Magicube a Rubick s Cube game and Color Data Organizer Steve Odneal s FLEX had by this time been converted to operate on the newly released Exatron system and it worked like a champ According to Steve theExatron expansion board was key as it allowed the ROMs to be turned off and RAM turned on Steve while converting FLEX for the Radio Shack disk system doubted the system would be capable of switching ROM to RAM Steve would surely have gotten an F for his specu lation that the Exatron disk system would be the standard disk system for the Color Computer possibly surpassing even Radio Shack s Tandy s Little Wonder The month for trick or treating October saw the first details about the Radio Shack disk system the debut of Bob Nay s Color Computer Users Notes in 68 Micro plus the release of Aardvark 80 s first 7 games Another October treat was Dennis Kitsz s article detailing a modification that
351. troduced a very powerful word processor for the CoCo 3 Word Power 3 amazing how original thetitles for CoCo3 only software could be This original version supported only 80 column displays Inadditionto the usual word processing features Word Power sported mail merge and a 72K 450K text buffer for 128K or 512K CoCos A punctuation checker was added in April of 1988 Word Power3 1 FHL advertised their newhard drive interface It was similar in some respects to the Owl Ware and Disto interfaces in that it was really just an adapter between the CoCo and a controller The secret to the speed was in the controller used a high speed WD 1002 05 Cognitecs Telewriter 64 had long been the most popular word processor for the CoCo so the February introduction of Telewriter 128 for the CoCo 3 was no real surprise a coming soon blurb was in the January ad The new version was kept as close to the original command wise as possible while taking full advantage of the CoCo 3s new power Like Word Power only the 80 column screen was supported Fortunately Telewriter 64 ran ona CoCo 3 with no problem and an upgrade option was available so those not yet having an 80 column monitor weren t totally left out A real surprise this month was SD Enterprises announce ment of VIP Writer III SD apparently had gained rights to the full source code ofthe VIP Library products This wasthe first CoCo 3 word processor to support 32 40 64 and 80 colum
352. ts with a color adjustment or by turning the color burst signal off via software on a CoCo 3 Turning off the color burst requires machine language programming for the CoCo 1 2 CoCo 1 2 programs using high density text screens usually have this feature built in Changing colors also helps A problem is that most programs will override your changes Some text based software automatically turns the color burst off A 10 12 inch B amp W TV will render readable though small 80 column text in most cases with no hardware modifications TURN OFF COLORBURST SIGNAL For CoCo 3 only 40 80 column text on TV or Composite monitors 10 WIDTH 80 REM or 40 20 POKE amp HE033 16 POKE amp HEO3C 19 POKE amp HE045 19 REM turn off color burst 30 PALETTE 8 255 REM change background color 40 PALETTE0 0 REM change foreground character color Try experimenting with the PALETTE values 8 63 and 0 0 or 0 63 and 8 0 may be more to one s liking The TV signal coming out of the CoCo is not the best Though the cable supplied by Tandy is shielded it is small and interference will be noticed especially with disk drives The best way to remedy this would be to get a composite or RGB monitor and avoid use of a TV altogether Fortunately there is an easier solution What is needed is better shielding on the cable between the TV and computer Simply get a suitable length of 75 ohmcable the type used with cable TV VCRs and antennas with F conn
353. uage commands is available for download athttp www sandelman ottawa on ca People Alan_DeKok interests 6309 techref The biggest problem with using the additional 6309 instruc tions is that code written to do so will require the presence of a 6309 and will not run on a 6809 Putting It All In One Case The Ultimate CoCo Upgrade Many CoCo users don t like having their system spread all over a desk It doesn t look neat there is a tangle of cables and the possibility of moving the MPI and shorting out the CPU Some bolt the bottom halves of the CoCo case and MPI to a piece of plywood and add an extended keyboard cable while others repackage the CoCo MPI or Y cable if used and disk drives allin one case usually a surplus PC case but homemade cases are used as well These can be anything from a custom made sheet metal case toa wood case lined with aluminum foil glued to the inside and ground to the motherboard to reduce RFI Almost any old obsolete computer case found at a salvage sale can be used Since the CoCo 3 will drive a CGA monitor even an old luggable PC case equipped with said monitor will work quite well or a small TV screen can be substituted or the BarSoft TTL monitor adapter can be used withamonochrome screen Some older CP M computers such as the Tandy Model IV and IVP IV is monitor computer keyboard and drives in one case IVP is a luggable and Kaypro 4 and 10 models used composite monitors which ma
354. uctively first then try removing without damaging the chip or circuit board You ll bea decent solderer in no time 6 Always ALWAYS replace a bad chip with a socket Sockets only cost a few cents only 1 fora 40 pin and if the repair has to be repeated it will be much easier Using sockets also reduces the possibility of heat damage to the replacement IC General Troubleshooting Let s start with checks at the major chips These checks will indicate a lot of potential problems Problems aren t necessar ily the same in all cases so check the suspected chip as well as any others in the same circuit It is possible that conditions other than those shown could cause the same results listed A short description of the major components and common problems follows troubleshooting tips The following charts list logic probe readings computer turned on of the major ICs A VOM will read highs as 5V lows page 83 as OV A pulse should read as a bouncing or wavering reading between OV and 5V Low pulse will read OV high pulse 5V VOMis not very accurate when reading anything other than a steady high or low signal 6809 5 DESC READING NO DESC NO READING 2 NMI high 2 4 A10 A8 47 49 h p 3 IRQ h p 7 VEK n a pulse 4 high 8 DAO n a h p 1 7 high 9 HS n a h p 8 11 A0 A3 pulse 10 WE 0 10 h p 12 4 h p 11 CAS 5 pulse 13 A5 pulse 12 RAS 4 pulse 14 18 A6 A10 h p 13 Q 7 pulse 19 20 A1
355. und on the Radio Shack Color Computer though the ad mentions true lower case lacking in the first Radio Shack Color Computer and a full travel keyboard The ports are shown on the right side of the computer It could have been a clone of the Dragon instead of directly a clone of the CoCo page 130 Tandy s Little Wonder 1983 magazine advertisement Tandy s Little Wonder TRS 80 COLOR COMPUTERS BETTER THAN EVER Our Color Computers Are Ideal for Entertainment Education and Home Use 16K Standard 16K Extended Color Computer 2 Color Computer 2 34900 45900 Each Model Uses instant Loading Program Paks Eight Vivid Colors Exciting Sound Effects TRS 80 Standard Color Computer 2 We improved our most popular family computer with a compact white case low profile electric typewriter quality keyboard anda price that s 100 less than last year s model Easily attaches to any TV then Program Paks let you set up a budget or monitor your investments and help the kids develop math and reading skills You can also learn how to program battle starships run maze play basebali and lots more Expand with a cassette recorder disk drives a printer or telephone com munications With entertaining 308 page beginnor s manual 26 3026 349 00 TRS 80 16K Extended Color Computer 2 All the features of the Standard Color Computer 2 plus advanced programming capa bilities to make spectacular high resolution color grap
356. unes Rainbow Max 10 was similar to the Apple MacIntoshs MacWrite word processor It was all graphics based with mouse controlled pull down menus Since graphics and text could be mixed it was billed as a desktop publishing system when combined with CoCo Max 3 Many different fonts and styles were available and since all could be displayed on the graphics screen Max 10 was the CoCos first true WYSIWYG what you see is what you get word processor The ad stated that Max 10 was not copy protected but that wasn t entirely true The disk itself had no copy protection but a hardware key the first and only one ever for a CoCo product was included This was a series of resistors and diodes which plugged into the cassette port If the software didn t find it it simply wouldn trun Though the keys components were cast into an opaque resin disk hack ers soon discovered how to mimic its signals and defeat the protection Such an outcry was made over this new to the CoCo world protection scheme that Colorware soon dropped itin future versions SD Enterprisesreleased an updated VIP Database for the CoCo 3 in June VIP Database owners could upgrade at a reduced price THE NINTH YEAR Jul 88 Jun 89 In the beginning of the Rainbow s seventh year CoCo s ninth there are 79 advertisers Many long time advertisers had started dropping support for the CoCo as their CoCo 1 and 2 products became dated They just didn t see putting in the
357. uperb Graphics Resolution and Uncompromising Performance at Anl ible Price 21995 iis Choose From a Palette of 64 Brilliant Colors Produce Sharp Crisp Graphs and Illustrations Display 32 x 16 40 x 24 or 80 x 24 Text 160 x 192 320 x 192 or 640 x 192 Resolution Use With a High Resolution Monitor or Your Own TV s Expands Easily As Skills and Needs Grow 128K Extended BASIC Color Computer 3 Introducing Radio Shack s newest version of our famous Color Computer The Color Computer 3 can be used in a variety of applications such as graphics programming budgets word processing data base management spreadsheet analysis and many others The Color Computer 3 comes with 128K memory expandable 10 512K and gives you the advantage of greater programming and data processing power as well as higher resolution graph ics Simply connect the Color Computer 3 to a high resolution monitor like the new CM 8 monitor sold separately at right and you can create incredibly detailed charts and engineering drawings in vivid colors The special higher graphics mode lets you paint 160 x 192 or 320 x 192 resolution graphics 16 out of the 64 total colors Or produce razor sharp 640 x 192 resolution 4 colors The 21 new commands featured in the Color Computer 3 s Extended BASIC allow you to switch between screens colors and backgrounds at a higher resolution and in a greater variety of colors than any previous C
358. uspect pak under aDECB program fit works fine then replace the 6551 witha 2MHz rated 6551A Note that most 6551 chips work fine at 2MHz with no problems The majority of non Tandy RS 232 paks use the 6551A Inrare cases the crystal may be damaged If the pak initializes DTR and RTS line change status when a terminal program is run but no data is sent or received suspect the crystal First check for continuity of the traces between the 6551 and 1488 1489 and between them and the DB 25 connector If all is well replace 1 8432MHz crystal Multi Pak Interface MPI Repairs If intermittent program problems are occurring with an MPI connected to a CoCo 3 check to see if the MPI has been upgraded The 26 3024 MPI large gray or white case requires anew PAL The upgraded Tandy PAL will have NOT have a Tandy number on it The four digit date code should be after 1986 The original MPI PAL DOES have Tandy and a part number 8075 144 for the later model The small 26 3124 MPI requires a Satellite board The board and necessary wiring should be visible through one of the slots or cooling vents See Upgrades for details Ifsome slots work and others do not the problem is most likely inthe SCS CTS and or CART select circuitry In the 26 3124 MPI newest small one the big custom IC handles slot selection In the large MPIs slot selection is handled by the LS139 SCS amp CTS LS153 CART LS368 CTS amp SCS and LS374 CTS
359. ust delivery It seems everybody was out to capitalize on the outstanding graphics capability ofthe new CoCo EvenOwl Ware got into the act with the introduction ofDaVinci 3 in August A unique feature was that no hi resolution adapter was needed fine control of the input device joystick mouse X pad or touch pad was accomplished via software Tandy s Little Wonder Diecom Products quickly followedComputize andOwl Ware witha graphics program of its own in September the Rat This package came complete with a two button digital mouse not the Tandy analog mouse Almostall functions were accessed through the mouse with pull down menus Iron Forest a unique game which used aSEGA light gun and several other CoCo 3 only games were also introduced Not to be outdone in the graphics field Colorware introduced an updated version of its popular CoCo Max programs CoCo Max naturally for the CoCo 3 which also debuted in the September issue of Rainbow Rather than creating an entirely new hi res adapter Colorware supplied a modified Tandy hi res adapter that did not require using the cassette port Animation and color sequencing were special features of the new program The November issue of Rainbow featured a Colorware ad comparing CoCo Max III to Color Max 3 Inter estingly the ad was back to back with a Computize Color Max 3 ad Cer Compreleaseda terminal program word processor and BASIC compiler for the CoCo 3 only in Septembe
360. ustralia asked if there were an easy way to create new icons graphics representing programs for OS 9 s Multi Vue Another reader replied in September indicating that Tandy said Multi Vue was originally intended for program devel opers and that a 10 page document addendum was avail able directly from Tandy This prompted Tandy Computer Customer Relations to respond through a letter to the editor stating that this impression about Multi Vue was incorrect the STYLE that Multi Vues documentation was written in was more suited to programmers Tandy also offered Multi Vue and Pre Existing Applications the 10 page addendum re Tandy s Little Wonder ferred to above for publication in Rainbow it was published the very next month December The number of advertisers for the 1989 December issue was 59 One of these Orion Technologies had an ad announcing a new hardware product for the CoCo the XPort This was a direct replacement for the Multi Pak but with only three slots These slots were ona short ribbon cable which came out of a box which contained the circuitry and plugged into the CoCo A separate power supply provided 12 volts to the slots Also debuting was Howard Medical s MP II later calledSlot Pak II possibly due to concern that Tandy might object to Multi Pak II This was similar to the Xport but builtin along disk controller case Power for this multi pak replacement was drawn directly from the CoCo with
361. ves Early Tandy drives are most often made by TEC Tokyo Electric Com pany These are full height units notorious for not staying in alignment as are many early floppy disk drives Most after market suppliers stuck with higher quality Tandon Shugart or TEAC models Tandy later switched to Shugart drives and other manufacturers Most full height units provided by Tandy were capable of reading only 36 tracks with a seek access time no faster than 12ms access time is the amount of time measured in millionths ofa second ms it takes the read write head to move from one track to another The old TEC page 66 units may not work faster than 20ms The only full height drive supplied by Tandy that will read 40 tracks is the white cased unit Nearly all single sided half height drives whether sup plied by Tandy oranother vendor are capable of accessing 40 tracks and most will work at 6ms The FD 502 drives are all double sided 40 track The best thing about CoCo disk systems is that the drive is a standard model available almost anywhere computers are sold Any 360K 40 track double sided drive will work and should be used for replacing older full height and single sided drives These drives are available used for as little as 20 25 in most areas Many IBM people have upgraded to higher capacity drives and no longer want or need these drives Check with local computer shops if searching for a drive The old full height drives were qu
362. ween 1 and C29 cut the main trace between the leg that goes to C29 and that goes to SALT pin 16 Apply 12V to trace that goes between pin 16 of the SALT and the input of Ql 12V i CUT HERE SS CUT HERE C30 1 45V CUT HERE C15 4 Tandy s Little Wonder PAL European CoCos The PAL version of the CoCo follows the same procedures as outlined for the American Korean made units and CoCo 3 The only difference is that the PAL encoder a satellite board near the modulator requires 12V on one of the connectors seven pin CN9 on the CoCo 3 The 12V input point is clearly marked on the encoder circuit board Cut the trace on the motherboard going to the 12V pin and then supply the pin with 12V from the power supply Note the voltages fed into certain points These voltages are supplied by the normal CoCo power supply and may be used for testing Voltage Amperage Requirements 5V 12V 5V 12V 1 1 3254 400mA 100 100mA CoCo 2 2 00A 100mA CoCo3 2 00A 100mA MPI 135A 400mA 100 Disk Drive 300mA 600mA Hard Drive 300mA 1 2A 600mA Floppy drive rating is fora typical 5 25 half height drive The 12V currentis with spindle motor and stepper running at the same time In a two drive system both spindles will be on at once but only one stepper 12V at 1 0A would therefore be sufficient Old full height drives require as much as 5096 more power than listed Full height drive cases have
363. will fit on a decent number of disks in other words itcan be like MS DOS Microware took the third tack OS 9 and OS 9 programs are split into modules which can be loaded as needed or unlinked to free up memory You ll see this in action when running config or os9gen out of all the things that could go into OS 9 the user picks the ones he needs OS9gen packs them into a small quickly loaded boot file There are afew additional space saving tricks Firstall ofthese modules are reentrant One copy in memory can be ran many times simultaneously Each separate iteration gets it s own block of data space but uses the same copy of the code The other trick involves how a moduleisrun For example the OS 9 prompt you see on screen doesn tcome from OS 9 itself but a special program called shell When you type a command shell reads it then runs that module It doesn t go away but waits in the background for the new process to finish This is called forking a process The old process known as the parent is still around just hidden in the other fork of the road waiting for the new process the child to finish Now if you really need every byte of RAM you can chain the new process using the ex command The parent shell is killed freeing up the memory it used but if the child process ends the window seems to lock up It hasn treally crashed but there is nothing for it to run To keep track of all these modules OS 9 has a special di
364. with BASIC programs one side and OS 9 on the other It was predicted that OS 9 would play a leading role in the future of the CoCo 3 especially since Tandy announced that all new software development would be under OS 9 with the exception of ROM pack games Disto finally followed the lead ofOwl Ware andJ amp M by advertising a hard disk adapter for their Super Controller coming soon Yet another Color Computer magazine was advertised in the November issue of Rainbow Spectrogram offered users columns on telecommunications BASIC and Pascal program ming OS 9 and more Bill Bernico was the most known contributor In the coming months it is almost like the introduction of the original CoCo Owners of the new CoCo 3 were pouring over the remaining CoCo magazines looking for new products and information that took advantage of the great new features Except for a few offerings from Tandy such as Decembers unveiling of DeskMate 3 the pickings were few and far between Spectrum Projects became the first third party vendor to advertise software for the CoCo 3 First came Draw a graphics program in December thenElite Word 80 in Febru ary a word processor that used the 40 and 80 column screens andexpanded memory Like many programs to come this one DID NOT work on previous CoCo models Cer Comp started advertising versions of their software for the CoCo 3 in January These special versions are only interim versions though C
365. xpensive Hewlett Packard Scientific Calculators Some less expensive HP calculators and most others use Algebraic Notation AN AN is familiar and easy to understand If we want to add 3 and 5 with an AN calculator we simply press 3 5 and the answer 8 appears in the display With an RPN calculator we press 3 ENTER 5 and the answer 8 appears in the display The answer is the same but the procedure isn t as clear or natural Similarly under BASIC we would enter PRINT 3 5 but in CF83 FORTH we would enter 3 5 Algebraic Notation makes things easier forus But RPN makes things easier spell that F AS TER forthe computer FORTH programmers will readily testify that the additional speed is well worth the added effort FORTH Extensible In BASIC and other languages you have aset of reserved operators and keywords like PRINT INPUT RETURN STRINGS etc These are the only words you can use in writing programs If you want to PRINT This Phrase at three different points in the program you either have to repeat the program line three times 110 PRINT This Phrase 260 PRINT This Phrase 430 PRINT This Phrase or set up a subroutine and call it three times 110 GOSUB 1000 260 GOSUB 1000 430 GOSUB 1000 1000 PRINT This Phrase 1010 RETURN But in CF83 FORTH when you define a new word you can use it just like any other word If you define the word ptf ptf This Phrase which does the same thing as
366. y Routines for the Tandy amp COCO Vol I Kishore M Santwani 1986THE BOOK Assembly Language Programming for the TRS 80 COCO Tepco 1986Utility Routines For the Tandy amp COCO Vol II Kishore M Santwani 1986Supplement To 500 POKEs PEEKs amp EXECs Kishore M Santwani Zebra Systems see 1984 1987THE ADDENDUM CoCo 3 supplement toTHE BOOK Tepco 1987Super Extended Basic Unravelled Kishore M Santwani Available free as PDF files at http www coco3 com ind_unravelled php 1987300 POKES PEEKS EXECS for the CoCo III Kishore M Santwani Zebra Systems 1987The Complete Rainbow Guide to OS 9 Level II Vol I A Beginners Guide to Windows Dale Pucket amp Peter Dibble Rainbow Bookshelf see 1985 1988 Start OS 9 step by step tutorial Paul K Ward 1989A Full Turn of the Screw 83 89 Articles from Rainbow Tony DiStefano Rainbow Bookshelf see 1985 1990Connecting CoCo to the Real World William Barden Jr 1992The OS 9 Catalog description of all OS 9 68000 mod ules useful for OS 9 6809 also Tandy s Little Wonder Past Magazines The Color Computer definitely had its share of publications over the years The large ones were Hot CoCo The Color Computer Magazine andThe Rainbow These were all three published simultaneously during the CoCos heyday It wasn t long before all succumbed except for The Rainbow Accord ing to Lonnie Falk founder of The Rainbow and Falsoft the others just didn t offer as much as The R
367. y and Sunday October 1987 was justa memorable month for the CoCo Not only were the previously mentioned software packages first available but SD Enterprises started advertising Softlaw s VIP products for the CoCo 3 The original versions would not all run on the new CoCo page 19 The first commercial desktop publishing package CoCo News room appeared in the NovemberSpectrum Projects ad Over 140K of code 22 fonts and 50 pictures were boasted With new products being introduced it is hard to believe that faithful Spectrum projects would not be in the CoCo market much longer Howard Medicalbegan selling hard drive systems using the Burke amp Burke adapter shown at the last RainbowFest in December They didn t say it directly in the ad but phrase will also work with IBM amp clones sort of gave it away Complete 20MB systems were sold for 699 a much better deal than the 999 95 5MB systems first sold in 84 The next month the first Burke amp Burke ads appear selling the hard disk adapter and software as individual components This allowed individuals to get used PC hard drives and make their own systems at a substantial savings Maybe the earlier systems just paved the way and the Burke amp Burke ad is correct 1988 The Year of the Hard Disk FHL also enticed us with an upcoming hard drive interface claiming it to be the fastest We ll see Frank we ll see In February of 1988 Microcom Software in
368. y be adaptable for use with the CoCo Before attempting to repackage your CoCo please remember to be careful It is next to impossible to replace a damaged motherboard It will take some careful planning and basic electronics and soldering knowledge but it can be success fully accomplished It may be a good idea to read the Periph erals Upgrades and Repairs sections of this book for some hints and tips before continuing The following is an account by one person who repackaged his CoCo successfully Use it as a guide be careful and good luck ATCoCo Putting it all in one Box By Mike Haaland Written December 14 1988 Updated January 15 1989 Edited added to by F G Swygert February 17 1993 This article is the procedure I have used to get the clutter of computer components off my desk and into a single PC AT clone case It has been put together and distributed to aid those CoCo owners who are tired of the mess to do the same Tandy s Little Wonder I nor the author of this book cannot take responsibility for any damage you may do to your system while attempting this project The need for such a transplant depends totally on your own tastes The nicest thing about the ATCoCo CoCo in a full size IBM AT type case 15 you have so much room for drives expansion packs etc and that your system will be nice and neat without the need of having cables running all over the place Inan AT size case you have room for Three ha
369. y the major problem Tandy didn tdevelop a diskoperatingsystem DOS perse What was developed was an extension to the existing BASIC language that allowed direct disk operations If one has ever programmed GW BASIC or BASIC A on an IBM compatible then the fact that many disk activities can t be done in BASICis known The DOS PC DOS or MS DOS must be called to perform all but the most rudimentary disk opera tions such as a directory Tandy s Disk Extended Color BASIC DECB can write and read directly from disk and is much more convenient to program disk operations with The term RS DOS is often used to refer to DECB but the term is technically incorrect Only two versions 1 0 and 1 1 of DECB were ever published by Tandy The CoCo 3 changes the first one to atwo 2 0 2 1 but does not alter the disk commands themselves DECB must be patched for reliable double speed disk operation CoCo drives are numbered from 0 to 3 meaning four single sided drives can be accessed Tandy chose an odd method of selecting which drive was which by removing the contacts from the connector of the three that the drive wasn t This method had one merit it was foolproof All the drive select jumpers could be selected on a drive from the factory Anyone could then plug in a drive and it would work properly no configuration necessary Another oddity was that position 32 Tandy s Little Wonder on the cable was used for drive select 3 instead of

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