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1. cnn TOL pc E 50 Polyglot TSR Package includes reminder bookmark virus catcher cache manager amp speech generator 50 HELP pop up help system builder 4 4 e 50 Multi User BBS chat mail menus sysop displays uses Galacticomm modem card Version 4 4 0 a 50 Make macros all languages built in rules 6 4 ee ee ee ee n o n n n n 50 Coder s Prolog inference engine for use with C programs s 1 4 4 4 e e eee eh e oe n oh non 45 Virtual Memory Manager by Blake McBride LRU pager dynamic swap file image save restore CaN ar er area Heap I O treat all or part of a disk file as heap storage Sos fas UVP ten av n ute UE he EP AS a wg ange DU ARE fan ToS aaa a e 40 Biggerstaff s System Tools multi tasking window manager kit 4 4l l4 elle hor nn 40 OOPS collection of handy C classes by Keith Gorlen of NIH Version2 2 eee 35 Bison amp PREP YACC workalike parser generator amp attribute grammar preprocessor now includes documentation 35 PC XINU Comer s XINU operating system for PO 4 44 e 4 4 eee eee eee o ooh oh nn 35 CLIPS rule based expert system generator Version 4 2 osoasa e eoe oh non on 35 Tiny Curses Berkeley curses package 1 2 a 4 e ee leere eee he homo oho eoo ho hon onn 35 Polyglot RAM Disk han e disk size on the fly includes utilities eee 30 SP spelling checker
2. cee 99 Cant Pass Up COMPLETE 80386 20DX SYSTEM with Rotary Voice Coil Hard Drive MOTHERBOARDS XT Turbo 4 77 10 setae ates 75 AT 6 10 Award Phoenix DTK Bios eese 229 AT 6 12 Award Phoenix DTKBios ee 279 Baby AT 6 12 AMI DTK 249 AT 8 16 DTK Bios 395 80386 8 20 DTK Bios 799 XT AT Memory CALL SOFTWARE MS DOS 3 21 w GW Basic 49 DR DOS 3 3 W GEM 49 MS DOS 3 3 w GW Basic 95 DISK DRIVES Teac Toshiba 360K 69 Teac Toshiba 1 2 MB 85 Teac Toshiba 3 720K 79 Teac Toshiba 3 1 44 MB kit 90 XT 20 MB Miniscribe 8425 65ms 279 8425 w controller 319 XT 30 MB Miniscribe 8438 65ms 299 8438 w controller 349 HARDWARE MANUFACTURER MicroSphere COMPUTERS SINCE 1983 1 800 234 8086 855 N W WALL BEND OREGON 97701 Reader Service Number 02 This machine features an 80386 CPU running at 20 Mhz on a full size DTK motherboard For extra quality and reliability we ve included a 5 Mb Miniscribe 3053 Hard Drive with a 25 ms access time 1 2Mb amp 1 44Mb Toshiba or TEAC floppy drives 2 8Mb 32 bit memory slots 1Mb of fully optimized 80ns RAM Runs an incredible Norton SI test of 24 2 serial ports 1 parallel port 101 key keyboard Graphics Combo video card with amber or green monochrome monitor DTK B
3. 725 1 FD and 1 Miniscribe HD 4 77 10 Mhz with 20 Mb HD 949 4 77 10 Mhz with 30 Mb HD 975 AT SYSTEM Includes 640K RAM 1 2 Mb FD 1 44Mb FD 40 Mb Miniscribe 3650 HD serial parallel game ports clock calendar 101 key keyboard turbo switchable slide cabinet power sup ply Graphics Combo video card with amber or green monitor Full 1 year warranty Ask for FREE assembly and testing 6 10 Mhz 1359 612Mhz 1395 Color options for any kit includes video card and monitor CGA Color eee 175 CGA EGA Color 380 VGA analog with Mitsubishi monitor 650 CGA EGA EGA 480 Multisync sees 450 ure PC XT amp AT Parallel LPT 1 2 or 3 Serial Port Card 1 installed Switchable Com 1 2 30r 4 18 Kit for 2nd SerialPort 18 Multi I O Serial Par Game 32 2nd Serial Kit 20 Multi Drive Controller 39 Supports 1 44 720K 1 2 360K drives PC XT Floppy Controller 19 Multi function 1 ser par clk game 2 floppy 47 640K RAM OK 25 150 Watt Power Supply 50 Slide case lock LED 38 2 MB EMS Memory Board OK Installed 49 AT 200 Watt Power Supply 75 AT 386 Case Lock LED 72 Tower AT 386 Case Lock LED amp 200 Watt ps 239 2 MB EMS Memory Board OK Installed
4. asm pop DX asm pop F void receive block dbyte buffer unsigned int count CX count _BX buffer DX BASE 2 waitl asm in AL DX hshake_lo asm dec DX asm test AL 00001000B asm jz waitl wait for handshake to drop BASE 1 asm in AL DX asm and AL 11111000B mask off pertinent bits asm mov AH AL stash it asm inc DX BASE 2 asm in AL DX asm and AL 00000111B asm or AL AH rest of byte combine the byte asm xor AL 10000011B flip inverted bits asm mov byte ptr BX AL store the result asm inc BX move pointer to next mem location _DX BASE asm mov AL 11111110B asm out DX AL _DX BASE 2 lower byte recd line wait2 asm in AL DX asm test AL 00001000B asm jnz wait2 wait for handshake to rise _DX BASE asm mov AL 11111111B asm out DX AL _DX BASE 2 asm loop waitl De assert byte recd void send block dbyte buffer unsigned int count CX count BX buffer DX BASE send asm mov AL byte ptr BX get a byte to send asm inc BX asm out DX AL DX BASE 2 asm mov AL 1100B asm out DX AL lower handshake wait3 asm in AL DX wait for byte recd to go low byterecd asm mov AL 0100B asm test AL 1 asm jz wait3 raise handshake asm out DX AL wait4 asm in AL DX asm test AL 1 wait for byte recd to go high asm jnz wa
5. 009 9090009909 ececcccccccoce BACK OF COMPUTER PC EXT Ready ton Drive select Z Motor enable 2 n c Index n c Direction Step pulse Write data Write enable Track 0 Write protect Read data Side select n c Ground NEC didn t know 22 28 Ground Hon t NOTE Order of pins is reverse of what you might expect Pins are not numbered Ground pins 1 and 21 in the external drive through 3 9K This is how the NEC knows the external drive is there white 9 6 volts black ground them Cute considering that BACKUP reported no errors and naturally I re formatted the hard drive before I found out that the disks were no good BACKUP and RECOVER in DOS 3 3 work perfectly I am pleased with the NEC now that the bugs have been appeased For a time I was ready to trash it Weight wise it s a little heavy keyboard is good screen very readable runs about an hour and a quarter on a battery pack 2400 baud modem extra power supply too bulky I built my own I travel a lot and always take it along I m becoming very dependent on it Lynn Smith 3051 Shirley Dr Newbury Park CA 91320 Power Hungry Mouse Solution Regarding Rod Morimoto s technical tip Logitech Zenith Compatibility in Micro C issue 41 I too had the problem with interfacing a Genius Mouse GM 6 Plus with a Zenith 181 92 laptop com puter The problem is that the open cir cuit output voltage of the la
6. 48 July August 1989 V Keyboard GetKoy real out to gt debugger we running SII IOI XXX ARKARKRARKARKAKKAKARKRARKKARKAAKARKKAR es IVIDE BY 0 EXCEPTION HANDLER ide by 0 exception handler is org ea at a special Was done because a program running wild very often ends up t location 0 0 This can happen because of a jump or call indirect through an uninitialized long pointer Or very commonly by executing an INT xx for an interrupt whose vector has not been initialized Gnd is therefore 0 o ee Us S Remember t hat COMMAND COM sets its own Divide by o interrupt so nstall UE from ROM before 1 DOS boots it will be Possible uses of TRAP are to detect invalid opcodes in long strings of line code of the Turbo Pascal variety find the source of that pesky Divide by 0 bug or figure out which long pointer to a subroutine wasn t initialized Load TRAP before you start up the debugger It s a TSR remember I used MASM 5 1 to assemble TRAP You could probably twitch it around to work with earlier versions but I would recommend just upgrading to 5 1 and getting it over with Trap uses a few subroutines for printing numbers and strings which though not listed in the magazine are available on the Micro C BBS or on the Issue 48 disk 8088s Sorry about this all you 8088 users but TRAP just won t work on an 8088 or 8086 system They don t have the facilities to trap o
7. An absolutely perfect child according to papa Scott Of course a person s perspectives have to keep changing if they are to grow as a human being This is one thing which sets us apart from computers humans always have the potential to better themselves and the world around them All that aside this is a technical column so I suppose I had better say something technical After all I ve got these creative juices flowin TOOLBOX Due to the length of C EXPLORATIONS this issue l ve dropped the TOOLBOX section After all C EXPLORATIONS has gotten short shrift in the past I ve found that parts of this column argue with each other if they re not treated fairly So you re not reading this since it doesn t exist C EXPLORATIONS It s been a while since I presented a signifi cant piece of code in this column So I began looking through my pile of programs seeking an interesting and educational piece of code What I found were my standard library func tions for doing file searches While that may s FileSrch File Search 41 00 02 Apr 1989 E ANSI c Nh MS pos extensions This module will search subdirectories for files to be deleted It can query the user as to whe ch files anode be deleted Written by Scott Robert add No eights reserved Hie eed ERR us So o define FILESRCH H 1 e defined Jen ab defined 98 ae 1 defined 3 k 1 seem old hat this mod
8. Call or write for our complete catalog of software parts accessories and complete repair services for the Kaypro Xerox 820 and IBM PC AT Prices subjectto change without notice VISA and Mastercard accepted Include 6 00 shipping and handling 8 50 for COD UPS Blue or RED Label additional Please include your phone number with all correspondence EMERRLD MICROWARE 503 641 8088 dins WA MICRO CORNUCOPIA 48 July August 1989 41 42 MICRO CORNUCOPIA 48 July August 1989 a INPUT VECTOR omy VECTOR If the status bits show the task as inac tive PAUSE skips the task and resumes the search for another valid task and TDB If the task s status bits show it s not yet started PAUSE resets the bits to show the task as active and proceeds with startup Starting a task requires updating the current user number incrementing the task s activation count contained in the TDB and loading the task s I O vectors into RAM Finally PAUSE pulls the task s stack pointer from the TDB re loads all registers including the stack pointer and executes an RIS returning control to the now active task PSTAT provides a visual check of the multitasking kernel Executing PSTAT gives a short display of all tasks defined by the TDBs Information supplied by PSTAT includes the task name stack pointer activation count and current I O device assigned The activation count contained in each TDB
9. END Editor s note I dug out a few video boards at Micro C did a little digital vivisection and came up with a few very general tips on attributes Don t let anyone tell you differently R amp D really stands for Ruin and Devastate The one byte attribute associated with each character controls reverse video under line blink intensity and foreground and background color Be aware that available attributes vary a bit from Hercules to CGA to VGA etc Our mission should we decide fo accept it is to intercept the attributes 92 MICRO CORNUCOPIA 48 July August 1989 set all characters to one attribute turn attribute on and beep E O7 turn attribute off and beep before they get combined with character data to form the final dot stream It turns out to be easy sorta The video controller reads one charac terjattribute pair at a time and stuffs em into buffers We just have to figure out which chip buffers the attribute byte Often octal flip flops like the 273 and 374 per form this function So here s the drill Run a little program like the one in Figure 4 that toggles the attribute you want to control Make it beep every time the attribute changes Now start digging around on the video board with a logic probe or volt meter Look for a pin or pins that goes high and low with the same frequency as the beep A board extender to bring the video card up out of the bowels of your
10. Reader Service Number 62 MICRO CORNUCOPIA 48 July August 1989 19 File Transfer Via The Parallel Port And An XT Controller Update You ve perhaps heard about these paral lel file transfer packages that pass data at the speed of light Pretty fancy with all that file handling Right Well Bruce s is just as fancy and it s a lot cheaper Free eady This time I ll show you R row to transfer files very quickly via the parallel printer port I ve successfully transferred files at speeds of 1 4 megabyte per second be tween a 10 MHz XT and a 6 MHz AT So with a couple of cheap printer cards 20 each from MicroSphere and a little rewiring on a cable you can create a 2 node tiny LAN well the file transfer part of a LAN anyway This article temporarily diverts from my turn your XT into a controller ser ies although I could try to slide it in under the auspices of communicating with a controller In the meantime I do have an update on the XT controller pro ject which should keep you happy until next time when I return to the series XT Controller Project Update Your response to the XT Controller series has been great I guess a lot of you realize that XTs don t die they just get cheaper DOS is the most powerful development environment around for the price so why roll your own hardware when you can use an XT In one of the upcoming projects in this series I ll look at modifying the R
11. agine disassembling an IBM keyboard and installing a mechanical Control Lock Alt Lock and Shift Lock Not a job for just anyone I hoped there was a better way I wrote to PC Magazine describing the problems of using a mouthstick and they By Dallas Vordahl 13720 E 26 Ave Spokane WA 99216 published my letter The result was Toggle Key a TSR program written by Ernest Kraut His program turns the Control Alt and Shift keys into toggle switches and displays their state on the screen David Rose of RoseSoft whom I also asked for help wrote a one finger mode into the following version of Pro Key ProKey is a TSR macro program He took a different approach to the prob lem than Kraut He kept the Control Alt and Shift keys toggled for one keystroke That saved a keystroke each time I used a single control key command Superkey by Borland has a similar feature Other Solutions PC Magazine readers offered many _ other solutions ranging from TSR pro grams to mechanical arms to using weights to hold down those keys The re sponse was terrific and their help made it possible for me to use IBM type com puters However I m now faced with three button mice and 101 key keyboards I can just manage the width of 101 key key boards with my mouthstick but mice are simply out of the question it seems that every advance leaves me farther be hind Out from the shadows behind you pounces a beard
12. 1 Serial 1 Parallel 1 Game Bi Dual Floppy Dual H D Controller iB Monochrome Graphic Card 101 Key Enhanced Keyboard iB TTL Monitor 12 E 20MB Hard Disk E MS DOS 4 0 NGW BASIC Optlons i vestes metere I ere Call resolution 640x400 super twisted LCD with adjusta ble intensity and screen angle The screen size is 9 5 x6 It s as readable as a CRT You can also plug in a digital or analog color monitor or a digital or 189900 16MHz 0 Wait State Assembled amp Tested IBM AT Compatible MS DOS OS 2 amp UNIX Compatible WM 80386 16 8 MHz Norton V4 0 SI 17 6 B Phoenix BIOS E 1MB expandable to 16MB RAM 80387 Coprocessor Socket E 200W Power Supply B 1 2MB Floppy Drive W Ports 1 Serial 1 Parallel 1 Game WB Dua Floppy Dual H D Controller ii Monochrome Graphic Card 101 Key Enhanced Keyboard E TTL Monitor 12 E 20MB Hard Disk 28MS E MS DOS 4 0 NGW BASIC Optlons veis iesre er hh en Call Also available in PLASMA PORTABLE Including Hard Disk Only 19 Ibs composite monochrome moni tor Included also is an exter nal 54 floppy port for read ing and converting to 3 disks 5 4 external drive w case 179 when purchased with LCD Portable The Mc Tek Rabbit 286 LCD Portable comes fully assembled with our one year parts amp labor guarantee and sells for an amazing complete price of only 1 799 386 20 MHz 2599 W IMB 219900 20MHz 0 Wait State Assembled
13. Don t let incompatible diskette formats get you down read them all with your PC Teach your PC to speak CP M UniDOS Z80 Coprocessor Board by MicroSolutions Run your Z80 and 8080 code programs at LIGHT NING speed on your PC or AT with the UniDOS 8MHz Z80 coprocessor board UniDOS auto matically switches from MS DOS to CP M mode when your CP M program is executed UniDOS emulates most common computers and terminals such as Kaypro Xerox 820 Morrow Osborne and VT100 All standard CP M system calls are supported Includes UniDOS and UniForm PC UniDOS Z80 Coprocessor Card 169 95 UniDOS by Micro Solutions Equip your PC XT with an NEC V20 chip and run your favorite CP M programs without taking up another card slot Runs 8080 code directly on the V20 and uses emulation mode for Z80 code or systems without a V20 UniDOS by MicroSolutions UniDOS w UniForm amp V20 8 chip UniForm PC by MicroSolutions How have you ever wished you could use your CP M diskettes on your PC Now you can access your CP M files and programs on your MS DOS computer just as you would a standard MS DOS diskette Install UniForm and use standard DOS commands and programs right on your original diskette without modifying or copying your files UniForm PC allows you to read write format and copy diskettes from over 275 CP M and MS DOS computers on your PC XT or AT With UniForm PC and the Compaticard you can use 5 high density 96TPI 3
14. For instance how do you look at address and data at the same time The Z80 has 16 address lines and 8 data lines That s not counting the control signals such as CAS MUX read and write Fortunately this processor was running ROM code and for tunately the initialization routine lay in the first 256 bytes I hooked up 8 channels to the ROM s lowest 8 address lines I hooked up the other 8 to the data bus I hooked one of the analyzer s qualifier leads to the power line and made it active high Then I hooked the other qualifier to the ROM s write enable line and turned on the copier Blam I had the low order addresses and data from the first 2048 ROM accesses At startup the processor begins by loading the instruction at address 0000 00 C3 01 29 02 00 Well a C3 is a jump so the processor knew it should load the following two bytes to see where to jump to It loads the low order byte first 29 followed by the high order byte 00 The first three bytes in my printed listing were C3 29 00 so things were fine so far I looked at the next ROM access 2D E3 Oops The processor was supposed to jump to address 0029 but went to 002D instead I quickly dug through the schematic to see if there was something between the processor and the ROM something that might misread the processor s address selection Nope So it must be the processor Right However it couldn t be the Z80 Larry had mentioned replacing it But I
15. My prestige would suffer a blow let me tell you 2488 To NATHAN ENGLE From SYSOP Nathan I m surprised You d pass up a chance at immorality Pardon me immorTality How about a collection of these messages I ll do all the work and you can take the credit Merry Christmas Larry July August 1989 ee 2489 To ENGLE SYSOP From NATHAN Well Larry I ve been thinking about it and I may be taking the wrong attitude going into the closet like I had planned It just doesn t seem to be in keeping with the spirit of Open Disclosure in this age of Enlightened Media I ve been listening to this station a lot recently and it may be affecting my thinking but it seems to me that if we can get to the root of this if we can save one single child from the same dread fate Well darn it You put it that way I don t see how I could refuse Only I m not doing any posters Oh by the way a very merry holiday to everyone at Micro C You have helped make this a banner year for me When I was a kid my father used to take me to art fairs where he had a display It was an overwhelming experience more than once camping out in central Kentucky with a gang of the most bohemian ar tists and musicians you ever saw That s a long way away now some of those people have died many have changed but those are my kind of people I can t help but feel that Micro C people writers and readers alike are like that
16. They also tend to be less expensive than their external equivalents You don t have to bother with dip switches and baud rates However if the computer will contain many cards an in By Debee Norling Grassroots Computing P O Box 460 Berkeley CA 94701 ternal synthesizer may create IRQ con flicts Some internal cards are designed specifically to fit in some of the popular laptop computers especially the To shibas and run off the laptop s battery An external synthesizer has its own power supply and usually communicates with the computer via a serial or parallel interface A lightweight durable external synthesizer is a good choice for someone who must move from computer to com puter Because of its exposure and porta bility it s more susceptible to damage or theft than an internal unit So far no battery powered external synthesizer has had a major effect on the market A good speech synthesizer still isn t enough Suppose you send a print screen to your printer Imagine that you can only read that printout by starting at the first word and reading nonstop to the last word Do you remember the spelling of the syntax error on line seven and the typo on line three and the faulty in denting on line sixteen This isn t the best system for a blind operator He needs a way to conveniently and interac tively read selected portions of the screen Screen Access Software Is The Key A screen access packag
17. and ugh rede bugging the ROM BIOS from scratch If you have to build the ROM BIOS from scratch don t I found two guys in San Diego who have done all the work for you John Foster amp John Choisser have created a small friendly they an swer the phone this is John although I can t tell which one Micro C style com pany which puts out very interesting self published books and products for getting into the guts of the PC One of their products is a little hand book called The XT AT Handbook for En gineers Programmers and Other Serious PC XT and PC AT Users It s a brief sum mary of all the hardware and low level software facts and features of your XT or AT It includes the bus memory map I O map hardware interrupts DMA channels power on error signals switch 20 MICRO CORNUCOPIA 48 July August 1989 settings DOS amp BIOS summaries includ ing the BIOS entry point addresses AT CMOS memory programming informa tion about the important chips on the motherboard etc It also has one small fascinating page called User ROM Scan which starts like this The BIOS provides a means whereby builders of adapter cards may hook into the power on initialization sequence Hmmm very intriguing A warning this booklet assumes you already know what you re doing Don t get it expecting to learn the basics If you do know something about the inside of an XT or AT though it s a wonderful summary and a
18. everything from white canes to stereo receivers have added computers to their product line Many of these companies are run or owned by blind people They know little or nothing about computers and sell bottom end clones at discount house prices If you can provide all the required support and feel good about no name clones these dealers may be a good place to shop because of their fa miliarity with blind people s needs Several companies have grown by developing specialized technology specifically for the blind They are the only source for exotic equipment such as computer driven braille embossers talk ing 3278 terminals and speaking OCR scanners etc One even sells a photo copy machine that produces raised line drawings Generally these products tend to be very expensive and you can only pur chase them through their authorized rep resentatives If you have a specialized need and are willing to pay the price these companies can help you Try Before You Buy Many local junior colleges have a talk ing computer in their computer training lab or disabled students center Some states now have computer training pro grams for blind clients of their Depart ment of Rehabilitation The Commission for the Blind Inde pendent Living Center Lighthouse for the Blind or residential school for the blind in your area might have a talking computer to show you The local branch of the National Federation of the Blind or th
19. provide for variable typecasting This tech nique allows us to view and operate on a data type as if it were some other type Because of the variable typecasting there is no way to determine the size of the buffers dy namically The untyped parameters src and dest must be passed by reference so they are pointers to the buffers Since the type of buffers is unknown the function SizeOf can not be used The variable typecasting allows a type to be declared that defines how we will view the typecast variable Ouch that one tied my tongue The RleDComp unit declares the type bytes It is an array of 65535 bytes This is the largest buffer that the compression routines can handle The input buffer now appears to be an array 1 srcSize of byte You assume the out put buffer to be an array 1 srcSize 1 of byte In Modula 2 this can be avoided by declar ing the buffers as array of byte in the parame ter list and using the HIGH function to deter mine the size of the array passed Encoding The compression flag is passed to the com pression routine Since the flag character can change depending on the type of file I also make it the first character in the output buffer The srcSize parameter specifies the size of the input buffer or the amount of data in the buffer I assume the output buffer will be large enough to hold the compressed data Because of the addition of the compression flag to the beginning of the output buffe
20. reset dta return res Sp E FILE DATA static void set dta void new dta Helse static void reset dta vosa S qraad esregs regsh ah OxlA sregs ds old dta seg regs x dx old dta Toff v n Ub regs h ah Ox2F intdosx amp regs amp regs geregelt old dta seg sregs s old dta off regs x bx regs h ah 0xlA ifdef SMALL DATA PTRS es regs x dx aada new sta intdos reg amp regs i n UR sregs ds FP SEG new dta CUISSON US Ioregs x dx FP OFF new dta E intdosx amp regs seega 8sregs PEN endif intdosx amp regs sroga rarega D Doo I IC PROMPT DELIVERY SAME DAY SHIPPING USUALLY QUANTITY ONE PRICES SHOWN for APRIL 30 1989 OUTSIDE OKLAHOMA NO SALES TAX DYNAMIC RAM SIMM 1 256Kx36 80 ns 450 00 SIMM 1Mx9 80ns 250 00 SIMM 2 i1mx9 85ns 210 00 SIMM 256Kx9 80ns 99 00 1Mbit 1Mx1 100ns 17 95 41256 256Kx1 60 ns 9 95 41256 256Kx1 80 ns 7 95 41256 256Kx1 100 ns 7 75 51258 3 256Kx1 100 ns 7 95 41256 256Kx1 120 ns 7 50 41264 4 64Kx4 8 50 EPR 27C1000 128Kxs 200 ns 28 50 270512 64kx8 200ns 12 95 27256 32Kx8 150 ns 8 25 27128 16Kx8 250 ns 4 75 STATIC RAM 62256P 10 32Kx8 100 ns 26 50 6264P 12 8Kx8 120 ns 8 50 6116AP 12 2Kx8 120 ns 5 50 OPEN 61 2 DAYS 7 30 am 10 pm SHIP VIA FED EX ON SAT SAT DELIVERY MasterCard VISA or UPS CASH COD
21. s a marvelous tool for proofreading Braille has some disadvantages too It s hard to utilize interactively Using a hard copy embosser as your primary access is like having to print your docu ment every time you want to see your screen Using a soft braille device requires you to move your hands to the braille display However your hands also need to remain on your keyboard for typing Braille embossers must punch the dots into very heavy paper typically 100 card stock This makes a lot of noise Paper braille output is bulky and expensive The standard braille page is 11 x 11 5 yet it holds only about a third of the text of an 8 5 x 11 printed page A standard desktop dictionary sold by a major agency takes 72 volumes it requires about 24 feet of oversized shelving Soft braille devices have a display composed of pins which move rapidly up and down to create a changing dot pattern These devices show only 20 or 40 characters at a time The blind user is obliged to move this braille window around in screen memory in order to get a feel for the whole screen Soft braille devices have too many moving parts A standard 40 cell braille display has 240 pins to move up and down plus the actuators to move the pins thousands of minute parts each of which must be machined to a fine tolerance and protected from damage Braille devices are very expensive and there s no mass market to amortize development costs
22. t We decided to use the character set that s there in EGA VGA and emula tor ROM the real CGA doesn t have it You have to create your own or load it with DOS So I ran GRAFTABL Load Graphics Table included on the DOS disk and lo and behold a perfect image Case closed If you re in the publish ing or programming biz consider this package PCX Toolkit Genus Microprogramming 11315 Meadow Lake Houston TX 77077 800 227 0918 199 ASM source extra Quality amp Price You Fea Display Color Graphics on a monochrome monitor All Microsphere XT AT amp 386 systems NOW include the GRAPHICS COMBO multimode video card The Graphics Combo combines the video functions and software compatibility of the IBM Mono chrome Display Adapter MGA the Hercules Graphics Card and the IBM Color Graphics Adapter CGA all on a single card In ad dition the CGA graphics are auto matically converted to display on a standard TTL monochrome monitor in 16 shades of gray SPECIAL OFFER Order a Complete MicroSphere Computer System and receive 7 FREE disks of our best public domain games XT SYSTEM Includes 640K RAM serial parallel game ports clock calendar 101 key keyboard turbo switchable slide cabi net power supply Graphics Combo video card with amber or green mon itor Full 1 year warranty Ask for FREE assembly and testing 4 77 10 Mhz with 2 360K floppies
23. too People with passions al ways are whether it s for flying old planes running fast computers or play ing five string banjo Thanks for keeping the fires burning Sol Libes going out of business and Steve Ciarcia leaving BYTE have really hit home with me this year and made me more nostalgic than usual 2495 To ENGLE From SYSOP NATHAN By Nathan Engle 6465 Piping Rock Lane 30 Indianapolis IN 46254 Thanks Nathan I do wish you d recon sider your poster decision We ll even let you keep your clothes on Larry 2503 To SYSOP From NATHAN ENGLE I just don t go onto posters very well People keep on mistaking me for a 19 century European statesman and it con fuses them Why have they put Mr Gladstone in a poster I m confused We d have to have a big label identify ing me as a 20 century poster child in stead and that might tend to spoil the effect Anyway I m glad you ve taken up the cause Save the children 4 5X 6 5X 38x AX 170X 9x 32x 12x 600KC 600KC 55kC 455KC 455KC 400 400 100 Da 1 128507 e aay aan 35L 06 1237 12317 4 i234 123Q7 11 7 1334 2 1 1 0 IF 455KC Belmont 1947 Schematic MICRO CORNUCOPIA 48 July August 1989 65 By Patrick O Conley President Abraxas Software Inc 7033 SW Macadam Ave Portland OR 97219 Growing A Software Business Succeeding Without Venture Capital And Other Impediments Occasionally som
24. 0 puts cannot open output file outportb BASE Oxfd set abort line switch errno case ENOENT puts path or file name not found break case EMFILE puts too many open files break case EACCES puts permission denied break case EINVACC puts invalid access code exit 1 for incr signed filesize BUFSIZE gt 0 BUFSIZE filesize bytecount 0 bytecount lt filesize bytecount incr incr filesize bytecount gt BUFSIZE BUFSIZE filesize bytecount receive block filebuf incr write outfile filebuf incr close outfile void main int argc char argv struct ffblk file block int i done if argv 1 0 azgv 1 1 s amp Sargv 1 I 1 r usage use s or r receive files if argv 1 1 r receive files send files using wildcards if argv 1 1 s if argc lt 3 usage not enough arguments for i 2 i lt argc i done findfirst argv i amp file_block 0 while done send file file block ff name done findnext amp file block if argv 1 2 h puts receiver ready for more files exit 0 send_byte ATTN send_string end of transaction send byte LDELIMIT Figure 6 BLOCK C pragma inline include ppxfer h define SVE asm push AX asm push BX asm push Cx asm push DX asm push F define RST asm pop AX asm pop BX asm pop CX
25. 286B AT XT AT power supply case Samsung RGB color 259 Multi 1 0 widisk contrir 59 810 O wait ss 249 keyboard monitor NEC Multisync 559 640k RAM card 39 McTek 386 16MHz 799 rentes edicts 380 410 Sony Multiscan 619 2MB Expansion card 89 McTek 386 20MHz 859 Eprom burner 4 socket 139 HGC compat mono card 49 RS232 2 port card 35 McTek 386 24MHz 999 LCD Portble 759 Color graphic card 49 4 serlal port card 79 Locking sllde case 59 Plasma Portable Kits 999 EGA Paradise 480 149 Game l Ocard 15 200W power Supply 65 AC power strips 15 VGA Paradise 279 384k Multifunction card 69 Enhanced keyboard 59 Diskette file box 9 Genoa Super VGA 299 FCC app slid XT case 29 WD FDIHDC 129 Printer or serlal cable 8 150W power supply 49 DTC FDC HDC 1 1 189 Archive Tape Backup XT keyboard sessen 42 3MB EMS OK 99 40MB oa 339 Clock Card aa 19 as E RT e Floppy Controller 19 DESKTOP XT 10MHz 640k Uinouse du eie es 2 Drive System 699 Reader Service Number 42 MICRO CORNUCOPIA 48 July August 1989 37 A 68000 Based Multitasking Kernel Or How To Fix A Perfectly Good Singletasking System Well here it is multitasking Micro C style Karl shows us how he s written a multitaskin
26. 4 3 Two of these beauties would easily fit within the 13 5 bumper contact skirt Price 22 50 But how well would these motors work driving LIMBO around the maze That would depend on how much robot they would have to move This is the first of many times in the robot design nlike well written procedures the Subsystems of a robot interact through the hairiest global variable of all the real world Test Set up in Dangling Wire Stage process that you must make a few in formed guesses I reckoned by guess and by golly that LIMBO would weigh in somewhere around eleven pounds Five pounds of that would be stepper motors and struc tures most of the rest could be allotted to the battery I arrived at these figures by considering power consumption versus battery life required for a day at the races By Bob Nansel 816 North 105 St Seattle WA 98133 Batteries Lead acid gelled electrolyte cells have an energy density of about 16 watt hours per lb Two phases of each stepper would be energized at any one time for a current draw of 4 amps The electronics could be expected to add another amp for a total of 5 amps This current multi plied by the time LIMBO could spend wandering through the maze would give the required amp hr rating hence weight of the battery With each run limited to 10 minutes three runs would be half an hour at 5 amps or 2 5 amp hr Choosing a 6 volt battery system for the sake o
27. 6 0 is available for 250 To order send check or money order to Lattice Inc 2500 S Highland Ave nue Suite 300 Lombard IL 60148 Or order by credit card at 800 444 4309 FAX 312 916 1190 TELEX 532253 Send to Lattice for a free complete report on the benchmark analysis Reader Service Number 153 MICRO CORNUCOPIA 48 July August 1989 5 Interactive Disassembly My congratulations to Mr Flusche for his well written article The Art of Disassembly in Issue 46 of Micro C This is a subject near and dear to me as well as many of your other readers My company C C Software has been marketing the Masterful Disassembler MD for many years now starting with a Z 80 version and then the 80x86 I have personally disassembled 50 000 lines of code and can attest that this is not a simple task But good usable source code can be generated with the tools we have today I realize this was not intended to bea comparison of disassemblers but only a report on the use of one product Sourcer However a few additional points would be worth mentioning Mr Flusche s five step procedure for disas sembly is required only for non interac tive disassemblers These are the type that require users to examine listings step 3 edit a command file step 4 and repeat the process steps 2 5 until you like the result Step 3 is the real catch This is fine only for short programs When I disas sembled
28. 8 1 2 x 11 300 dpi 8 bit grayscale image would require 8 5 MB Fortunately a method called Run Length Encoding RLE compresses PCX image data In RLE any repeating data is stored as a count byte and a data byte If for ex ample 60 bytes of the image repeat only 2 are stored instead of 60 This will save here 97 eee Figure 1 PCX File Header stypadet struct posheadar char manuf lt echar hard Hor ehar gt encod ehar o bitpx unsigned xl unsigned yl unsigned x2 unsigned y2 unsigned hres 20 wnsigned o vres Hees ghax S ochar Oo char ooo unsigned unsigned unsigned unsigned char xy PCXHEADER vmodea nplanes bplin shres lt svres xtra 54 Here s the pseudo code for data un compression For each byte read X if top 2 bits of X are 1 then repeatcount 6 low bits of X data next byte after X else repeatcount 1 data X end if The data compression algorithm is ex actly the opposite For each byte read Y if byte Y repeatcount repeatcount l next byte then else if repeatcount 1 then if top 2 bits of Y are 1 set top 2 bits of repeatcount on write count byte end if write data byte else set top 2 bits of clrma 48 palinfo Always 10 for Paintbrush Version information EE Run length encoding 91 Bits per pixel E Picture dimensions inet M
29. A very desirable photocopy machine that makes raised line drawings has sold fewer than 100 units since it was invented several years ago despite a constant sales effort The cheapest embosser on the market costs a little under 2 000 for a kludged rework of a daisy wheel printer that puts out barely readable braille There are several embossers in the 3 500 to 4 500 range The user must also purchase text to braille translation software Among the cheapest soft braille displays is a unit which costs around 1 000 It is so sensitive to damage that if you don t protect the pins with plastic wrap you void the warranty A very nice soft braille device that attaches to the com puter s serial port has recently been introduced for about 4 000 Meanwhile you can obtain a speech synthesizer with screen access software a usable tool for as little as 500 No wonder speech despite its potential for error is more popular 18 MICRO CORNUCOPIA 48 July August 1989 Let s use the following menu line as an example Add Delete eXit Assume that the text is normal white on black and that the A D and X are in bright yellow except that the current choice A is in green Read white says dd elete e it Read yellow says d x Read green says a The information is there but it takes a lot of keystrokes to get to it Put the cursor at the first character of the current choice so read current word can speak the cur
30. But right up front he made it clear he d not accept help with the writing even from his 24 hour live in aid So this article is the product of months of effort by a man who s found INDEPENDENCE in a com puter to the counter at the local Radio Shack and told the salesman I wanted to see a computer He looked at me rather curiously wondering I sup posed what a guy paralyzed from the neck down wanted with a computer He pointed to a nearby display I turned my wheelchair and there next to a telephone answering machine and a pile of stuffed toy radios sat a small gray and black television attached to a keyboard The screen was blank ex cept for READY displayed in the upper left corner So that s a computer I thought rather disappointed It didn t seem like much I tried out the keyboard with my mouth stick making sure I could reach all the keys All the while the salesman pitched the computer as he would have pitched a stereo or CB radio He didn t know what 16K RAM was any more than I did I sat there staring at that blank screen wondering how I could justify 600 for a computer Ostensibly I needed it for keeping the books of our three family run variety stores Frankly it was a com puter and I wanted it It was a big decision Not until later did I realize it was a decision that would completely change my life I shudder at how easily I could have decided rot to buy that computer It s been ten years
31. Developing a cooperative kernel involves blending these I O calls with the scheduler code The major drawback to the coopera tive system lies in its name Each task must release control to the scheduler properly and in a timely manner or other tasks won t be run Generally the cooperative system forces release of the CPU by embedding the scheduler trans fer inside an I O call Whenever a task transfers data to a 38 MICRO CORNUCOPIA 48 July August 1989 console device or serial port the sched uler gets activated instead It temporarily suspends the I O request and activates the next task Eventually the original task comes up for scheduling again at which time the I O request gets handled Some computationally intensive tasks such as fractal calculations would not release the CPU for a long time For these cases a special routine provides a forced scheduler call Obviously the program mer must imbed such calls at key points in the program if the cooperative system is to work smoothly If you want to play with a truly ele gant implementation of a cooperative multitasking system try the public domain Forth 83 system check your local BBS For an elegant description of how the F83 scheduler and multitasking system work consult the book Inside F83 by Dr C H Ting This superb explanation of F83 s internal workings may be ordered from Mountain View Press More On Cooperation The cooperative system usually r
32. Display horiz resolution T Display vert resolution ut V S Pallete e ignored Number of planes ver 2 Bytes per line tA Palette Info l col Gegeybe t Scanner resolution v 2 WA o F Extra space filler ay 9 9 Xepeatcount on write count byte write data byte end if end if For a compression scheme the PCX format is as straightforward as they come It could be used to encode almost any kind of data but is really only effec tive where bytes repeat such as image data Finding The Data You might assume that you d display an image by reading a byte testing it writing it to the display etc until you reach the end of the file But this method has a serious problem data isn t always contiguous Sometimes you may include extra data at the end of each scan line to round the number of bytes per line to an even word boundary You may also in clude extra data at the end of the file either to round the number of lines up to a multiple of 16 or for additional palette data By Chris Howard Genus Programming 11315 Meadow Lake Houston TX 77077 What s A Palette Anyway Display palettes have always been a bit of a mystery but they re conceptually simple analogous to a painter s palette where the term comes from Although the painter may have thousands of jars of paint on his shelf he can only fit a limited number of colors on his palette On an EGA you can choose 16 colors f
33. Francis who was smarter and faster than the rest of us announced that the distance was zero the lines inter sected That s impossible said the prof I picked those points at random Do you realize what the odds are that I would pick a pair of lines that intersect at ran dom The distance may be small but it can t be zero Go back and do it again Now Francis was smart but he wasn t a politician He said I don t care what the odds are I did it right the first time and the lines intersect As the conversation got more and more heated it was clear that Francis was in deep trouble He was winning the argument but losing the war and the profs face was getting redder and red der As the two elevated the argument to a shouting match they were too engrossed to notice that all over the classroom the rest of us were carefully erasing the lines A Primitive Computing Device l 1 that we too had by this time found to intersect One of the nice features of solv ing things graphically was that you could always move the lines a bit when it seemed prudent Into The Space Age After college I went to work for NASA I was going to help put men on the moon which I did My first day I received the two tools of my trade an 18 government issue slide rule and a book of 5 place trig tables See NASA figured that the three digit accuracy of the standard 10 slide rule just wouldn t cut it for space tra
34. I got garbage in large dBASE and WordStar files and sometimes the machine would just lock up CRCs confirmed that something was wrong and a manual check of the data confirmed it Many long distance calls to NEC with the usual 15 minute delay to get a technician finally resulted in a solution It turns out that you have to kill all their built in software actually you can t get rid of all of it If you run KILL640R and right after it run KILLPOP most of the problems will disappear There is a better solution use DOS 3 3 No problems runs perfectly without a glitch If you do this the ma chine will come up running in low speed 4 77 MHz Run a program from the NEC BBS 312 860 2602 called LV9SPEED COM to switch to high speed 9 54 MHz Save your NEC DOS 3 2 in case you need to change start up settings screen attributes etc One other note NEC s BACKUP util ity is garbage totally useless The ma chine ate up part of a FAT a while back and my backup disks two sets were unusable RECOVER didn t recognize 90 MICRO CORNUCOPIA 48 July August 1989 Of Mice And Bugs Figure 1 NEC Battery Pack 9 6v THERMAL SVITCH S AMP FUSE Notes Use 1 8 ah ni cads with solder tabs factory 2 2 ah Thermal switch normally closed open 70 C Good substitute is ECG 8063 thermal fuse Place thermal switch inside battery pack red charge path Figure 2 NEC HD Drive Pinout EXT FOC FDE v e 900
35. I try to keep the itera tions short and frequent Dimensions As a rule of thumb LIMBO s widest point should be no more than about 2 3 of the passage width or 14 5 The pas sages are 22 Its turning radius should be less than 11 half of the passage width My observations of other robots in maze contests told me that LIMBO should be circular as viewed from above with no projections to hang up The mechanical bumpers would have to fit smoothly into LIMBO s body be rugged and be easy to build After a few weeks of searching I found that plastic trays used to catch water leaking from flower pots were ideal The tray I chose for LIMBO is a Super Pot with the TerraPot brand name The diameter of this tray is about Surplus IMC Magnetic Steppers go down stairs Coming back up is harder Micros live forever ending their use ful days resting contentedly on a high closet shelf while robots lives are con stantly threatened by vibration power spikes and disrespectful puppies Designing A Bot Designing a robot from scratch is not a linear top down process Hierarchical Flux gate Magnetometer Compass The first thing to ask an unborn robot is What s your function Most times I get a murky answer With the LIMBO robot the answer was a crystal clear Running mazes faster than Murphy With the function known I settled down with a copy of the Robots Thru the Maze rules for a copy contact the S
36. M V Lady Rose a Scottish Coaster steams down Al bemi Inlet and Into Barkley Sound to Bamfield or through the Broken Groups ls lands to Ucluelet and returns in late after noon A tour can be set up for 11 or more at 39 each Port Alberni Canada Other activities In the area are scuba diving hiking museums the new Harbour Quay and much much morel The community sports twelve motels six bed and breakfasts and lots of camp sites and traller spaces With the registra tion kits the BC organizers will tell you more about accomodations Talks are scheduled on Friday and Saturday at North Island College The facility wil open Thursday evening the 6th for early arrivals They ll also have a space for the traditional all night techni cal forums the Jolt SIG Special events Include a planned minimaze competition put on by the Seattle Robotics Society and a fresh sal mon BBQ scheduled for Friday evening There is a 50 person maximum limit on barbeque if you are planning to attend get your reservations now Sponsors David Stern amp Randy Young ask that you pre register by June 15 NOW A COMPLETE PASCAL FOR ONLY If you re a vendor swapper or hacker bring your wares the meeting and display area will be open from Thurs day Saturday evenings Eight foot tables are only 10 00 each Prices Registration eene 910 per family BC SOG T shir 10 specify size Salmon Barbequ
37. amp Tested IBM AT Compatible MS DOS OS 2 amp UNIX Compatible il 80386 20 8 MHz Norton V4 0 SI 22 Bi Phoenix BIOS B 1MB expandable to 16MB RAM IM 80387 Coprocessor Socket il 220W Power Supply i 1 2MB Floppy Drive B Ports 1 Serial 1 Parallel 1 Game Dual Floppy Dual H D Controller ii Monochrome Graphic Card E 101 Key Enhanced Keyboard m TTL Monitor 12 E 40MB Hard Disk 28MS liM MS DOS 4 0 NGW BASIC Opll ns cesse eorr yc s Call McTek Systems Inc 1521 San Pablo Avenue Berkeley CA 94702 415 525 5129 DISK DRIVES PRINTERS MONITORS EE PCIXT PC AT Fujitsu 360k sss 69 Citizen CD 120 149 Fujitsu 1 2MB 89 Citizen CD 180 189 Tea cosas crean e 75 HPLASAR Serlal2 1699 Teac 1 2MB vn essen ee 95 Epson LX 800 219 Toshiba 3 720K 89 Epson LQ 500 379 Teac 34 1 4MB 105 Toshiba 321 XL 519 20MB Hard Disk Kit 279 NEC P2000 369 30MB Hard Disk Kit 309 Call for prices of other brands 8425 Miniscribe 249 8438 30MB Min scribe 259 3650 40MB Miniscribe 349 3675 60MB Miniscribe 379 ST 157 49MB 34 479 Everex Int 3001200 79 Everex 2400 external 195 Everex 2400 Internal 179 Samsung amber 79 640k TurboMothrbrd 80 McTek286 20MH2 449 KIngtech CRT Portable Kits Samsung EGA color 359 10MHz TurboMothrbrd 85 Baby McTek
38. an ordinary ob server considering the accused micro code as a whole would recognize it as having been taken from the copy righted sources Here is a clear case where 1 except for some improvements the NEC code was clearly designed to achieve the same result as the Intel code 2 be cause it did the same job it had many similarities 3 NEC apparently had dis assembled Intel code 4 NEC had even copied a part of the code which was re quired to overcome a hardware prob lem And yet the court found that NEC did not infringe Obviously there is more to the story than SEA says The only way to decide copyright infringement is to examine the actual code Even then when the code implements the same algorithm or procedure which is not copyright able and there is a particular way in which any reasonably skilled program mer would implement that algorithm code similarity does not prove infringe ment Peter A Stark P O Box 209 Mt Kisco NY 10549 In Support Of New Paths I ve stumbled along for quite a while wondering whether there were other people out there who shared a combina tion of interests that don t appear too obvious on the surface computers and what I guess I ll call self actualization My house guests are fascinated to find Micro C underneath a book on meditation Imagine my surprise to open the last issue and find your little manifesto See the Editorial in Issue 58 MICRO CORNU
39. become an issue with me unless PC Tech de MICRO CORNUCOPIA 48 July August 1989 47 cides to put a PS 2 mouse port on one of their designs but it may be useful information to those of you closer to the mainstream By the way the books indicate that the ballistic control is the result of the new mouse driver software and that it works on the older mice as well I know absolutely nothing about Logitech s up grade policy for mouse drivers but you might give them a call if you re inter ested The Logitech Mouse 139 Logitech 6505 Kaiser Drive Fremont CA 94555 800 231 7717 800 552 8885 in Calif 41 21 869 9656 in Europe Zortech Debugger Since Scott Ladd said in his last column that he might talk about the new Zortech Debugger ZTCDB this issue I won t spend a lot of time on the subject There are a few things that I just can t bear not to mention though The first thing a CodeView user will notice about ZTCDB is how many win dows there are There is a window for the source of course But it also has a window that shows all global data items one that shows all automatic data items local variables one with a directory listing one that lists all func tions in the program and several others Things difficult to impossible to see with CodeView are simple with ZTCDB For example you don t have to spend the time typing in all the varia bles you want to watch They re alrea
40. child or a housewife then select ing an IBM PC compatible may not be so important A few CP M machines the Apple II family and some Radio Shack TRS 80 models can also talk Several soft ware packages have been written for the Apple II family especially for children Fast amp Slow Up amp down Speech devices don t magically talk any more than printers magically print Both synthesizers and printers need special software You must select a syn thesizer which will turn ordinary ASCII text into intelligible speech Many of the built in speech synthe 12 MICRO CORNUCOPIA 48 July August 1989 sizers are little more than speech chips capable of generating simple phonemes Since hobbyists mainly make up the speech synthesizer market synthesizers seldom include sophisticated ASCII to speech conversion software Types Of Speech Digitized speech can sound very human but it requires huge amounts of hard disk space even for a small vocabu lary I don t know of any screen access program which uses digitized speech Rule based speech sounds more me chanical and sometimes mispronounces a word but it has an unlimited vocabulary Algorithms make their best guess about the pronunciation of each word The more recent and the more expensive synthesizers usually have better algo rithms Consistency and phoneme clarity are far more important than a human like voice and correctness of the English pro nunciation Th
41. compass will either be a modified unit available from Radio Shack or a home brew ver sion I m still evaluating cost vs per formance between these two options The presence of ferrous materials such BORLAND PROGRAMMERS the simplest most complex tools you will ever use to create a user friendly interface between your program and the computer operator Thirty functions provide for the design and control of menus in either a text or graphic screen and the number of menus is limited only by your computer memory Menus sup port only C amp Pascal Create bit mapped screen fonts icons amp graphic mouse cursors The keyboard or mouse will control the pro gram flow CREATIVE INTERFACE TOOLS is yours for only 69 95 MAXX DATA SYSTEMS INC 1126 S CEDAR RIDGE SUITE 115 DUNCANVILLE TX 75137 1 800 622 8366 214 298 1384 FAX 214 709 7674 A e Ali user modules furnished as source code No run time system No royalty fees System requirements PC XT AT CGA EGA VGA DOS 2 1 or greater 384K RAM Output routines provided for Turbo C 1 5 amp 2 0 Turbo Pascal 4 0 amp 5 0 Turbo Prolog 2 0 amp Turbo Basic 1 1 MAXX DATA and CREATIVE INTERFACE TOOLS are trademarks of Maxx Data Systems Inc Other brand or product names are trademarks or registered trademarks of their respective holders Copyright C 1989 by Maxx Data Systems Inc Reader Service Number 151 MICRO CORNUCOPIA 48 July August 1989 31 w
42. digits See Figure 1 The first set 86 MICRO CORNUCOPIA 48 July August 1989 rounds X 999999999949 up to 99999999995 The second does not By comparing the two sets you can see the error accumulate By the 20 iteration the values are very far apart and by the 25 itera tion they will be at opposite ends of the range Similar behavior occurs regardless of where we round A Turbo C double precision real for example exhibits virtually identical be havior by the 30 iteration or so More on the 0 to 1 range and compiler precision later To see this chaotic behavior play with the Strange Attractor program I wrote for last issue it s on Micro C issue disk 47 In short chaos theory looks at mathemati cal models or representations of physical sys tems and determines that these representations are unpredictable Let me emphasize representations and explain why Representations amp Models When we model a dynamic system we use an equation or equations to describe how the system changes from state to state In the lo gistic equation for example we say that the Nextx or the next state of X is determined or described by the current X times a rate of change constant R times some other factor 1 X in this case Many different kinds of scientists and en gineers use nonlinear equations like this one to model dynamic systems Consider a simple biological system where we want to describe how a
43. elec tronic mail Heard But Not Seen Your software can talk by writing to the screen via the BIOS When you call a BIOS screen service using interrupt 10 hex screen readers watching that inter rupt can intercept the data and send a copy to the synthesizer I use an interesting trick to make my software talk while keeping my screen displays fast First I write the entire screen directly to video memory Then I repaint it using the BIOS If I only want part of the screen spoken I just repaint that part There s no flicker and the screens snap into place as rapidly as if I weren t doing any BIOS screen writes at all Summary Avoid multitudinous modes screen clutter and overlapping windows Use consistent screen locations consistent colors consistent layouts consistent mes sages and consistent keystrokes En hance the information with well thought out sounds Try some little tricks to im prove your screen s listenability Most importantly don t banish the cursor gt Fully BIOS SOURCE Commenting Disassembler SOURCER SOURCER creates detailed commented source code and listings from memory and executable files Built in data analyzer and simulator resolves data across multiple segments and provides detailed comments on interrupts and subfunctions l O ports and much more Determines necessary assembler directives for reassem bly Includes a definition file facility to include your own remarks and
44. ever used 99 George F Goley IV Contributing Editor Data Based Advisor September 1988 To order direct call aD dE Gd 6 ame Add 3 00 for aaa 00 for overseas shipping UPS 2nd DAY AIR available within l the U S for ONLY 5 00 COD saccepted please add 3 00 Georgia residents add 4 sales tax SEMWARE 73OEIk Cove Ct e Kennesaw GA 30144 QEdit and SemWare are trademarks of Applied Systems Technologies Inc 1989 Applied Systems Technologies Inc MICRO CORNUCOPIA 48 July August 1989 63 A while back Nate logged on to Micro C s bulletin board with an unusual problem I don t know that we were able to help him but at least he found a couple thousand sympathetic modems 2431 To ALL From NATHAN ENGLE Hey I m a radio I was play ing around with op amps tonight and I hooked up a speaker to the thing While I was twiddling with the wires on the protoboard I suddenly found that I was tuned in to some AM radio station The signal only comes through when I touch the input on the op amp so I guess I m the antenna Can anybody explain this to me I appear to receive some sort of Rockabilly Country station Is this com mon I expected something more along the lines of a quiet Mozart or maybe a Celtic band like Silly Wi zard but Country amp West ern 2449 To NATHAN ENGLE From SYSOP Obviously you ve repressed your true musical nature Just be thankful that y
45. for voice recognition verification response A complete superior speech and sound development tool SOFTWARE CONVERSION CODES The Volce Master Key System operates a growing list of third party talking software titles using synthesized phone tics text to speech or digitized PCM ADPCM and CVSDM encoded sound files Voice Master Key System does it all EVERYTHING INCLUDED Voice Master Key System consists of a plug in card durable lightweight microphone headset software and manual Card fits any available slot External ports consist of mic inputs and volume controlled output sockets High quality throughout easy and fun to use ONLY 149 95 COMPLETE ONLY 89 95 FOR TANDY 1000 SL TL MODELS SOFTWARE PACKAGE ONLY Requires Tandy Brand Electret microphone ORDER HOTLINE 503 342 1271 Monday Friday 8AM to 5PM Pacific Time Visa MasterCard company checks money orders CODs with prior approval accepted Personal checks subject to 3 week shipping delay Specify computer type and disk format 31 2 or 5 when ordering Add 5 shipping charge for delivery in USA and Canada Foreign inquiries contact Covox for C amp F quotes 30 DAY MONEY BACK GUARANTEE IF NOT COMPLETELY SATISFIED ONE YEAR WARRANTY ON HARDWARE CALLOR WRITE FOR FREE PRODUCT CATALOG Reader Service Number 143 COVOX INC 675 D Conger St Eugene Oregon 97402 U S A TEL 503 342 1271 FAX 503 342 1283 MICRO CORNUCOPIA 48 July Aug
46. haven t scattered bread crumbs along the way or made marks in the walls nor do I have a map I don t care because I m never going back I m forever lost in this computer adventure And that s just fine Products Mentioned Toggle Key Ernest A Kraut 11 Haystack Road Reading MA 01867 ProKey 4 10 RoseSoft P O Box 70337 Bellevue WA 98007 The Magic Wand Keyboard In Touch Systems 11 Westview Road Dept 11 Spring Valley NY 10977 914 354 7431 9 DIAGNOSTICS The Complete Diagnostics Solution for Your PC XT PC AT or Compatible INCLUDES PC XT System Diagnostic Software DRIVE TESTS Complete diagnostics for Hard and Floppy drives including controller cards Tests read write and format capability as well as seek timings hysteresis and rotation timings 1 0 PORTS For both parallel and serial ports confirms internal and external loopback capabilities at all baud rates and configurations MEMORY Performs over eight different tests to check standard extended and expanded memory KEYBOARD Verifies that all keys send correct key codes including shift CNTL and ALT modes CPU amp NUMERIC COPROCESSOR Verifies that all single and multiple instructions perform correctly and accurately as well as testing all internal registers VIDEO DISPLAY Checks video controller cards Confirms attributes graphics colors if applicable and CRT alignment patterns REAL TIME CLOCK Verifies
47. in both large and small model Lattice C is over 10 faster than Microsoft 5 1 and over 15 faster than Borland 2 0 These results are due to our new op timizer and the many perform anceimprovements in the library You can make your applications run even faster by using our new register variable support and built in functions Lattice 6 0 is the performance leader The Leader in Compatibility Lattice C is fully compliant with the ANSI standard We pass not only the Computer Language ANSI Test Suite but 100 of the Plum Hall Test Suite Version 1 09 Lattice is the compatibility leader The Leader in Debugging Lattice C includes CodePRobe a new full screen symbolic debugger for DOS and OS 2 CodePRobe ed the familiar look of the CodeView and can be used with a mouse It also enables you to easily debug family mode programs Presentation Man ager applications and OS 2 mul tithread applications And for those humongous programs and system killer bugs CodePRobe can be used remotely from a different PC Lattice is the leader in debugging The Leader in Innovation Lattice has long supported popular Ane EE extensions suchas near far an pascal In our previous version we introduced align chip volatile interrupt nopad and pad to handle important memory management problems in DOS OS 2 and embed ded systems Version 6 continues this evolution with critical and private Critical defines a function that must run a
48. is im portant for beginners and for carefully studying a complex screen A fast rate is useful for quickly finding information in a mass of text As I become more ex perienced with a synthesizer I can in crease the speech rate Editor s note No kidding Debee demon strated her synthesizer at SOG At the slowest rate we could understand it after a few minutes adjusting to some off the wall sounds At her normal rate probably four times normal speech the sound was completely unintelligible to our sighted ears peech devices don t magically talk any more than printers magically print Both synthesizers and printers need special software The synthesizer must have a way to change the volume and pitch A tone control is also desirable An easily definable substitution table often called an exception dictionary is a nice enhancement though hardly man datory Some synthesizers have a diction ary of correct pronunciations built in Acronym processing is handy but you should be able to turn it off I once beta tested a synthesizer which said New York every time I typed F7 n y for exiting WordPerfect Remember all synthesized speech requires getting used to Innies amp Outies Synthesizers are either internal cards or external boxes Internal synthesizers are safe from spills and falls and they re less likely to be stolen There are no power or com munications cables to become entangled or unplugged
49. is simply the number of times PAUSE has started that task It allows external programs to monitor a task s progress and trigger other events based on the count Finally BLINKER demonstrates that the multitasking system works It turns a status LED on and off at a two second rate Because BLINKER s status bits are initially set to active and not started it will start the first time it becomes a can didate task Improvements Anyone MTASK offers considerable power but you can always add features The first upgrade that comes to mind con cerns communication with the scheduler Currently changing values inside a TDB requires a rewrite and reassembly hardly a robust procedure Better would be a set of routines directly supporting manipula tion of the TDBs This would permit ex ternal programs to start and stop tasks determine status of the tasks or alter task parameters An obvious way to provide this com munication lies with the TRAP instruc tion I might choose a presently unused TRAP vector such as 7 and write into it the address of a dedicated program for servicing scheduler requests To invoke a scheduler service request a program could load AO with a service request code load A1 with a pointer to a block of data and execute a TRAP 7 Another possible way to handle scheduler service requests could be via a vector in the monitor ROM Since MTASK doesn t have to be in RAM only the TDBs and a few support variabl
50. keyboard input string and numeric variables and control over the size position and color of windows Source level macro debugging with breakpoints and tracing Macros developed with VEDIT PLUS also run under VEDIT 30 day money back guarantee Call for pricing of XENIX OS 2 and FlexOS versions Very attractive quantity pricing is avail able for schools hardware and software vendors VEDIT and Compuview are registered trademarks of CompuView Products Inc BRIEF is a trademark of UnderWare Inc Norton Editor is a trademark of Peter Norton Computing Inc QEdit is a trademark of SemWare Supports IBM PC XT AT PS 2 and clones with CGA MGA EGA VGA Wyse 700 Amdek 1280 and other displays Also supports Concurrent DOS DESQview Microsoft Windows PC MOS 386 and most networks Also available for MS DOS CRT terminals TI Professional and others Free evaluation disk is fully functional and can edit small files Introducing The 1st Family of Low Cost Powerful Text Editors VEDIT Jr 29 VEDIT 69 VEDIT PLUS 185 FREE Evaluation Copy Call 1 800 45 VEDIT Compare Features and Speed VEDIT BRIEF 2 10 Norton 1 3 QEdit 2 07 Pull Down menus Yes No No Yes Pop Up ASCII table Yes No No No Keystroke macros 100 1 No 100 Regular Expressions Yes Yes No No Cut and Paste buffers 36 1 1 100 Text book markers 10 10 No No Undo keystroke by keystroke Yes Yes No No Undo line by
51. line Yes No No No Normal max Undo levels 500 1000 30 300 Variable tab positions Yes Yes No No Configurable keyboard Yes Yes No Difficult Integrated mouse support Yes No Yes No FILE LIMITS Edit files larger memory Yes Yes Difficult No Maximum line length gt 8096 512 65 535 512 Maximum lines file 8 388 607 65 535 265535 20 000 COMPILER SUPPORT None None Menu driven Yes No Select Compiler options Menu Difficult Support Include files Yes No BENCHMARKS 50K FILE Simple search 0 2 sec 1 sec 1 sec 0 3 sec Save and continue 1 sec 2 sec 2 sec 1 sec 1000 replacements 3 sec 19 sec 17 sec 2 5 sec BENCHMARKS 3 MEG FILE Simple search 1 40 min 1 36 min Cannot Cannot Save and continue 105 min 3 23min X Cannot Cannot 60 000 replacements 3 18 min 1 44 hour Cannot Cannot Block column copy 40 x 200 2 sec 30 sec Cannot 2 sec Insert 1 Meg file in middle of 1 Meg file 1 111 min 15 13 min Cannot Cannot PRICE 69 195 75 54 95 CompuView 1955 Pauline Blvd Ann Arbor MI 48103 Reader Service Number 7 31 3 996 1299 Fax 31 3 996 1308 MICRO CORNUCOPIA 48 July August 1989 7 AA T sy c 1 omputer Aided Inde H The Adventure Begins oo ee When I first spoke with Dallas on the phone there was no indication that he d spent days entering the letter proposing this article It was only later that I found out how much work it had been for him
52. more professional and more capable BATCOM extends DOS with new commands so you can read keyboard input perform arithmetic use subroutines In addition BATCOM and much more protects your source code and you can dis tribute your compiled programs without roy alties For IBM PC 49 95 Z N Wenham Software Company T e 5 Burley St N 4 Wenham Ma 01984 508 774 7036 FREE catalog Reader Service Number 124 The 25 Network Try the 1st truly low cost LAN e Connect 2 or 3 PCs XTs ATs e Uses serial ports and 5 wire cable e Runs at 115 K baud e Runs in background totally transparent e share any device any file e Needs only 14K of ram Skeptical We make believers Information Modes Adis P O Drawer F Denton TX 76202 817 387 3339 Reader Service Number 149 CROSS ASSEMBLERS PseudoCode releases the PseudoSam professional series of Cross assemblers All popular processors Macros Conditional Assembly and Include Files Virtually unlimited size For IBM PC s MS DOS 2 0 or greater with manual 50 00 Simulators and disassemblers also available MI res 4 tax S amp H USA 5 Canada 10 Foreign 15 Visa MC KORE Inc 6910 Patterson S E Caledonia MI 49316 616 887 1444 30 Day satisfaction guaranteed or purchase price refunded ReaderService Number 136 MICRO CORNUCOPIA 48 July August 1989 91 Rod s unimplemented suggestion is doable but unduly complex My so
53. ones who offer it with no strings hoping that I ll find what I need and grow with it So pitch what doesn t feel right or file it for later I ve found that Buddhism offers me something that turns out to be nicely complimentary to the yoga You can read about Buddhism in Buddhist Amer ica By Don Moreale perhaps best ordered direct from him at 1220 1 2 E 20 Denver CO 80205 12 95 Chop Wood Carry Water A Guide to Finding Spiritual Fulfillment in Everyday Life has been another good one for me By Rick Fields and others Jeremy Tarcher Inc 9110 Sunset Blvd Los An geles CA 90069 11 95 and often on the shelf at B Dalton It is nice to know that there are kindred souls out there You ll find em around you too Oregon s not exactly a desert in this regard Life doesn t al ways seem easier once you get started with this stuff but it is fuller and more meaningful Once started it s hard to stop Loren Marshall 1705 Bartlett Dr Anchorage AK 99507 A Skeptical Response I was somewhat intrigued by your comments on your search in the May June Micro C Each person must ulti mately choose his own belief system However I felt the need to comment on common traps in logic frequently com mitted in pursuit of things mystical I feel these show through in your edi torial One of the most fertile aspects of the human mind and also one of the most tricky is the ability to map symbols onto e
54. ping file Editor s note It s not what it sounds like really it isn t This lets you distribute a program and its companion files in an EXE file that unzips itself upon execution Phil Katz distributes his new utilities in a file called PKZ090 EXE The version number 0 90 indicates that this is a new venture You should see release 1 00 shortly in fact it may be out by the time you read this I don t know whether the ZIP format can carve a niche in the market While Katz won the sympathy of many BBS QE dil zi ADVANCED The fast easy to THE use fully featured text editor at an affordable price If you are looking for the right combination of price and value in a text editor then give QEdit a try At ONLY 554 95 and a money back guarantee you just can t go wrong QEditis fast easy to use and simple to install At the same time you get all of these features and more W Completely configurable in cluding keyboard and colors E Edit as many files simultaneously as will fit in memory E Open up to eight windows E 99 scratch buffers for cut and HU paste or template operations E Exit to DOS or a DOS shell from within QEdit H Pop Down menu system and customizable Help Screen E Column Blocks E Easy to use macro capability including keyboard recording E Wordwrop and paragraph reformat capabilities W Recover deleted text E Automatic indentation for C programming M Import fil
55. rafting you ll find horseback riding hiking and great fishing are recreational opportunities to explore Gunnison County has some of the most beautiful wilderness in the country Rocky Mountain SOG will be held during the same weekend as nearby Crested Butte s Aerial Weekend which features parachuting hang gliding and hot air balloon rides and races This will be a family vacation as well as an edu cational experience When you register they ll send you a packet In that packet you ll find informa tion on activities ranging from tours of the Black Canyon to ghost town excursions You ll also receive hotel and airport infor mation Both Continental and United Alr lines service Gunnison s airport The Keynote speaker for the Saturday Night Banquet will be Walter Bright author of Zortech s C Prices Conference registration 25 in advance 30 at the door RM SOG Tee Shirt 910 specify size 1 2 day raft trlp eee 35 Fun Guy ian Iesse DOU Saturday night Banquet wee 15 Thursday night Barbeque 10 Cafeteria Lunches Fri Sat 10 5 each Registration Info Please register as soon as possible If you preregister please do so before July 1 Make checks payable to Rocky Mountain SOG include names addresses and phone numbers of everyone you re paying for and list what each Is ordering Contact Rocky Mountain SOG
56. replace both 76 MICRO CORNUCOPIA 48 July August 1989 John Konopacki Analytical Detectors Co P O Box 1024 Stafford TX 77477 More CP M Suppliers After running Samuel Vincent s list of CP M vendors in Issues 45 and 46 we received several tips on other com panies catering to CP Mers Derby W S P O Box 2041 Livermore CA 94550 General utilities SASE for information Elliam Associates P O Box 2664 Atascadero CA 93423 805 466 8440 All manner of public domain and commercial software Most CP M disk formats supported Catalog 1 Quinsept Inc P O Box 216 Lexington MA 02175 800 637 ROOT or 617 641 2930 Genealogy software Also for MS DOS Apple Commodore Mac and TRSDOS Information available Plu Perfect Systems Current Address 410 234 St Santa Monica CA 90402 213 393 6105 ZCPR system tools Micro C Staff By Michael S Hunt 2313 N 20 Boise ID 83702 208 233 7539 Compression Routines Putting The Squeeze On Data Data compression doesn t have to be dull In fact it might be just the thing for your next party Step this way Mom step this way Dad and I ll show you how to get rid of repeating characters Who knows they might get the hint pression Before I get started I should state that I have seen neither SEA s nor PKWare s source code The source code listed here is entirely of my own design I am solely responsible for its conten
57. s small enough to fit in a briefcase For me it s perfect Weight and size are most important so I can go even farther up in the mountains to write my edi torials Operating time away from power is also significant some portables won t run 2 hours and any machine I own must have at least one drive I spent one frustrating vacation tapping away on one of Radio Shack s imitation laptops No drive limited memory Boy not having a drive made me nervous and really limited the time I could be away from a real computer Toshiba has fancier machines with backlit screens very nice two floppies handy faster processors more memory you can add memory to the 1000 expansion slots hard drives etc These features are wonderful if you need them but they all add weight and none of these souped up systems runs 5 hours between charges So the basic 1000 is optimum for me The only thing I miss about the Kaypro laptop is the key PCYACC Version 2 0 PROFESSIONAL LANGUAGE DEVELOPMENT b TOOLKIT FTWARE Inc Includes Drop In Language Engines for SQL dBASE POSTSCRIPT PCYACC HYPERTALK SMALLTALK 80 C C PASCAL and PROLOG Complete grammars Lexical Analyzers and Symbol Table Management for ANSI C K amp R C ISO Pascal dBASE Ili Plus and IV SQL C Smalltalk 80 APPLE Hyper C amp M Prolog YACC LEX and POSTSCRIPT are included OS 2 and MAC versions are available Example application sources are provided
58. so did my proficiency with the slide rule My grades depended on it and I studied it earnestly Before a quiz I would carefully adjust it like a soldier cleans his rifle before a battle Those three strips of bamboo had to be spaced just right to slide freely but still stay where I put them I actually lubri cated them with talcum powder for max imum speed without overheating I could always tell the guys who were seri ous about their grades they had talcum powder stains on their shirts 80 MICRO CORNUCOPIA 48 July August 1989 Hi Res Graphics Our skills in graphics were sharpened too In those days the worth of an en gineer depended just as much on his abil ity to draw a straight line or to plot a graph as on his book larnin We solved many problems in those days with graphs and nomograms that we now do by computer One of my favorite courses was Descriptive Geometry There we learned to do all kinds of magical things with a pencil and T square We solved real life geometry problems like estimating the volumes of highway cuts and fills or the distance by which a power cable would miss a hillside One day our prof gave us the four sets of coordinates defining two skewed straight lines The problem was to find the miss distance between them We did this by generating projections of the lines onto different planes until one of them appeared end on as a point While I was working diligently on the problem
59. start printf starting time d n secs start endif TIME while readsize read infile filebuf BUFSIZE gt 0 ifdef MASM send block filebuf readsize else MASM without MASM do it the slow way for i 0 i lt readsize i send byte filebuf i endif MASM close infile ifdef TIME time amp secs end printf ending time d n secs end printf f Kbytes sec n filesize 1000 secs end secs start endif TIME void receive files void char c int i j outfile unsigned long incr filesize bytecount readsize char buf 30 filename 30 dbyte filebuf BUFSIZE idle while 1 while receive byte ATTN if kbhit if getch 27 exit 1 hunt for ESC from the port or the keyboard for i20 c receive byte LDELIMIT buf itt c buf i 0 end of control string if strcmp buf end of transaction 0 puts end of transaction exit 0 if strcmp buf filename 0 for i 0 c receive byte RDELIMIT filename i c filename i 0 for i 0 c receive byte LDELIMIT throw away chars until left delimiter for i20 c receive byte RDELIMIT buf it c store until right delimiter buf i 0 filesize atol buf printf receiving 15s size s bytes n filename buf if outfile open filename O WRONLY O BINARY O CREAT S IREAD S IWRITE lt
60. sys stat h gt include lt stdlib h gt include lt errno h gt include lt dir h gt include lt time h gt include ppxfer h to cale transfer speeds header file with defs dbyte base plus two global so output value at BASE 2 doesn t accidentally get changed define RAISE HANDSHAKE outportb BASE 2 base plus two amp 1 lt lt 3 fdefine LOWER_HANDSHAKE outportb BASE 2 base plus two 1 lt lt 3 define TESTKEY if kbhit break Prints a byte in binary for testing void print_binary dbyte c int i 7 do printf c c amp 1 lt lt i l 0 while i Set the channel to the idle state void idle void outportb BASE 0xff all lines high initialize for all inputs handshake is high outportb BASE 2 base plus two 0x04 26 MICRO CORNUCOPIA 48 July August 1989 dbyte receive_byte void dbyte data while inportb BASE 2 amp 1 lt lt 3 data inportb BASE 1 amp Oxf8 inportb BASE42 amp 0x07 outportb BASE Oxfe send BYTE RECD signal data 0x83 flip inverted bits while inportb BASE 2 amp 1 lt lt 3 outportb BASE Oxff de assert BYTE RECD sig return data void send byte dbyte data outportb BASE data LOWER HANDSHAKE while inportb BASE 2 amp 1 if inportb BASE 2 amp 2 puts aborted by receiver exit 1 TESTKEY RAISE
61. t been very dependable or very lightweight or very easy to haul around or easy to fix The 2000 is a kludge However I had the 2000 and I kept futzing with it inter 68000 SINGLE BOARD COMPUTER ae a uw 7 e 4 RS 232 SERIAL PORTS e REAL TIME CLOCK 512 1024K DRAM e FLOPPY DISK CONTROLLER NEW LOWER PRICES BASIC KIT 8MHZ BOARD MICROPROCESSOR HUMBUG MONITOR BASIC IN ROM 4K SRAM 2 SERIAL PORTS 200 PACKAGE DEAL COMPLETE KIT WITH 10MHZ MICROPROCESSOR SK DOS OPERATING SYSTEM 512K DRAM 525 SYSTEM BOARD 12MHZ ASSEMBLED TESTED 1MEG RAM 6 PC XT PERIPHERAL PORTS SK DOS 799 PERIPHERAL TECHNOLOGY 1710 CUMBERLAND POINT DR 8 MARIETTA GA 30067 404 984 0742 COD MASTER CARD VISA CHECK SK DOS IS A TRADEMARK OF STAR K SOFTWARE SYSTEMS CORP Reader Service Number 119 MICRO CORNUCOPIA 48 July August 1989 73 Around the Bend mittent main board flaky drive dead battery until I saw the little Toshiba T1000 The T1000 isn t a killer computer 4 77 MHz 8088 512K unlit LCD screen single 720K drive but it has some very re deeming features It s light just over 6 Ibs versus 11 for the 2000 and it runs 5 hours on a charge versus 3 It has built in serial and parallel ports built in CGA interface MS DOS 2 11 and DOS utilities in ROM and an LED that glows red 10 minutes before the batteries expire It s silent the screen is more readable than the Kaypro s and it
62. the way and some suggested tests to per form At this point the Kaypro II was ap parently fully operational but it could not read the last 40 tracks on drive B Normally on warm boot both drives were read by the monitor ROM and set to the appropriate drive configuration Drive B should have been set for DSDD disks on a DSDD drive However the ROM assumed it had DSDD disks in a quad drive This was the reason that it double stepped when formatting When the machine was forced to look at drive B by asking for its directory it then rec ognized the drive as DSDD and the sys tem worked fine The initial cause for the problem was thought to be the monitor ROM and it was replaced with a newer version 3 3 However then the system would not boot at all The old ROM was reinstalled and a new cause was sought U49 an 8 bit buffer 74LS241 that fed low order addressing to the monitor ROM was checked found to be good and replaced anyway The problem was solved Evidently the LS241 had weakened over time and the monitor ROM was getting the wrong addressing informa tion The LS241 still appeared to be working but not well enough to prop erly address the ROM The monitor simply bypassed part of its own code and went merrily on its way So if this problem ever comes up again or if your system ever has prob lems booting check U49 carefully Try swapping it with U62 another LS241 At 1 each or less you might want to
63. the default DTA There is one other point in favor of providing your own DTA The file infor mation retrieved contains data used by ensuing calls to FIND NEXT By using multiple DTA buffers of your own crea tion you can have several different file search operations going simultaneously Most C compilers provide a pair of functions which use FIND FIRST and FIND NEXT to retrieve file information Unfortunately there are several prob MICRO CORNUCOPIA 48 July August 1989 51 lems with the free function provided by C compiler vendors First the ven dors do not coordinate so that Turbo C s findfirst and findnext are slightly different from Microsoft C s equivalent functions dos findfirstO and dos findnext Some compilers provide only simplified access to these functions For example WATCOM s opendir and readdir do not allow the specification of file attributes Zortech s findfirstO and findnext cannot be used for simul taneous searches since they use a static buffer for the DTA The hierarchical directory structure of MS DOS borrowed from UNIX is one of its best features With a properly organized tree of directories it is theoretically much easier to control your files I have more than 2 500 files on my 386 system and you can imagine the chaos that would result if they were all in the drive s root directory Unfor tunately the MS DOS directory services only look in one directory at a time So
64. the new debuggers brings with it a more stringent form which doesn t exist in the free and easy do what you like but be prepared for the con sequences world of SYMDEB and DEBUG I suppose I ll always be a rebel at heart MICRO CORNUCOPIA 48 July August 1989 49 By Scott Robert Ladd 302 North 12 Street Gunnison CO 81230 303 641 6438 Searching For A File And Not Just Any File We all use a directory program of one sort sorry or another but the generic packages usually don t do everything Every time my 20 meg drive gets full I m forced to run through all my directo ries looking for duplicates and temp files How about a directory search routine that digs these out Well Scott has the answer ning to have a bad case of exploration fever Symptoms include a distinct distaste for four walls an urge to saddle up the moun tain bike and a strong desire to head for the hills Moving to Gunnison has been an enlight ening and entertaining experience Just like writing for and reading Micro C Micro C is a truly unique magazine as I m sure you re aware I feel somewhat privileged to write for this bimonthly tome of wit and wis dom The May June issue was especially inter esting to me although the reasons for my reac tion have nothing to do with computers Larry s article on Creativity with a capital C parallels many of my own feelings on the sub ject A walk among the aspen and pine rea
65. to do anything for yourself unable to do anything without the assistance coopera tion and permission of someone else Before I owned a computer I had CAPITAL only a few ways to relieve that frustra tion Today as I figure the quarterly pay roll taxes or land an F 16 on the deck of an aircraft carrier or write this article as I press each character with my mouth stick I am doing it by myself without the help of anyone That is independence That is the hidden treasure Forever Lost There are many paths in this adven ture with computers that I have yet to follow I will explore the technology as far as it allows taking detours around mice and other devices designed only for people with able bodies I imagine computers becoming a part of my life in many other ways I imagine smart TVs stereos and other electronic gear smart in that they will respond to a voice or a thought or a blink of an eye I imagine a computer linked to a robot arm that obeys my spoken commands possibly even a robot capable of moving from place to place While mobile robots exist now they are merely toys Meanwhile l ve used present com puter technology to improve almost every aspect of my life the way I work and play the way I communicate and in teract with other people and the way I learn and think and challenge my mind Without a computer I would be without the most important tool I have for making my life worthwhile I
66. to be used as skeletons for new omes Examples include a desktop calculator an Infix to Postfix Translator a DBASE and SQL Syntax analyzer en Trptementation of the PiC ture language and a C to C ranslator ABRAXAS a Lexical Analyzer Generator ABRAXAS PCLEX is included 8 Quick Syntax analysis option m Optional Abstract Syntax Tree Manual Compiler Construction with PC S included s Ali nee include FULL SOURC 30 day money back guarantee m Advanced Error recovery a No charge for shipping Support Provided anywhere in the world Professional Version 395 Personal Version 139 ABRAXAS SOFTWARE INC 7033 SW Macadam Ave Portland OR 97219 USA TEL 503 244 5253 FAX 503 244 8375 AppleLink D2205 MCI ABRAXAS Reader Service Number 157 74 MICRO CORNUCOPIA 48 July August 1989 board That keyboard had an absolutely wonderful touch better than any portable laptop or desktop The Search Thanks for all the cards letters calls and messages on the BBS regarding my search Yoga rolfing psychic readings I haven t had a chance to get back to all of you but I thank you for your help and support Also see Letters this issue Some of you wondered how you could locate a national or regional new age support group You shouldn t have to look beyond your own community People who are doing this are like folks running CP M they re there they re just not adver tising Usually you can
67. when the application software controls the colors there is a way to override and reset colors by using a special EGA card or monitor Maybe the problem is easier in the CGA display In monochrome displays maybe certain driver cards could accept a change to reverse video showing it as underlined text like WordStar allows in its installation procedure At present I have an AT compatible with a Quad EGA board and Hercules compatible monochrome graphics board Thanks for any ideas Carl H Schmitt 3201 Coquelim Terrace Chevy Chase MD 20815 TO COMPUTER ieee pS GENE nd Lo agen 20 3snoN OL JUNCTION BOX _ Figure 4 Short Program to Locate Attributes On Video Adapter PROGRAM FindAtr Toggles an attribute repeatedly until a keystroke Configured here to find the reverse video attribute on a CGA card CONST Normal 07 normal video attribute Reverse 70 reverse video attribute VidBase b800 base address for CGA text memory VAR use ABSOLUTE to force this array to overlay video memory Screen ARRAY 0 3999 OF Byte ABSOLUTE VidBase 0 PROCEDURE SetAttribute Attrib Byte VAR I Integer BEGIN Tired FOR I 0 TO 1999 DO Screen 2 I 1 Attrib END SetAttribute BEGIN MAIN WHILE NOT Keypressed DO BEGIN SetAttribute Reverse Write G Delay 1000 SetAttribute Normal Write G Delay 1000 END WHILE
68. with dictionary and maintenance tools tn 30 Clisp Lisp interpreter with extensive internals documentation 2 6 4 44 ee ee A 30 Translate Rules to C YACC like function generator for rule based systems eee ren 30 6 Pack of Editors six public domain editors for use study amp hacking S er mi Vesp Le qe qu ve Pise Rr iu d a vi ewig es Voc IT TRE IN VOS at 30 Crunch Pack 14 file compression amp expansion programs s soe ee te 44 ee oor n n 30 Pascal P Code Compiler amp Interpreter or Pascal to C Translator Wirth standard Pascal 6 6 lees 25 ICON string and list processing language Version 7 5 6 6 6 4 44 4 4 44e 4e ee nn 25 FLEX fast lexical analyzer generator new improved LEX Version 1 1 s 6 6 eren 25 LEX lexical analyzer generator an oldie but a goodie ww 4 e eee eh nn 25 AutoTrace program tracer and memory trasher catcher 2 1 eee 4 4 4 e ee e eoo oe eon on 25 Data Handling Utilities in C data entry validation amp display specify Turbo Cor Microsoft lll 25 Arrays for C macro package to ease handling of arrays 6 4 a n 25 A68 68000 cross assembler 6 we ee hn s n 20 List Pac C functions for lists stacks and queues oaa he eee or n s 20 XLT Macro Si agra penen purpose text translator 6 4 44 4 4 44 e ehe ooo ooo t o n 20 Creativity Eliza based notetaker o eee a 4 4 4 44 4 4 4 4e a ho ooo
69. you ve found something new you find out it doesn t work Both packages work fine on ATs how ever MICRO CORNUCOPIA 48 July August 1989 71 Around the Bend SuperCalc 5 Occasionally we do real work at Micro C For spreadsheets and the like Sandy s been using SuperCalc 4 Great package absolutely dependable Then she purchased the upgrade to 5 She expected truly marvelous things like laser printer output a selection of fonts more graphics Unfortunately it appears they didn t test their fancy new printing routines before shipping the product Outputting to a dot matrix printer is frustrating For in stance if you re outputting regular text it outputs properly if you select carriage return no linefeed If you re outputting condensed text to the same printer you must select carriage return and linefeed Otherwise it prints everything on a single line Okay that s no worse than an adventure game Except Sandy needed regular text followed by condensed text So she either got double spaced regular text or all the condensed text on a single line So she tried outputting on our laser printer However outputting to either a Laserjet or PostScript printer turned out to be an even bigger adventure Sometimes she d get the first page never any following pages But usually she wouldn t even get the first page Even after she d successfully output the first page she couldn t out put that same page again Of
70. 0 a month at Metheus The first year and a half I did royalty work and in the end averaged about fifty cents an hour Then I tried consulting and my income rose to over 100K a year When I was designing graphics controllers I used YACC to build C compilers for Bit Slice engines I realized at Microfield that the PC market needed a YACC for professionals In 1987 I brought out Abraxas first product PC YACC Important note If you can t get through the first two years of poverty don t even think about starting a business It s called paying your dues and unless you go through it you ll never learn to do great things with very little Tell Us About Abraxas Software Right now we sell PCYACC MACYACC and PCYACC 2 for OS 2 Later this summer we ll have some exciting products that will solve portability and maintainability problems Our products sell because of their value and depth There are over ten man years in PC YACC and for 395 that s an incredible value for someone serious about language design We publicize our products via press releases and advertising We support our users by help ing them solve problems with the pro gram We don t teach people how to use PCYACC In fact the only reason we charge 395 is so we don t have to deal with amateurs At 99 our custom ers would drive us crazy I once spent an hour with a customer only to find that he had the disk upside down in his drive Belie
71. 12 VDC Sample Software and manual User optional on board clock I O connections hardwired lO MODULE CARDS 19 95 AC to 220 volts 19 95 DC to 24 volts Each card is a set of 8 which can be separated into single units See HAL Demonstrating Himself At Our Techna Kit Display ROBOTICS ROBOTIC MOTORS United Products Corp is the sponsor of the Seattle United Products Corporation Robotics Society If you are interested in Robotics you Stocks all kinds of them may wantto call us for more details M F 9 6 SAT 9 5 qi united products corporation DISTRIBUTORS OF ELECTRONICS SINCE 1968 PHONE 206 682 5025 FAX 206 682 5593 1123 VALLEY STREET SEATTLE WA 98109 4425 Reader Service Number 101 MICRO CORNUCOPIA 48 July August 1989 89 NEC HD Laptop Tips I have a little info on the NEC HD laptop 20 Meg hard drive Figure 1 shows how to build your own spare battery pack for about 35 NEC gets 100 for theirs Figure 2 covers the pin out for an external 5 1 4 drive 360K NEC s documentation on the pinout was incomplete and their tech support people were unable to help They want you to buy their expensive external drive I m running a Canon drive on mine but almost any drive should work The 5 1 4 drive must have its own power supply I had a lot of trouble with the NEC at first Their built in software conflicted with many of my utilities dBASE III WordStar MASM 5 1 and others
72. 2 SELECT INPUT ceiver on hold after the last file is transferred This way you can send a batch of files move to another sub directory send some more files etc Try changing the program so you can send messages to the receiver and make it change directories too and even make new ones Software In Turbo C To understand the code you ll need to study Figure 2 the map of the bytes on the parallel printer card You can see the pin numbers on the DB 25 connector shown in the cells representing the bits The I O location of the bytes is rela tive to a value called BASE which the jumper selections on your printer card established The byte at BASE is the printer data port which you can write and read although on an unmodified card you can only read what you ve written BASE 1 is read only BASE 2 can be read or written If you want to read bits 0 through 4 you must write a 0 to bits 0 1 and 3 and a 1 to bit 2 I know it sounds a bit like voodoo economics but you ll have to stare at the circuit for the printer card in Computer Interfacing In Pascal amp C if you really want to understand how it works Or You Asked for Precision And Tele created a World of Possibilities Berry Computers presents The Tele Toolkit a complete Operating Systems Kernel Need to get all possible performance from your embed ded controller Using tele will save you a lot of work Tele measures all t
73. 2 720k 1 44M and even 8 drives UniForm PC by MicroSolutions Also available for Kaypro amp other CP M computers 64 95 CompatiCard by MicroSolutions THE universal four drive floppy controller board for the PC or AT Run up to 16 disk drives 4 per CompatiCard including standard 360K 96 TPI high density 1 2M 8 SSSD or DSDD and 720k 1 44M 312 drives Comes with its own MS DOS driver and format program Use it with UniForm PC for maximum versitility CompatiCard Board CompatiCard with UniForm PC 8 Drive adaptor External 5 drive cable Compaticard Il by MicroSolutions Two drive version of the CompatiCard sorry no 8 or single density CompatiCard I CompatiCard Il with 1 2M or 3 internal drive Megamate by MicroSolutions This is the 3V2 drive package that you ve been waiting for Run 720k or 1 44M diskettes in this attractive external drive Comes complete with its own controller card Easy to install just plug it into your PC or AT and go Megamate 329 95 MatchPoint PC by MicroSolutions The MatchPoint PC board for the PC XT AT works with your standard controller card to let you read and write to NorthStar hard sector and Apple Il diskettes on your PC INCLUDES a copy of the UniForm PC program as well as utilities to format disks copy delete and view files on Apple DOS PRODOS and Apple CP M diskettes MatchPoint PC Board 179 95 MatchMaker by MicroSolutions Now you can co
74. 26 Parallel Port File Transfer When I began the controller series I used the parallel printer port that came with the cheap Hercules imitation card on my XT clone After a few experiments the card mysteriously stopped working Knowing what I did about the parallel printer card I was certain there was no way the printer port could be damaged Upon further investigation I dis covered that the circuit used for the par allel printer port on Hercules clone cards and I assume the original Hercules card is very different from the hardy TTL parallel printer cards you can buy so cheaply The printer port consisted of one chip And the chip was CMOS which can be fragile especially when exposed to static electricity So I tried to replace the chip attempting to blow it up again with the same circuit thus proving the destructive nature of the circuit or at least the de structive nature of the experimenter But after a long search I found that only one company manufactures the chip and an obscure one at that I m not sure if it s even possible to buy this chip through regular channels Perhaps the designers of the card expect you to throw it away if you break it So I ve come to this conclusion if you want to build this project you should buy two cheap printer cards the kind that are about 20 and chock full of TTL chips I ve had success with these and if you have an accident you ll prob ably only damage one c
75. 3 to 30 times faster than the competition on large files where speed really counts Call for your free evaluation copy today See why VEDIT has been the 1 choice of programmers writers and engineers since 1980 VEDIT Jr Unmatched performance for only 29 All VEDIT editors include a pull down menu system with hot keys context sensitive on line help pop up status and ASCII table a configurable keyboard layout and flexible unlimited keystroke macros Edit files of any size and any line length Perform block operations by character line file or column Undo up to 1000 keystrokes keystroke by keystroke line by line or deletion by deletion Automatic indent block indent and paren theses matching speed program development Word wrap paragraph formatting justification centering adjustable mar gins and printing for word processing Run DOS programs VEDIT A best value at only 69 Simultaneously edit up to 36 files and split the screen into win dows Search replace with regular expressions Includes the best compiler support available menu driven easy selection of compiler options supports Include files and MAKE utilities VEDIT PLUS Ultimate programmers tool for only 185 VEDIT PLUS adds the most powerful macro programming language of any editor It eliminates repetitive editing tasks and permits creating your own editing functions The macro language includes testing branching looping user prompts
76. 302 N 12th Street Gunnison CO 81230 303 641 6438 September 7 amp 8 Nestled In York Pennsylvania this SOG will bring the best of the West to the East In York you ll find antiques Penn Dutch cooking crafts and more Historic Gettysburg is only 30 minutes away York is 25 minutes from the Harrisburg airport and about 60 miles from Bak timore Washington International Tentative Schedule Wednesday Night 4pm 9pm Twilighter Railroad Excursion Steam train ride and dinner trip 25 A special trip Just for SOG attendees and families Thursday Meetings Speakers Thursday Supper Volleyball frisbee BBQ Penn Dutch style outdoors 15 per per son Thursday Evening Rooms available all night for talking JoltSIG etc Friday Speakers Friday The York County Fair begins largest livestock and agricultural show on the East coast Lots of food free show entertainment October 13 14 15 1989 The Dallas computer club has over 4 000 members in some 15 user groups Dallas weather should be marvelous this time of year So plan to come and enjoy the southern sun and hospitality If you d like to speak you should contact Stuart immediately November Terry Sherb called just before deadline to say he s having trouble finding a facility in which to hold SOG So he s tem porarily postponing the Cal SOG until possibly November We ll carry more details in the next Issue Saturday Morning Anot
77. 386 View gives you the features privilege level and break point registers to provide real time hardware level break points or FAX 603 888 2465 necessary for professional level systems debugging 30 day money back guarantee GG Visa Master Card and AmEx accepted MagicCV and Soft ICE can Soft ICE is a product any MS DOS work in concert with Code developer serious enough to own a NU MEGA TECHNOLOGIES View to provide the most 386 machine should have powerful debugging Dr Dobb s Journal May 1958 54 P O BOX 7607 NASHUA NH 03060 7607 MB platform you will find Both require 80386 AT compatible or IBM PS 2 Model 80 MagicCV requires at least 384K of extended memory CodeView is a trademark of Microsoft Corporation 2 MICRO CORNUCOPIA 48 July August 1989 Reader Service Number 110 anywhere THE MICRO CORNUCOPIA MICRO TECHNICAL JOURNAL JULY AUGUST 1989 ISSUE 48 FEATURES COLUMNS 8 12 16 20 28 34 38 80 Dallas Vordahl The Adventure Begins How does a quadriplegic declare independence It s not easy but with a mouth stick and a computer almost anything s possible Debee Norling Selecting A Talking Computer For A Blind Friend There are a lot of well meaning people who ll help you pick out a computer for a blind friend Debee s a lot more than well meaning Debee Norling Writing Software F
78. 820 Column Restarts BBI Double Density BBII 5 6 Interface Fix Kaypro ZCPR Patch Adding Joystick To Color Graphics Recovering Text From Memory 52 pages ISSUE 17 4 84 Voice Synthesizer Kaypro Morse Code Interface 68000 Based System Review Inside CP M 86 56 pages ISSUE 18 6 84 Kaypro EPROM Programmer l O Byte A Primer Kaypro Joystick Serial To Parallel Interface Business COBOL 60 pages ISSUE 19 8 84 Adding Winchester To BBII 6 MHz On The BBI Bulletin Boards Track Buffering On Slicer 4 MHz For The 820 1 64 pages ISSUE 20 10 84 HSC 68000 Co Processor DynaDisk For The BBII Serial Printer On BBI Sans S10 Cheap amp Dirty Talker For Kaypro Extended 8 Single Density 72 pages ISSUE 21 12 84 Analog To Digital Interface Installing Turbo Pascal Low Intensity BBI Video Turbo Pascal The Early Days 80 pages ISSUE 22 2 85 Xerox 820 I To A Kaypro 8 Sound Generator For the STD Bus Reviews Of 256K RAM Expansion 88 pages ISSUE 23 4 85 Automatic Disk Relogging Interrupt Drive Serial Printer Low Cost EPROM Eraser Smart Video Controller Review MicroSphere RAM Disk 86 pages ISSUE 24 6 85 C ing Into Turbo Pascal 8 Drives On The Kaypro 68000 Versus 80x86 Soldering The First Steps 88 pages ISSUE 25 8 85 Why Wrote A Debugger The 32 Bit Super Chips Programming The 32032 Modula Il RS 232C The Interface 104 pages ISSUE 26 10 85 Inside ZCPR3 Two Me
79. 9 Quantum Software 129 Research Group 142 RJSwantek Inc 127 SemWare 150 Software Development 106 Software Masters 40 Star K Software Systems 152 Stony Brook Software 101 United Products 62 V Communications 124 Wenham Software When you write for information please tell these folks you read about their products in Micro Cornucopia Order From Micro Cornucopia PO Box 223 Bend OR 97709 1 800 888 8087 with Pascal amp C Now Available From Micro C Computer Interfacing by Bruce Eckel Use your PC parallel port for digital input and output Build an Adapter Card for your PC Control a stepper motor Design and build electronic circuits With wit and superb technical figures Bruce captures the essence of making electrons out of bits and vice versa Jeff Dunteman Dr Dobbs Only 30 ppa Includes Book amp Disk Interfacing 16 bit Devices to the AT Bus Capturing Video Images A Modem Operated Switch Industrial Computers amp Programmable Logic Controllers Introduction to Post Script The Further Exploits of LIMBO MICRO CORNUCOPIA 48 July August 1989 95 If you think desktop publishing has solved the graphics file compatibility issues you should have been around here last issue but we hope not this issue gram I can use right now Genus Mi croprogramming down in Houston sent me a set of PCX tools I can use right now and with every issue Thanks guys For you joi
80. 9423 MyFLIN is a TSR database loaded before your programming editor MyFLIN reads YOUR procedure and funcfon information directly from the screen storing itin an indexed database for instant recall You simply press A to add the entire description to the database No more scraps of paper to lose no more terse invalid data type messages MyFLIN requires MS PC DOS 2 xx or 3 xx and an IBM PC XT AT ar dose compatible machine Normally 69 but for a limited time at the introductory price of 49 P amp P For a brochure or to order MyFLIN contact Opal Fire Software Inc 329 North State Steet OREM UTAH 84057 Phone 1 800 336 6644 No surcharge for Visa MC Amex ReaderService Number MOTHERBOARD 20 Mhz switchable to 8 Mhz scores 24 on Norton Si Test two 32 bit memory Slots eight slots total standard full size motherboard manufactured by DTK 799 1099 wt Mb Memory Order Hotline gMicroSphere 1 800 234 8086 Tech Calls 855 NW Wall St Bend OR 97701 503 388 1194 Reader Service Number 02 LATEST AWARD BIOS PC XT xx 286 vx 386 Support for Enhanced Keyboards EGA amp VGA Graphics 3 5 inch Floppies More Authorized AWARD Distributor 800 423 3400 KOMPUTERWERK INC 851 Parkview Bivd Pittsburgh PA 15215 Reader Service Number 126 Why you want BATCOM BATCOM is a batch file compiler that compiles your bat files to exe files to make them faster
81. A Definite Change Of Pace The books I ve mentioned so far have been authored in a very normal way Someone comes up with an idea takes key board in hand and writes In my search I ve also stumbled onto a whole different style of book untouched by human mind These are channeled books the words dictated by spirits Whether you re comfortable with the idea or not these books make interesting reading of course you can pick your spirit just as you d pick any other author AT LAST YOU CAN STEP BACK AND TAKE ALOOKATYOURCODE FLOW CHART AND ANALYZE YOUR ASSEMBLY LANGUAGE SOURCE CODE Flow Charts Tree Diagrams e Stack Sizing Register Analysis CPU Timing Analysis Procedural X Reference 8088 87 to 80386 387 Context Sensitive Help Menu Batch Command line Operation MASM 5 1 Compatible SUN line editor warning Save screen display warning restore screen editor warning insert blank line adjust line join line QUANTUM SOFTWARE E editor warning djust li 19655 Stevens Creek Bid Suite 154 delete edit lino ino CA 95014 editor line out edit line out VISA MC 30 Day Money Back Guarantee Reader Service Number 139 Seth and Lazaris are two of the most famous spirit authors You can breeze right through Lazaris books while Seth takes work But Seth will challenge and stretch your ideas about life the universe and everything I started with the volume called Seth Speaks Bot
82. Also most people are afraid to go alone Misery loves company and most people do not like to suffer alone Also never announce vaporware and don t ship a product with bugs It only takes one mistake one message that you are a flaky company and that s it No ifs buts or anything It s the old story If you don t have time to do it right the first time where are you going to get time the second time I see this over and over If you ever make this mistake go back to square one and re name your company because the public will never forgive you Finally pet rock software I ve seen gobs of stupid software The public isn t stupid If you can t spend the time to develop an excellent product then don t bother If you develop a high quality useful piece of software that solves real problems really works and doesn t cre ate more problems you can t fail You use remote programmers Why Tell us about them When I started my business I knew I didn t want to build a home for orphan programmers I have known so many programmers who spend their day reading the UNIX Net or playing com puter games I just didn t want to be a baby sitter Remote programmers by their very nature must be disciplined or they don t eat I prefer to hire first generation immi grants They are the hardest workers They understand that in terms of starting their own business America is without limits Since
83. BY AT XT TURBO Motherboard 6 amp 10 Meg Motherboard Zero Wait State 5 amp 8 MHz Switchable 8 Expansion Slots 8088 V20 Optional 640K RAM On Board Optional Co processor Math Co processor Option 8 Expansion Slots Phoenix Bios ERSO or Bison Bios 200 Watt Power Supply 640K RAM Hercules Compat Video Bd 150 Watt Power Supply Parallel Port Hercules Compat Video Bd 2 Serial Ports Active Parallel Port Game Port 2 Serial Ports Active Clock Calendar Game Port Hard Disk amp Floppy Controller Clock Calendar 20M Hard Drive Hard Disk and 1 2M 514 Floppy Drive Floppy Controller 360K 5 Floppy Drive 20M 5 4 Hard Drive 5061 Keyboard 2 ea 360K 514 Floppy Drive AACells 6ah eae 12V Pack AA Cells 6ah 6 50 Sub C Cells 1 58h 1 50 12V Pack Sub C cece eee Double D Cell 2 5V 4ah unused 8 00 OGG anane pean fost 1 75 9 9 9 go 0 s 8 9 9 3 5 6 8 6 o9 0 0 aon s n t 55 0 09 0 5 1 102 9 9 peer evr 6 9 3 0 a 9 6 n n n DCell 25ah c cce 2 00 ROBOTICS 5V DC Gear Motor w Tach 1 x2 7 50 Case with Turbo amp Reset AT Style Keyboard Joystick 4 switches 1 knob 5 00 Hard Drive Light and Keyboard Disable Switch Amber Graphics Monitor 1581 EGA ADD 449 40M HD ADD 150 6 amp 12 MHz ADD 73 Standard Slide Case Amber Graphics Monitor EGA ADD 429 40M HD ADD 5 amp 10 MHz ADD 21 nal or external 24VDC batt
84. COPIA 48 July August 1989 Continued from page 6 47 Congratulations on the new course you ve found for yourself and for af firming it in print I began taking yoga classes a little over a year ago and I m completely hooked Apparently something pushed me into a bit of an identity crisis then my job at the fire department no doubt and I got busy looking for ways to figure out who I really am Yoga was one of several and I con tinue to be amazed at what it does for me I think you ll find that it will keep paying big dividends over a period of time if you stick with it In the East Asia not Kansas the path towards self knowledge is re garded as an intensely spiritual one It also tends to be pretty exclusive You choose a path and stick to it often dic tated by the culture you live in We westerners are more eclectic we have a menu oriented approach to life Who knows where you ll end up It may not be such an exotic experience You sound like you ve already found something that has you moving in the direction you want and there are risks in dabbling in too many things at once We have a more compulsive left brain to keep happy than the average Burmese or Nepali though so it really helps to have some reading to keep the deductive circuits pacified I have a few suggestions but the only one that will definitely be pertinent is to use your own intuition The people who have something for me are usually the
85. I m on this subject I want to mention that most PCYACC sales come from northern Europe Here we have one of the most technical products available for the PC and only discip lined North European developers buy it This tells me that in the near future Europe will blow us away I work with a programmer in New Mexico who has a wonderful lifestyle in an enchanting village He s an in credible producer When he isn t pro gramming for profit he s teaching his five year old son theoretical physics He has developed an asteroid game that teaches Lorentz transformations Eu clidean geometry general relativity and astrophysics all on a Macintosh He also has developed technology that al lows the Mac to be an inhouse bird sanctuary by playing songs and dis playing real birds Any more suggestions for other entrepreneurs Work hard Be original and ask your self every day how badly do I want this Don t abandon the people you love And in the end you re doing it all for only one person yourself Play hard and work hard Don t quit playing because if you do you ll lose your sense of value and then you have nothing Give away your best ideas Being selfish with your products and talent will only hurt you in the end Every three years take everything you ve learned and throw it away Today DOS is hot Eight years ago it was CP M In two years OS 2 will be hot Learn the NeXT Its hardware theme will be the basis of
86. INCLUDED ON MICROPROCESSORS UNLIMITED INC FED EX ORDERS 24 000 S Peoria Ave 91 8 267 4961 gy RECEIVED BY BEGGS OK 74421 Th Std Alr 6 2 b No minimum order Please note prices subject to change Fr P1 12 25 1 Ib Shipping insurance extra up to 1 for packing materials 80287 8 80387 16 135 00 225 00 80387 20 8087 2 Reader Service Number 37 MICRO CORNUCOPIA 48 July August 1989 55 returns the carry flag as an error indica tor The implementation of these func tions deserves some comment Because of the existence of multiple memory models in MS DOS C compilers point ers come in different sizes see Micro C 41 for my discussion of memory mod els MS DOS services work with far or 32 bit pointers This is fine when work ing with the large or compact models but causes problems in the small and medium models where data pointers are only 16 bit offsets in the data seg ment FILESRCH handles this problem All MS DOS C compilers define macros to indicate which memory model it uses for the current compilation When FILESRCH detects that it s using a memory model which has near 16 bit data pointers it defines a macro called SMALL_DATA_PTRS The find first and set dta functions then know what type of pointer they are working with and can adjust themselves at compile time This is an excellent example of how you can use the C preprocessor to make one source file handle multiple s
87. Jeremy P Tarcher Inc 1983 Hogben Lancelot Mathematics for the Million Norton amp Co 1937 1940 1943 1951 1983 Techna Kit TK USMD C ADVANCED DC MOTOR Control standard 6 lead CONTROLLER stepper motors with Control 2 DC motors with a computer or other logic computer or other logic source 1 Source For motors rated 6 24 VDC For motors rated 1 7 12 0 Control forward reverse run cw VDC cew stop Optical Isolation Up to 6 Amp starting surge 4 amp Control forward reverse step continous rate stop Will also run most 4 lead stepper Industry standard 22 pin motors edge card connector 29 95 29 95 AUTOMATION CENTER Use your computer to HAL 2000 provide automation 8 separate driver ports Per Imagine sitting in your easy SA a chair while HAL is adjusting Ae sense your airconditioning or watering That means he can turn on off 6 24 VDC ae mite ae peak i Is 48 different AC or DC devices i MSO WANNY NO MOS SANG A He can measure temperature 4 amps driver max curren cake or preparing the evening resistance and anything that 29 95 dinner can be turned into an analog signal with his A D converter All of this is done with our Hal 2000 and your PC Hal has With your software there is A D conversion which monitors TK USMD and senses the real world Astand alone driver for HAL 2000 PC CARD 79 95 6 lead steppers Unpopulated board with For motors rated 1 7
88. Need to know just how a non maskable interrupt occurs and how to mask if Is your keyboard dead or do you just want to know how to disable it A trip through our schematic will answer your questions Although clones use slightly altered board layouts and different chip location names they re close enough to the original for this schematic to be very useful As an example you have a dead clone Lil sucker won t even beep A look at the schematic shows the location of parallel port A You know that the power on self test loads a checkpoint number into port A before each test So now all you have to do is read port A with a logic probe to see how far The system went before it puked We include these checkpoints and other trouble shooting information with the schematic IBM PC XT Scheridlic ao eoe tice Rests vei cnc cent tiene 15 00 CP M KAYPRO SCHEMATICS Of course we still provide a complete schematic of the processor board in your CP M Kaypro It s logically laid out on a single 24 by 36 sheet and comes complete with an illustrated theory of operation that s keyed to the schematic You get detailed information available nowhere else For instance those of you with the 10 and newer 84 systems get a thorough run down of the processor board s video section complete with sample driver routines All packages contain serial and parallel port details and programming examples Also coverage of the processor clock I O and disk c
89. No 48 July August 1989 3 95 fH E M wal ECHNICAL JOURNAL o Tools For The Physically Impaired What s important to people who have handicaps We asked them Their responses may surprise you The Adventure Begins pages E Dallas Vordahl demonstrates what you can do with a computer a mouthstick and a very limited amount of head motion Writing Software For page 16 The Blind Don t exclude the blind from your next software package File Transfer Via The page 20 ERE Parallel Port The LIMBO Project page 28 Build a maze running robot And More Debugging A Processor page 44 Growing Your Own page 66 Software Business Great SOGs page 83 And Much Much More 0 3 gt 74470719588 Turn yeu OZ mes Powerfull Laboratory ane 2noqlimeorlnG els Introducing The PC LabCard Family Only from HSC Electronic Supply DU De Digital I l O and Counter Card 32 Digital Input Channels TTL compatible Low loading 0 2 mA at 0 4V input 32 Digital Output Channels TTL compatible Driving capacity Sink 24 mA source 15 mA Intel 8253 Timer Counter 8 channels of timer counter Breadboard area for flexible user configuration Prototype Development Card Large breadboard area 3290 holes Independent memory and I O address decoders built in Memory and I O ports are jumper selectable All bus signals are buffered marked and rea
90. OM MAND COM installs the default one It prints a message and then terminates the current program The behavior of TRAP s Divide by 0 is slightly different but this will only show up with buggy programs anyway The information given is so much more useful that it s worth any inconvenience TRAP The resulting program see Figure 1 is installed from the DOS command line It traps out and reports 1 execu To detect execution at 0 0 immedi ately we must make the first byte at 0 0 some known opcode which branches to a known place The first opcode that comes to mind is opcode CCh the breakpoint instruction which causes a branch to the interrupt 3 handler De bugging programs use INT 3 though so it would be more convenient to use something else I came up with the solution to put a 66h at 0 0 This is an invalid opcode on the 186 and 286 but not the 386 and causes execution to branch to the In valid Opcode interrupt handler The handler for invalid opcodes can then check to see if the opcode in question is at 0 0 and prints a message accord ingly What about the pointer to the Divide by 0 routine That should be at 0 0 after all And we just trashed it The solution to that problem is to force the address of the divide by 0 in terrupt handler to an address such that the byte at 0 0 is guaranteed to be 66h tion of invalid opcodes 2 attempts to execute at 0 0 and 3 divide by 0 ex ceptions
91. OM BIOS This is fundamentally important to making an XT controller It s the ROM BIOS which requires a keyboard a moni tor RAM and all those other doodads you may not want on your controller I plan to look at this problem from several angles The simplest angle will involve disabling the keyboard and monitor check routines so you can run your con troller as a standalone box but still boot from a floppy disk The most involved angle will be re writing the ROM to use static RAM in stead of dynamic RAM eliminating the RAM refresh interrupts and executing a program in EPROM instead of looking for a floppy disk For those of you who have to know how to do it now I ve received a couple of excellent leads which should get you going Laine Stump who s back in Turkey by now has written several BIOSes for PC Tech He suggested the following get an EPROM burner which can read and write you can find these for the PC at under 150 and suck the contents out of your XT ROM BIOS Then find the power on reset vector and change that to an adjacent ROM socket in your XT there are usually several Blow the modified ROM BIOS con tents into a new EPROM and put it back into the original socket After figuring out where the entry points to the various ROM BIOS routines live more about that in a minute you write your own code in C which picks and chooses from the routines in the ROM BIOS This is much easier than rewriting
92. PC compatible and included a speech synthesizer with speaker Unfortunately acquisition is easier than implementation He quickly learned that the speech synthesizer was merely a chip The fact that a speaker was at tached didn t mean that the synthesizer had anything to say So Ray started writing code His code made explosive sounds siren sounds fly ing saucer sounds breaking saucer sounds rainy weather sounds and chirpy bird sounds He even made the synthesizer count from one to ten and made the program menu driven The sounds were almost intelligible Ray had a wonderful toy but unfortunately Tina didn t have a talking computer Important Points Ray and Tina s situation is common Ray could have done much better if he had known four simple facts e Many synthesizers in today s market do create terrific speech A speech synthesizer isn t enough The blind user needs screen access software the high level interface between the talking box and the computer s operating system The right word processor database or spreadsheet must be purchased Ease of use for a blind person is much more complicated than it is for the sighted A dealer knowledgeable in the needs of the blind could have guided him to a more appropriate purchase Since the IBM PC is the business computer it s the obvious choice if the blind person will use the computer pro fessionally If the user is a grandfather a school
93. SCII This means that pull down menus can be useful in stead of intrusive and that Video Voice can even cope with multiple pop up win dows Video Voice can read a specific range of screen coordinates say from row 3 column 12 to row 20 column 66 It can also read from a certain line to the bot tom or from the top to a certain line It can read six types of text charac ter word sentence paragraph row and screen For each of these types except screen it can read the previous the cur rent or what follows This means that with two keystrokes I can read the cur rent sentence the following paragraph or the previous row Furthermore adding a single keystoke to the sequence will force Video Voice to either spell the selected text letter by let ter or to spell it with military phonetics alpha bravo charlie etc The system cursor s position determines the current location A screen reading program such as Video Voice gives the blind access to Lotus WordPerfect dBASE or just plain old FORMAT and XCOPY Thanks to Video Voice I write using QEdit and WordPerfect program with Turbo C back up my hard disk with Backit and use Memory Mate to take notes Choosing Applications For The Blind Finding a workable speech synthe sizer and screen reading program doesn t end the project The applications com pilers text editors database handlers also must pass the blind test There is a big difference betw
94. When encountering one of these con ditions it prints a message and register dump along with a few bytes of the code at the last known CS IP Then after waiting for a key to be pressed it executes an INT 3 The idea is that you can run the program in question under DEBUG or SYMDEB then use the de bugger to examine the area of the pro gram in question after the crash MICRO CORNUCOPIA 48 July August 1989 45 Computers For The Blind Talking computers give blind and visually impaired people access to electronic information The question is how and how much The answers can be found in The Second Beginners dur Guide to Personal Com UEOOUODUDODOUUDOOUUPOUHOOUHOOEGODOOUE puters for the Blind and Visually Impaired pub lished by the National Braille Press This compre hensive book contains a Buyer s Guide to talking microcomputers and large print display processors More importantly it in cludes reviews written by blind users of software that works with speech This invaluable resource book offers details on training programs in com puter applications for the blind and other useful information on how to buy and use special equipment Send orders to National Braille Press Inc 88 St Stephen Street Boston MA 02115 617 266 6160 12 95 for braille or cassette 14 95 for print 3 extra for UPS shipping NBP is a nonprofit braille printing and publishing house 46 MICRO CORNUCOPIA
95. _HANDSHAKE while inportb BASE 2 amp 1 if inportb BASE 2 amp 2 puts aborted exit 1 TESTKEY void send_string char string while string send _ byte string stringtt void usage char msg puts nusage ppxfer s filel ext puts to send files through the parallel port using the special puts cable configuration the list of files can be any length puts wildcards may be used in the file name or puts ppxfer sh filel ext puts to send files and leave the receiver on hold so other puts files may be sent or puts ppxfer r puts to receive files puts msg exit 1 void send file char unambiguous name int i infile unsigned long filesize readsize char buf 30 dbyte filebuf BUFSIZE long secs start secs end for timing if infile open unambiguous name O RDONLY O BINARY lt 0 puts cannot open file to send puts unambiguous_name exit 1 filesize lseek infile OL 2 find file size lseek infile OL 0 reset file ptr to start ultoa filesize buf 10 idle send byte ATTN send an escape send string filename send byte LDELIMIT send string unambiguous name send byte RDELIMIT send byte LDELIMIT send string buf send byte RDELIMIT printf sending 15s size s bytes unambiguous name buf ifdef TIME time amp secs
96. ager needs to keep an eye on its working space DL monitors your hard disk and will share the information with you at the press of a key Sometimes roaming about your hard disk and poking into various subdirectories might not interest you If you plan on a file fiddling session that will be confined to a single directory Director includes the pared down DB program which stands for Dan Baumbach DB saves some time and memory since it can ignore the directory structure and go directly to the local files Baumbach says Most of the time I used DB instead of typing DIR to see what s in a directory and be able to scroll through it and view files Baumbach has continued to polish Director and added configuration programs to cus tomize the features of DL and DB To assist im patient users are there any other kind he has written a quick start manual that gets right into the program His 45 page user manual takes a more lei surely approach describing each feature in detail providing a shareware registration form and giving a plug to the Association for Shareware Professionals There are two registration levels for Director At 30 you get the entire suite of programs and a printed manual for 25 the manual is on disk only and you have to print out your own copy I say pop for the five bucks and save yourself the hassle you ll get both the on disk version and the printed copy Baumbach has made a speci
97. al ar rangement for Director registration with Nelson Ford s Public Software Library one of the more notable shareware dis tributors in the country Call PSL at 800 2424 PSL and register Director on your credit card PSL then contacts Baumbach that very same day and he will mail your registered copy to you Of course you can call PSL to order many other shareware products as well You may also write directly to Helpware Director 1 0 Reg with printed manual 30 Reg with on disk manual 25 CA residents add 6 sales tax Helpware 100 Bayo Vista Way 6 San Rafael CA 94901 SemWare s Quick Editor Every new computer user soon learns that smirks and laughter are the only proper response to any mention of EDLIN the text editor that comes with DOS Although it s a very capable line editor it can imbed any character in a file its line orientation and user inter face are more Stone Age than Silicon Age Just as several programmers have striven to shore up DOS s weak file handling with DOS shells and file managers many others have offered re placements for EDLIN The essential improvement in virtually all cases is screen orientation If you re not an old timer in the mi MICRO CORNUCOPIA 48 July August 1989 61 Rack amp Desk PC AT Chassis Integrand s new Chassis System is not another IBM mechanical and electrical clone An entirely fresh packaging design approach has been taken
98. alid reads the byte and lowers its DO line to indicate it has successfully received the byte The sending computer sees this raises its SELECT INPUT line to acknowledge that the receiving computer got the byte and waits for the receiving computer to lower its DO line When the receiving computer lowers its DO the cycle is completed and a new byte transfer can begin File Transfer Protocol Now that bytes can be transferred we need a way to transfer entire files This program uses a very simple file transfer protocol which you might want to im prove with some error checking ie a checkvalue at the end of each file partic ularly if you re in a noisy environment See Figures 3 through 6 for all the code A file transfer goes like this when the program starts on the receiving computer established by the r flag it sets its printer port to idle and waits for the sending computer to say something You have to start the program on the receiv ing computer before you start the pro gram on the sending computer When the sender established by the s flag starts up it too sets its printer port Figure 1 Parallel Port Transfer Cabling Machine A Printer Port DB 25 Connector STROBE Do D1 D2 D3 D4 D5 D6 D7 ACK BUSY PAPER END SELECT AUTO FEED ERROR INITIALIZE DATA VALID SELECT INPUT GND 5 to idle The sender begins each file transfer with a block of information called a control b
99. alls as pipes conduits and rebar in concrete naturally affects magnetic sensors To minimize the affects of local distortions in the Earth s magnetic field the flux gate coil will be mounted on a central mast so that it will be at least 36 from any ferrous objects in the floor or maze Figure 3a Range Equation Further to guard against magnetic distortions caused by very large steel structures the compass should only be used for relative heading readings when making turns As long as LIMBO turns about its own center relative change in heading is sufficient to make accurate turns the ab solute heading indicated by the compass is unimportant Unless the contest area is known to be free from distortions though don t try to maintain an absolute heading while the robot is in linear mo tion ESS EEE LE Infrared Range I described the IR range finders last Ri Ro Py time but it wouldn t hurt to review The Ry 4 rs Po idea is to measure reflected IR with two sensor emitter pairs a known distance apart see Figure 3a The two sensor emitter pairs are aimed roughly along the same line of sight so the sensor closest to the object will receive the strongest signal The equation in the figure shows that the ratio of the fourth power of the received signal strengths determines the distance to a diffusely reflecting object Unfortunately signal intensity varies as the inverse fourth power of the dis t
100. alues for log P1 and log P2 2 Subtract the second from the first 3 Use the above result to index into a lookup table of ranges Even I can understand a program like that But I get ahead of myself The next subsystem to consider is the Status console A 7 segment display shows the current operating status of LIMBO r for Ready S for Stopped L for Locked b for low battery Digits 1 through 3 show the number of runs executed through the maze Ready denotes that LIMBO is ready to start a run through the maze Stopped shows after a completed run and Locked indicates the keylock switch is in the Locked position This last is essential when the robot is in a public maze contest because every one wants to touch a real robot The keyswitch interlock allows said touching without such embarrassments as reset Port Alberni B C Canada Rocky Mountain Gunnison Co July 1 SOG East York Pennsylvannia Longhorn Dallas Texas See All the Details on pages 83 85 ting system memory changing run num ber or sending LIMBO tumbling off the table Besides the keyswitch Start Stop and Reset switches are part of the console performing the functions of starting a run stopping a run and reset ting LIMBO for a new series of runs The Controller The last subsystem the controller is a single board computer expressly de signed for LIMBO It uses a 10 MHz HD64180 CPU from Hitac
101. am from the same manufacturer The only package that would display Gary s new PCX format was Sam Azer s No wonder Sam s article on the PCX format was so popular I understand it was required reading at several graphics houses Meanwhile Ive mentioned that we re trying out Gem Art line Powerful package Gem Artline runs under Gem Does this sound like d j vu all over again so it says it s completely compatible with Ventura Unfortunately it s not completely compatible with any Ventura prior to 2 0 unless you install the newest GEM We installed the newest GEM on one of our desktop machines so we could properly display and print Artline illustrations Never do your experi i PRR f LED ey 74454 DA y AL a a P Li 7 Hn o iati e E LAC x Re Fee k ARTEI Ec NITE BET di Continued from page 4 ments on your main machine it s a guaranteed way to shut down your operation Unfortunately no one s willing to use the ma chine with the new Gem For instance to get into Ventura the old way you entered VP lt CR gt Now you enter Gem lt CR gt and then you have to make three mouse selec tions among zillions of unreadable little boxes Wonderful Exiting out of Ventura and Gem is even more fun because once you re out the screen doesn t work Why should I want to use the screen except to select a little box Maybe it s time to concentrate on t
102. ance from the wall giving at least a 3 de cade dynamic range for distances from 0 22 5 On the controller side of things it would be nice to digitize this signal with a cheap 8 bit converter You see I do GU LL To think a little about the controller at this Sonto stage like I said this is not a linear process But 8 bits is clearly not enough resolution to digitize signals accurately with more than a 1 1000 dynamic range I haven t even mentioned the necessary math routines What to do An elegant solution presents itself Re member those peculiar tables in the back of high school algebra texts those log a rhythms This is not the name of a dirt band really If I take the log of a signal it s the same as compressing the dynamic range of that signal I can do this with a logarithmic amplifier Once in the loga rithmic domain I ll perform multiplica tion or division by adding or subtracting the logarithms of the numbers I m so keenly interested in Powers and roots are found almost as Figure 3b Logarithmic Signal Compression IR Sensor Emitter Ry F Log P1 Log P2 32 MICRO CORNUCOPIA 48 July August 1989 easily with single multiplications or divi sions In order to get the full benefit of using logarithms however I should use a different form of the equation see Fig ure 3b With this equation a simple al gorithm leaps forth 1 Read converted v
103. angles and how to keep our pen cils needle sharp without breaking them you use sandpaper The Slide Rule A lot of that changed when I went to college I ll never forget that first day in the college bookstore where I was out fitted for a career in engineering I watched bug eyed as the clerk stacked up my standard issue equipment a set of drafting instruments a drafting board T square triangles and french curves and that most wonderful of all calculat ing instruments the slide rule For me the slide rule was magic No more log tables no more trig tables The K amp E slide rule had all that inscribed in 10 of porcelained bamboo To multiply divide take square roots or any other root or power for that matter you had only to manipulate the slider and hairline cursor on that magic instrument The trig functions were there too My first technical class in college covered slide rules those silent calcula tors that never left our sides housed as they were in scabbards hanging from our belts Unfortunately the slide rule could not add or subtract For that we still had to do things by hand although in graduate school I got a neat little pocket adding machine that helped immensely As a sidelight I entered a sports car rally as a navigator the sports car was a custom 41 Chevy We won thanks to the invincible computing power of my slide rule and adding machine As the years progressed
104. asks with better than 1 usec precision Tele is an operating system requiring the Intel 8086 in struction set Tele is designed to be efficient and precise It s most im portant features for controlling equipment are multitask ing and windows Full C source code is provided including diagnostic programs to verify operation The multitasking scheduler is preemptive Tasks are scheduled by an initiator task that automatically reschedules itself It is easy to customize one or more in itiators for specific scheduling algorithms The scheduler can easily be locked out allowing high speed experimental data to be collected during interrupt service Another task running under control of the scheduler can merge the data with that from other experiments or store it for later analysis Multitasking often simplifies program design by reducing or eliminating communication and synchronization issues On a 10 MHz processor with 16 bit bus the Tele task scheduler requires 5 2 of processor cycles Because that represents a fixed number of instructions Tele s overhead is inversely proportional to the processor clock speed Therefore it takes 2 6 at 20 MHz Tele also runs on the original PC Tele uses overlayed windows to allow independent tasks to share a common display screen Each task can create any number of virtual displays The operating system then maps rectangles from selected virtual displays to the con sole Tele s scheme is o
105. ation s maximum Values of X in chaotic states then oscillate farther and farther apart over and under some possible state of equi librium We can t tell if the system is or isn t at equilibrium since we can t get round the real number problem In particular at the maximum range 88 MICRO CORNUCOPIA 48 July August 1989 of the model at values nearing R 4 in the logistic equation chaos is greatest Cheney amp Kincaid in their book Numerical Mathematics And Computing have shown that round off errors are extremely great in subtractions where the values being subtracted are very close together They suggest program ming around subtraction in these cases if possible to reduce but of course not eliminate loss of significance Look again at the logistic equation When the value of X approaches 1 we subtract values that are closer and closer together We would then expect greater round off error to occur which it does I suggest that one explanation for the strangeness in chaos belongs to the error inherent in any system which uses real numbers to represent countable values In other words representations being only approximations are limited in what they can say about the nature of approximations And that s Tidbits References Cheney Ward and Kincaid David Numerical Mathematics and Computing Brooks Cole Publishing 1985 Guillen Michael Bridges to Infinity the Human Side of Mathematics
106. ay it appears But if you talk to live wire folks handicapped or not you ll find them ignoring fighting through beating exceeding strain ing their limits So the computer their computer perhaps the only thing they can use can communicate with that doesn t go home at 5 p m doesn t get bored or hoarse or ob noxious is very important And it better not limit them For instance I just received a call from a fine lady who s visually impaired she s lost most of her central vision She wants to work at home and she s interested in getting a computer so she can do word processing and database projects for businesses in her area Wonderful idea However she can t read normal sized characters on a 12 screen The characters have to be 1 5 times normal before she can read them Then a friend of hers called The two of them had wandered over to Emerald Microware to see if Brian could locate any 25 displays that would take standard Hercules or EGA output No luck so far Then the friend mentioned he might call Jim Button of Buttonware and see if Jim would write special word processor and database packages The packages would display fewer larger characters SSS ae Sede 4 MALE N N gt 7 M No A A A SSS Se 5 ae em Continued on page 71 k 80 70 The Leader in Performance Lattice C 6 0 for DOS and OS 2is the fastest compiler overall on the eight PC Magazine bench marks
107. be a prime candidate for RLE because typical screens contain large identical areas You must remember to reset or rewrite the files used by the file compression routines with a record size of 1 Example reset srcFile 1 rewrite destFile 1 RleCompFile srcFile destFile 255 The file routines are slow because they aren t buffered The buffer routines can be called repetitively to compress file fragments that are reassembled on disk An example of this will be on the Issue 48 disk Next Time I recently started working for Micron Technology Inc One of my new toys at work is a Digital VAX cluster running the VMS operating system In the next few issues I will explore some of the system routines available to the VMS programmer The first one is a sorting routine that maintains multiple sorts in memory You can define the number and type of keys for each sort After all the data has been passed for a particular sort it re trieves the data one record at a time in sorted order Next time I will present my PC based sort routines that model this concept Good logic to you References Held Gilbert Data Compression New York John Wiley amp Sons 1987 ISBN 0 471 91280 8 MICRO CORNUCOPIA 48 July August 1989 79 The Really Early Days Of Computing Or How I Delayed VisiCalc This is the beginning of the Bits From Your Past In future issues we ll be run ning excerpts from many of the let
108. be the maxi mum torque of the stepper 53 oz in here 0 374 N m But torque alone can t move LIMBO There has to be a way to translate that rotational torque into a linear force and pO MN LIMBO keep from spinning its wheels and get ting lost in the maze despite the LIMBO name it would be better if LIMBO accelerated at a more sedate 1 10 gee 3 22 ft sec To calculate the force required to ac celerate 11 Ibs at 3 ft sec you need to first convert the 11 Ib weight to a mass In the English system of units mass is measured in the unfortunately named unit the Slug which is just the weight divided by 1 gee 322 ft sec An 11 Ib weight corresponds to a mass of 0 342 slug and the force required to accelerate it is F2ma 0 342 slg x 3 22 ft sec 1 10 Ib I prefer to use SI units because like most right minded people in the Pacific Northwest I hate slugs F 5 Kg x 981 m sec 49 Newtons round up to 5 N I like Newtons better 30 MICRO CORNUCOPIA 48 July August 1989 wheels are the simplest answer The size wheel to use should be about 1 3 the maximum diameter of LIMBO 4 would work well but 5 wheels are easier to come by The linear force developed by the wheel at the ground is F T r T is the torque r is the radius of the wheel see Figure 1 Plug in the values for torque and wheel radius and you get F 53 oz in 2 5 in 212 oz for each motor wheel combina
109. big deal since the theory s principal claim is that values numbers very close together in one state can lead to results very far apart in future states If we use the logistic equation and MICRO CORNUCOPIA 48 July August 1989 87 Organize Query amp Make Connections Between Files of Information MICRO EINSTEIN The Expert System Shell Create expert systems easlly in minutes With pulldown menus and windows Automatic rule generator Context sensitive help Free example expert systems Interactive full screen text editor DOS access from shell Turbo fast execution NOW 5 times faster For Diagnosing Monitoring Indexing Organizing Classifying amp Discovering links between files of information Only 100 Plus 5 S H Reader Service Number 72 ACQUIRED INTELLIGENCE P O BOX 2081 DAVIS CA 95617 1916 753 4704 examine each Nextx calculation care fully we find that usually within the first three or four calculations the com puter rounds X off and feeds the rounded X back into the equation The rounded X Nextx is again rounded within three or four iterations at most Each successive round off goes back into the equation Eventually through round off error alone two very close X values will lead to very far apart Nextx values The claim made by chaos theorists that iteration of nonlinear equations or models like 1 will lead to unpre dictable Nextx
110. ble specify system QP M without CBIOS installs on any Z80 system Complete parts and repair services available P O Box 1726 Beaverton OR 97075 Reader Service Number 10 Special Purchases PC Mastercard by Magnum Computer This is probably the BEST multi function card on the market Use mixed banks of 64k and 256k chips to install up to 1 5 Megabytes of RAMDISK and PRINT SPOOLER or fill your system up to 640k Serial parallel game ports and real time clock installed Comes with complete software PC MASTERCARD Ok installed Turbo Editor Toolbox by Borland International 29 95 Ever wanted to add text editing to your Turbo Pascal application or write a word processor that does things the way that YOU want Comes with source for two sample editors modules for win dowing multi tasking and many other options Requires PC or compatible and Turbo Pascal 3 0 COPY II PC by Central Point Software 24 95 Stop worrying about your copy protected disks COPY II PC lets you back them up so you can keep going when your master disk can t Printer Data Switches Quality with economy These boxes switch all 25 lines so they can be used with either RS232 or IBM paralle DB25 printer cables Four port data switch Two port data switch IBM style Parallel Printer Cable 12 00 Three cable set xx Special xx 30 00 MicroPro Manuals WordStar V3 3 Manual InfoStar Set DataStar amp ReportStar
111. cated to the public domain with the fervent and sincere hope that it will not be attempted to be appro priated by anyone else for their exclu sive use but rather that it will be used to refer to data compression and li brarying software in general of a class or type which creates files having a for mat generally compatible with this soft ware Obviously PKWare hopes to claim the high ground in the battle for market share by disavowing any interest in making ZIP a proprietary format or process However do PKZIP and PKUNZIP have any other features that will help them compete with SEA s ARC The speed edge that characterized PKARC and PKXARC is no longer a consideration since SEA s ARC and QARC Quick ARC now offer com parable performance The court settle ment between ARC and PKWare re sulted in SEA s acquisition of the PKARC and PKXARC source code In addition SEA is optimizing the ARC code However the ZIP utilities have a brand new directory storage feature That is you can create a ZIP file that not only stores and compresses your files it also remembers the directory structure and the location of the files therein Upon unzipping a ZIP file the PKUNZIP utility will recreate the directory tree for you and place the files in their appropriate subdirectories This is a nifty addition As with PKARC and PKXARC the ZIP programs come with a utility called PKSFX to create a self unzip
112. cent uara pager dynamic expansion of swap file 140 Turbo G Graphics Library all popular adapters hidden line removal et ee ee 135 TurboGeometry library of routines for computational geometry e 4 4 e ee ehh th rt nn 125 Install 2 1 automatic installation program user selected partial installation CRC checking cres 120 TE Editor Developer s Kit full screen editor undo command multiple windows s lees 105 Minix Operating System Usex like operating system includes manua eee erre 105 H Viewer sample hypertext system multi file documents includes Tiny Curses 2 eee 100 P ae AP implementation for PCs 44 4e eee eh ho o e oh m onn 100 B Tree Library amp ISAM Driver file system utilities by Softfocus 6 44 44 44e eee een o onn 100 Tele Operating System TeleKernel TeleWindows TeleFile amp TeleBTree by Ken Berry cles 100 The Profiler program execution profile tool 2 2 ee ee rns o D Pr 100 QC88 C compiler ASM output small model no longs floats or bit fields 80 function library lle 90 C Windows Toolkit up pull down spreadsheet CGA EGA Hercules leer onn 80 JATE Pay Termina ulator includes file transfer and menu subsystem 5 ns 80 Polyglot isp to C Translator includes Lisp interpreter Prolog and simple calculus prover 6 1 e
113. ch and wc enable you to easily main tain your source files and cxref produces comprehensive cross referencereports Lbind produces family mode executables that can run under both DOS and OS 2 Lattice is the productivity leader The Leader in Libraries Ourlibrary has often been praised forits comprehensive and sophis ticated features Now we include graphics communications and curses libraries The communica tions library supports XMODEM YMODEM KERMIT and ASCII protocols The graphics library provides a graphic windowing model Curses provides a UNIX compatible screen manager Lattice is the library leader The Leader in Convenience Lattice C uses an automated installa tion procedure that has been praised by reviewers The compiler automati cally configures itself so that you do not need to specify complicated options Yet a full set of options is available to the professional who needs to customize to a particular environment Lattice is the conven ience leader The Leader in Documentation Lattice C includes over 1500 pages of high quality documentation in ring binders It contains all the informa tion that professional programmers need ina thoroughly indexed format Lattice is the documentation leader The Leader in Support Best of all Lattice support comes free with Lattice C Lattice s bulletin board and telephone SUpport are the attice is the support leader 30 Day Money Back Guarantee Lattice C
114. ching for files the module illustrates several other interest ing facets of C programming in the MS DOS environment The first functions I wrote were those for accessing FIND FIRST and FIND NEXT Oddly enough I named these functions find first and find next Since as I stated earlier some compilers already have functions of this type it may seem strange that I would rein vent the wheel My purpose was twofold to provide portable directory search functions and to furnish these functions for compilers such as WAT COM and Zortech which did not have built in functions find first accepts three parameters the file specification which may contain standard wildcards the file attributes desired and a pointer to a file informa tion buffer You can assign attributes manually or with the defined ATTR_xxxx constants in FILESRCH H The header file also defines the format of the file information buffer It is particularly important that you compile this module and any which call it with byte alignment in structures The FILE_DATA structure like most MS DOS structures aligns some infor mation on odd byte boundaries A pragma takes care of the problem for Microsoft and WATCOM compilers Turbo C defaults to byte alignment and Zortech C requires the a compiler op tion when compiling the module I prefer the way Microsoft and WAT COM handle this situation with the pack pragma only the structure need ing byte alignmen
115. computer will make life immeasurably easier Available for 20 or so from Jameco and others Once you ve found the appropriate pin be sure it s an input to the chip not an output just pull the chip bend out the pin so it doesn t contact the socket tie it high or low through a 1K resistor and plug the chip back in I used this method to defeat a single attribute reverse video But you should be able to gain more complete con trol Find all 8 bits of the attribute probably 8 inputs on the same chip and tie them high through a DIP switch to 5 volts Now you can set any attribute by simply chang ing the DIP switch setting Careful though the attribute will apply to the entire screen I find a blinking reverse video display to be most restful but that may not be appro priate for all users Larry Fogg Micro C Staff Books For The Blind Computerized Books for the Blind CBFB is a nonprofit organization devoted to providing written informa tion in computer accessible format to disabled persons CBFB accepts requests from registered members and attempts to provide the written material in com puter format compatible with the in dividual member s equipment CBFB would like to welcome all in dividuals regardless of their disability Although this program is oriented toward the visually impaired we recog nize that other disabled individuals can also benefit from this service To become a registered member a
116. correct timing all internal registers and battery backed up RAM and many more features to insure the integrity of your computer PC XT Disk Diagnostics w test diskettes PC XT 1 0 Loopback Test Plugs COMPLETE PC XT DIAGNOSTICS SET save 28 PC AT System Diagnostic Software PC AT Disk Diagnostics w test diskettes PC AT I O Loopback Test Plugs COMPLETE PC AT DIAGNOSTICS SET save 28 BOTH PC XT and PC AT SETS save 75 Capital Software presents the definitive disk based diagnostics package for the IBM PC AT and XT Atechnical tool detailed enough for the repair technician A friendly interface that places problem solving skills in the hands of the end user An uncompromising solution SEND CHECK OR MONEY ORDER TO USE YOUR VISA OR MASTERCARD CAPITAL SOFTWARE 951 2 OLD COUNTY ROAD SUITE 224 BELMONT CALIFORNIA 94002 FOR INFORMATION CALL 408 293 5279 CALL TOLL FREE 800 541 0898 arse VISA p MICRO CORNUCOPIA 48 July August 1989 11 Selecting A Talking Computer For A Blind Friend It was a real eye opener for me when Debee demonstrated her vociferous Toshiba laptop at SOG VII In fact it was an ex perience for a lot of us Though totally blind Debee can write text and code with the best of us and she does it all by ear hen Ray s wife Tina began to WV her vision Ray decided to get her a talking computer He found just what he was looking for at the local Computer Heaven It was IBM
117. d A Graphics Scanner For 6 Part 2 Writing A Resident Program Extractor In C 96 pages ISSUE 39 1 88 PC Graphics Drawing The Mandelbrot And Julia Sets Desktop Graphics Designing APC Work station Board Around the TMS 34010 96 pages ISSUE 40 3 88 The Great C Issue 11 C Compilers Writing A Simple Parser In C C An Object Oriented C Source Level Debugger For Turbo C 96 pages ISSUE 41 5 88 Artificial Intelligence 3 D Graphics Neural Networks Logic Of Programming Languages Applying Information Theory 96 pages ISSUE 42 6 88 Maintaining PCs Keeping Your Hard Drives Running Troubleshooting PCs XT Theory of Operation Simulating A Bus Ray Tracing 96 pages ISSUE 43 9 87 Building Databases Build a C Database Selecting a dBase Ill Compatible Compiler Working with Paradox Designing Custom PC Cards Accessing dBase Ill Plus Records from Turb Pascal 96 pages ISSUE 44 11 88 Object Oriented Programming A Taste of Smalltalk Actor Thinking Objectively Building MicroCad Peripheral Technotogy PT68K 2 Hercules Graphics Printer Dump 96 pages To Order ERCETIGUNEENU ISSUE 45 1 89 Computer Alded Design CAD In A Consulting Business Choosing PCB Layout Systems Building Circuits With Your Computer Secrets of Optimization Finding Bargains in the Surplus Market MASM 5 1 96 pages Issue 4446 3 89 Software Tools The Art of Disassembly Hand
118. d at all They re still looking Take a look at Debee Norling s article Writing Software For The Blind for one solution to this problem But Graphics May Be Handicapped We had fun putting together the last issue We used to get graphics on paper Sandy would redraw everything with pen and ink It took hours Two years ago we were just getting into Ventura and we could see that the computer would be the way to do graphics One year ago Sandy was taking the papered il lustrations from authors and entering them in Auto Cad or Publisher s Paintbrush Occasionally she d scan something and then edit it Getting AutoCad to speak something that Ventura could reproduce properly took hours and hours and hours Now we re starting to see illustrations on disk rather than paper In the last issue Gary sent PCX files for his Last Page Okay PCX has never been a problem so we just sucked them into Ventura No luck We tried loading them into Publisher s Paint brush no luck We tried using Reflection to convert them to TIFF or something and then convert them back to PCX They converted sort of but the TIFF file wouldn t convert back Reflection bailed back to the system and the system announced it couldn t find COMMAND COM Gary started investigating and no doubt you ll be hearing more about this whole thing from him A PCX file is not necessarily a PCX file even though it was generated by the same version of the same progr
119. d disap pointed with the numerous alternatives Don t be misled by the 1 0 in Director s name It s a fairly mature product that recently began to sport a new name Actually a pair of programs called DL and DB the double utility reached version 2 5 before Baumbach repack aged them under a single name and reset the version counter The components of Director have reached version 3 0 DL which is probably short for Directory List continues to be Director s mainstay It displays a directory tree and lets you highlight the subdirectory you re interested in When you press ENTER you see the subdirectory s files in sorted order The default order is alphabetical but you can choose date size extension or unordered the order in which the directory stores the files Press enter on a highlighted filename and DL displays the file s contents there s a hex option so you can view binary files in hexadeci mal You can do practically anything within DL copy delete rename move to another directory print change attributes or run in 60 MICRO CORNUCOPIA 48 July August 1989 Pons everyone has advice for Bill Gates and company on what is wrong with DOS but few actually do something about it executable files If you want to operate on several files DL lets you mark them for batch operations Another DL feature allows you to shell out to a text editor to work on a highlighted text file Since a file man
120. derable power in fact it gives two users full access to my ROM monitor This simple multi user capability results from careful monitor design But this discussion deals with MTASK as a multitasking kernel MTASK con tains several modules the I O overlays the startup sequence the scheduler routine and a special program for dis playing information about scheduled tasks Development of MTASK started even before I got SK DOS running on my sys tem The design seems rather schizo phrenic because I changed vital system details in midstream For example SK DOS requires all programs to be posi tion independent able to run properly regardless of load address I wrote 99 of MTASK that way simply out of habit However it was impossible to pro vide the execution address of tasks to the scheduler if I didn t know what they were going to be For test purposes only I ORGed MTASK to run at location 3D000 This locks the internal entry points into place allowing me to give ac tual addresses to the scheduler routine This means that MTASK in its current form will not run properly under ach task knows precisely where it will give up control to another task and precisely where it will regain control SK DOS That doesn t concern me right now as SK DOS file control system does not support multi user operation any way In the future I will probably imbed MTASK or son of MTASK in ROM and add system service routine
121. descriptive labels force data types and more Complete support for 8088 87 through 80286 287 and V20 V30 instruction sets We welcome comparisons with any other product because no product comes close to the ease of use and output clarity of SOURCER On my list of programs that I simply won t do without Robert Hummel Senior Technical Editor PC Magazine 4 26 88 E SEE HOW PROGRAMS WORK B EASILY MODIFY PROGRAMS SAMPLE resetprn st ResetPRN v1 01 Sourcer Listing 2 Mar 89 4 46 pm Page 1 OUTPUT a 60 132 RESETPRN r Created 15 Apr 88 automatic i Version 1 01 Passes 3 Analysis Flags on H Program header 0040 0008 376h t bl Assembler 7 acne uni qe devseaca ss stack_seg_b directives resetprn proc far 658E 0000 start EB 23 jmp short loc 1 52 65 73 65 74 50 db ResetPRN v1 01 ODh 52 4E 20 76 31 2E Determines P data areas db OOH OAh Reset Printer and type H cs 658E 0026 ds Detailed 658E 0027 dx offset data 3 658 0013 0Dh ah 9 comments fik onan 658E 002E 658 0030 DOS Services ah function Olh i get keybd char al with echo Den DOS Services ahefunction 09h display char string at ds dx 658E 0032 sty E Jump if not equal 658 0011 40h i H dx ds data le 0040 0008 378h Simulator 2 follows dx al segment 0044 B9 8000 cx 8000h A locloop 2 changes H E2 FE locloop 2 Loop if cx gt 0 BO oC al 0Ch EE out dx al port 37Ah pri
122. disabled individual or an institution serving the disabled must apply directly to CBFB The registration forms request that the individual applicant provide as surance of their disability to CBFB by having their doctor counselor or em ployer complete and sign the verifica tion section Additionally CBFB re quires that the applicant sign a state ment prohibiting them from distributing the computerized materials in any form to others There is an initial registration fee of 25 which should accompany the appli cation If prospective members cannot afford the fee a letter requesting a waiver should accompany their applica tion Each member will receive a packet with information on how to use CBFB materials and the additional services we provide For more information on computer ized books hardware software graphics etc contact Computerized Books for the Blind George Kerscher Director Computerized Books for the Blind 33 Corbin Hall University of Montana Missoula MT 59812 406 243 5481 Editor s note An application form more general information and a list of computer related titles resides on the Micro C BBS under the name CBFB ARC The impressive list of titles even includes an offering from Peter Norton I wonder if that one comes on a pink disk Access To Micro C Listings For those of you whose pocketbooks object to long distance calls to the middle of nowhere Bend we have an alternative actual
123. dly software for everyone else In general Keep modes to a minimum Keep the screens consistent Keep the keystrokes consistent Keep the messages simple In some ways however writing user friendly software for the blind is quite different Remember that the blind can t take in a whole screen at once Even when the blind have the best screen access packages which verbalize charac ter attributes highlighting and screen formatting can become distractions Its important to keep the screen as simple as possible Blind people must al ways know where to find the most im portant piece of information some ways writing user friendly How Blind People See Basically a blind person can access a computer screen three ways Speech access consists of a speech synthesizer and a screen reading program which lets the blind per son interactively review portions of the screen Braille displays consist of rows of pins which rapidly rise and lower to create a changing pattern of dots The braille window is usu ally only 20 characters long a few are 40 The window must be moved about on the screen to take in the information e Large print screen display soft Debee and Duchess ware enlarges a portion of the screen for partially sighted This enlarged window must be moved in order to see the whole screen Cursors amp Pseudo Cursors Virtually all screen reading programs know where the syste
124. drag ging down the system Nope He even mentioned replacing the processor As he left he wished me luck I got out the scope and started looking for the obvious System clock Check Address lines wiggling Check Data lines wiggling Check Control lines wiggling Check Usually when the address and data lines are moving you can assume the kernel is running That means the clock pro cessor ROM and ROM select logic are all working That means I could write some diagnostic code burn it into ROM and let the Z80 find the problem However as I dug around for the materials to assemble Z80 code and burn a ROM I realized that creating even a simple diagnostic ROM would be a two week project Not an attractive prospect Well I did have the source for the current ROM If only I knew how far it was getting into the code I might have a clue about what was hanging up the system I needed a logic ana lyzer Fortunately at that very moment John Worman walked in the door and even more fortunately he d just finished build ing a Heathkit logic analyzer Three hours later I was hooking the new untested analyzer into my old cranky copier The Heathkit logic analyzer is not exactly competition for Tektronix s super collider Instead of 500 MHz the Heathkit maxes out at 10 MHz Instead of 128 channels it supports 16 I mean it s your basic minimum machine and it s really the minimum for even an 8 bit processor
125. dy there in the Data or Auto window If you want to dereference a pointer just hit the Ins key the same trick shows the members of a structure or items in an array Also the debugger recognizes that the compiler places some variables in registers so these can be properly moni tored There is a Functions window too which gives the name of all functions in your program You can bring the source code of any function up on the screen by moving the cursor to the function name and typing Enter ZTCDB handles breakpoints much easier too There are several commands to set breakpoints on for example all lines of a function the first line of all functions and all lines of the program This is much more powerful than CodeView s BP command which only 48 MICRO CORNUCOPIA 48 July August 1989 Ir gt Seringout i DB PC Tech Invalid Opcode amp Divide by 0 Exception Trap Copyright ex 1989 PC Tach Inc CR LF 0 os po SSI QSI ir AL NewIntTable si IntNo l DX Newintrable st IntVector SET VECTOR SI size Intinfo S D PrinterFlag ReportToPrinter SUNT DK LASTRYTE FIRSTBYTEt1S 16 o CAGO 2 US KEEP PROCESS allows a single breakpoint at a time You can select eight different condi tional breakpoints in the same way A conditional breakpoint will be taken only if an expression you supply evalu ates to TRUE This can be useful for pinpointing the spot where a cer
126. dy for use IBM PC XT AT and it s compatible models are moving into Industrial Laboratory applications at an increasing rate The reasons for this include their price performance ratio and short user learning curve PC based data acquisition boards are now taking the place of the traditional data loggers or recorders which cost several times more PC LabCard is a family of add on cards to turn your PC into a high performance data acquisition 60 00 s testing system at an attractive price It includes not only the hardware cards but also the software accessories and application support packages which come together to make a thoughtful solution to your PC based automation needs 12 Dit Malhi lak 2 Bit MUIS San Analog Re ED onenen 44 bit 26K sec sample adco 7 n range 45V to 5V Vo 1 Analog Output DIA converter i hai 5 D A Channels 1 standard 1 option 14 bit 2 uel Tage CE 1 channel of aoir Programmable pacer function ve 295 00 a eo x Santa E 6819 Redwood D QuickMod V2 0 Compiler Just think what the two of you can do You can make software engineering faster and easier than its ever been before The high performance QuickMod by Stony Brook delivers a compilation speed that exceeds 15000 lines per minute on AT machines And its a true two pass Modula 2 compiler with an intelligent envir
127. e sssr vee 10 PA eae 95 00 12 and under All prices In Canadian dollars Contact David Stem 4403 8th Ave Port Alberi BC Canada V9Y 4S6 604 723 5917 or 604 724 2019 Randy Young Goodbye BASIC C COBOL hello PASCAL Now to make this most advanced language available to more micro us ers we ve cut our price to an amazing 29 95 This astonishing price includes the complete JRT Pascal sys tem on diskette and the comprehensive new user manual Not a subset it s a complete Pascal Check the features Separate compilation of external procedures Auto loading 14 digit FLOATING POINT arithmetic e True dynamic storage Verbal error messages e Fast one step compiler no link needed Graphing procedures Statistics procedures Activity analyzer prints program use histogram Operating system interface THIS IS THE SAME SYSTEM WE SOLD FOR 295 So how can we make this offer why the unbelievable deal Very simply we think all software is overpriced We want to build volume with the booming IBM market and our overhead is low so we re passing the savings on to you AND AT NO RISK When you receive JRT Pascal look it over check it out If you re not completely satisfied return the system within 30 days and your money will be refunded in full THAT S RIGHT COMPLETE SATISFACTION GUARANTEED OR YOUR MONEY BACK In addition if you want to copy the diskette or looseleaf
128. e American Council of the Blind might help you find someone with a talking computer A few dealers who specialize in talking computers produce demonstra tion tapes for their lines of synthesizers Conclusion Pick a good intelligible synthesizer Buy a screen access program Carefully choose appropriate mainstream software Purchase from a dealer who will give you the level of support you need Fol low these basic guidelines and your blind friend will enjoy his new talking com puter for many years Iwo great tools SAYWHAT The lightning fast screen generator TOPAZ The breakthrough toolkit for Turbo Pascal 4 0 and 5 0 If you d like to combine the raw power and speed of Turbo Pascal with the simplicity and elegance of dBASE I Topaz is just what you re look A ing for That s because Topaz our brand new collection of Ke units for Turbo Pascal 4 0 and 5 0 was specially created ow to let you enjoy the best of both worlds The result You can create truly dazzling applications in a very short time And no wonder Topaz is a comprehensive toolkit of dBASE like commands and functions designed to help you produce outstanding polished programs fast Check out these powerful features Whether you re a novice N programmer longing for simplicity or a seasoned pro searching for higher productivity you owe it to yourself to check out Saywhat You see with Saywhat you can bu
129. e DECtalk synthesizer has ee the most natural sounding unlimited vo cabulary speech available Even though I have a DECtalk I continued to use my 250 Echo PC for a long time I found the Echo s quick response and crisp although often not very human sounding speech more useful than the DECtalk s ponderous marvelous voice My primary speech source is now an Aicom Accent It combines the con sistency and quick response of the Echo with better pronunciation and a large predefined vocabulary As a technical writer and programmer I use the Accent for most of my work but still occasion ally use the Echo when writing code The 4 000 DECtalk continues to gather dust In speech synthesis there is such a thing as being Too Smart Take the letter combination PGUP for example A primitive synthesizer will simply spell it out P G U P A more sophisticated syn thesizer will see the vowel decide that it must be pronounceable and make a best guess The result will be a pseudo Eng lish word such as peggup or worse A speech synthesizer must be able to shut up To a blind user quick silence is more important than correct pronuncia tion If I look up a phone number in my database I want to hear the information then immediately stop the speech If I have to wait while it reads the entire screen I ll probably forget the number Choose a synthesizer that has several speech rates A slow speech rate
130. e Turbo com piler flag B default If any of the above three conditions fail we are ready to output data If the repeat count is greater than three we output the compression flag followed by the repetitive byte and the repeat counter If the repeat count is less than or equal to three no compression is nec essary and we output the raw bytes Two variables sPos and dPos con tain the current position in the sre and dest buffers When sPos equals srcSize the encoding terminates dPos main tains the count returned in destSize Decoding The decoding sequence is very simple The first byte of the input buffer contains the compression flag After the compression flag is identified a byte is read from the input buffer If it is not the compression flag it is written to the output buffer If it is the compression flag then another byte the repeated byte gets read and the pro gram grabs the count It executes a loop that writes out count number of the re 78 MICRO CORNUCOPIA 48 July August 1989 petitive byte to the output buffer The cycle repeats until the program has processed the entire input file File Vs Buffer The file based routines can handle the largest files that Turbo Pascal can accommodate The buffer based routines are limited to 65535 bytes If you wanted to compress a VGA screen you would have to compress one fourth of it at a time Depending on the bit plane mapping video memory can
131. e blind user to hear the status line repeated with each charac ter typed On the other hand installing Procomm Plus to do BIOS screen writes makes it usable It s always a good idea to test drive an applications program with speech before you buy it Remember that program demos are often slide shows totally unrelated to how the real program will react with speech Test the real thing not a demo Choose software with good telephone support Unless the documentation is on disk the blind person can t look up infor mation in the manual Remember your own burnout factor You won t mind helping your blind friend in the begin ning but you don t want him calling you for support for the rest of your life Choosing Your Dealer A few computer dealers such as my company Grassroots Computing specialize in working with the visually impaired They know a lot about talking computers and a lot about blind people s needs They sell quality name brand equipment give lots of service and ex pect to get paid for it just about every computer store is willing to sell a talking system to a blind 14 MICRO CORNUCOPIA 48 July August 1989 person A few dealers have even made it a regular sideline They typically know nothing about the blind person s special needs sell the wrong equipment and are incapable of providing meaningful sup port A few companies which have special ized in selling other products to the blind
132. e provides a link between the speech synthesizer the computer the blind operator and the mainstream applications program I use Video Voice a TSR utility that watches the keyboard and can speak the keystrokes either character by character or word by word Video Voice also checks for the appli cation program s keystrokes and per forms various routines based on the user s keypresses For example when I press the down cursor Video Voice monitors the cursor waits for it to land on the new line then speaks the text of the line or the character under the cursor When I press control left arrow Video MICRO CORNUCOPIA 48 July August 1989 13 Voice reads the word that the cursor has moved to When I press tab Video Voice speaks either the row and column posi tion of the cursor or the previous word as in a database prompt Video Voice environments which are loaded for major application pro grams control these actions Thus I can move rapidly within a document editing in very much the same way as a sighted person Video Voice also watches the screen Text that s written to the screen using the BIOS video services will be spoken auto matically Because of this DOS and some programs will talk automatically Gener ally information that s written directly to screen memory cannot be captured by Screen access programs Video Voice can search for colors highlighting underlining text characters and IBM extended A
133. eattle Robotics Society or see it on the Issue 48 disk or the Micro C BBS 503 382 7643 24 hr N 8 1 28 MICRO CORNUCOPIA 48 July August 1989 Training Wheels and Swivel Castors 13 5 perfect for the maze The tray is also sufficiently flexible to allow the bumpers to bend quite a bit without damage and soak up shocks that the electronics would otherwise have to ab sorb I found this brand tray in three differ ent garden supply departments of dis count stores in Seattle for under 2 I got several because I knew LIMBO would tell me that I cut the first tray wrong ae ee ae When you plan on making mistakes you stand a fair chance of correcting them Now I had basic dimensions and some fine flower pots The next step was to select a motor drive Stepper Motors I chose stepper motors for the con venience of open loop operation A look through catalogs of new motors quickly showed that this convenience would be expensive Okay how about the surplus market I found a likely motor in the C amp H Sales catalog an IMC Magnetics 023 2024 12 This stepper is a 5V four phase unit with 200 step rev The catalog listed running torque as 35 oz in and the holding torque as 53 oz in with a cur rent draw of 1 amp per phase The di Prototype of Driver Board mensions are 2 25 dia x 2 05 deep plus two 1 4 shafts front shaft 7 long rear shaft 1 55 long for a total length of
134. ectronics Corp This com pany was either from Mountain View or Menlo Park both in California and appears to have gone out of business Another friend suggested I write to see if you can suggest where I may find some information on it I have all the manuals but am trying to find the ROM BIOS listings and schematics I m also looking for information on some of its optional accessories such as the RS 232 board When companies go out of business is the information passed on to some other organization or is it lost Is there a user group around for this product Thomas B Lerman 8273 Wightman Ave Fair Oaks CA 95628 Editor s note Information on products from dead companies just dissipates into the electronic ether quite literally Your best re sources will be the closets and garages of other Pied Piper users Any closet Pied Pipers out there who can help Thomas Kaypro II Fix I use an old Kaypro II 83 as a Z80 and Z8601 development system I in stalled double sided drives and the Pro 8 monitor ROM in 1984 the monitor version was 2 2 After a longer than average pro gramming effort the B drive started generating bad sector errors Formatting and disk exercising programs confirmed that all tracks beyond number 40 had bad sectors After opening the case my eagle eyed son noted that the B drive CP Miscellany was double stepping when it should have been single stepping A call to Micro C got a new monitor ROM on
135. ed only one other direction I moved NORTH into BASIC Learning BASIC was at first just something to do I had no plan or goal just curious how to tell the computer what to do My first program simply dis played the word Hello But with that simple program I be came more independent I was control ling something even if it was only char acters on a screen I had lost most of that kind of control when I became a quadri plegic confined to a wheelchair five years earlier Programming the computer gave me back some control Still I didn t see what the computer could do for me Keeping Track At the time I used a calculator and a typewriter to do my bookkeeping work It was a hard job considering the hassle of getting someone else to shuffle through papers and forms and note books filing and finding certain records and setting them all where I could see them Then it dawned on me that maybe I could use the computer and I began to write programs with that in mind First I wrote programs to enter and store check stub entries and cash transac tions then general journal entries and payroll records I wrote a program to bring all that information together and print it out in financial statements Soon I was able to do my bookkeeping using the computer almost exclusively with minimum outside help J even took on a few outside bookkeeping jobs Expanding The Horizons When I bought an IBM XT its power expa
136. ed pirate He snatches your treasure and vanishes into the gloom And the problem isn t exclusive to hardware Programs sometimes use strange key combinations or require a mouse Worse yet some programs defeat ProKey and Toggle Key by taking control of the keyboard or other BIOS functions There Is Another Way There are in fact many other ways around the standard IBM keyboard There are keyboards and keyboard emu lators designed specifically for the physi cally disabled optically controlled zero pressure on screen single switch scan MICRO CORNUCOPIA 48 July August 1989 9 ning flat membrane add on function calculator style and voice controlled Several years ago I beta tested a Key Tronics voice controlled keyboard For someone who can t use a keyboard but has the ability to speak it would seem a natural solution It is but only for rote applications It wouldn t have for ex ample been of much help writing this ar ticle And when I write that steamy sex scene into my next novel it wouldn t do to write it out loud The voice controlled keyboard worked like a macro program except that spoken words replaced keystrokes as macro names It could store about 300 words each word representing one or more keystrokes By assigning a spoken word to each key and using macros for frequently used commands and text I could avoid the keys altogether However the voice controlled key board was just too cumbersome I
137. ed to send or receive depending on whether you run the program in send mode or re ceive mode You must make the determi nation when you start up the program by a flag on the command line which in dicates send or receive Figure 1 shows the line configurations when the machine on the left is sending and the machine on the right is receiving The byte organization of the printer card lines guided the selection of most of the wires I attempted to minimize the bit twiddling necessary to reconstruct a byte from the data on the wires How ever the handshake line had to be a bi directional line so the handshake signal could flow in either direction The hand shake line is the printer port s SELECT INPUT line pin 17 Notice that pin 17 and the ground wires are the only lines left undisturbed from the original cable configuration It uses an additional signal to indicate that the receiving computer has read the byte This signal however doesn t need to be bidirectional The receiving com puter uses the DO line to signal the send ing computer via the sending com puter s STROBE line that it has received a byte Note that the receiving computer doesn t need its data lines so they re available The byte transfer sequence goes like this the sending computer places a byte on its printer data port DO D7 and lowers its SELECT INPUT line to indicate that data is valid The receiving computer sees that data is v
138. ee John slowly fall apart His jaw fell slack his shoulders slumped and he seemed to age by years right before my eyes That sparkle of ex citement in his eyes dimmed and went out Finally he turned and left a beaten and broken man I never saw John again He sent me an example of the output of his program I recall that it could do automatic graphing of its results which was quite an innova tion at the time I promptly filed it under dumb ideas I heard through the grapevine that he kept trying for a while halfheartedly to interest someone in it As I had predicted he was never able to do so and he faded into obscurity along with his program And thats why we had to wait 15 more years for VisiCalc Lotus 1 2 3 and Excel July 7 amp 8 If SOG s your attempt to get away from it all then the BC SOG is your spot Vancouver Island s Port Albemi is about as far from anywhere as you re golng to get by car plane or boat 195 highway miles northwest of Victoria British Colum bla This lumbering and fishing community of 18 500 lies at the end of a fjord like saltwater Inlet Famous for Its salmon fish ing its sheltered islands and inlets this is a popular area for kayaking canoe camp ing boating Port Alberni has an excellent sport sockeye salmon season You have an op portunity to book a spot results are not guaranteed but you can pretty well bet on getting a fish For famiy excursions the
139. ee ee ee eres 80 MultiDOS Plus DOS based multitasking intertask messaging semaphores 6 6 44e eere 80 evalQ C function to evaluate ASCII infix expression string 17 built in functions ee ee ee te et 75 Kinetic Image Synthesizer 3 D animation system Saturday morning on your PC e s we 75 XT BIOS Kit AG your own BIOS with this complete set of basic input output functions for XI ee ee 75 Professional C Windows lean amp mean window and keyboard handler 6 1 1 we ee 70 Hea as perg use LIM standard expanded memory as an extension of the heap leen 65 Ip flexible printer driver most popular printers supported eere 65 con Tbols Full featured icon display and editing system ehua e 65 SYSKIT rommable or TSR debug monitor easily expandaded soaua e 60 miny interactive C interpr ter ss 20 99 sanes 6K om mom 6 ab Sy Ree E A 0e e OR FR We ch Gece my Bie 60 general purpose symbol table construction and management package 6 6 6 ee ee ee ee e 60 P general p parse tree construction and management poe q o Mis fe E ee be Oe dae Ie 60 pope Restore Utility by Blake McBride multiple volumes file compression amp encryption lens 50 Su rep exceptionally fast revolutionary text searching algorithm also searches sub directories ee ee 50 OBIASM convert obj files to asm files output is MASM compatible
140. een soft ware that works with speech and that which is truly usable Much software will coexist fine with a screen reader loaded in memory So in the technical sense the software works with speech However features which make a program easy to use for the sighted often make it difficult for a blind person A program which works well for the blind should have an uncluttered screen WordPerfect is a good example When a blind person writes the only thing on the screen is his document When he calls up a menu it completely covers the text un derneath Pop up windows menu bars dialogue boxes and all those other fancy interfaces are unnecessary complications If they re created in pixel graphics they re totally invisible A program should keep the system cursor where the action is Some pack ages park the system cursor off screen or in a corner and use a pseudo cursor or a reverse video blob to indicate the current item of interest This makes it very diffi cult for the blind user to know where she is on the screen This is currently the big gest single problem in using talking com puters with mainstream software You can t always tell by looking at the screen It helps if the program can talk auto matically Most modern software writes directly to screen memory You can force some programs to use BIOS screen writes This automatic speech is a mixed blessing For example an early version of WordStar forced th
141. elies on I O calls to trigger the scheduler This means that the scheduler must somehow intercept each I O request yet it must also complete the I O request properly This I O interception can be handled in various ways If a system uses software interrupts to trigger an I O request the scheduler can simply overlay a transfer to itself into the interrupt vector location For example if a 68000 system relies on TRAP 0 for pro cessing I O requests the scheduler would simply write its own entry address into location 80 I O requests would then be routed through the sched uler which would eventually direct them to the original I O code If however a system uses explicit calls to I O subroutines the scheduler must insert a hook into those sub routines This is not normally a problem ee as any self respecting DOS uses RAM based I O routines In this case you ll need to know precisely how these I O routines behave Calls to the scheduler then overlay the entry points providing the needed interception Even if the machine uses ROM based I O modules you can still create a cooperative multitasking system In my case all I O requests pass through a RAM based vector before returning to the ROM for processing This RAM vec tor gives me an intercept point About MTASK The program MTASK written in 68000 assembly language provides a simple multitasking kernel See Figure 1 for listing It is capable of consi
142. emory locations memory ranges execution I O ports hardware and software interrupts More powerful break points than ANY software only debugger on the market Soft ICE gives you the power of an in circuit emulator on your desk Break out of hung programs With a keystroke no external switch necessary Even with interrupts disabled Breaks the 640K barrier Soft ICE uses ZERO bytes of memory in the first 1MB of address space This is especially useful for those subtle bugs that change when the starting address of your code changes With Soft ICE your code executes at the same address whether the debugger is loaded or not Works with your favorite debugger Soft ICE can be used as a stand alone debugger or it can add its powerful break points to the software debugger you already use You can continue to use your favorite debugger until you require Soft ICE Simply pop up the Soft ICE window to set powerful real time break points When a break point is reached your debugger will be activated Solve tough systems problems too Soft ICE is ideal for debugging TSRs interrupt handlers self booting programs DOS loadable device drivers non DOS operating systems and debugging within DOS amp BIOS Soft ICE is also great for firmware development because Soft ICE s break points work in ROM How Soft ICE Works Soft ICE uses the power of the 80386 to MagicCV surround your program in a virtual machine Soft ICE This gives you complete co
143. ems is the least affected by the gritty environ ment a robot lives in In effect I design Infrared Ranging Status Limbo Controller Left Stepper Drive drive them directly from the shaft of a motor The training wheels require a 3 8 shaft but the shafts on the motor are only 1 4 so we ll have to build up the diameter of the motor shaft Another thing these wheels are made in Taiwan specials so examine several pairs closely before buying You ll want to select the truest most uniform pair you can find but there will still be variations between wheels which soft ware will have to compensate for I didn t say this would be easy just fun Back To The Design Now that we have a better idea of the size shape and motive power of LIMBO we can skip back up to a higher more abstract level of design LIMBO consists of seven subsystems see Figure 2 Console robots from the outside in sensors and motors first controlling electronics and software last It works The bumper contact system consists of a bumper skirt the flower pot tray and eight snap action microswitches plus some supporting structure The battery power supply includes the battery power conversion circuitry distribution wiring and fuse protection The drive system consists of one stepper motor and one wheel each for left and right as well as swiveling castors front and back mounted on a simple suspension The flux gate magnetometer
144. eone expresses an opinion in Micro C I know that sounds strange especially for those of you who join me Around The Bend but it happens You ll find that Pat has a few opin ions opinions that I share I don t recall but I distinctly remember feel ing I d connected with an entrepreneur s en trepreneur So I proposed an On Your Own But I don t write Pat countered Ill interview you on the phone I offered Better than that send me the questions via fax and I ll jot down some answers and return them the same way he said That same afternoon I sent half a page of ques tions and within 24 hours our little fax was spit ting out the longest single page ever transferred Guinness are you listening What follows is that page l ow I wound up talking to Pat the first time You have been working for yourself for quite a while How did you wind up starting Abraxas Software In our system the lack of control an in dividual has over his own life has always frustrated me I realized at an early age that if I were going to be free I had to own my own business Simple things like what time I get up how much vacation I take how I spend my time and where I live are really important In 1983 during the venture capital rage I left a good paying job as a software engineer designing graphics systems and started a com pany building graphics boards for the PC Ven ture capital came very easily and within one mont
145. er Service Number 155 16 Megabytes EMS and or Extended Memory Works on 8 or 16 bit bus 16 bit transfer on AT bus eSingle board design e ncludes RAM disk and extensive diagnostics eQuantity OEM discounts Designed ps Manufactured y Sold and Serviced by wu NC 90 North 6th St Lake City MN 55041 612 345 4555 Reader Service Number 03 XT and AT Compatible Micro Ads A Micro Ad is the inexpensive way to reach over 22 000 technical folks like yourself To place a Micro Ad just print out your message make it short and sweet and mail it fo Micro C We ll typeset your ad no charge and run it in the next available issue You can also send camera ready copy Rates 99 for 1 time 267 for three times 474 for 6 times a best buy at only 79 per insertion Full payment must accompany ad Each ad space is 2 JA inches by 1 inches THE DISK ACCELERATOR EASY to Install Cache up to 32 MEGS of EXTENDED and or EXPANDED Buffers up to 26 DEVICE driven drives ORDER NOW 69 95 800 25 FLASH SOFTWARE MASTERS 6352 North Guilford Ave Indianapolis In 46220 317 253 8088 5 00 Shp hnd in USA amp CANADA 15 00 overseas Reader Service Number 106 Mr MOX 99 by Epoch Data Modem operated power controller for your PC Makes any PC with external modem remote accessable Software included Order direct from Epoch Data P O Box 1093 Cardiff CA 92007 619 543
146. ery when line goes down Typical transfer time 12MS Battery supplied For AT XT amp Kaypro 150 NEW 24V INTERNAL BATTERY Z80 Controller with 8 Bit A D 15 00 Brushless 12VDC 3 Fan 7 50 12V Gear Motor 30 RPM 7 50 Cable DB9M DBOF 1 ft length 2 00 High Voltage Power Supply Input 15 30V DC Output 100V 400V 16KV 6 50 KAYPRO EQUIPMENT BARGAINS 9 Green Monitor 83 9 Green Monitor 84 K16 9 Amber CRT 45 Keyboard PRO 8 Mod to your board Host Interface Board TEST EQUIPMENT OSCILLOSCOPES TEK 7403N 7A18N 7B50A 60 MHz 650 TEK 465 Dual Trace 100 MHz Scope Probe x1 x10 100MHz USM338 50MHz Dual Trace Delayed Sweep 5 ANALYZERS TEK491 10MHz 40GHz TEK 2215A Dual Trace 60 MHz Biomation 805 Waveform Rerdr 259 Biomation 8100 2 Channel Waveform Recorder HP1600A Logic Analyzer 600 HP1600A 1607A Logic Anlyzr MISC Optronics 550 MHz Freq Cntr Data Royal Function Gen F210A 200 HOURS Mon Fri 9 6 Sat 10 4 MINIMUM ORDER 15 00 TERMS VISA MasterCard Certified Checks Money Order NO COD Visa and MasterCard add 3 Personal checks must clear BEFORE we ship Include shipping charges California residents add 7 Sales Tax For more information please call Replacement Power Supply Drivetek 26M FD
147. es need to be changeable burning MTASK into EPROM might make sense Pro grams needing scheduler support could then enter the service routine via a ROM vector Uses For MTASK Even in its present form MTASK can handle such jobs as data collection data buffering monitoring of external condi tions and anything else not directly in volving SK DOS Because of my ROM monitor design I can even hook two se rial terminals to my Mini Frame and have two users running my ROM moni tor simultaneously In fact the TDB for task 1 in the listing shows how to set this up To demonstrate MTASK s power I once wrote an assembly language pro gram for a two player hunt the battleship game The program lets each user run in real time entering commands and seeing the results immediately The program made quite an impression at our com puter club meeting Even though SK DOS does not pre sently support multiple users I can use MTASK to run SK DOS as the primary task with a secondary task running my monitor from another serial port The BLINKER task and both serial ports be have perfectly SK DOS never even knows other programs are running The problem of SK DOS overwriting MTASK can be solved one of two ways MTASK could be burned into EPROM as I discussed above or you could hide a section of memory from SK DOS using SK DOS DOSPARAM command Then MTASK could be loaded into this area You could write a BAT file to handle th
148. es and export blocks W Locote matching braces and parentheses E Execute command line compilers from within QEdit operators during the ARC wars there s a natural reluctance to convert all those existing ARC files Though the UCLA PC Users Group has gone over to ZIP wholeheartedly HAL PC s BBS requests that you not upload ZIP files Yet another battle has begun A full registration of the ZIP utilities is 47 which includes a disk that con tains the files and their user manuals Corporate rates and distribution ar rangements are also available from PKWare call them for details PKZIP PKUNZIP and PKSEX v 0 90 Registration 47 PKWare Inc 7545 N Port Washington Rd Glendale WI 53217 3442 414 352 3670 Voice 414 352 7176 BBS The Original As previously noted SEA created the original ARC program Once nearly el bowed aside by the high performance PKWare alternatives SEA s program is now out in a faster version called 5 32 For even greater speed they now also offer OARC To enhance their public image in the wake of the legal scuffle with Katz SEA has launched a newsletter called Making Waves It appears to be a quarterly Call SEA for more information on their products and the new newsletter System Enhancement Associates 21 New Street Wayne NJ 07470 201 473 5153 Cloud On The Horizon PKWare s ZIP format is not the only contender for ARC s market A new en trant called LHARC has just
149. esizers popular with blind users Each has differ ent pronunciation rules Some pronounce better than you think Use sound effects sparingly and make sure they can be disabled When you change modes a sound is helpful Blink ing characters or an enlarged cursor warn the sighted user of a mode change How I long for a text editor which would make a squishing noise whenever I ac cidentally turn off insert mode I d like to hear those little characters squeal as I type over them by mistake Procomm Plus uses a distinctive rising tone to indicate when a window opens onscreen and a descending tone as the window closes Backit uses a pretty flute like warble to prompt for a new disk As an example of incorrect use of sounds I have a notetaker which beeps whenever it finds a search string or gets a disk or printer error Since it uses the same beep to indicate success and to an nounce an error it cries wolf too many times and I ignore its warning Make the important obvious and get rid of the trivial When I log on to a BBS it invariably greets me with a gabble of tedious statistics I don t care that I am caller number 3 465 that I have logged on 20 times before and that I have downloaded 14 files and uploaded 2 If I wanted statistics I d ask for statis tics Unlike the sighted user who can skip over that which he doesn t care to see I m forced to sit through a cacophony of data just to find out if I have any
150. esley e Programmer s Guide to the Hercules Graphics Cards by David Doty published by Addison Wesley In general a planar image is stored one scan line at a time one plane after the other For instance start at line 1 and encode the Red plane the Green plane the Blue plane then the Intensity plane for that line Then store line 2 RGBI line 3 RGBI etc Maintaining A Standard When anything claims to be a stand ard we generally infer that it s well de fined accepted and supported With PCX the format meets two of those three it s accepted and supported but it s not well defined In other words there s no outline in my opinion for future revisions and no way for developers to know which revi sion of the PCX format they re dealing with There is a version byte in the header which references a PC Paint brush version but this version byte hasn t changed Take for example the 256 color modes Granted it was impossible to predict in 1983 we d be supporting huge palettes when at the time there were only CGA and Hercules adapters But it s not excusable for the company controlling the standard to issue a tem porary work around ie storing the 256 color palettes in the Paintbrush PAT TERNS file and then finalize on a for mat six months later Developers who went ahead and sup ported the pattern file format were left out in the cold since Paintbrush now doesn t even support the separate palette i
151. ext editors The good folks at SemWare are now at version 2 07 of this small but powerful program For example QEdit is perfectly happy in only 128K meaning that you can run it on a PCjr although it will take advantage of a full 640K A single disk drive suffices since QEdit requires only 50K on disk Okay so QEdit is tiny What can a program that small do Plenty Load as many different text files as your computer s memory can hold Open up to 8 windows each can display a different file or a differ ent part of the same file You get 99 scratch buffers for dumping or retrieving chunks of text You can even customize the key board It lets you create macros by either recording keystrokes or writing macro scripts in a text file Shell out to DOS from within the editor Customize screen colors and de fault format settings Modify the Help screen to contain your own tips and notes Invoke C mode for automatic indenting of source code Is that enough There s more This Quick Editor both lives up to its name and travels light unencumbered by companion files Even the extensive customization is accomplished in a patch area of the executable Q EXE file Once you ve used the QCON FIG EXE utility to patch Q EXE the Q EXE file is all you need to run QEdit with all your special features Only macros or key redefinitions create exter nal files QEdit is the brainchild of Sammy Mitchell A pr
152. f the 5 volt steppers that meant a minimum battery weight of about one Ib 6V x 2 5 amp hr 15 Watt hr But each contestant would get three runs through the maze LIMBO so more battery mass would be required Panasonic makes a 6 volt 10 amp hr rated battery which would give two hours total running time This allows four contestants to complete three maxi mum time limit runs each before LIMBO would pass out with a drained battery The Digi Key catalog lists this battery P170 as weighing 3 86 lbs and priced at 19 35 I decided for the sake of cost to use MICRO CORNUCOPIA 48 July August 1989 29 Can t Afford A NOW YOU Print PostScript Language Text and Graphics On ANY Printer PostScript amp Language Interpreter for the IBM PC GoScript Software the Low Cost PostScript Language Printing Solution Choose the one that fits YOUR needs GoScript 195 With 13 Fonts GoScript Plus 395 With 35 Fonts Both include our High Quality Scalable Outline Fonts Includes Drivers for NEC Pinwriter HP LaserJet DeskJet PaintJet Canon LBP 8ll BubbleJet BJ130 Epson LQ and FX Toshiba 24 Pin Fujitsu DL 24 Pin Panasonic KX 24 Pin IBM ProPrinter Quickwriter Quietwriter ORDER TODAY Contact Your Local Dealer or call the LaserGo Order Line 800 451 0088 outside Calif In Canada Contact CDP Communications Toronto ON TEL 416 323 9666 FAX 416 323 3878 Exclusive European Dist
153. find a bookstore that specializes in new age material Stop in when you have some time to browse and chat Pay special attention to their message board Or your local college may offer evening classes on Yoga Eastern Re ligions or meditation give the instructor a call Also check with alternative health professionals such as rolfers reiki healers or even massage therapists and Na turopaths Any of these should be able to put you in touch with local support groups I d avoid the local paper especially the little ads that read Psychic Reader Tells All Special Introductory Prices Also be cautious if something or someone doesn t feel right to you then step back a bit Stay away from anyone who has all the answers especially one who has the only answers Staying Balanced Most people seem to plug along in the middle never really comprehending the scientific world left brain and never con necting with the psychic or spiritual world right brain The rest of us seem to go either left or right and hang out there We usually reserve our serious talk for folks who ve been properly initiated who already understand us However I m finding a surprising number of people who have been very connected with the scientific my side but have begun to investigate the spiritual and I m finding some spiritual types who are now soaking up the physical side I m talking about C classes and hardware design labs The two sides are not mu
154. g supervisor for his truly unique 68000 system And guess what he s work ing on a 68000 based embedded controller for around 30 Great robot guts s I m writing this my surplus Ac system is running three tasks simultaneously the SK DOS operating system my ROM monitor and a simple LED blinker No collisions no crashes no muss no fuss All made possible by a tiny home brew multi tasking kernel called MTASK Tasks And Scheduling Multitasking uses two types of pro grams tasks and task schedulers Any program whether ROM or RAM based qualifies as a task A scheduler program controls the switching of tasks The pro grammer defines tasks to the scheduler using a table of parameters appearing in memory as a block of data Each task definition block or TDB must contain as a minimum the execu tion address of the task the task s stack pointer and some form of validation flag The flag gets checked by the scheduler prior to task startup protecting the sys tem against corrupted TDBs Additional TDB information may be provided for controlling I O and system resources as signing task priority and aiding inter task communication CPU control passes periodically to the scheduler The scheduler shuts down the previous task checks for the next task and transfers control to it As each task gets switched on or off the scheduler up dates the appropriate TDB The signal that interrupts a task and activates
155. gabytes On DSI 32 SOG IV The Future Of Computing Graphics In Turbo Pascal 104 pages ISSUE 27 12 85 SOLD OUT ISSUE 28 2 86 Rescuing Lost Text From Memory Introduction To Modula 2 Inside The PC 104 pages ISSUE 29 4 86 Speeding Up Your XT Prototyping In C C Interpreters Reviewed Benchmarking The PCs 104 pages ISSUE 30 6 86 PROLOG On The PC Expert Systems Logic Programming Building Your Own Logic Analyzer 256K RAM For Your 83 Kaypro PC DOS For Non Clones 104 pages ISSUE 31 8 86 RAM Resident PC Speedup Practical Programming In Modula 2 Unblinking The PC s Blinkin Cursor Game Theory In PROLOG and C 104 pages ISSUE 32 10 86 Public Domain 32000 Hardware And Software Writing A Printer Driver for MS DOS Recover A Directory By Reading amp Writing Disk Sectors 96 pages ISSUE 33 12 86 ISSUE 34 2 87 ISSUE 35 4 87 SOLD OUT ISSUE 36 6 87 Mouse Control Build A Midi Interface For Your PC Designing A Database Part 2 Interrupts On The PC Digital To Analog Conversion A Designer s View 96 pages ISSUE 37 9 87 Desktop Publishing On A PC Build Your Own Hi Res Graphics Scanner For 6 Part 1 Designing A Database Part 3 Controlling AC Power From Your PC Expanded Memory On The PC XT AT Uninterruptable Power Supply For RAM Disks 96 pages ISSUE 38 11 87 Parallel Processing Laser Printers Typesetters And Page Definition Languages Buil
156. good jumping off point if you are delving into a particular mys tery They also create some very reasonable kits for modifying the low level software inside your computer One of these the PromKit which I haven t seen yet pro mises to put anything into PROM that you can put on a disk even DOS The other which I have but haven t used yet is the XT BiosKit which get this is the whole XT BIOS rewritten in C You can modify it to your heart s con tent burn it into an EPROM and you re done Boy I m glad somebody did this be cause I sure wasn t looking forward to it The price is incredibly reasonable 99 with a 2 production royalty and they have one for the AT 199 with a 4 pro duction royalty My only criticism of John amp John is that they ve done too much pioneering work and put too little of it down on paper The XT BiosKit has a brief intro duction which gives you the bare necessi ties the rest of the manual contains the C source listings and the XT AT Handbook is really a large summary card It s ob vious these two know a lot about the in sides of the PC and I think they should write about it Come on you two get busy I be giving the details of BIOS modi ee fications including How To Put Pro grams Into EPROM in the future once I figure it out John Foster amp John Choisser Annabooks 12145 Alta Carmel Ct Ste 250 262 San Diego CA 92128 619 271 95
157. h Seth and Lazaris have become so popular that even the mall bookstores carry them And if you re thinking of writing science fiction Seth would make a wonderful jump start The Lazaris Books Concept Synergy Publisher 279 S Beverly Dr Suite 604 Beverly Hills CA 90212 The Seth Books Jane Roberts Channeler Bantam Books And that s Around The Bend David Thompson Editor amp Soothsayer YOU WANT THE SOURCE WELL NOW YOU CAN HAVE IT The MASTERFUL source code from program files EXE or COM And the files are labeled and commented so they become USEABLE MD86 is an interactive disassembler with an easy to use word processor like interface this is crucial for the REAL programs you want to disassemble With its built in help screens you wont have to constantly refer to the manual either although there are valuable discus sions on the ins and outs of disassembling which you won t want to miss E The Code Bestetel MD86 is a professionally supported product and yet costs no more than shareware And of course it s uot copy protected VERSION 2 NOW AVAILABLE MD86 V2 is ONLY 67 50 1 50 s amp h tax C C Software 1907 Alvarado Ave Walnut Creek CA 94596 415 939 8153 Reader Service Number 31 MICRO CORNUCOPIA 48 July August 1989 75 Whither STM Not too long ago a friend gave me an old CP M machine called the Pied Piper manufactured by a company called STM El
158. h my partner and I had a business I learned my first lesson venture capitalists are the worst bosses in the world Taking money from them is like taking money from the devil Second I learned what Howard Hughes said is true Partners are dead weight In a small business you can only have one person in charge The advantage small businesses have over the big companies is that they react quickly However if you have to spend all your time in meetings you might as well kiss your 66 MICRO CORNUCOPIA 48 July August 1989 business good bye In working with venture capitalists the partners must stick together but like all strategists the venture folks know how to divide and conquer During 1981 1983 I designed graphics con trollers at Tektronix Metheus and then Micro field I learned my third lesson At Tektronix forty of us developed a system What a mess all the group wanted to do was sit in meetings and eat croissants the project took two years At Metheus four people did the same thing in half the time Finally at Microfield one person did it in six months The lesson one person can do a heck of a lot Alexander the Great taught this to his men Well it wasn t long before the ven ture some bought me out of Microfield I used that cash to start Abraxas in 1984 I printed business cards sold my house zero gain got rid of my car payment and for the next two years I lived on 500 a month I made 5 00
159. had to train it to recognize my voice by saying each word at least six times It was a pain entering and editing long sequences of keystrokes I mumble a lot And I don t like wearing a microphone headset Someday I imagine I will use a voice input device Thatll happen when the units become speaker independent and require no voice recognition training when they have built in and user defined vocabularies of thousands of words not hundreds or when they convert words directly into text A better solution might be a keyboard designed for mouthstick users One such keyboard The Magic Wand Keyboard features 96 negligible force metal key pads contained in a 5 4 x 3 area This keyboard doesn t force you to press two or more keys simultaneously It also features a switch to regulate the sensitivity of the keypads and has six programmable keys up to 200 charac ters per key Its only drawback is the price 1 200 I am prepared to offer you a hint but it will cost you points I have not tried The Magic Wand Keyboard and at 1 200 I probably won t I ll continue to use my standard keyboard until mouthstick keyboards be come affordable or voice input devices become practical Exploring The Cave After solving the pressing problem of pushing two or more keys simul taneously I began to explore the TRS 80 It came with only two programs black jack and backgammon I played them but the fun quickly faded There re main
160. he Arts amp Letters Editor It runs under windows Unfor tunately Carol has discovered Editor and she s hogging the machine Hey Dave you ought to try this Arts and Letters package it does some really incredible things and it s fun What can I say Under Windows However Windows isn t the cleanest of pack ages either Though Arts amp Letters works well under its runtime windows and our scanner software Eyestar Plus works fairly well under its runtime windows we have real problems with one after installing the other We install Arts amp Letters and Eyestar Plus won t run We reinstall Eyestar Plus and usually neither runs They re in separate directories but that doesn t seem to make a difference I need to reformat the drive anyway So afterwards I ll get out CRC COM do the reinstalls and see what gets tromped on On second thought I ll put them on different systems Speaking Of Hard Drives I m reformatting the drive because I formatted it last with Spinrite the old nondestructive for mat on an XT trick I did the same thing on another drive using Disk Technician and soon it had trouble booting After it began showing er rors I ran the exhaustive monthly Disk Techni cian test The test found half a dozen soft errors none of them even close to track 0 I replaced the drive So I ll be doing a low level destructive refor mat the old fashioned way DEBUG FDISK FORMAT Boy just when you think
161. heck you probably have six good issues left notwithstand ing the fact you haven t had any good assembly language articles for some time now David E Michener Custom Computer Service 10525 S E Cherry Blossom Dr Suite 200 Portland OR 97216 Editor s note Let s see Modula 2 Pas cal 8088 and 68000 assembly Prolog oh and C You re right we need to cover more languages Perhaps Pilot and RPG would be fun Seriously we use the language most appropriate for the task I wouldn t twiddle bits with Pascal any more than I d write a biorhythm generator in assembly New Slant On SEA vs PKWare I d like to add my own two cents to the discussion in Micro C Issue 46 re garding the SEA vs PKWare con troversy You can copyright the expression of an idea but not the idea itself If you write a book with the same plot as someone else s book but you do so in different words you do not infringe Even if by some fluke your book has exactly the same text as the other book your book still doesn t infringe if you wrote it independently Note the difference here between a copyright and a patent you can in fringe someone s patent even if you in vent something totally on your own with no contact with the outside world Not so with a copyright But there s more if there is only one reasonable way to express an idea then you can use the same words as another book and not infringe its copyright even if you do so with fu
162. her piece of hardware the modem has also become an important part of my computer system Beyond its ability to upload and download pro grams and information from other com puters the modem provides an easy way for me to be a part of society Society groups and activities and almost every thing else is geared for people with able bodies and that often makes it hard for someone in a wheelchair to join in On line computer forums and special interest groups and especially BBSs are groups of people interacting almost solely through their computers Whether a person is sitting in a wheelchair typing with a mouthstick makes no difference Without a modem I wouldn t know nearly as much as I do about computers and how to use them and l d miss knowing and interacting with a lot of in teresting people The Hidden Treasure Most adventures have hidden treasure but usually they re only bars of silver or sparkling gold nuggets In my ad venture with computers however I found a different and more valuable kind of hidden treasure It was lying just be yond that READY prompt of my first computer my independence Not complete independence not nearly But a lot more than I had Paralysis is not just a loss of move ment and feeling in one s arms and legs paralysis is a loss of independence That means relying on someone else to do the things you would normally do yourself It is intensely frustrating being unable
163. her special purpose subprogram Transfer to MTASK occurs when the program first executes MTASK builds up a TDB for task 0 This consists of writ ing the channel 0 I O vectors into the RAM links and putting an initial stack pointer address into the TDB MTASK then pushes the monitor entry point onto the stack and jumps to the monitor using an RTS instruction PAUSE does the task scheduling I gave it the same name as the F83 task scheduler Though PAUSE seems short a great deal takes place here Refer to Fig ure 1 for the following discussion Bear in mind that the stack pointer used by PAUSE upon entry seldom matches the stack pointer upon exit This can get quite confusing as you go through the code It might help to grab a pencil and paper PAUSE first pushes all registers in cluding the stack pointer onto the cur rent task s stack It then generates a pointer to the TDB of the current task where it tucks away the current stack pointer for later use Next PAUSE determines the number of the next potential task and generates a pointer to that TDB The validity flag is checked and if not okay the routine re peats the procedure with the next task After arriving at a valid user and TDB PAUSE checks the task status bits MICRO CORNUCOPIA 48 July August 1989 39 ACTIVATION COUN RESERVED LONG 40 MICRO CORNUCOPIA 48 July August 1989 CP M NorthStar Macintosh Apple Il MS DOS and PS 2
164. her train ride Sat urday s trip Is open to the general public so you ll need to make reservations early There ll be space to display your treasures to because to bring along any thing you d like to sell They d like verbal reservations as soon as possible so they can reserve the train rooms etc Please get your money in by August 1 Also speakers and exhibitors tables 35 please call right away Free admission for speakers call early so they can schedule you Registrants will receive lodging and transportation information by retum mall Make checks payable to The CDS Group Prices SOGEast registration 25 SOGEast T shirt 10 specity size Wednesday Train amp Dinner 925 Thursday BBQ PICNIC 15 Contact Stuart Yarus The Computer Council of Dallas 1950 Stemmons Fwy Box 277 Dallas TX 75207 214 867 8012 evenings Dallas Texas Info Mart York Pennsylvania Contact John Ribar The CDS Group 3161 Honey Run Dr York PA 17404 717 792 5108 8 12pm Easter 717 854 3861 Weekdays 8 9am East em You can also talk to Carol Park at this number Compuserve 73577 1652 See You All Soon T By Gary Entsminger 1912 Haussler Dr Davis CA 95616 Faith In Numbers Chaos In Chaos This issue Gary may appear to be a bit chaotic but that s because this is only an approximation of a co
165. hi 64K CMOS static RAM 64K CMOS system EPROM and a 28 pin ZIF socket for the competi tor s firmware There are 48 bits of parallel I O 22 of which are available for expansion A Counter Timer chip generates the pulses to drive the left and right stepper motors so the CPU needn t spend time twiddling bits just to run the motors An 8 bit A D chip with 16 channel MUX handles the flux gate compass 8 IR sensor emitter pairs and battery voltage and battery temperature sense very important Although there are extra I O lines available most of the expansion will probably be via the high speed multi drop RS 485 port This will facilitate mul SOG VIII Reservation Deadlines All packages support 12 compilers for BAS PAS C FOR ASM and Clipper Source available tiprocessing and will encourage the development of modular subsystems vi sion anyone On a more mundane level I ve in cluded an RS 232 port for debugging from a terminal Finally the software will include a monitor running under a multi tasking real time operating system I ll have a lot more to say about the control ler in future issues Next time LIMBO stops looking so much like a garage sale and more like a robot when we build stepper drive boards PC layouts included and as semble the motor box We ll also fabri cate the bumper contact skirt wire the switches and more Mail Order Firms C amp H Sales Company P O Box 5356 Pa
166. hip which you can easily and cheaply replace o lve come to this conclusion if you want to build this project you should buy two cheap printer cards the kind that are about 20 and chock full of TTL chips The cheap printer cards also have a full set of address jumpers so you can place the card anywhere in the PC s I O space instead of just LPT1 or LPT2 More expensive cards use DIP switches and restrict your choices I ve found it convenient to put the printer cards for both machines in an un used I O area so they won t interfere with normal operations See Chapter 7 of my book Computer Interacing With Pas cal amp C for details about changing the address jumpers One of the most useful places you might use this program is to transfer files between your laptop and your desktop computers Alas I don t know what kind of circuit they use for the parallel printer port in a laptop so I don t know if it s safe to use this scheme However there are several packages on the market that appear to use the parallel port to transfer files so it s probably safe Don t hold me to it though MICRO CORNUCOPIA 48 July August 1989 21 By Bruce Eckel Eisys Consulting 501 N 36 Street Suite 163 Seattle WA 98103 Cabling The hardware portion of this project is quite simple it consists of wiring a cable Both ends of the cable are male DB 25 connectors which plug into the parallel printer cards of each machi
167. ife But there s more to success The real reason for starting the busi ness is vacation time Two weeks a year is ridiculous From the very beginning I have taken at least two months of vaca tion a year I take very inexpensive trips but I go all over the world I try to go mountain climbing every weekend I ride my bicycle to work and I do martial arts in the evening Another thing I like most about my business buying new toys I just bought an Apple SE 30 it s a beautiful machine My next machine will be a NeXT One new exciting thing about busi ness as an entrepreneur you can do something Give your money away Yvon Chouinard of Patagonia gives away ten percent of his company profits and the rest goes back into the business He donates this money to environmen tal causes He will not relocate his busi ness to a town that accepts strip malls If we had more people like this Amer ica would be a place to live instead of a place to work pm this copying tendency we have as Americans You are rewarded in school for behaving the same So when most people start a business they copy big business A big mistake You must start lean and mean and never leave that path There s a book called Growing a Busi ness please read it This book describes many things entrepreneurs can do to make this a better world Currently I m involved in supporting National Public Radio boycotting EXXON and sa
168. ild ae md beautiful elaborate color D coded screensin minutes y That s right Truly fantastic screens for menus data Here s what you get entry data display and help panels that can be displayed with as little as one line of code in any language Over 200 routines all with easy to use dBASE like syntax e Dataentry routineslikeSAY GET PICTURE RANGE color selec tion unlimited data validation Open up to 10 DBF files with up to 7 indexes each with database routines like USE SELECT SKIP APPEND PACK INDEX ON SET INDEX TO and FIND No need to buy dBASE CREATE BROWSE and REPORT utilities included ORDER NOW YOU RISK NOTHING Thousands of satisfied customers have already ordered from us Why not visit your dealer or call toll free rightnowand putSaywhatand Topaz to the test yourself They re fully guaranteed You don t risk a penny Special limited time offer Save 26 Buy Saywhat and Topaz together for just 99 plus 5 shipping amp handling Visit your nearest dealer or call toll free 800 468 9273 In California 800 231 7849 International 415 571 5019 The Research Group Software Science Inc 100 Valley Drive Brisbane CA 94005 e Design screens windows and moving bar menus Easy to use powerful editor lets you create screens in a jiffy Pop up your screens and menus with one line of code in dBASE all the dBASE c
169. ings didn t stay that way for long We eventually did get real comput ers the 701 followed by the 704 709 7094 etc By this time I had a different job had learned how to program in FOR TRAN and other peculiar languages and was building a bit of a reputation as a computer expert I had written some slick simulation programs and we were flying imaginary spacecraft all around a simulated moon The number of computations we per formed in a day would have taken those lady computers their whole lifetimes multiprocessing or not It was an exciting time I still had my slide rule the 10 one NASA took back the 18 one and the 6 place tables I even had a 6 rule for my shirt pocket and a 1 1 2 one as a tie clasp strictly for emergencies But the slide rule got used less and less as better ways came along A Keal Spreadsheet One day a colleague whom I ll call John came to see me He said Jack I ve come up with a neat computer program that I d like you to take a look at Okay John said I What does it do Remember the good old days when we had to do computing by hand Re member the way we used to make up those spreadsheets and turn them over to the computer ladies he asked Well l ve developed a computer program that works the same way All you have to do is to define the formulas for each column of the spreadsheet and give the data The computer does the cal culations just like the
170. ions at the top of the header One of the fields is of course a header length field This allows for header expansion at any time say to accommodate that 1024 color palette for new fields Programs that support previous formats wouldn t use the new fields They d automatically skip over them 4 Variable field placement Keep in mind that field locations should vary without causing problems By this I mean that the header field can hold an OFFSET to the actual data The offset field has a fixed position but the data can be located anywhere in the file This works well with variable length data such as palettes and string information 5 Allow information areas Put op tional fields in there for file information strings copyright areas etc 6 Backward Compatibility The for mat must always be backward compat ible 7 Maintain a Format Specification A format specification guarantees consistent support in not only your own programs but in other software vendors programs Never release an intermediate version If the format must change in a way that s not backward compatible solutions must be made available to developers supporting the format 8 Release a Toolkit A toolkit serves both the format developer and other supporting developers It makes it easy for other vendors to support your files and it also allows you to change the for mat transparently and consistently without affecting every
171. ios socket for an 80387 20 math coprocessor 200 watt power supply clock calendar and housed ina sophisticated tower case Full 1 year warranty Ask for FREE assembly and testing vow 323951 emar cue 2295 std case Other configurations Call DTK 8 MB RAM Crd 99 32 BIT K DISK DRIVES Continued AT 40 MB MiniScribe 3650 61ms 339 AT 40 MB MiniScribe 3053 25ms 489 AT 71MB MiniScribe 6085 28ms 631 AT MFM HD amp FD Controller card DTK 110 WD 127 AT RLL HD amp FD Controller 2 202 eee 189 MONITORS CARDS EGA CGA Autoswitch 31 dot 385 CGA EGA VGA MultiSync 31 dot 495 CGA Color Lees 249 Amber Green 12 TTL 89 Graphics Combo 79 VGA Analog Mitsubishi 28 dot 549 Color Graphics Par Card 49 Mono Graphics Par Card 49 CGA EGA Card e 175 VGA Analog Digital Card 249 KEYBOARDS Casper Enhanced 101 54 Keytronic KB101 Focus 101 Tactile Switchable Control Caps Lock Dust Cover eee ees 89 1 find by MicroC Staff All keyboards XT AT switchable x Prices are subject to change without notice Shipping CHARGES will be added BUILDING YOUR OWN CLONE V2 1 FREE BOOKLET 9 day warranty 30 day money back subject to restrictions Tech Calls 503 388 1194 Hour
172. is In Conclusion MTASK offers considerable power in only 1K of code I believe that the cooperative nature of MTASK will per mit others to easily stage it on their 68000 systems MTASK serves as an excellent tool for exploring multitasking If any readers add to MTASK please share your efforts with the rest of us CONSULTANTS PROGRAMMERS ANALYSTS get IBUCLOB TOT Vl the most advanced SOURCE GENERATING DISASSEMBLER AVAILABLE for the IBM PC XT AT PS2 compatibles DIS DOC can help you find and fix bugs in any program re create lost source code a great companion utility to compiler and assembler able to give you a great source of professional programming examples And Much Much More DISeDOC is FAST Disassembles files up to 500kb in size OR RAM ROM memory at a rate of 10 000 lines per minute ACCURATE Uses seven passes and over 20 SECRET algorithms to separate code from data to make the most accurate listing on the market FLEXIBLE Creates a MASM ready listing for easy re assembly of your disassembly and only needs 320kb of memory TECHNICALLY ADVANCED The only disassembler that disassemles all instruction sets including 80386 80387 And has a built in patcher to make changes without having to re assemble DIS DOC also includes BIOS labeling and its own word processor in its package DIS DOC is a proven programmer s too
173. is reminds me of what Mitch Kapor once said All you need to start a software company is a garage a com Heathkit A leader in quality electronics for the technically sophisticated customer When you need kit or assembled electronic products for work home or hobby you can be sure Heathkit products are designed to perform reliably and effectively year after year puter and five million dollars It s really not hard Back to reality There are ways to market without spending money Simply assume you have none Solu tions will manifest themselves because hunger really puts the old brain in gear I suspect it s best to publish your own software To a point it really de pends on your resources and the pro duct target It would be ridiculous for instance for a small company to bring out a better word processor License it to the big company that needs one for their product mix In general it s better for small com panies to go after new niches The people I know who do the best have their own niche sewed up solid But you don t have to market your own software There are three ways to get paid when someone else markets your pro duct stock royalty or cash Stock is a joke 99 of the time It s worthless Royalty is good only if your product is published by a sincere publisher who will market your product and nothing else that season Cash is always the best Powertul Kit Laptop and Desktop Co
174. it4 _DX BASE asm loop send MICRO CORNUCOPIA 48 July August 1989 27 LIMBO Motors On Gentlemen Gather Your Parts If you d like to build the ultimate maze machine does Bob have a project for you This is Part 2 continuing the design obots are cantankerous creatures Roa love em Robotic Behavior is constrained by the sweaty physi cal world in ways no respectable micro could long endure Micros sit safely on the desk gentle breezes fanning their warm parts while robots grub about the floor dodging dust bunnies and Twinkie wrappers Micros dreamily contemplate the frac talness of the Mandelbrot set while robots bumble about the room some times finding their goal sometimes find ing the basement instead Any robot can system specifications make pretty pic tures but lousy robots Yes I believe in structured programming and I try not to use global variables on Sundays I just don t think structured design works very well in motion Unlike well written procedures the subsystems of a robot interact through the hairiest global variable of all the real world Motors affect batteries batteries affect electronics electronics affect mo tors and round you go At the same time you have to begin somewhere The iterative design ap proach I use is more like a conversation than a hierarchical list I talK to my robot by adding or changing a subsystem The robot replies by working or not
175. itua tions The preprocessor is the C facility I miss most when working with other compilers We now have functions to handle simple directory searches The next problem is to create a function to search a directory tree The sub find function and its workhorse slave function sub find workO handle this problem sub find is lazy it receives the infor mation from the caller then makes sub find work do all the work The parameters for sub find are a pointer to a file specification once again it can include wildcards a byte containing the file attributes being searched for a pointer to the name of the directory in which the search should start and a function pointer This last parameter points to a function which will be called with file information each time a file is found sub find begins by checking to see if the file specification is a NULL pointer If so it assumes that we want to search for all files Whatever the file specification turns out to be a global variable stores it Next sub find saves the attribute and func tion pointer parameters in global varia bles If the directory parameter is NULL it assumes the search should begin in the current directory otherwise it uses the given directory Once it determines the starting directory it calls sub find work After sub find work is done sub find cleans up after itself and returns Why do I use several global varia bles instead of
176. l and is simply a must for the consultants programmers or analysts We CHALLENGE you to find anything that can beat DiseDoc DISeDOC 99 95 EXE Unpacker 29 95 FREE DEMO DISK add 4 00 for S amp H in the USA 10 00 for outside USA 30 day money back guarantee To order or get more information CALL 800 446 4656 today RJSwantek Inc e 178 Brookside Road wl Newington CT 06111 isa 203 560 0236 Reader Service Number 142 MICRO CORNUCOPIA 48 July August 1989 43 By Laine Stump Redhouse Press Merkez PK 142 34432 Sirkeci Istanbul Turkey Debugging A Processor Or You Can t Always Execute An Address If you ve had an itch to get into debuggers C debuggers assembly debuggers TSR debuggers smart debuggers and not so smart debuggers then park your flea and read on Laine s not starting from scratch tolia again Time to unpack my bags and make sure the Bactine didn t leak all over the PostScript books Time to unroll the boat and check for rot Time to renew all my old contacts in Istanbul and Ankara Time to dredge through all those things I did at PC Tech and find something to fill in this column in place of my planned topic which I left along with my common sense somewhere in the passenger s lounge at JFK International I am back at the threshold of Ana A Little Trick A while back I was helping out with the de bugging of a PC Tech design based on a new NEC p
177. lady computers used to and gives you a printout that looks just like a spreadsheet I think it ll 82 MICRO CORNUCOPIA 48 July August 1989 be just the ticket for those people who don t know how to program in FOR TRAN It will open up the use of com puters to lots more people I thought about it for thirty seconds and said John that s the dumbest idea I ve ever heard There was a moment of silence as John absorbed what I had just said The sparkle in his eyes dimmed a bit Finally he whispered Why Now in my defense you have to un derstand in those days we were taught that computer time was precious 600 per hour in a time when 600 would buy more than a ticket to a rock concert It was important we were told to keep the CPU busy in productive work at all times It was better to spend engineer s time than computer time So I explained John now that we have electronic computers we have to learn to do things their way Anybody who plans to be an engineer in the 60s is going to have to learn to speak to com puters in their language You and I have learned to program so we can do that What you re trying to do is to let the computer make up for the deficiencies of the engineer You re forc ing the computer to do extra work just because the engineer is too lazy or too dumb to learn the computer s language You re never going to sell an idea that uses a computer so inefficiently As I spoke I could s
178. licate we have to pay top dollar A special mention regarding advertising the big companies get great breaks that big magazines claim don t exist I think that crossing this advertising cost wall is the biggest obstacle to becoming a big company However at this point I want to keep Abraxas small because small com panies are fun and you get to work with the customer In a big company you spend all your time dealing with fi nancial and managerial problems Why is it financially successful We re not trying to rip anyone off We sell quality products that we use ourselves Every product I ll ever sell will be something that I need to solve a software engineering problem Let me clarify something Success cannot be measured financially Money is simply the blood of a business If the patient is low on blood he dies Too much money is not good either The politicians would take your blood if they could they will take your money Furthermore if you re rolling in cash some company like Microsoft will come and take your business away before you know what happened There are probably a hundred times as many companies out there who would rather copy products than inno vate and they have full time people just looking for fat little niches Finally the purpose of this business is to stay in the game If vou run out of revenue you re out Playing the game is fun if you like to travel meet people and have full control of your l
179. ling Interrupts With Any C Hacking Sprint Creating Display Drivers Greatest C Compilers Turning A PC into An Embedded Control System Practical Fractals 96 pages Issue 47 Robotics The LIMBO Project Starting A Robotics Company How To Write and Use A System Profiler Problem Solving and Creativity Turn Your XT Into A Controller Writing Code For Two Operating Systems 96 pages 1 800 888 8087 PO Box 223 Bend Oregon 97709 United States Issues 1 34 Issues 35 current Canada amp Mexico All issues Foreign air mail All Issues 3 00 each ppd 3 95 each ppd 5 00 each ppd 7 00 each ppd ADVERTISERS INDEX Issue 48 Service 137 Abraxas 72 Acquired Intelligence 04 Austin Codeworks 147 Berry Computer 155 Business Computer Systems Capital Software Cascade Electronics CC Software CompuView 143 Covox Inc 133 DATArx 10 Emerald Microware 137 Eigenware 135 Epoch Data 93 Erac Company 11 HaltedSpecialties InsideFront 156 Heath Company 149 Information Modes 22 Integrand 154 JRT Systems 126 Komputerwerk 136 Kore Inc 91 144 Lasergo 153 Lattice 151 Maxx Data Systems 42 McTekSystems Micro Cornucopia 37 Microprocessors Unltd 02 MicroSphere Inside Back Cover National Braille Press 110 NuMega Technologies GenusMicroprogramming y Contact Advertiser Directly Opal Fire Software 03 PCTech 119 Peripheral 13
180. ll knowledge of the other book The reasoning here is that if only one way of expressing the idea exists then copyrighting this ex pression would constitute protecting the idea and that cannot be done by a copyright The extension of these ideas from Continued on page 58 Block Edit File Goto Help MEW Print Search Undo Window Config i lNDOU PODTRCTRNN SS mti while TRUE meena ASCH Table DOS Shell Run DOS Progran Color Toggle VGAZEGA Toggle Execute Macro s Check for delinite Keystroke Macros il match or error Jrgetseq keybuf i ny length key sequence if i 09 4 rst keypress if xkeybuf ZEE ELIES Add Hacro Display Macros Check if displayabl Load fron Disk Save to Disk if Ckeybuf gt 8 x printf Cze keybuf codbuf keybul codbiff 00 co buf KFF return TRUE d High byte 00 for chars H SIND n s n INSTALL C 675 error 65 codbif undefined VINDOW H Edit source file then press CTRL E for next error lt ESC gt for nenu Finally you can choose the best editor for your needs without compromising performance or paying too much And organiza tions that want the same editor for everyone can pick VEDIT for most users and VEDIT PLUS for their power users The new family of VEDIT text editors are upwards compatible easy to use and offer exceptional performance flexibility and stunning speed
181. lly loosens up the creative juices There are few sights more extraordinary than the flight of a red tailed hawk as it glides over the fields un less of course you re a rodent I also enjoy watching deer graze in a mountain meadow And of course the sight of mountains reflected in a high altitude lake takes my breath away Now Dave knows why my columns are al ways late There is more to life than computers and technology SOG exemplifies this attitude It s a technical conference for people who want to get away from technology By the end of SOG VII in Bend Maria and I felt that we had spent a weekend with a group of friends That s a feel ing l ve never had at other technical confer ences When Dave announced that Micro C was not going to hold another SOG Maria and I de cided we had to keep it going Thus was born Rocky Mountain SOG Something as special as SOG cannot be allowed to expire this is evi t s springtime in the Rockies and I m begin 50 MICRO CORNUCOPIA 48 July August 1989 denced by the number of other people who want to hold SOGs in their own areas By the time you read this Maria s and my first child will have been born No technology or science has the potential of a newborn baby It is remarkable how the bringing of a new life into the world changes one s perspective p m is more to life than computers Editor s new product announcement Elora Marjorie Ladd was born April 17
182. lock A control block begins with the ATTN character estab lished by a define in the header file an ASCII escape is used here which gets the receiver s attention The word filename and several pieces of information about the file fol low the ATTN There are only two pieces in this program the file s name and its size in bytes Each piece of information is called a control message If you want to add more information a checkvalue etc simply add more control messages A control message can be any length and is delimited by the characters LDELIMIT 4 used here on the left and RDELIMIT used here on the right When the receiver gets a complete control block it opens a file and starts putting bytes into it It counts each byte until it reaches the size specified in the control block then it closes the file At this point the receiver looks for another ATTN followed by a new control block This can be information about the next file so you can send a batch of files or the special string end of transaction The sender can be told with the h flag in the command line to leave the re 22 MICRO CORNUCOPIA 48 July August 1989 Line Configuration for Machine A Sending Machine 8 receiving a 3 m m m o m lt m o p Machine B Printer Port DB 25 Connector Do STROBE AUTO FEED INITIALIZE ERROR SELECT PAPER END ACK BUSY 06 07 DS D4 D1 D3 D
183. lu tion was to stick a standard 5 RS 232 junction box between the computer and the mouse as shown in Figure 3 I got the two 2 cell AAA battery holders 59 each from a Radio Shack and glued them to the top of the junc tion box I wired the batteries in series for 6 volts and threaded the plus and minus leads into the junction box Dis connect the mouse when not in use to conserve battery energy This simple circuit has been success fully operating for some time However the mouse will only work in Microsoft mode at the 6 volt level On another subject does anyone know how to interface a 3 5 1 44 MB floppy disk and or a hard disk to this model Zenith Sidney Epstein 140 Cadman Plaza West Apt 17G Brooklyn NY 11201 Video Attribute Control I would appreciate help with a prob lem Since I have cataracts and retinitis pigmentosa I see a great deal of glare when large areas of the screen are dis played as reverse video in mono chrome systems or bright colors Although many programs have an installation which allows color selection or the use of underline instead of reverse video many others do not Does anyone know 1 how reverse video can be changed or defeated on monochrome CRTs 2 how colors can be changed to dark background and light characters An example of software that gives me the problem is Eight in One which has a large part of the screen in bright reverse video I would hope that
184. lumn Fortunately he rounds it off with refer ences lems that can occur in the modeling of dynamic systems which include a non linear factor The simplest of these the logistic equation C theory attempts to show the prob 1 Nextx RX 1 X has been studied extensively and is known to exhibit unpredictable behavior when iterated or fed back into a feedback loop In a feed back loop the value of X in one generation de termines the value of X in the next For more information about feedback loops see The Last Page Strange Attractors Order In Chaos Micro C 47 The take home message of the theory is these models behave unpredictably because they re extremely sensitive to initial condi tions Nearby values of X in one state or generation may lead to values of Nextx which are far apart in the next state For example in the logistic equation a slight change in valuc of X far from the deci mal point say 0 999999999949 versus the rounded off value of 0 99999999995 would be enough to produce far apart i e un predictable Nextx values in succeeding generations or states It doesn t matter where you round the deci mal eventually the round off error will work its way left In general the farther from the decimal point you round the longer it takes for the error to show up I created two sets of numbers by iterating equation 1 using Turbo C floats 11 or 12 sig nificant
185. ly several The fol lowing BBSs have joined the Micro C BBS in offering our issue listings for download Generation 5 BBS 301 495 6680 Located in Washington D C and acces sible through PC Pursuit Subscription board but free downloads of Micro C files See bulletin 7 24 hr Tec PC 714 355 0373 Fontana CA board accessable from 2 p m to midnight weekdays and all day on weekends Free board with a Ham slant The Computer Nookery 201 423 4258 Free board donation requested in Hawthorne NJ PC Pursuitable 300 2400 baud or 9600 if you have US Robotics modem 24 hr VOICE MASTER KEY VOICE RECOGNITION SYSTEM FOR PC COMPATIBLES amp TANDY 1000 SERIES A FULL FEATURED VOICE 1 0 SYSTEM GIVE A NEW DIMENSION TO PERSONAL COMPUT ING The amazing Voice Master Key System adds voice recognition to just about any program or application Voice command up to 256 keyboard macros from within CAD desktop publishing word process ing spread sheet or game programs Fully TSR and occupies less than 64K Instant response time and high recognition accuracy Voice recognition tool box utili ties are included A genuine productivity enhancer SPEECH RECORDING SOFTWARE Digitally record your own speech sound or music to put into your own software programs Software provides sampling rate variations graphics based editing and data compres sion utilities Create software sound files you can add to macros
186. m cursor is they usually query the BIOS My screen access program Video Voice queries the 6845 video controller directly Screen access software has a more dif ficult time finding a pseudo cursor or moving highlight bar These screen pro grams tend to depend on the system cur sor to indicate the user s current screen location For example if you ask Video Voice to read the previous sentence it must first determine the location of the current sen tence It does this by scanning both ways from the cursor searching for the current sentence s start and end If a blind user asks his screen reading package to read the current line current is determined by the line where the cursor rests 16 MICRO CORNUCOPIA 48 July August 1989 Unfortunately modern software tends to park the cursor up on row 1 column 1 destroying any opportunities for the blind person to find his current place Even worse are those programs which move the cursor off the screen say to row 26 Figure 1 shows a C program which can turn off the blinking cursor so that sighted folk won t see it move Call this routine and with the cursor invisible continue to use it to point to the user s current location on the screen For ex ample put the cursor after the Enter your choice prompt In a database put it at the beginning of the data entry field If you don t have a specific screen coordinate defined as the current loca tion and you use a
187. manual so long as it s not for resale it s o k with us SO ACT TODAY DON T DELAY ENJOYING PASCALS ADVANTAGES AT 29 95 THERE S NO REASON TO To JRT SYSTEMS Enola PA 17025 SA phone 717 732 1093 understand that if I m not completely satisfied can return it within 30 days for a full refund JRT Pascal program formatter too for only 14 95 Name City 1 State Zip O Check M 0 OCOD O Company PO add 20 US Canada US funds on a US bank only Needs only 192K and 1 floppy drive Pass it on to your friends This is a Limited Time Offer WAIT P O Box 187 O K You ve sold me Send me JRT Pascal by return mail need O 51 4 disk or O 312 disk O Send me the Address PA residents add sales tax Add 10 for shipping outside ansanenSRERAMERDEOUEERENEREEEORESAS BE D ARD D OAD OD OA OD GA OD D OD MD OO ON AD OR GRS OD SD D GD GD GD OD OD ED GO D OA DS D a Nj Reader Service Number 154 MICRO CORNUCOPIA 48 July August 1989 83 July 27 29 1989 Rocky Mountain SOG kicks off on Thursday the 27 with a traditional SOGgy favorite white water rafting Friday and Saturday will be filled with workshops and presentations followed by a banquet Sat urday night Scott s arranged an all night room for the Jolt SIG Gunnison population 6 500 lies nestled In the Rockies along the Gunnison River Raft tips In Gunnison offer both a full and a half day excursion with plenty of excitement Besides white water
188. mputers Precision BW Test m L1 LLLA Instruments umes se s See what we have to offer To get your FREE Heathkit Catalog fill out and mail the coupon below or call toll free today 1 800 44 HEATH 1 800 444 3284 YES Please send me a FREE copy of the Heathkit Catalog Send To Heath Company Dept 027 834 Benton Harbor Michigan 49022 Name Address City State Zip A subsidiary of Zenith Electronics Corporation CL 801 Dynamic Home Entertainment Products Skill Enhancing Educational Courses and Trainers Reader Service Number 156 70 MICRO CORNUCOPIA 48 July August 1989 Have you ever noticed That s what lawyers doctors and accountants take Companies only offer royalties for one reason They can t afford to front the cash If they really believed in the product they would never offer royal ties because that s their profits If the product does sell well they ll do every thing possible to void the royalty con tract and to keep the money Summarize your experience I believe most people want to be in business for the form and not substance When I see people start a business they re forever haggling over business cards stationery going public titles of fices furniture autos travel expense accounts and clothes Note that I haven t mentioned product Most people I ve found are simply interested in the image of business To be successful yo
189. n current versions I m not finding fault with ZSoft but raising a question how do you maintain a standard so that it s expandable and al lows for future innovations while allow ing other developers to support it This happens time and again in the computer industry program stores in formation in its own private format and then without the vendor s permission the format becomes widely supported The original vendor gets locked in no longer having control He s now re sponsible not only for maintaining his own products but for maintaining The Standard Some Suggestions Although I don t have the whole solu tion for this kind of problem I do have some suggestions for developers who find it necessary to create a new format 1 Uniquely identify the file Don t rely on extensions for identifying files Maintain an ID byte usually the first byte of the file Multi byte IDs are better 2 Maintain a version field Always put a version number in the header However this must be other than the ID field don t encourage developers to key on it but encourage its use as a features supported number New versions of the format must be backward compatible with new features available if the soft ware supports it 36 MICRO CORNUCOPIA 48 July August 1989 3 Design an expandable header Fixed length headers may be easy to write but lead to dead ends The fields always remain constant i e at the same locat
190. nald Graham Donald Knuth and Oren Patashnik 1989 Addison Wesley ISBN 0 201 14236 8 Its subtitle A Foundation for Computer Science de scribes the contents of the book quite succinctly Have you ever wondered how algo rithms are analyzed and created This is the book for you Fun to read it even has graffiti in the margins The graffiti was taken from used copies of the text book this is Stanford graffiti folks WRAP UP Another issue another column I have definite plans for the next three In September October 49 I ll present ways of doing very accurate calcula tions by showing methods of generat ing pi to hundreds and thousands of digits Following that in issue 50 I m en tering Larry s realm to talk about using fractal geometry to generate alien land scapes and planets Finally we ll go a little further afield as I submit a star chart generator for your pleasure in issue 51 And as always I ll update you on what is happening in the world of C We hope to C you at Rocky Moun tain SOG in July Until we next meet good luck Micro Cornucopia Schematics MICRO CORNUCOPIA XT SCHEMATIC 4 7K CONTROL BUS SNS VLYO IWNYSLX3 m o 2 9 i gt 5 c gt aa 5 in uv o U QU c a At last you can plumb the mysteries of your computer with this single sheet schematic of the IBM XT s main board A wealth of information for both True Blue and clone owners
191. nded my options Its speed memory hard disk and graphics capa bilities opened the door to things I never imagined I could do You are in the Hall of the Mountain King with passages off in all directions With my mouthstick and the XT I could use a spreadsheet to calculate depreciation keep payroll records and chart sales Figuring income and payroll taxes and filling out the forms is still a pain even with a computer Using a desktop publishing program I learned to design and print notices and advertising flyers When one of my bookkeeping clients bought a Compaq I used the skills I learned from writing my own bookkeep ing programs to write him a general ledger program He still uses that pro gram and so do four other people I learned to fly an airplane using Mi crosoft s Flight Simulator flying a Cessna 182 with a mouthstick now that s a challenge and I learned to play games like Monopoly 10 MICRO CORNUCOPIA 48 July August 1989 My TRS 80 didn t have a word pro cessing program and when I bought one for my XT I wondered if I was throwing my money away Surprisingly the word processor has become the program I use most I use it to write everything from fiction to BBS messages to this article and letters too many to count now everyone s entitled to my opinion Using my computer I ve learned to do what other people are doing despite my being paralyzed from the neck down The computer ha
192. ne You can approach the cabling in two ways The easy but more expensive way is to buy two DB 25 ribbon cable connectors and a length of ribbon cable long enough to connect your two ma chines Ribbon cable is convenient be cause it keeps all the wires in order for you Use a vise to clamp the connectors onto the cable cross a few wires and you re done If you want a hard but cheap way buy a printer cable with a male DB 25 connector at each end slice it open and switch some wires around You ll need to trace each wire with a continuity checker DB 25 connectors usually have some kind of numbering next to the pins some connectors only number one or two pins and some connectors number all the pins Building your cable this way is more tedious but it will keep your mind off real work The Circuit Figure 1 shows the cable connections This circuit uses the fact that each paral lel printer card has 8 lines which are out put only 5 lines which are input only and 4 lines which can be configured with software to be inputs or outputs It uses the 8 output only lines to send informa tion from the card to the remote com puter and it uses the 5 input only lines and 3 of the bidirectional lines to receive information from the remote computer It uses the remaining bidirectional line as a handshake to see when a byte is available during receiving or to indicate a byte is ready during sending The handshake line is configur
193. ne com puter as the server and the other as the client and use the parallel port in terrupt or modify the board to use a different interrupt So the client can let the server know it has a request And the request can be either to send a file or re ceive a file since you have more than one handshake line now This is much tougher but for those of you who love a challenge and have time on their hands If you make improvements or un thinkable as it might sound bug fixes please post them on the Micro C BBS for all to share Future Shocks I plan to design a board to handle many interrupts using 8259 interrupt controllers like the one on the mother board of the XT All these interrupts will be fed into a single interrupt line on the XT bus The C software will make adding a new interrupt almost effortless You just tie a wire to the board do a little software configuration and a little plain C programming and voil you ll have a new interrupt l 24 MICRO CORNUCOPIA 48 July August 1989 X Don t Care Signal Gets Inverted Now here s where I need some reader feedback I m considering creating a printed circuit board so this project will be easy to build I suspect there ll be a lot of interest but I need a show of hands before I sink my hard earned money into something like this The board will in clude a complete manual parts list and assembly instructions including those for s
194. ngs 34 MICRO CORNUCOPIA 48 July August 1989 you can create with programs like these which create vector mapped images are limited And sometimes you need the bit mapped images generated by programs like PC Paintbrush As far as I know no toolkits exist for displaying vector mapped images from within your appli cations So a vector mapped project starts by reinventing the wheel As long as we have different video modes we ll have problems with graphics applications I don t want to sound unsympathetic but I d like to en courage developers to move their sup port to higher resolutions EGA and VGA instead of CGA Programs that try to support the lowest common denomi nator are forever penalizing the users of higher resolution monitors I think EGA should be the new bottom end The Format A PCX file is identified by a PCX or PCC extension and a OAH 10 decimal as the first byte of the file The PCC ex tension merely identifies the image as a partial screen image or cutout The first 128 bytes of any PCX or PCC file consists of an image file header This header de fines the width and depth of the image the number of planes the bits per pixel and other information necessary for re creating the image see Figure 1 Run Length Encoding After the header comes the image data An uncompressed CGA screen takes 16K an EGA 112K a VGA 154K and some extended VGA screens can be as large as 480K or more A scanned
195. ning late Mark Zach mann founder and president of ZSoft invented the compressed graphics file format PCX in 1983 Now most im portant desktop publishing programs Ventura PageMaker Word Perfect 5 etc and most good graphics programs read and import some form of the PCX format Some form since PCX isn t yet all that standard Inventor Zach mann has changed it during revisions of his program PC Paintbrush See the PCX article in this issue Two utilities in the Genus toolbox help clear up the nonstandard mess like it when someone writes a pro The Publisher s Toolkit pcxHdr displays the PCX header in formation the original display resolu tion of an image its width depth palette version number encoding mode and more If an image isn t making sense the pcxHdr display might tell you why pcxFix goes a step farther it fixes im ages in the latest PCX format it knows Specifically pcxFix makes the latest ver sion whichever one that is of PC Paint brush the standard The toolkit utilities expect to see the latest format so they recognize the fix standard pexShow displays an image or a group of images _ pexPrint prints an image but only supports two devices HP LaserJets and compatibles and IBM or Epson dot matrix and compatibles pexCut lets you cut an image or trim the parts you don t want You define a box and pcxCut scissors off everything outside the box Cuts are ide
196. nion REGS inregs outregs if off high 0x0030 inregs h ah 1 inregs h ch unsigned char inregs h cl int86 0x10 s inregs amp outregs return off General registers Set bits 4 and 5 if turning cursor off high unsigned char low This program will turn off the cursor and leave it in the same location so that screen access software will correctly find it but sighted folk won t see it move or blink Note that the cursor can be turned off without being repositioned Most software authors don t realize that so they park the cursor on row 26 to make it invisible Even if the cursor is on the screen the system cursor is often parked in the wrong place Software which uses the system cursor even if invisible works much better with speech since the blind user always knows where he is Avoid Multiple Columns When possible avoid displaying data in several columns If you must use columns space them as widely apart as possible so that screen access software can tell where each column ends Don t Overlap Windows Avoid overlapping windows If you must have a previous window peeking out from underneath the current win dow make sure you display it in a differ ent color or surround it by IBM ex tended ASCII frame characters You must give the screen access program some thing to find Though Video Voice can find the graphics frame and box drawing charac ters s
197. nter 2 control ale 8 initialize printer port 37Ah printer 2 control al Ch init amp strobe off loc 3 B4 4C mov ah 4Ch pt CD 21 int 21h DOS Services ahefunction 4Ch Easy to terminate with al return code read oggi format Pe 2 2 2 2 stack seg b Stack seg b segment para stack 6593 0000 OOCO FF db 192 dup OFFh Stack seg b ends end start Source code output and inline cross reference can also be selected B CHANGE AND ADD FEATURES B CLARIFY INTERFACES for PS 2 AT XT PC and Clones The BIOS Pre Processor with SOURCER provides the first means to obtain accurate legal source listings for any BIOS Identifies entry points with full expla nations Resolves PS 2 s multiple jumps for improved clarity Provides highly descriptive labels such as video mode and much more Fully automatic SOURCER Commenting disassembler 99 95 UNPACKER Unpack packed EXE files and more 39 95 SOURCER with BIOS Pre Processor 139 95 ASMtool Assembly source analyzer and flowcharter 89 95 USA Shipping amp Handling 3 Outside USA 15 CA Res add sales tax PS 2 AT XT and PC are trademarks of IBM Corp All our products come with a 30 day money back satisfaction guarantee Not copy protected To order or receive additional information just call mw 1 800 662 8266 V COMMUNICATIONS INC 3031 Tisch Way Suite 905 Dept M3 San jose CA 95128 408 296 4224
198. ntified by the PCC file extension a PCX file in disguise You can do anything to a PCC file you can to a PCX pcxLoc lets you identify specific pixel coordinates 100 200 for example Some input devices need this enumerated information pcxLib lets you create and manipulate libraries of images pcxGrab is a screen grabber with a clever twist it grabs text and graphics screens In graphics mode pcxGrab saves the image as a PCX In text mode it saves the image as an SCR and you take a second step You run the utility pcxTrans to translate the text to a PCX image file You can then import this file into Ven tura Word Perfect etc and manipulate it as you would any PCX image The Programmer s Toolkit Anyone can do everything I ve men tioned so far by using the EXE versions of the utilities But programmers can do a lot more The utilities come in two forms ex ecutable files and object libraries So C Pascai BASIC Assembly Language Fortran and Clipper programmers can call any toolbox function from their own programs Functions are available for saving creating and manipulating images displays libraries etc Each package includes all the librar ies along with several programming ex amples to get you going It took me at most a couple of minutes to write a C program which displayed an image And no royalties as long as you do something new with the toolbox i e don t just re
199. ntrol of the DOS environment while Soft ICE runs safely in RUN CODEVIEW CodeView is a great integrated debugger but it uses over 200K of conventional memory MagicCV uses advanced features of the 80386 microprocessor to load CodeView and symbols in extended memory This allows MagicCV to run CodeView using less than 8K of conventional memory on your 80386 PC Don t let 640K be your limit If you are closing in on the 640K limit and would like the power of CodeView MagicCV is for you Don t let the debugger hide the bug Even if you re not closing in on the 640K limit running CodeView with MagicCV makes your debugging environment much closer to the end user s program environment You can use CodeView to locate subtle bugs that only occur when there is plenty of free memory or those difficult bugs that only occur when your program is running with a couple of TSRs loaded How MagicCV works MagicCV uses the 80386 to create a separate virtual machine for CodeView MagicCV uses between 4K amp 8K of conventional memory as a bridge between the DOS environment and CodeView MagicCV is easy to use If you are a CodeView user you already know how to use MagicCV too Just type MCV instead of CV everything else is automatic Save 86 st MagicCV 386 Buy Both and Save 86 with Soft ICE protected mode Soft ICE uses 80386 CALL TODAY Using Soft ICE with Code protected mode features such as paging I O 603 888 2
200. o developing high quality software development tools for DOS OS 2 Mac Sun Aix VMS and NeXT We want all our tools to be portable to every platform In the 90s the most important thing will be porta bility No longer will firms invest mil lions of dollars on systems that support only one platform The dinosaurs who don t see this will simply become ex tinct Sometime in the future l ll move Abraxas to a smaller and more livable town The politicians are now trying to sell Oregon and make it more like Cal ifornia in terms of L A so we ll prob ably move to Eastern Oregon Note we are not a software publishing company we are a soft ware development com pany How well is it doing financially In the last question I mentioned that we re a software development company I believe that only publishers can make money on software To be a publisher you need to be doing at least five mil lion dollars a year Other wise you don t have the economy of scale to do mass mailings cheap advertising and low cost duplication and printing Money comes in and money goes out I still only pay myself 500 a month after all I learned how to live on that About 75 of our revenue goes towards advertising A publisher probably spends about 15 20 on advertising So we re staying in business but nobody is getting rich If you want to be rich become a publish er At the level we advertise print and dup
201. of the patterns In the PCX Programmer s Toolkit we chose to extend the format by storing the palette at the end of the encoded image data The palette was identified by the same OAH 10 decimal as the PCX ID byte by preceding the palette with the ID byte The format of the palette is BIOS compatible RGB triples The latest versions of PC Paintbrush now Also store the palette at the end of the file However they shift each byte left two bits to match their internal palette format We requested that the ID byte be different so that the toolkit could auto matically identify and compensate for the palette differences transparently The ID byte for the new format is OCH 12 deci mal The toolkit can read either palette format but now only writes new images in the new format The Hard Part l The hard part is programming the video hardware To compress the image data you must read and access video memory and align it in a linear format This varies with almost all display modes For instance CGA memory is in terleaved EGA memory is planar VGA is planar Hercules is interleaved differ ent from CGA and extended VGA modes well there is no standard To get a better handle on the hard part I recommend the following books e Programmer s Guide to the PC and PS 2 Video Systems by Richard Wilton published by Microsoft Press e Programmer s Guide to the EGA and VGA Cards by Richard Ferraro published by Addison W
202. of us didn t have access to the square root machines and a measure of your proficiency was how quickly you could find a square root on a non square root Friden There was a neat algorithm for it that I ve never forgotten no it s not Newton s method I also learned the famous Friden March a calculation that caused the carriage to chunk along in a neat rah rah rah rah rah rhythm The big advantage of the Friden other than its tendency to get the right answer was that it was accurate to as many as twelve digits unheard of until then But most of our calculations were done to only five digits or so because that s as many as we had in the trig tables Later I managed to get a book of six place tables It was a big book When you think about the space race and the high tech things that go on there it helps to remember that at least through projects Mercury and Gemini it was mostly done with Fridens Graphs As in college a lot of our output in those days were graphs Again a large part of our skill was our ability to plot microscopic dots at the right places on a piece of log log paper and then draw a smooth curve through them MICRO CORNUCOPIA 48 July August 1989 81 Back in college we plotted graphs with from three to seven points but NASA needed much more accuracy A lot of our time went into calculating the data for plotting the many points That s where I learned about spreadsheets These were the o
203. ofessional programmer Mitchell has worked with both main frames and micros SemWare distributes Mitchell s QEdit in two forms The 54 95 registra tion package includes a nicely printed spiral bound 100 page manual The 44 package contains just the QEdit disk with the user s manual in a text file SemWare accepts credit card orders by phone or you can write to them QEdit 2 07 Reg with printed manual 54 95 Reg with on disk manual 44 00 GA residents add 4 sales tax SemWare 730 EIk Cove Court Kennesaw GA 30144 4047 404 428 6416 The Infinite Loop Taking advantage of a lull in the ARC wars we peek out of the bunker and what do we see strange new utili ties roaming the battle scarred land scape Phil Katz PKWare has released PKZIP and PKUNZIP They represent his attempt to launch a new standard for file compression and conflation I would have said archiving but Katz scrupulously avoids the word Naturally mindful of the trouble caused by the legal battles of the ARC wars Katz is trying to make his new ZIP format attractive by issuing the fol lowing declaration The file format of the files created by these programs which file format is original with the first release of this software is hereby dedicated to the public domain Further the filename ex tension of ZIP first used in connection with data compression software on the first release of this software is also hereby dedi
204. oho a E e n non 15 ata GenBank DNA Sequences Release 59 0 includes demo disk of Pearson FAST A programs 2 lc rers 150 Protein Sequences over 10 000 sequences includes demo disk of Pearson FAST A programs e we ee ee ee 60 Smithsonian Astronomical Observatory Subset right ascension declination amp magnitude of 258 997 stars 2 ee ee ee 60 Dictionary Words 234 932 words in alphabetical order no definitions eee 60 U S Cities names amp longitude latitude of 32 000 U S cities and 6 000 state boundary points llle 35 The World der 100 000 longitude latitude of world country boundaries Suis pO ewe ru ei cu UPON dr i cat Vr TA n 30 KST Fonts 13 200 characters in 139 mixed fonts specify TEX or bitmap format een 30 USNO Interactive Computer Ephemeris high precision moon sun planet amp star positions ceres 30 King James Bible Old and New Testaments 4 44 44 42 ee ee oy hoy o oot n 9 oss on oon on 25 NBS Hershey Fonts 1 377 stroke characters in 14 fonts 4 ee ee eee lr 15 U S Map 15 701 points of state boundaries 4 ee n 15 The Austin Code Works Voice 512 258 0785 11100 Leafwood Lane acwlinfo uunet uu net BBS 512 258 8831 Austin Tezas 78750 3409 USA FAX 512 258 1342 Free surface shipping for cash in advance For delivery in Texas add 7 MasterCard VISA Reader Service Number 4 MICRO CORNUCOPIA 48 Jul
205. oldering if you haven t done that before as well as the software and test programs on disk Please call Micro C or write me I need to know who you are Do you want to do this project If so are you the do everything yourself type who wants to build things from scratch or do you want a circuit board and instructions If you want the board do you want the board all the parts and the instructions or just the board all assembled and tested Get in touch I need to make an edu cated guess about whether to leap or not Acknowledgement Thanks to OrCAD for their excellent circuit drafting program Editor s note Bruce often refers to articles in previous issues You can get a book of his hardware articles Computer Interfacing with Pascal amp C and a disk of source code by sending a check for 30 to Micro Cornu copia P O Box 223 Bend OR 97709 or phoning 800 888 8087 with Visa MC NEW NEW Updated NEW NEW NEW NEW NEW Updated NEW NEW C CODE FOR THE PC source code of course MS DOS File Compatibility Package create read amp write MS DOS file systems on non MS DOS computers 6 0 6 500 Bluestreak Plus Communications ess ports programmer s interface terminal emulation een 400 CQL Query System SQL retrievals plus windows 2 44e e eee eee ho oho oho oon on 325 G zm 41 high resolution DISSPLA style scientific plot
206. ome TTL Amber EGA Color Video Card CITIZEN PRINTERS 120D 120 CPS 9 180D 180 CPS 9 MSP 15E 160 CPS 15 MSP 40 240 CPS 9 MSP 45 240 CPS 15 MSP 50 300 CPS 9 MSP 55 300 CPS 15 CASCADE ELECTRONICS INC ROUTE 1 BOX 8 RANDOLPH MN 55065 507 645 7997 Please ADD Shipping on all Orders COD Add 3 00 Credit Cards ADD 5 MN Add 65 Sales Tax Subject to change Reader Service Number 15 MICRO CORNUCOPIA 48 July August 1989 69 They have no time to develop new pro ducts They get squeezed and die I ve seen this happen to many com panies in the industry It is simply bad planning First most products have a life of only a couple years So it makes sense that you should develop new pro ducts all the time Also if you have a small customer base you need to sell upgrades to maintain your cash flow You need at the least two people one to market and one to implement Marketing is a full time job I spent one year and 150K of my own money marketing PCYACC I mean that s all I did Press releases and more press re leases Surveys talking to customers solving problems So you can see what happens when you have one person who tries to do it all To succeed you must be able to develop market and support concur rently Otherwise you will fail I have no solutions This is a hard problem I got around it by hiring programmers to work on new ideas while I was spend ing my time announcing PCYACC Th
207. ome other screen review programs aren t as sophisticated If your window is within a frame or in a color not used elsewhere on the screen Video Voice can find it If a frame consistently resides in a specific screen location then virtually all screen access software can be configured to find it But the best way for the blind is to have menus la WordPerfect These By Debee Norling Grassroots Computing P O Box 460 Berkeley CA 94701 overlay the whole screen obscuring any thing behind it never sharing the stage with other actors Be Consistent Be Consistent If you display hunks of information repetitively try to display each category in its own screen location For example if the user always knows that error mes sages are on row 24 then he can check that row periodically Turbo Lightning is hard for blind novices because it doesn t always pop up its information in the same place Few screen access programs can dynamically locate pop up boxes If your program puts text such as a status line on a certain row keep it there Don t let the information get pushed around the screen by pull down windows pop up boxes and error mes sages The blind user will lose track of his information if it drifts aimlessly from one screen location to another The best place for a status line is the very bottom row The second best is the top row Find a safe place to put your messages then keep them there If you use colo
208. ompilers your favorite BASIC Pascal or any other language e Screen Library Manager Generates runtime code MD Easily implement Saywhat and Lotus style moving bar menus e BROWSE any DBF file with just one line of code Programmable and windowed too No runtime license or royalty fees Comes with a 100 page manual plus dozens of sample programs and free utilities 495 e Comprehensive Time amp Date math in 7 international formats e Powerful code and REPORT generators included Es pi3 DX i Sox MONEY BACK GUARANTEE ASL 07 HE or Topaz for any reason return them within 30 days for a prompt friendly refund Comes with a complete 250 page manual plus sample programs to get you started 7 95 Ifyouaren tcompletely delighted with Saywhat Dealers SAYWHAT and TOPAZ are available from Kenfil Distribution and in Europe from ComFood Software W Germany 49 2534 7093 Guaranteed 200 or M 2 E ORE G R o U P Reader Service Number 129 MICRO CORNUCOPIA 48 July August 1989 15 Writing Software For The Blind Making It Perfectly Clear Just as there are ways to optimize menus for the sighted user there are ways to op timize them for the blind Debee should know the field well she writes software and she s blind software for an audience that in cludes users with visual impairments isn t all that different from writing user frien
209. omputer resources But in every sys tem every real number has a known range of significance In Turbo Pascal real numbers use 6 bytes 48 bits of memory and range from 2 9 x 10 to 1 7 x 10 with 11 or 12 significant digits equivalent to a Turbo C float If you re using a math coprocessor you can mi rove from 3 4 x 10 to 1 1 x 10 with 19 or 20 significant digits equivalent to a Turbo C long double In Ture Prolog r reals range from 1 7 x 10 to 1 7 x 105 with 15 or 16 sig nificant digits equivalent to a Turbo C double An HP 11c scientific calculator gives about 5 significant digits What does all this talk about signifi cance mean Well for starters each of these compilers and the calculator will quickly produce very different values for Nextx when used to iterate equations like 1 Chaos In Chaos Consider what happens when a com puter or calculator encounters an ir rationa number or a rational number that has more digits than it can repre sent accurately It rounds off the number What else can it do One irrational number head ing off toward infinity would distract a computer for an infinite length of time Editor s note However with a math co processor an infinite length of time doesn t take nearly as long In many calculations of course rounding is no big deal Engineers and statisticians thrive on limits and ap proximations But in chaos theory rounding is in fact a very
210. one adversely Conclusion In summary the PCX format is a powerful way to break your graphics ap plication into the myriad of software packages that now support PCX The easiest and most reliable way of doing this is through the PCX Programmer s Toolkit since it handles the PCX support issues for you automatically ensuring backward compatibility If you decide to implement your own standard keep the above design points and issues in mind You may be the only one using the format at first but by look ing ahead and allowing expansion you can avoid being locked in to a dead end format This will also encourage developers to standardize on your for mat without the worry of needless or spontaneous changes LCD Portable The McTek Rabbit 286 LCD Portable combines the fastest most reliable AT motherboard available with most visible full size LCD portable screen on the market Run ning at a switchable 8 or 10 MHz 0 wait state it includes a 20MB hard disk 1 44MB 3 floppy drive parallel amp serial ports Award 3 03 bios 640k amp turbo indica tor LCD The screen is a fantastical ly readable electroluminescently backlit 80 column by 25 line high 129909 12MHz 0 Wait State Assembled amp Tested IBM AT Compatible MS DOS OS 2 Compatible ii 80286 12 6 MHz E Phoenix BIOS W 640K of RAM Expandable to 4MB Bi 0 Wait State E 200W Power Supply E 1 2MB Floppy Drive E Ports
211. onment that determines dependen Cles automatically and builds your pro gram with a single keystroke You do little more than enter the program text then let Stony Brook handle the work load QuickMod is more than a supercharged compiler it is a fully supported package backed up by a text editor a linker a library manager a symbolic debugger and a runtime library that offers more func tionality than anything else on the market All for 95 Versions available for DOS and OS 2 1989 Gogesch Micro Systems Inc And when you need more horsepower you can move into the Professional Modula 2 Stony Brook s fully optimized compiler You get the same high productiv ity environment with code generation and flexibility you can t find in any other product in the industry Stony Brook we design our products specifically to improve developer perfor mance And we know software engineer ing Put us to work for you Call us direct and we ll mail product information to you within 24 hours 800 624 7487 805 496 5837 Sia lncernational 805 496 7429 Fax h SOFTWARE Your Partner in Software Development Reader Service Number 152 187 East Wilbur Road Suite 9 Thousand Oaks CA 21360 MICRO CORNUCOPIA 48 July August 1989 1 SERIOUS DEBUGGING at a REASONABLE PRICE All the speed and power of a hardware assisted debugger at a software price Hardware level break points REAL TIME break points on m
212. ontroller information that s not even available in Kaypro s own dealer service manual Kaypro Il amp IV pre 84 eese nnne nnne nnnm tnnt tn sata natn atate sesta sea sensn 0s 20 00 Kaypro 10 without modem esescsssssesssscessessesecsscssssccsesstesesseesessasseeneessesssseseesnesesseesces 20 00 Kaypro 2 4 and 10 84 series occ csessessssssscssssssssseeseecsevssesseuseessususesausetecstucetacetseeseetaess 20 00 NOTE These packages cover only the main boards You re on your own when it comes to disk drives power supplies video cards etc Phone Orders 503 382 5060 or 1 800 888 8087 Monday Friday 9 AM 5 PM PST MICRO CORNUCOPIA 48 July August 1989 57 Letters books to software still requires time to be completely defined but it would ap pear that some of the arguments which were given in Micro C as being offered by SEA against PKWare contradict these established principles For example on page 61 is a state ment that SEA asserts PKWare Would be in violation of copyright law even if they hadn t copied any of SEA s code Henderson argues that Katz s admission of seeing SEA s pro gram code establishes a presumption of infringement Although there exists a court settle ment between SEA and PKWare which according to your article appears in SEA s favor please note that a settle ment does not indicate who is right or wrong The matter was not judged by a judge o
213. or The Blind Debee suggests some not so obvious things you can do to make your software easier to use for the blind things all your customers will appreciate Bruce Eckel File Transfer Via The Parallel Port Tired of moving data one bit at a time Think there might be a faster way A much faster way There is and here s everything you need to do it Bob Nansel The LIMBO Project Part Two Bob begins his mechanical rug rat And you thought you d be left in limbo Chris Howard PCX Compatibility As we create fancier graphics we place more demands on our standard graphics file formats Can a standard format support change Karl Lunt A 68000 Based Multitasking Kernel As long as you re going to design your own ROM it might as well do two things at once Right Jack Crenshaw The Very Early Days Of Computing Jack describes NASA s first multiprocessor It sat at many desks LIMBO Drive System 44 86 World 50 cing Clearly 60 shareware 64 culture Comer 66 on Your Own 77 Units And Modules 83 SOG Information 76 CPM Notes 90 Tech Tips FUTURE TENSE 86 Tidbits 96 Last Page COVER Cover Illustration by PoE ae Paul Leatherwood m B MICRO CORNUCOPIA 48 July August 1989 3 THE MICRO TECHNICAL JOURNAL MERO CORNUCOPIA Editor and Publisher David J Thompson Associate Editors Gary Entsminger Larry Fogg Cary Gatton Contributing Writers Anthony Barcellos Bruce Eckel Michael S H
214. or your palette out of 64 possible colors or jars The VGA can display 256 colors out of thousands CGA The first byte of the CLRMA array is the CGA background The top four bits of the byte represent a background color between 0 and 15 The fourth byte of the array is the CGA foreground palette The upper 3 bits control the palette settings as follows bit 7 Color burst 0 color 1 mono bit 6 Palette 0 yellow 1 white bit 5 Intensity 0 dim 1 bright EGA VGA 16 color The palette is stored as 16 triples A triple is a three byte value representing RGB one byte of red one of green and one of blue On the EGA and VGA there are four levels of Red four of Green and four of Blue Divide each byte by 4 to get the appropriate level as follows Divided Byte Level Xx 0 63 Level 0 00 64 127 Level 1 01 128 192 Level 2 10 193 254 Level 3 11 To format this as a BIOS palette value which expects a byte formatted as OORGBrgb takes some bit manipulation Use the Xx value above to match the MICRO CORNUCOPIA 48 July August 1989 35 level to the appropriate bit values For in stance a Red level of 2 a Green of 1 and a Blue of 0 yields a byte of 00100010 VGA 256 Color The VGA palette format for 256 color modes won t fit in the CLRMA array since it takes 768 bytes For awhile ZSoft didn t support the 256 color palette It then started storing the palette in the sep arate PATTERNS file at the end
215. ou heard American music rather than some punk band like the Dead Milkmen Larry 2452 To SYSOP From NATHAN ENGLE Well yeah there is always that still it was a shock I listen to Public Radio most assiduously don t even own a TV It was kind of a shock to realize that I m receiving that Country amp 64 MICRO CORNUCOPIA 48 honest to by God NY ZA IAM A ALIO Western muck all the time I think it s gotta be bad for me By the way I ve discovered that my toolbox also tunes to this particular station so maybe it just comes from the neighbor hood 2458 To NATHAN ENGLE From SYSOP You may be on to something here Why don t you have some fun with it and upload a submission for the Culture Corner Fame and fortune await Well infamy anyway Larry 2462 To SYSOP From NATHAN ENGLE An article about my unfor tunate condition I think I ll hold off for a while I ve been listening to this station my station for a couple of days Yesterday a guy gave a sort of pseudoscientific explanation of the Black Hole at the center of the Milky Way which this guy had identified as Satan There are a lot of truckin and you done me wrong songs as well This religious stuff is what re ally stymies me I m the original secular humanist well me and Carl Sagan and if it got around that I m actually a radio antenna for a Christian rock a billy country station
216. package and sell it The manual is well written clear and includes many useful discussions about adapters images and the pro gramming details of the PCX format The help and detailed information I received from programmer Chris 96 MICRO CORNUCOPIA 48 July August 1989 By Gary Entsminger 1912 Haussler Dr Davis CA 95616 A PCX Toolkit For Publishers amp Programmers Howard at Genus also impressed me At one point while working on a page I tried unsuccessfully to trans late a grabbed text image into a PCX image which I could show on my portable CGA AT Rabbit Chris insisted that the toolbox worked perfectly with CGA After all displaying an image using the CGA is child s play compared to displaying im ages in the 11 extended VGA modes up through 800x600x256 that the Toolbox supports Sorry Chris I said but I m get ting garbage We duplicated our efforts my CGA produced garbage his emulation worked great Emulation Im using multi sync and hmmmm he added that s the prob lem Your real CGA adapter doesn t load the IBM extended character set My CGA EGA VGA emulator does But wait a minute I said I can run a whole bunch of nifty graphics programs with my CGA and no prob lems well only a few What about Borland s BGI It works great The BGI creates its own extended character set he responded So do many other packages We don
217. passing information on the sub find work as arguments sub find work is recursive so globals reduce stack overhead The search specifications which don t change file spec attributes and handler function pointer would merely waste stack space if they had to pass as arguments every time sub find work got called Placing this constant data in global variables also makes it accessible I used the static qualifier on the global items so they wouldn t be visible out side the scope of FILESRCH sub find workO does two things First it reads file data for all the files in the directory specified by the dir spec parameter Your own handler function can then process those files which have names and attributes matching those passed to sub_find If a file is a directory it gets stored in a linked list Second after all files in the directory are processed sub find work calls it self recursively for each directory Thus it reads the file data for the directory specified and all subdirecto ries thereof You may want to refine and expand on these functions They provide a basis for developing programs which can access files in multiple directories And they show several aspects of working around and with MS DOS All memory models of Borland Turbo C 2 0 Microsoft C 5 10 and QuickC 2 0 WATCOM C 7 0 and Zor tech C 1 07 have tested FILESRCH C It should work with any MS DOS C com piler which supports intdos or another
218. performance processor cards It contains the mass storage interfaces necessary for a complete sys tem plus the basic O required in most systems Extra care has been given to FCC compliance by design 34010 Monochrome Graphics Adapter II e Up to 384k bytes display memory e Upto 2 Megabytes program memory e Software is RAM based allowing complete operating software replacement and timing re programming from the host bus e 34010 program loader included Assembler debugger and C compiler available e Full hardware and software CGA MDA and Hercules emula tion E e Single bit shared memory bit map with optional resolution up PC Tech Mono ll to 2048 x 1536 736 x 1008 standard e Very high resolution COLOR version available e Custom 34010 software development available The TMS34010 is a true general purpose graphics processor PC Tech makes the total processing power of the 34010 available to both programmers and end users Our 34010 Monochrome Graphics Adapter is designed to allow programming from the PC XT AT host bus You can completely replace our 34010 software with yours to directly harness the incredible image processing power of the TMS 34010 for your application We make a complete set of development tools available including an assembler C compiler program loader 34010 debugger and PC interface tracer debugger Our stand ard product includes support for extended CGA MDA and Hercules emulation as well as a host addressable graphics bi
219. population the number of wolves for example changes from season to season Equations like 1 above model these changes X represents some value between 0 and 1 where 1 represents the largest possible number of wolves and Nextx represents number of wolves in the next generation What exactly is the largest possible number of wolves Well if we were counting wolves it would be the most we could count a finite number So a Nextx 0 5 says in effect we have half the possible number of wolves And 0 55 says we have slightly more than half the possible number of wolves And 0 555 says we Figure 1 Round off Error Accumulation x 099999999995 x 4 0000447398E 11 x 0 00000000016000178959 X 0 00000000064000715825 v x 0 0000000025600286313 x 0 000000010240114499 x 0 000000040960457577 X 0 0000001638418236 X 0 00000065536718702 x 0 00000262146703 5 x 0 000010485840632 _ x 0 000041942922716 00016776465403 _ 0006709460362 0026819834704 x 0 01069916174 x 0 042338758714 1621847529 0 5435234353 0 99242284232 0 030078977454 have slightly more than Specifically we re not counting wolves we re repre senting wolves with an infinite num ber of real numbers not integers and there s the rub Real Problems A real number like a columnist can be rational or not A rational number is a number which meets either of the fol lowing req
220. ptop s RS 232 port is less than 4 volts but the mouse requires more than 5 volts at about 10 milliamps JENTIFIC LIB Y VEU UELEELECEEEEEELEEEEELELEEEEEEEEEEELELEEELEELLECELELEEELEELUELE LLL EL UELLE GG LEG C programming library for computations in re search and mathematical analysis Each rou tine is designed and documented for use by technical specialists and programmers Comprehensive Over 500 functions Superb Documentation Matrix Math Microsoft or Turbo C Statistics More Eigenware Technologies 13090 La Vista Drive Saratoga CA 95070 408 867 1184 Reader Service Number 137 STOCKS OPTIONS FUTURES Tum Your PC Into A MARKET QUOTATION MONITOR 100 page book covers satellite and radio data reception of financial news and quotes for yout PC 19 includes demo diskette Free informative catalog of Data receivers and kits Quote processing and display software Deecranbing So bite ul ities 303 223 2120 5 Demo Diskette DATArx 111 E Drake Rd Suite 7041 Fort Collins CO 80525 Reader Service Number 133 Complete C Source Code No Royalties Simple Screen Definition x Windows Pop up Menus x Context Sensitive Help Lots of low level functions Introductory Price 69 95 Plus 5 00 shipping 10 00 outside US CA residents please add sales tax Business Computer Services 1800 S Robertson Blvd Suite 206 Los Angeles CA 90035 VISA MC orders 213 836 5026 Demo disk available 10 00 Read
221. py your Macintosh diskettes right on your PC XT AT with the MatchMaker Just plug your external 312 Macintosh drive into the MatchMaker board and experience EASY access to your Mac diskettes Includes programs to read write initialize and delete files on your single or double sided Mac diskettes MatchMaker Board MatchMaker w External Mac Drive 325 00 Hard Disks for CP M systems Pep up your CP M computer with hard disk per formance Our simple to install kits allow you to connect up to two 5 hard drives to your Z80 system The Winchester Connection software customizes your system from an easy to use menu with flexible drive parameters partition and block size and includes complete instal lation and diagnostic utilities A complete system requires a HDS daughter board WD1002 05 hard drive controller board hard drive software package and cables HDS Host Board with Software 79 95 HDS Board WD1002 05 and software 245 00 WD1002 05 Controller Board only 185 00 External drive cabinet with power supply 139 95 Parts and accessories for the Kaypro and Xerox 820 1 Plus2 ROM Set for Xerox 820 1 Plus2 ROM with X120 bare board KayPLUS ROM for Kaypro 2 4 10 specify Kaypro 2X Real time Clock parts kit Kaypro 2X Hard disk interface parts kit Kaypro 10 Hard Disk controller 39 95 49 95 69 95 29 00 16 00 Kaypro four drive floppy decoder board QP M Operating System boota
222. r Data bit 1 The re ceiver can assert this line if it s having problems and call the whole transaction off Check the code to see how it s used Faster If You Have MASM I found that the C code for byte trans fers was a bit slow If I had an optimiz ing compiler perhaps I could have saved myself some trouble but instead I wrote the time critical routines in Turbo C in line assembly These routines move a block at a time instead of a byte at a time The fast trans fer times are achieved with the assembly routines receive block and send block0 Unfortunately you must have MASM to make them work If you don t you ll just have to use the C routines Nails amp Glue To finish the program main must handle an arbitrary number of files and allow wildcards in the command line Main uses the Turbo C library functions findfirst and findnext to expand the command line arguments Bit4 SELECT Pin 13 Bit 4 ENABLE INT The code comes with a makefile To build it simply type make assuming you ve installed Make with Turbo C A Design Alternative With a slight modification to the board shown in Chapter 7 of CIWP amp C you can turn the 8 bit output only port on the printer card into an 8 bit I O port Then you can use any cable without changing it and rewrite the software to control the direction of both 8 bit I O ports and use pins 1 14 16 amp 17 as handshaking lines You could even designate o
223. r the worst case size for the output buffer is srcSize 1 DestSize returns the size of the output data in the dest buffer so you can use that value as the scrSize in the decompression You could alternately store the destSize as the second byte in the output buffer The encoding sequence first outputs the compression code We then consider three cri teria to determine if the repeat counter can be bumped First we must make sure we are not at the end of the buffer Second the current byte must equal the current byte plus 1 and MICRO CORNUCOPIA 48 July August 1989 77 third the repeat counter must not be at its maximum Short Circuit Your Boolean If you look closely at the if statement in RleCompBuff you may notice a potentially illegal array reference If sPos was set to the last element in the array the bytes src sPos 1 reference would generate an out of range error You can instruct the Turbo Pascal com piler and others to generate code that will stop evaluation or short circuit the expression once the outcome is known pm file based routines can handle the largest files that Turbo Pascal can accommodate Since the if statement ANDs three expressions only one has to fail to ren der the entire expression false The sPos lt srcSize subexpression will al ways evaluate false when there is a danger of out of range error Because I relied on the short circuit this code must be compiled with th
224. r jury a settlement merely indi cates a compromise between the parties Sometimes as in the GEM suit be tween Microsoft and Digital Research a larger opponent can force a smaller op ponent into an unfavorable settlement under threat of a costly court process It would be presumptuous of us to judge who is right or wrong in the SEA vs PKWare case merely by the terms of the settlement If you want to see how the courts view program copyrights look at the four year old legal battle between Intel and NEC which was just recently settled Intel claimed that NEC copied their microcode and that NEC s pro grammer all but admitted in court that he had used disassembled Intel code in writing NEC code U S District Judge William Gray concluded that because of a technical ity Intel s copyright was invalid But even if it had been valid he held that NEC still would not have infringed He agreed that there were routines which were substantially similar but pointed to some in which close simi larity in approach is not surprising He further stated that some similarities were unimportant because NEC was forced into the use of certain routines to achieve a required result In his decision Judge Gray also quoted an article in a UCLA law jour nal which stated that courts do not allow the accused work to be dissected into pieces and the pieces isolated as if each stood alone One criterion he used was whether
225. rent choice Or write part of the text of the prompt in the same color as the screen background That way this sort of menu Print Save Exit can speak without interfering with the visual aesthetics I add an invisible trig ger letter and equals sign before each menu choice On the screen the real menu looks like this P Print S Save E Exit Light bar menus especially reverse video ones are generally easy enough to use so long as there is nothing else of the same color on the screen Keep your borders simple Sighted people tend to underestimate how te dious repetitive speech can become In stead of using hyphens and vertical bars which are spoken use the line draw characters of the IBM extended ASCII character set Screen access software either doesn t read graphics characters or lets you op tionally turn graphics off Runs of alternating characters such as 2 are extremely tedious since each character gets spoken A continuous run of any single character can be sensed and counted Thus most modern screen access packages pronounce a row of equals signs something like counted 40 equals signs Not great but definitely acceptable However remember that a box framed with characters other than the IBM extended ASCII character set won t be seen as such by a screen access program Helping Don t misspell words so the synthe sizer will pronounce them correctly There are many speech synth
226. reverse video blob or color highlighting to indicate a variable size pseudo cursor move the system cur sor to the first character within the highlighted area If you turn the blinking cursor off use the method in Figure 1 to disable the cur sor Don t use ANSI SYS as that just moves the cursor to row 26 Don t use the technique in Robert Jourdain s book which positions the cursor offscreen In stead turn it off by calling the BIOS func tion to set cursor size and set bit 5 of the scan lines signaling the BIOS to make the cursor invisible Keep the cursor invisible but let it shadow your pseudo cursor Screen access software will find the system cur sor even when you have made it invis ible Screen Layout When formatting your screens re member that the simpler they are the easier they ll be for the visually impaired to read Think about the placement of columns the layout of windows and the organization of menus Above all re member that displaying trivia is espe cially frustrating for the blind user he can t avoid listening to it ee Figure 1 Turning Off The Cursor Call with the parameter off set to TRUE 1 or FALSE 0 The parameters high and low are for top and bottom scan lines of the cursor We actually turn off the cursor by calling a routine in the BIOS to change its size include lt dos h gt int setcursor off high low int off int high int low u
227. ributors Graphic Sciences Ltd Surrey England TEL 01 940 9480 FAX 01 948 2851 LaserGo Inc lE TEL 619 530 2400 FAX 619 530 0099 9235 Trade Place Suite A San Diego CA 92126 LaserGo GoScript are trade of LaserGo Inc PostScript is a registered trademark of Adobe Systems Inc All other product names are trademarks of their manufacturers Reader Service Number 144 just one of these batteries LIMBO con testants would be advised to provide their own fully charged batteries during the competition to assure adequate power reserves for the inevitable pre and post contest fiddling and demonstra tions After sensors and software batter ies are the weakest link in robotics Now about that cold fusion A Moving Moment Of Force Would the steppers move an 11 Ib LIMBO By Newton s formula F ma the force required to accelerate a mass is given by that mass times the acceleration of the mass A good sports car will accel erate at half a gee about 16 ft sec To Figure 1 LIMBO Drive System except for the new apple flavor Fine Push it with a pound of force and LIMBO will accelerate at 1 10 gee But what does that mean in terms of mo tors Now we talk torque The relevant torque here is the stepper motor holding torque This is the torque developed by the stepper when the rated DC currents flow continually to two of the phases of the four phase motor The holding torque happens to
228. riginal spreadsheets of course real sheets of 14 x 17 paper ruled into rows and columns We organ ized the input data into one or more columns then we worked down the list calculating each new column as we went For simple problems with not too many entries we used the good ol 18 slide rule For more complex problems we used the Friden For long problems we would turn the thing over to Donna our secretary Donna supported some seven engineers and had the patience of Job She would sit there all day day after day crunching out those numbers which we would then plot up and analyze Donna prided herself on using 12 digit accuracy for everything even if the input data was only good to three digits If there were any errors they certainly weren t going to come from her One day I got a really big problem too big for Donna I asked one of the old hands What do you do with problems that are too big for Donna He said very matter of factly Oh you take them to the Computer Room You should have seen my eyes light up l d read all about the Giant Brains had even learned to program one in college though I never saw it the school didn t actually have one I couldn t wait to see how the folks in the Computer Room dealt with my prob lem Eagerly I got directions from my colleague prepared my data and rushed over to the building he described Fol lowing his directions I walked down the hall until I a
229. rmat has be come a widely supported graphics stand ard partly because major OEM hard ware vendors such as Tecmar and Mi crosoft bundle PC Paintbrush with their video boards and mice ZSoft has also managed to support hundreds of display adapters printers scanners and drawing devices making PCX a very widely used format for stor ing bit mapped images Device Dependence PCX is a device dependent for mat meaning that an image created on a CGA will only look right on CGA or CGA mode Likewise a picture created using a VGA 16 color mode can t be dis played on a CGA i e 2 color or 4 color mode This causes some problems for developers who want to support Her cules CGA EGA VGA and extended VGA modes with one image file Put simply you can t support all modes with one file One way around the problem is to draw two copies of every image one for CGA and one for EGA VGA modes Another is to use only black and white images which can be displayed on any adapter But black and white alone won t solve the problem since the display s aspect ratio will distort the image elon gating circles To achieve device independence you must use a graphics primitive package This means you must create the image with lines circles squares etc then re draw it later on the screen You ve seen this method used in CAD CAM pack ages and programs like Micrografx De signer Unfortunately the types of drawi
230. rocessor sorry but I m not sure how much I m supposed to say so I won t say much As with most new hardware products this one seemed to be branching off to Never Never Land at random times Of course we were a bit curious about it The first step was to make an interrupt serv ice routine that would intercept all the bad interrupts and print a register dump Then we could look at CS IP and see what caused the problem The interrupt service routine or trap was written in assembly language and assembled into a TSR Terminate and Stay Resi dent program which installed itself at system startup Coprocessor Exception The TRAP program was useful for figuring out a few problems For example this particu lar NEC processor would generate a Co processor Exception interrupt when it en countered an 8087 instruction The same facility is available on the 186 286 and 386 and it can be selectively enabled disabled by software It turned out however that the NEC processor had this feature permanently turned on 44 MICRO CORNUCOPIA 48 July August 1989 Since nearly every program written these days executes an 8087 instruction to see if an 8087 is present we couldn t run any software without the machine crashing By trapping the Coprocessor Exception in terrupt we discovered that an exception was occurring So we wrote a more permanent in terrupt service routine which incremented IP the Instruction Pointer pas
231. rrived ai a set of doubie doors with a large sign proclaiming sure enough Computer Room Holding my breath I eased open the door It was a huge room There must have been 300 desks all arranged neatly in rows At each desk sat a woman and on each desk was a Friden The women were the computer I kid you not I found out later that their official job description was GS 2 Computer Once I had gotten over the shock I approached the head computer She explained to me how things worked First you filled out the spreadsheet with all the input data Then at the top of each remaining column you wrote some operation such as 3 1 2 where each number referred to a column number In effect you wrote a program It was no different from defining the formula for Lotus or Excel After defining all the calculations you turned things over to the computers who filled in the numbers l The foreperson assigned different parts of the job to different women de pending on the load For a big job she would keep several parts running in par allel Most likely the first multitasking multiprocessing computer system It all went quite smoothly The com puters rarely made mistakes They also had independent verification so any mis takes were always caught They would even plot the results up for me although I rarely used that service since I found that I could plot more accurately Progress Is Wonderful Well th
232. rs use them con sistently Red can always indicate errors blue the current choice and magenta the status line Screen access programs can search for specific attributes and then read only that information Thus if a blind person hears a beep she can search for red just to get the error message without having to read the entire screen Give the user a way to reassign the colors of each type of information If you use drop shadows provide a way to dis able them Menu Dos amp Don ts Menus which display the trigger character in an attribute different from the rest of the word are difficult for the blind They are usable if the trigger char acter is always the first character of the choice If the trigger is embedded within the choice the screen gets confusing MICRO CORNUCOPIA 48 July August 1989 17 Look Ma No Dots Communicating Dot To Dot What about Braille Unfortunately only a small percentage of the blind population reads braille The world s largest circulation magazine for the blind has only 4 600 braille subscribers even though the subscription is free Since so few people use braille the market for braille devices is quite small Nevertheless through grants and goodwill there s a plethora of braille equip ment Braille has some definite advantages Unlike speech which often mispro nounces and sometimes misinterprets braille is accurate the blind person can see every character It
233. rts of other controversial fields UFOs faith healing creationism etc Jay Holovacs 95 King George Rd Warren NJ 07060 CIS 74756 413 You Are What You Eat As a licensed psychotherapist I have been very concerned about NutraSweet Aspartame since its introduction to re place saccharin One of my areas of spe cialization is Mood Disorders Your comments regarding flying apply to many other areas of our mental health Every container with NutraSweet says that it contains Phenylketonurics contains Phenylalanine Phenylalanine is one of the chemicals an amino acid that the body uses to produce Sero tonin Serotonin is one of four major chemicals that help send signals around the brain This increase in Serotonin has the same effect as most prescribed antide pressant medications These powerful mood altering medications should be used under close psychiatric supervi sion Research on the wide use of Nutra Sweet has shown definite side effects in people of all ages These side effects are similar to those of people taking an in appropriate medication dry eyes dry mouth sedation agitation irritability excitability change in sleep appetite sexual functioning or interest loss of equilibrium and coordination blurred vision constipation headaches and many more Ask your doctor or read the package insert regarding the side ef fects of Tricyclic Antidepressants Prop erly supervised the side effec
234. s Monday Friday 9 00 5 30 VERY HIGH PERFORMANCE Processors Memory and Display Adapters The X24 High performance processor e 12 or 16 MHz 80286 with TATES Small size XT height and length passive bus design 1 to 4 Mbyte 0 wait state dynamic memory Fully AT compatible Award BIOS Runs DOS versions 2 2 and later Xenix and OS 2 The X24 combines the best of motherboard and backplane designs in a 10096 AT compatible system Incor porating a 16 MHz 80286 the X24 processor is designed to operate with the PC Tech Advanced System Mother board which contains the peripheral interfaces hard disk floppy disk two serial ports and a parallel port The X24 processor can also be used with other totally passive bus backplanes Most critical components including the microprocessor and up to 4 megabytes of fast memory are contained on a single PC size plug in card This allows the processor and main system memory to be serviced or upgraded without disturbing other peripherals such as serial ports and disk drives d PC Tech X24 and ASMB The PC Tech Advanced System Motherboard e Built in IDE interface for AT interface type hard drives e Fully AT compatible floppy disk support for 3 5 5 25 drives capacities of 360k 1 2m and 1 44m e Two serial ports and one parallel port e 8 total expansion slots PC XT AT compatible 4 slots have 32 bit bus The PC Tech Advanced System Motherboard is designed to complement PC Tech s X24 and X32 high
235. s a critical section and private defines data that must be replicated for each execution thread Future versions will continue to improve the language for use in cutting edge environments such as OS 2 and AmigaDOS Lattice is the innovation leader 60 50 Performance H Bes Be De Ella Biila amp ziziilm Z Ze Zi Que am ow i o Iii zi te tm Uv Bi lope HALO d i pm i 1 i An g Ee X don e fee cee ie pe m ANSI And the benchmarks show it The Leader in OS 2 Lattice C includes bindings and header files so that you do not need to buy an expensive OS 2 develop ment kit The library also supports multithread programming with no built in limits to the number of threads The Lattice linker librarian editor debugger and utilities run in DOS OS 2 and family mode Lattice is the OS 2 leader The Leader in Productivity The Lattice C Development System now includes the utilities that our customers professional C pro grammers use most often Of course the system is based upon our C com iler editor linker librarian and de ugger In addition we now include our powerful project maintenance oe gt Lattice BOGANI Tw Libraries Professional Programming Tools Since 1981 2500 S Highland Avenue Lombard IL 60148 best in the business on Top tool Imk which is an advanced version of the UNIX make utility Build diff extract file splat tou
236. s changed my thinking I no longer think about the things I can t do I think about the things I can do Taking Inventory In the ten years I ve been using per sonal computers I ve progressed through a lot of hardware three computers three monitors and printers five floppy and three hard disk drives five keyboards and two modems In the process my RAM requirements have grown from 16K to 1 664K In that steady progression of older hardware to newer hardware the move from cassette tapes to floppy disks for storage was a big jump but the 10MB hard disk was magic A hollow voice says PLUGH No longer did I have to ask someone to switch floppies every time I wanted to change programs or needed last year s financial records or to play Frogger when everyone thought I was hard at work No single component has given me as much autonomy as the hard disk Soon CD technology may become as important to me as the hard disk is today I already have a spelling checker and a thesaurus on my hard disk but a CD ROM drive would allow me to use a real dictionary and encyclopedia and a host of other reference materials I wouldn t have to ask someone to come pull the dictionary from the shelf and set it up for me I wouldn t ever have to turn a page turning from the front to the back of a 1 200 page diction ary using a mouthstick gives me second thoughts of whether I really need to know the meaning of zymurgy Anot
237. s in color amp hardcopy rens 325 PC Curses Aspen Software System V compatible extensive documentation s s ww ee ee ee 290 Code Base database manager dBase and Clipper compatibile indes amp data files Version 4 0 less 260 Greenleaf Data Windows windows menus data entry interactive form cage specify compiler EN 220 Greenleaf Communications Library interrupt mode modem control XON XOFF specify compiler 175 uo TE RIP certified HP PS dot drivers CM fonts LaTRX eee eee hes 170 Sheri Gebugging aid lt 6 sis a a eee ee eee e e he heh eh hm e hoe t om 9 o e es 170 CBTree B tree driver multiple variable length keys PAS AS cubic ee iia eed n S Ser A eR Ged er Eus vip ae aa IO USC Cet Oe IS 165 AT BIOS Kit roll your own BIOS with this complete set of basic input output functions for ATs 6 6 ee ee lees 160 Greenleaf Functions 296 useful C functions all DOS services speaiy compiler vo 6 roia E E a od R EE AE Se aa nn 160 WKS Library Version 2 0 C program interface to Lotus 1 2 3 dBase Supercalc 4 Quatro amp Clipper esasa Sui ie Vea ar win nic alee 155 OS 88 U ex like operating system many tools cross development from MS DOS ee ee ee ee ee 150 ME Version 21 prostammers editor with C like macro language by Magma Software Version 1 31 still 75 ee 140 Vmen C virtual memory manager cas re
238. s to support external control of task assignments This would get around the position inde pendence imposed by SK DOS For now I have to work around SK DOS to run MTASK This involves changing SK DOS end of memory pointer MEMEND to 3CFFF then loading MTASK into RAM at its default origin of 3D000 This sequence prevents SK DOS from loading a program on top of MTASK I then transfer control to my ROM monitor from SK DOS Finally I use the monitors GO command to start up MTASK To return to SK DOS with MTASK still running I then GO to SK DOS warm start entry point 1006 Inside MTASK Six entry points support the low level I O functions for the two serial ports on my system INVO and INV1 handle in coming characters from ports 0 and 1 re spectively OUTVO and OUTV1 take care By Karl Lunt 7349 W Canterbury Peoria AZ 85345 602 878 0305 H 602 869 6146 W of outgoing characters KEYVO and KEYV1 check for a pressed key on the corresponding terminals Tasks may use either serial port for I O the entry points placed into a task s TDB by the program mer determine which port gets used The scheduler writes the selected three low level entry points into the monitors RAM vector locations before switching tasks Thus each task gets its own set of I O handlers In an expanded version of MTASK these vectors may not even point to the ROM based I O routines instead they might point to a queue handler or ot
239. sadena CA 91117 9988 800 325 9465 Digi Key Corp 701 Brooks Ave South P O Box 677 Thief River Falls MN 56701 0677 Break Out of the Text Barrier with your Herc CGA EGA or VGA gt PCX PROGRAMMER S TOOLKIT 195 Over 55 routines to display save print PCX bitmapped graphics Fast easy to use Display windows or full screen Image library manager use images from Paintbrush Scanners Clip Art or Capture Screens No Royalties PCX TEXT 99 Display text in any graphics mode Includes 12 fonts Create custom fonts with dual font editor User input routines Font scaling Additional fonts available PCXF X 99 Add Special Effects FX Fade wipe push roll slide split crush spiral explode your graphics Palette manipulation Animation Sound Eff PWV EO M CROP ROG RAM M s Meadow Lake Houston Texas 77077 713 TE 800 227 0918 MICRO CORNUCOPIA 48 July August 1989 33 PCX Compatibility Trying To Create A Graphics File Standard When is a standard a standard When there are many incompatible versions run ning around When is a standard an im pediment When it outgrows its intended use How does the PCX file format fit into this picture Read on standards for storing graphics im ages The most popular standards are TIFF Tagged Image File Format GIF popular on CompuServe and BBSs and PCX The PCX format has emerged as a de facto industr
240. similar function NEWS AND REVIEWS Here s a shocker not much is hap pening this month in the world of C At least I m not aware of anything But don t worry things are just getting going for 1989 Microsoft is busily at work on C 6 0 and it looks very good I can t say much now but I think Micro soft is about to provide programmers with a quantum leap in development environments Zortech has finally released their C debugger I haven t had much time to work with it but it looks good I have noticed some minor problems You 56 MICRO CORNUCOPIA 48 July August 1989 can t look at the value of local static variables for instance It also requires using both the CO CodeView info and LI line number info options when linking This seems strange since the LI option is a subset of the CO option according to Microsoft s docu mentation The biggest disappointment is that it does not truly support C They are releasing a version which does Soon With a little refinement Zortech will have one of the top debuggers available for MS DOS RESOURCES Rocky Mountain SOG of course will be a great resource It excited people in Denver so much that they merged the Micro Assembly conference which I ve mentioned in past columns into Rocky Mountain SOG Check the SOG ads in this issue for more details on what will be the best SOG ever As for books I highly recommend one called Concrete Mathematics by Ro
241. simply identified you as some kind of teacher Most people can quickly map this to them selves professional teachers parents those who help co workers learn jobs people active in churches or community groups clubs etc pretty much a sure fire hit Quite possibly other statements were made by the reader which generated less of a personal match and so are less likely to be recalled by the subject you But now you hit a train of thought you revealed your occupation narrowing the subject by orders of mag nitude The next comment contains a couple of guaranteed hits write quite a bit and dedicated loyal audience It s hard to imagine anyone interested in his her editing work that would score this as a miss And will write a book Pretty straightforward extension for a person already a professional writer I think I would bet on that prognostication without any belief in the system When properly tested these ap proaches have not shown themselves to stand up statistically However to the extent that people are willing to believe then they will appear to work Anyhow I enjoy your magazine and your free wheeling approach that al lowed this discussion in the editorial P S Feel free to drop into the Skepti cal Inquirer conference on Compuserve science forum last Tuesday of the month 9 30 Eastern time This is an in formal open discussion scientific not witch hunting of these and all so
242. since I made that my electric wheelchair I drove up decision the decision to buy a Radio Shack TRS 80 Model I with 16K RAM and a cassette recorder Recalling the mo ment it was first turned on reminds me of the beginning of an adventure You are standing at the end of a road before a small brick building Around you is a forest A small stream flows out of the building and down a gully Keyboards The First Barrier Computer keyboards were designed for people with two hands and ten fin gers I have two hands and ten fingers but they don t work So I use a mouth stick I can do a lot of things with a mouth stick I can turn the pages of books and magazines use a typewriter pilot a radio controlled model sailplane and race a radio controlled model sailboat dad and I put a lot of time into making them work The TRS 80 keyboard however was beyond us Try holding down one key while pressing another Do it with one finger and you ll understand the biggest dis advantage of using a mouthstick So al most before it began the adventure had stopped A huge green fierce snake bars the way Adapting the TRS 80 keyboard proved easier than I thought That key board had no Control or Alt keys only two Shift keys A computer repair shop installed a mechanical Shift Lock and in an astounding flurry it drove the snake away The IBM Keyboard Four years later when I encountered an IBM XT I found a larger barrier Im
243. ssse CPM COMPUTERS K4 83 350 K2 84 M 425 KAX coca nes CPU amp RAM amp MISC 41256 12 7 50 41256 15 6 00 4164 10 2 50 4164 12 2 10 4164 15 2 00 4164 20 1 25 MK48202B 20 52s Secale einn Dallas D1220Y ci Sex paiva doa l SIP DRAM 256 12 7 00 2016 ase ries 3 50 PARY a 3 75 2164 oc 4 00 27128 6 50 27256 5 25 MC68000 8 CPU Z80 CPU 75 00 Z80A CPU 1 50 ZOO GIG uso ek dM Ces EUER 1 50 Z80A PIO 2 00 Z80A SIO 5 00 6 1791 2 us 7 00 SPECIAL x External 312 Floppy Drive 720K Top Loading 5V Only wDocs 55 Reader Service Number 93 81 189 Video Pal sse 81 194 RAM Pal 000 81 Series Char Gen ROMs 81 Series Monitor ROMs SWITCHERS 5V 9 5A 12V 3 8A 12VI 8A 5V 3A 12VI2A 12VI 4A sss 5VI6A 12VI2A 12VMA 6 ee SVIGA 24V 1 4A 12VI 6A 12V 6A x SPECIAL x IBM PS2 Model 25 Freight damaged Works perfect 600 x SPECIAL x AT 80286 6 CPU BOARD with reset and mono color switch Connector for KB Battery amp SPKR Phoenix Bios tested with Award 3 03 6MHz can be upgraded to 8 or 10MHz Used with backplane add memory board I O board etc ony 125 MICRO CORNUCOPIA 48 July August 1989 53 and function prototypes and must be included into any program which uses the functions defined in FILESRCH C see Figure 2 While FILESRCH pri marily focuses on sear
244. started to appear on the bulletin boards While it is not as fast as PKZIP or QARC LHARC s claim to fame is that it couples decent performance with ex traordinarily effective compression beating its competitors by 30 percent or more That could produce major savings in disk space I haven t had a chance to try LHARC to evaluate its claims or examine its compatibility with the existing ARC standard Watch for more news next time Things are getting interesting all over again aaran OS 2 mi oro 194 05 6 6 This small blazing fast editor lets program instructions memos letters and assorted text data bases flow easily between brain ii and computer 9 EDITOR VGA 50 line mode 50k of disk space System Requirements systems and laptops Reader Service Number 127 David M Kalman Editor in Chief Data Based Advisor September 1988 E QEdit supports 101 key key boards EGA 43 line mode and E Great for use with loptops QEdit edits files entirely in memory saving drain on laptop batteries E Compact Even with all these features QEdit requires less than Full 30 day money back guarantee QEdit requires an IBM PS 2 PC AT PC XT PC PC Jr or compatible Minimum system requirements are 64 KB of memory PC DOS 2 0 or MS DOS 2 0 or greater 50 KB of disk space QEdit runs GREAT on floppy based 6 6 The editor s speed windows and other features make it among the best text editors I ve
245. stuck in a new processor and surprise surprise everything worked Then just for argument s sake I grabbed new data Things were hunky dory 00 C3 01 29 02 00 29 F3 Some details about the Heathkit Logic Analyzer Data Width 2 4 0 09 4937 SPG e eel erate DRIN RR Srl ere lnc 16 bits Data Depthl cde yc uhr UL e rt e wwe e Sie YI 2046 words Clock Input eee eee Rising or falling edge Clock Qual eee leere Two logic high or low Clock Period oo oie Soe 22 01 rs d ese 100 ns minimum Displays 5 vii RE SIE ASCII Hex Octal or Timing Delay Range cele eee eee hne 2 to 50 000 clocks Trigger Word e Selectable H L Don t care Logic Analyzer Model IC 1001 Price 279 95 kit Heath Company Benton Harbor MI 49022 616 982 3411 Good Luck By the way when Heath says it s a kit it s a kit You even assemble the three ring binder with two nuts and two screws before you insert the pages Don t worry however they re famous for their clear manuals and their knowledgable sup port The Toshiba T1000 I ve been dragging around a Kaypro 2000 for a couple of years and it s really spoiled me Now I feel naked if I don t have a computer with me The king has no computer After all there s no way to know when an idea s going to jump out at me or I m going to dig up some juicy gossip Plus we all know that paper s for cave dwellers Unfortunately the 2000 hasn
246. t map We also support and recommend the DGIS graphics interface standard from Graphic Software Systems for applications development as an alternative to native 34010 software development Ready to run drivers are available for most major applications software packages as well Custom Designs Available PC Tech will license most products for non exclusive manufacture We will also cus tomize any of our designs to better meet your needs on our in house CAD systems All of our standard products are available in private label versions About PC Tech PC Tech has been designing manufacturing and marketing high performance PC re lated products for over three years Our standard product line includes processor memory and video products All products are designed manufactured and sup ported in our Lake City Minnesota facilities Designed Sold and Serviced By AME Ke MAME SS ea High resolution fractal produced on the PC Tech COLOR 34010 907 N 6th St Lake City MN 55041 612 345 4555 612 345 5514 FAX Reader Service Number 3 PC XT AT DGIS Hercules and Award BIOS are trademarks or registered trademarks of their respective companies
247. t which is not copy righted in any way I release the following programs to the pub lic domain You are encouraged to use them change them and include them in programs you sell for profit or loss Editor s note I m sure you can also use them for party favors Ts month I m talking about data com Data Compression One of the simplest forms of data compres sion is to replace spaces with tabs Another form of compression run length encoding RLE replaces any repeating character with three bytes a flag the character and a count Since the compressed sequence requires three bytes there is no need to compress any sequence less than four bytes The compression flag must be a byte value that does not occur in the data you re com pressing For most text a byte value of 255 works well Some COM and EXE files how ever contain 255 and I found that 236 works for these To check this I wrote a small utility to count the number of occurrences of each byte value It s included with the Modula 2 version on the Micro C Issue 48 disk Variable Typecasting The unit contains compression and decom pression routines for both files and memory buffers See Figure 1 To avoid repeating my self let me say that again I will refer to both the file and memory buffers as buffers A generic routine to compress or decompress any kind of variable structure can present data type problems Turbo Pascal 5 0 and perhaps 4 0
248. t compiles that way everything else compiles in the default mode Not only does this make it harder for the programmer to miscom pile the module it also avoids problems with modules compiling with different alignments First find_first calls a function to set the DTA to the location of the user supplied buffer It then calls FIND FIRST saves the value of the carry flag calls a function to reset the DTA then returns the stored value of the carry flag as an error indicator find_next is much simpler It ac cepts only one parameter a pointer to a FIELD_DATA structure already initial ized by find_first It sets the DTA to point to the buffer calls FIND_NEXT and then resets the DTA to its former location As with find firstQ find_next 54 MICRO CORNUCOPIA 48 July August 1989 int find first char spec char attrib fo Uu unsigned res set dta fd regs h ah Ox4E regs x cx unsigned attrib dfdef SMALL DATA PTRS regs x dx unsigned spec intdos sregs amp regs Dens A IE eee Jsegread amp sregs PH sregs ds FP SEG spec regs x dx FP OFF spec NT Antdosx amp regs trega amp sregs iu endif d 0 res regs x cflag reset dta i return res int find next FILE DATA fd sp WD uu unsigned res S set dta fd um regs h ah 0x4F ntdos amp regs amp regs yes reqs x eflag
249. t the offending in struction and any possible operands and re turned This mimics the operation of an Intel processor with no 8087 all 8087 instructions are treated as NOPs Since Intel processors or any of the NEC processors you ve ever heard of don t need this facility I haven t included that part in the example program Too much clutter causes confusion I think Invalid Opcode Exception Another bad interrupt we trapped was the Invalid Opcode interrupt This interrupt is generated whenever the processor encount ers an instruction it does not recognize The same interrupt is also available on the 186 286 and 386 It turned out that some of the crashes re sulted from attempts to execute invalid instruc tions Being able to see when this happened helped but it didn t show us why After all the software we were running was all debugged Something earlier was causing the machine to jump to a nonsense location and execute non sense opcodes which eventually meant an in valid instruction In fact the machine bombed at the same location somewhere down in low memory every time Then Earl at PC Tech had an idea the most common cause of jumping to nonsense loca tions is an uninitialized pointer The most com mon value of an uninitialized pointer is 0000 0000 Go into SYMDEB and type g 0 0 he said I tried it Sure enough up came the Invalid Opcode Encountered message At the same address No
250. tain variable is modified or where a bound ary condition is reached ZTCDB also has the ability to set Tracepoints A tracepoint is a break point which instead of halting execu tion increments a counter and con tinues With this tool you can profile the execution of your program and de cide which portions you should spend time optimizing For example I ran the DISKEDIT program from the last issue after setting a tracepoint on every line of the pro gram I learned that as I had expected the program was spending about 80 times as much time in the procedures cprintf and Writel6Bytes as in any other part of the program If more speed concerned me I would rewrite these functions in assembly Finally in the breakpoint depart ment ZTCDB saves all your break points in a configuration file so you can use them the next time you debug the program Negatives As with any good program there are still a few distracting problems with ZTCDB There are always the little taste and preference kinds of things of course One example is that I don t exactly like the mouse interface I can t pin down why though I guess it s just because of the differences between ZTCDB mouse commands and MS Word mouse commands especially the method of scrolling Also I sorely miss having a simple mouse command that says execute up to this line I would also much rather see the as sembly language listings in the source windo
251. ten just selecting the print option would hang the sys tem We ve tried it on a 186 286 and 386 system S C A Videotape Presentation Considering C for your next project Confused after trying to read a C book Or just curious about all the hOOPla This VHS format videotape featuring author speaker William M Miller gives a comprehensive and understandable overview of the major features of C and Object Oriented Programming e Online access to lecturer via BIX e Moneyback guarantee Send 19 95 4 00 S amp H for 1 week rental or 59 95 for purchase postpaid to Software Development Technologies Inc Dept 102 P O Box 366 Sudbury MA 01776 Or call 508 443 5779 8 00 a m to 6 00 p m Eastern time for Visa Mastercard orders Inquire about our full C training course available for on site or videotape delivery Reader Service Number 150 72 MICRO CORNUCOPIA 48 July August 1989 Sandy has spent hours trying all the permutations For tunately there s tech support Unfortunately tech support doesn t know much Gee did you select the PostScript printer in the setup menu Yes And I m doing it again It should work now Yes it should While she was talking I trapped the output to see what the program was sending to the printer What I found was raw text no PostScript header no PostScript line information no PostScript end of page command She
252. ters we received from all you wonderful folks But to kick it off here s a bit I just couldn t take apart Jack even describes my experiences with the early calculators right down to the rat a tat tat may seem hard to believe but it s true We haven t always had PCs There was a time when we had no computers at all to play with Computing had to be done by hand F gt some of you young folks this Days Of Logarithms We had three tools in high school a table of logarithms a set of trig tables and a pencil Adding and subtracting we did by hand the old fashioned way For multiplication and division it was easier to add and subtract the logarithms then take the antilog I spent a good portion of my high school algebra class learning how to read and interpolate a table of logarithms I he trig books had tables of the trig functions giving both their value and its logarithm We used the latter most because trig functions tend to multiply things The ta bles were typically given to the nearest tenth of a degree enough for anybody Solving a relatively simple trig prob lem was not a simple matter it took lots of time and patience and it was easy to make errors Calculating the points in a single 3 D drawing would have been overwhelming We had another approach to problems like that graphics A drafting class was required for any technical career In that class we learned how to handle T squares and tri
253. the 90s Be come a registered developer for all the hardware people such as IBM Apple HP SUN NeXT and DEC This way you ll be in the same league as the big guys in terms of information and prices on new technology How about keeping a successful startup going My experience with our customers is that when they first come out with a great product it sells well They pay for their advertising and everything is great Then about six months after intro duction they start spending all their time doing support They never get back to upgrading the product and the revenue drops Now they re trapped CITIZEN MATE 12 286 SYSTEM 80286 With 12 5 MHz Clock Speed has on the Mother Board ONE Meg RAM with 1 Wait State Video Controller Supports EEGA EGA CGA MGA Hercules and Plantronics Color Plus Controller Provides Support for Two Hard Drives and Two Floppy Drives 5 25 and 3 5 Capability Mouse Parallel and Two Serial Ports 1 2 Meg Floppy Installed 32k Hard Drive Cache Installed 101 Enhanced Keyboard MS DOS 3 3 With GWBASIC Small Footprint Standard 1MB Expandable to 4MB Novelle Compatible Nation Wide Service dk ek eee ee ede de dede jedekekekekekekeke eee k81495 00 XT CLONE SYSTEMS PLEASE CALL FOR CURRENT PRICE HARD DRIVES FOR XT AND AT ST 225 KIT FOR XT 20 MEG ST 238 KIT FOR XT RLL 30 MEG ST 251 FOR AT 40 MEG MONITORS Color Monitor RGB CGA Color Monitor RGB EGA Monochrome TTL Green Monochr
254. the Turbo Pascal compiler a 21 000 line assembly program this step would take about four hours on a fast printer And to repeat this over and over again is prohibitive Interactive disassemblers like MD replace these steps with a visual dis play If you don t like some part of the disassembly you can change it and im mediately see the results on the screen Video screens are much faster than printers Also you don t have to switch over to DEBUG to understand what s happening Clark A Calkins Owner C C Software 1907 Alvarado Ave Walnut Creek CA 94596 6 MICRO CORNUCOPIA 48 July August 1989 Letters Nasty Language Periodically I go through old ma gazines cut out articles I want and then throw the mags away I keep trying to do that with yours but have been un able to because the magazine has too many useful articles Consequently I have no choice but to order another sub scription However this subscription is only for one year because you seem to have a fatal disease If you move quickly you might be able to get help for it but I don t have high hopes for you doing that OK OK I ll tell you the dreaded C disease You are doing just what all too many used to be good magazines have done You re selling your body and soul out to the C language How many times did you get dropped on your heads Or maybe you ran the rapids one too many times and hit your head on a rock Oh what the
255. the scheduler defines the type of multitasking kernel used Two main types of kernels exist the interrupt driven and the cooperative The Usual Way Most often multitasking refers to an interrupt driven task switching system Here hardware routinely interrupts a task s operation and control passes to the scheduler This is usually a simple system to im plement You need a source of periodic interrupt signals such as a 555 timer or a divider circuit driven by the CPU s clock and an interrupt handler program to pass control to the scheduler when the inter rupt occurs Of course you also need the scheduler The main drawback to this system lies in the hardware interface The hardware design and the software design must play together perfectly The software must know where the interrupts come from how often they will occur and how they can be controlled Thus the sched uler design is unique for each hardware design An Alternative The cooperative multitasking system uses a different approach for passing con trol to the task scheduler Here each task voluntarily abdicates to the scheduler which then wakes up the next task There are no hardware induced interrupts Each task knows precisely where it will give up control to another task and pre cisely where it will regain control This technique requires no special knowledge of the system s hardware It is necessary however to know how it han dles low level I O
256. tion Since LIMBO uses two such motor wheel combos each will contribute 21 2 oz of force for a total of 42 4 oz or 2 65 Ibs It looks as if our motors are more than adequate To be sure we need to make the same series of calculations using the Running Torque which is less than the holding torque after all we do want LIMBO to move around A few strokes of the calculator will reveal that the force produced by the two wheels acting under this torque is 28 oz or 1 75 lbs which still gives us plenty of margin Training Wheels Ive found injection molded plastic training wheels work best for maze robots especially young robots These are available in any K Mart for under 8 a pair so you don t have to steal from your kid s bike The utility wheels nor mally sold in hardware stores and gar den supply centers are too big the small est are usually 6 dia and have ball bearings which make it impossible to Figure 2 LIMBO Subsystems Flux gate Compass Bumper Skirt 1 Bumper contact sensor array 2 Battery power supply 3 Drive system 4 Flux gate magnetometer compass 5 Infrared range finder array 6 Status console 7 Controller Since this is a computer oriented ma gazine you may think it odd that I list the controller last Surely the controlling intelligence of the robot should be first on the list I purposely leave the controller until last because it among all the subsyst
257. told the guy there was no PostScript header Are you sure your printer is connected to the computer Dumb dumb dumb dumb Sandy finally discovered how to get the program to speak PostScript there s an additional carefully hidden menu not documented by man or manual But the program still didn t run dependably until she selected the default printer port rather than specifying LPT1 Seems that the program sends a reset to the printer after each page if you specify a port from their menu Now the program works though it still occasion ally paints random jagged lines across the screen Despite these initial frustrations Sandy really likes the pro gram She s liked ail the previous incarnations of SuperCalc Plus the graphics generated by this version jaggies aside are pretty incredible Cheap Logic Analyzer Larry had spent a week on and off trying to debug our disk copier It s a custom copier designed around the Z80 based Little Board The copier has worked well In fact out side of needing a new set of drives occasionally it s been flaw less Flawless that is until a few weeks ago After Larry had spent his week he decided it was time to take a vacation On the way out the door he reminded me that someone really had to fix the copier Larry had checked supply voltages they were fine He had also substituted another supply just to make sure No change He had disconnected ihe drives io see if one might be
258. ts of these medications are minimized So companies have removed or re duced some chemicals salt caffeine sugar and saccharin and in their place added a new one I think the new warn ing label should read Warning The Surgeon General has determined that this product contains a powerful mood altering chemical Allyn R Franklin M A M B A 6275 Canterbury Dr 204 Culver City CA 90230 Editor s note Boy put a message like that on all the diet pop and you d double the consumption by teenagers MICRO CORNUCOPIA 48 July August 1989 59 Anthony Barcellos P O Box 2249 Davis CA 95617 2249 Voice 916 756 4866 Data 916 758 1002 Tony describes a file handling utility a text edi tor and the latest in the ARC wars Speaking of ARC you might want to zip right down to the end of this column lar microcomputer operating system in the known universe it doesn t get much respect Often called a mere file loader or a CP M clone CP M DOS continues to frustrate users Almost everyone has advice for Bill Gates and company on what is wrong with DOS but few actually do something about it This time Ill talk about two examples Both address DOS s limitations in file handling and text editing A Ithough MS DOS may be the most popu Helpware s Director 1 0 Dan Baumbach created the Director file management utility because he was dissatisfied with DOS s file handling abilities an
259. tually exclusive In fact if you put them to gether you get an interesting balance Books Now for some light and not so light reading The book that got me started in this search is The Magic Of Conflict I know it doesn t sound very interesting but the sub title snagged me Turning A Life Of Work Into A Work Of Art Author Thomas Crum thinks of life as a playground espe cially when you re doing what you should be doing It s really about feeling good about yourself I found this a most readable and fascinating book Keep it at your bench The Magic Of Conflict By Thomas F Crum Touchstone Press 252 pages 9 95 paperback ISBN 0 671 66836 6 Another paperback The Tao of Physics provides an over view of the connection between Eastern philosophy and West ern science This is an interesting book and a good one to begin Around the Bend with if you re not ready to feel good about yourself Unfor tunately I found Fritjof Capra s writing a bit cumbersome Pre pare yourself to work at this one He s probably never written an editorial The Tao Of Physics By Fritjof Capra Bantam 346 pages 4 95 paperback ISBN 0 553 26379 X Of course I have to include three other authors Carl Sagan Carlos Castaneda the adventures of Don Juan and Richard Bach Jonathan Livingston Seagull is his classic These authors aren t particularly metaphysical just interesting thinkers and excellent writers And For
260. u must be product oriented Every moment must be spent on product improvement and sales Every dollar must be spent to improve sales Every minute during the day I ask myself Townsend s question he res cued AVIS in the sixties If you re not doing it for fun or profit then what the hell are you doing it for As for incorporating your business it doesn t help your profits so don t worry about it Worry about making your bus iness real Create a good product If you were starting over I absolutely would not do royalty work unless the publisher committed to marketing my software Also the pub lisher would have to guarantee to spend at least three times my guaranteed roy alties on advertising I had to learn for myself never to take anyone else s money If you do the business is not really yours even when you do all the work I learned my lesson quickly and even got some cash out of the deal Life is full of lessons You can learn from them or repeat them If you re smart you ll even learn from other people s lessons Good Luck Around the Bend Great idea Except She would be limited to that word processor and that database package If they could find the monitor there d be no limi tations She d be able to use any word processor any database package any spreadsheet any game and anything else that the rest of us use As far as the computer world was concerned she wouldn t be handicappe
261. uirements isreducible to an integer expressible as a terminating deci mal fraction expressible by a non terminating fraction of which one or more figures repeat themselves peri odically without end Any integer fractions like 53 8 or decimals like 3 923076923076 qualify as rational numbers The number pi 3 1416 and the square root of 2 1 144213 for ex amples do not x 0 999999999949 _ x 2 0000445744E 11 5x 8 0001782974E 11 x 0 00000000032000713187 x 0 0000000012800285271 55 x 0 0000000051201141017 x 0 000000020480456302 5 x 0 000000081921823531 x 0 00000032768726728 x 0 0000013107486396 x 0 0000052429876861 x 0 000020971840789 x 0 000083885603883 x 0 00033551426835 0 x 0 0013416067941 x 0 0053592275413 x 0 021322024886 x 0 083469584563 x 0 30600965206 x 0 84947097963 _ x 0 51148013759 Now consider how a computer repre sents real numbers In normalized scien tific notation a real number is repre sented by a sien or and a fraction multiplied by 10 Realx 4 F 10 In binary or computer terms this becomes Realx F 2 Using 48 bits we might represent a real as sign of real number 1 bit normalized mantissa 32 bits sign of exponent 1 bit exponent 14 bits total 48 bits This is how Turbo Pascal does it The representation varies among sys tems depending on memory and other c
262. ule presents some often overlooked ideas MS DOS provides four INT 0x21 services for directory searches Services 0x11 and 0x12 are outmoded file control block FCB functions They appear com plicated and restricted when compared to the recommended Ox4E and Ox4F services introduced in MS DOS v2 x Services 0x11 and 0x12 force you to load an FCB with file information In versions of MS DOS prior to 3 0 they do not support the wildcard character Services Ox4E and 0x4F use a file specifi cation stored in a standard NUL termi nated C type string and fully support the standard wildcard characters Service 0x4E known as FIND FIRST sets up the directory search and retrieves information on the first file if any which matches the given specification Subsequent calls to service 0x4F entitled FIND NEXT will return data on addi tional files which match the specifica tion A location known as the data transfer address DTA holds the data on the file The initial location of the DTA is at off set 0x80 within the PSP of the present program Service Ox2F called GET DTA retrieves the current address of the DTA and service 0x1A named SET DTA sets the DTA to a new address While it is possible to use the default DTA it s better to create a buffer and set the DTA to point to it This lets you de fine a structure for the incoming infor mation and also prevents conflicts with other MS DOS services which may be using
263. unt Scott Ladd Laine Stump Advertising amp Distribution Jeff Hopper Accounting Sandy Thompson Order Department Tammy Westfall Graphic Design Carol Steffy MICRO CORNUCOPIA ISSN 0747 587X is published bi monthly for 18 per year by Micro Cornucopia Inc 155 NW Hawthorne Bend OR 97701 Second class postage paid at Bend OR and additional mailing offices POSTMASTER Send address changes to MICRO CORNUCOPIA PO Box 223 Bend OR 97709 SUBSCRIPTION RATES 1 yr 6 issues 18 00 2 yr 12 issues 34 00 3 yr 18 issues 48 00 1 yr Canada amp Mexico 26 00 1 yr Other foreign surface 36 00 1 yr Foreign airmail 50 00 Make all orders payable in U S funds on a USS bank please CHANGE OF ADDRESS Please send your old label and new address to MICRO CORNUCOPIA P O Box 223 Bend Oregon 97709 CUSTOMER SERVICE For orders and subscription problems call 503 382 8048 9 am to 5 pm Pacific time M F TECHNICAL ASSISTANCE For help call 503 382 8048 9 am to noon Pacific time M F BBS 24 hrs 300 1200 2400 baud l 8 Bits No Parity 1 Stop Bit 503 382 7643 Copyright 1989 by Micro Cornucopia Inc All rights reserved ISSN 0747 587X Audit Bureau of Circulations 4 MICRO CORNUCOPIA 48 July August 1989 AROUND THE BEND By David J Thompson No Limits Computers Shouldn t Be Limitations A handicap is a limitation A limitation is a handi cap At least that s the w
264. using modular construction At present over 40 optional stock modules allow you to customize our standard chassis to nearly any requirement Integrand offers high quality advanced design hardware along with applications and technical support all at prices competi tive with imports Why settle for less unut unit HI nnt Rack amp Desk Models Accepts PC XT AT Motherboards and Passive Backplanes Doesn t Look Like IBM Rugged Modular Construction Excellent Air Flow amp Cooling Optional Card Cage Fan Designed to meet FCC 204 Watt Supply UL Recognized 145W amp 85W also available Reasonably Priced Call or write for descriptive brochure and prices 8620 Roosevelt Ave Visalia CA 93291 209 651 1203 TELEX 5106012830 INTEGRAND UD FAX 209 651 1353 We accept Bank Americard VISA and MasterCard IBM PC XT AT trademarks of International Business Machines Drives and computer boards not included 62 MICRO CORNUCOPIA 48 July August 1989 crocomputer business if say you got started after 1981 you might not even know the difference between line edi tors and screen editors EDLIN and its kin require you to specify the line you want to work on and there s no simple cursor movement to get you to the line above or below Full screen editors let you move your cursor around freely and edit where you will OEdit is one of the best known and most popular shareware t
265. ust 1989 93 Micro Cornucopia Back Issues Is There A Gap In Your Info Fill in your Back Issues of Micro C today ISSUE 1 8 81 Power Supply 1 2 PFM PRN 16 pages ISSUE 2 10 81 Parallel Print Driver Drive Motor Control 16 pages ISSUE 3 12 81 4 MHz Mods Configuring Modem 7 Reverse Video Cursor FORTHwords Begins 16 pages ISSUE 4 2 82 Keyboard Translation More 4 MHz Mods Modems Lync and S10s Undoing CP M ERASE 20 pages ISSUE 5 4 82 Two Text Editors Double Density Review 20 pages ISSUE 6 6 82 BBI EPROM Programmer Customize Your Chars Double Density Update 24 pages ISSUE 7 8 82 6 Reviews Of C Adding 6K Of RAM On Your Own Begins 24 pages ISSUE 8 10 82 SOLD OUT ISSUE 9 12 82 BBII EPROM Program Relocating Your CP M Serial Print Driver Big Board Fixes 32 pages ISSUE 10 2 83 ISSUE 11 4 83 SOLD OUT ISSUE 12 6 83 Bringing Up BBII Double Sided Drives for BBI Packet Radio 5 MHz for Kaypro 40 pages ISSUE 13 8 83 CP M Disk Directory More 256K for BBI Mini Front Panel Cheap Fast Modem BBI Printer Interface Kaypro Reverse Video Mod 44 pages ISSUE 14 10 83 BBII Installation The Perfect Terminal BBI Video Size Video Jitter Fix Kaypro Color Graphics Review 48 pages ISSUE 15 12 83 Screen Dump Listing Fixing Serial Ports Playing Adventure Upgrading Kaypro II To 4 Upgrading Kaypro 4 To 8 48 pages ISSUE 16 2 84 Xerox
266. ust figure out that all they had to do was look to 40 4Ah for number of columns and 40 84h for number of rows 1 and for get about all those stupid VGA equip ment checks No Assembly The biggest problem with the cur rent version of ZTCDB anyway is that it is restricted to debugging C programs and C in a limited fashion I tried several different attacks and could never get it to accept an assembly lan guage module No assembly is a big minus for me After all at least two thirds of all my work is in assembly lan guage This is disappointing since it means I will have to keep at least two different debuggers on my machine ZTCDB has already replaced CodeView as my debugger for C pro grams If Zortech makes it compatible with MASM and if CodeView doesn t get off its tail and make some drastic improvements I think I will switch over completely And if they make it support a screen that is 160 columns by 66 lines I might just die of ecstasy Footnote Keep in mind no matter how ad vanced all these hot new debuggers get they can still never replace SYMDEB At least not for me Although I ve been using CodeView for over a year now and ZTCDB for the last month I still use SYMDEB at least as often as the other two together Why Because I can run SYMDEB without giving it a program name to debug I spend a lot of time just looking at interrupt tables and ROM BIOS code and playing with internals The power of
267. ut invalid opcodes It will work on the V20 V30 186 and 286 It won t work as is on the 386 since 66 is a real live opcode With all the hard ware debugging options of the 386 though that shouldn t be much of a problem Of Mice And Me Every year when I leave Istanbul someone wants to buy my mouse Since mice are quite expensive on the local market although rats can be had dirt cheap I know I had a kitchen full of them I am usually willing to oblige I have always bought Logitech mice and have always been happy with them as have the people I sold them to This year when I was packing up to go I was planning on just getting another one of the standard 200 dpi boxy square Logitech mice Then I saw an ad for their new ergonomic model I immediately began to salivate Love those little miceys Miceys what I love to eat I have now used the new Logitech mouse for three weeks and I can say that everything in the ads is true The new shape fits my hand perfectly The ballistic control of mouse movement faster movement causes greater changes in position really works Plac ing the ball further forward gives more fingertip control of the mouse pointer Finally their new punk logo and bone white color give my desk that decadent graffiti esque look we all strive for I think I ll keep this one The same mouse can be plugged into either an RS 232 port or the mouse port of an IBM PS 2 This will never
268. values in succeeding generations is certainly true but not necessarily true because the system is unpredictable It s necessarily true be cause the real number representation of the system is unpredictable creating the conditions as it calculates the conditions it attempts to demonstrate Attempts to untease the problem separate real number errors from what s really happening in the sys tem seem doomed I think since no system is capable of maintaining real number accuracy to an unlimited signif icance And even if it could it would surely encounter at least one irrational number during the process which it would have to round off Chaos theory demonstrates a flaw or error in nonlinear models by using the error to demonstrate it In other words violating the requirement for in dependence or in simpler terms beg ging the question Summa Interestingly enough mathematical demonstrations and representations of chaos have been principally a computer or calculator created phenomenon Try multiplying a few 16 digit reals by hand and you ll see why But even hand derived calculations will eventually suc cumb to an irrational number Also interestingly enough when modelers iterate the logistic equation using R values in the mid range of the equation say 2 to 3 where the range of R is 0 to 4 the results are much more consistent in fact often at equilibria Chaotic behavior is most pronounced near the equ
269. ve me that can generate strange results if you re debug ging floppy disk drivers over the tele phone Our 139 personal version of PC YACC generates two percent of sales yet accounts for eighty percent of the support If I were smart I wouldn t even sell the product but I don t want to lock the students and the little guy out In the future the best innovations will come from the guy in some room somewhere in the middle of nowhere Don t believe Microsoft when they say that gone are the days of opportunity for the little guy this simply isn t true In truth the big guys are terrified of entre preneurs I assume that our customers are smarter than we are you can t fool them We give in expensive or free up grades Almost every suggestion from a cus tomer gets imple mented One thing that bothers me about our industry is what I call pet rock software That s junk software that just sits on people s shelves A lot of people think they can spend three months on a program sell it and rake in the dough Well the joke s on them Remember learned my first lesson venture capitalists are the worst bosses in the world Taking money from them is like taking money from the devil the average software entrepreneur doesn t even pay for his PC let alone make any money Where do you see the company going literally and otherwise in the next few years Abraxas is committed t
270. vel Generally to get one more digit of ac curacy you increased length 10 times It just happened that the 10 rule could al most get four digits it could over part of its range Increasing the length to 18 was just enough to get that precious extra digit Even more exciting NASA had real desktop calculators There were several such machines around Ours were the Fridens About the size of an AT they weighed much more They worked much like the adding machines used for busi nesses only these would multiply and divide as well The keyboard had twelve columns of ten keys each and a carriage like a type writer On the carriage spun numbered wheels You typed a number in by 9 CORRER ya ae pleut i i l i un rpuuum jit eng top y first technical class in college covered slide rules those silent calculators that never left our sides housed as they were in scabbards hanging from our belts punching that s the right word no elec tronics or power assist here one key in each column and then punching the go key To the accompaniment of considerable noise the carriage slewed the wheels spun and in a matter of Decaseconds your answer appeared Division was quite a sight to behold On those few ma t By Jack W Crenshaw Ph D 1220 E Idlewild Ave Tampa FL 33604 chines that could do square roots the noise level rose alarmingly as more and more wheels got into the act Most
271. vents or conditions This of course is at the heart of literature and art and creative thinking but also very easily misleading when trying to solve a prob lem Many things such as astrology psy chic readings Tarot cards etc are test able at least to a degree by objective approaches But this is often overlooked by devotees A classic example is astro logical prediction which in general is flexibly interpreted by the receiver of the prediction This has been repeatedly shown through simple tests give a large group of people their horoscopes except mix up some of them and not others Neither the person distributing the charts nor the recipients know if they have the correct one Repeatedly tests like these have shown that those with the wrong charts have found their charts true as often as those with the correct charts A re cent study in Germany in which the personality profiles of more than 2 500 people were statistically compared with their full horoscopes not just sun signs failed to show a statistically sig nificant correlation This test inciden tally was performed by an astrologer in an attempt to provide scientific valida tion for his beliefs This same result often accompanies Tarot and other psychic readings ex cept that here the personal feedback be tween reader and subject can strongly enhance the apparent power of the re sult Your anecdote is a prime example The original statement
272. ver 5 times as efficient as the standard BIOS display driver and the BIOS doesn t do windows An MS DOS file system is also available but that is a story for another advertisement Tele is available in the follow ing components Demo Diskette 5 refundable with purchase SK system kernel 50 multitasking CD console display 40 windows requires SK FS file system 40 MS DOS media requires SK Telephone support is freely available The Tele Toolkit is available from Crosby Associates P O Box 248 Sutter Creek California 95685 CALL NOW TO ORDER 209 267 0362 Visa Mastercard American Express amp Discover Card accepted MS DOS is a trademark of Microsoft Corporation Reader Service Number 147 MICRO CORNUCOPIA 48 July August 1989 23 Figure 2 Printer Port Registers VO Address BASE BASE 1 Read Only BASE 2 you can just trust me The software is broken up into func tions receive byte and send byte cre ate receive files and send filesO which are in turn incorporated into main It s straightforward except for the bit twid dling which you ll just have to stare at until it makes sense at least that s what they told me when I was 16 and learning to rebuild the transmission on my MG A problem might arise what if you tell the remote machine to create a file and it can t I ve added one more control line Abort going from the receiver back to the sende
273. ving our environment It sounds like your company is surviving because you ve avoided the traps There s this copying tendency we have as Americans You are rewarded in school for behaving the same To be popular you must dress and act accept ably So when most people start a busi 68 MICRO CORNUCOPIA 48 July August 1989 ness they copy big business A big mis take You must start lean and mean and never leave that path I ve seen small companies spend their first 100 000 in venture capital on furniture Two years later they still don t have a product If you get caught up in your ego and fancy car and all the garbage that goes with being an entrepreneur you will fail The first few years you must work long and hard for no return All things in life are this way Like mountain climbing and martial arts the paths are long but the rewards are great The second reason is lack of patience and commitment There is no quick way to get rich If that s what you want be come an investment banker and steal le gally You must be committed burn your bridges quit your comfortable job Make your business the most important thing second only to the people in your life Many people are afraid to do things alone so they bring a friend We usually spend less time picking a partner than picking a lover but remember partners must spend more time together When the relationship fails the business fails
274. w I knew that somehow someone was trying to execute code at 0 0 The next step was to backtrack and find out why Divide By 0 Exception Location 0 0 is the base of the 80x86 and compatibles interrupt vector table This is an array of long pointers to in terrupt service routines The first entry at 0 0 contains a pointer to the interrupt service routine for a Divide by 0 ex ception When a program attempts to execute a divide instruction with a divi sor of 0 this service gets called On the other hand when a program tries to execute code at 0 0 usually by jumping or calling indirectly through a pointer it ends up interpreting the pointer to the Divide by 0 interrupt service routine as opcodes Obviously this creates complete gibberish Eventu ally the machine works its way into a state which causes some kind of excep tion Usually in the process the proces sor obliterates all evidence of where it s been MAE T Copp V MITER SV ieee ere am back at the threshold of Anatolia again Time to unpack my bags and make sure the Bactine didn t leak all over the PostScript books Simple enough since 0 0 contains the least significant byte of the interrupt handler address So we put an ORG xx66h just before the start of the Divide by 0 handler Now we can report both a Divide by 0 and an attempt to execute at 0 0 A potential problem with making our own Divide by 0 trap is that C
275. w in upper case instead of lower case This helps to visually separate the C source code from the assembly lan guage it was compiled into Something completely missing from ZTCDB is the ability for a breakpoint to trigger execution of a list of debugger commands CodeView makes this avail able and it can be very useful And I like CodeView s register dis play format much better Those are just details though I can live without them I guess My first real complaint as with al most every program on the market is a lack of TRUE support for large screens ZTCDB does handle 43 line EGA and 50 line VGA displays but it doesn t know what to do with a 66 line display I was able to fool it into thinking that my 34010 Mono board was a VGA and got 50 lines out of it But then it kept switching back to 25 lines every time I stepped through a DOS or BIOS call This doesn t happen with a real VGA though Tracing through ZTCDP s code I was debugging ZTCDB with SYMDEB but that s another story I also noticed that a screen width of 80 columns is hardcoded into several places That means that I can t use the right half of my new double page monitor on the new 34010 Mono II board I shouldn t complain about this too much since neither Earl nor I could coax CodeView to do anything over 25 lines reliably Someday developers will all have huge displays then program mers will write programs to run on huge displays If they would j
276. we have to write our own functions for multi directory file searches With all this in mind I wrote FILESRCH FILESRCH H see Figure 1 is the header containing data definitions Continued on page 54 SK DOS A 68000 68020 DOS containing everything you expect in a DOS on line help multiple directories floppy and hard disk support RAM disk and or disk cache I O redirection and more Supplied with editor assemb ler Basic powerful utilities Supported by Users Group and BBS Software available from other vendors includes C compiler Basic editors dis assemblers cross assemb lers text formatter communica tions programs etc Priced at 165 with configuration kit less if already configured for your system HARDWARE 68xxx systems start at 200 Call or write Star K software Systems Corp P O Box 209 Mt Kisco NY 10549 914 241 0287 Fax 914 241 8607 Reader Service Number 40 52 MICRO CORNUCOPIA 48 July August 1989 8280 Clairemont Mesa Blvd Suite 117 San Diego California 92111 619 569 1864 ELGAR UNINTERRUPTIBLE POWER SUPPLIES 400 Watt MODEL IPS400 650 Power distribution center and sine wave UPS Only 2 high 560 Watt MODEL IPS560 350 Sinewave 560W complete with batteries 400 Watt MODEL SPR401 180 Supplies may have minor cosmetic damage but are electrically sound Squarewave output Run on inter ERAC CO AT BA
277. y August 1989 25 Figure 3 Make File for PXFER EXE PPXFER EXE transfers files between computers via parallel ports using a special cable configuration Copyright Bruce Eckel For non commercial use only C o0bj tcc IC TURBOC c c ppxfer exe ppxfer obj block obj tcc LC TURBOC eppxfer ppxfer obj block obj ppxfer obj ppxfer c ppxfer h block obj block c ppxfer h print print ppxfer h block c ppxfer c Figure 4 PPXFER H define MASM comment this if you don t own masm define TIME program generates timing information Base addr for my modified parallel printer card tdefine SPECIAL 0x270 define LPT1 define LPT2 define HERC Ox3bc define MGA HERC define BASE SPECIAL typedef unsigned char dbyte define ATTN 27 attention character escape define LDELIMIT left delimiter for cntrl msgs define RDELIMIT right delimiter for cntrl msgs define BUFSIZE 1000 ifdef MASM assembly language routines in block c These send blocks of dbytes quickly for fast file transfers Send a block of dbytes Send count dbytes located in buffer void send block dbyte buffer unsigned int count Receive exactly count dbytes place in buffer void receive block dbyte buffer unsigned int count endif MASM Figure 5 PXFER C include lt io h gt include lt stdio h gt include lt string h gt include fcntl h include lt
278. y standard largely because of the wide range of software packages and hardware device drivers that support it ZSoft Corporation originally de veloped the PCX format for its PC Paint brush family of products Most desktop publishing programs such as Aldus PageMaker and Xerox Ventura paint and scanning software fax boards clip art and file conversion programs can read it Although ZSoft makes the format of PCX images known developers like myself have had to start from scratch when writing PCX routines So you won t have to reinvent the wheel I developed a PCX toolkit which allows you to manipulate PCX images from within almost any program While developing the toolkit I uncovered some interesting information about PCX im ages which I d like to share the PC world there s a plethora of Some History Mark Zachmann ZSoft s founder and president invented PCX and PCC He chose the name PCX because it sounded like PICTURE In early development PCX was an uncompressed format But at the eleventh hour as ZSoft was about to release PC Paintbrush 1 0 in 1983 Zachmann decided to adopt a run length compression algorithm The extension PCC designated a cutout smaller than the screen file When Zachmann decided to implement his compression algorithm he intended to only compress PCX images Eventu ally he compressed both and PCC and PCX images are now in the same format Since then the PCX fo

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