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COSMAC Elf 2000 User`s Manual

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5. POST Description 99 Basic CPU checks 98 Calculating EPROM checksum 97 EPROM checksum wrong 89 sizing SRAM 88 SRAM size wrong no monitor data page 87 Testing SRAM key 86 Monitor data page failure bad SRAM 85 Clearing memory 84 Initializing monitor data page 76 NVR RTC initialization 75 RTC clock not ticking 74 RTC battery fail 69 UART Reset 68 UART initialization 67 UART loop back failure waiting for THRE set and DR clear 66 UART loop back failure THRE won t clear 65 UART loop back failure waiting for DR set 64 UART loop back failure wrong data 63 UART loop back failure waiting for THRE set and DR clear 59 PPI control register failure 58 PPI data bus failure 57 PPI address bus failure 54 Testing for GPIO PS 2 keyboard APU 53 Waiting for PS 2 APU version 52 No PS 2 keyboard attached 40 Initializing SCRT 39 CRTC status register test 38 CRTC command error test 37 Initialize video frame buffer 36 Enable video interrupts 35 No video DMA 34 No video end of frame interrupt 18 Console terminal failure or polarity wrong 17 Special CHM bootstrap mode 16 Waiting for auto baud 15 Printing system sign on message 14 Initializing master IDE drive 13 Initializing slave IDE drive 12 Printing date time 11 Auto restart 10 Auto boot OF 01 Used by EIfOS 00 startup completed 10 1 2006 4 23 PM Page 93 Spare Time Giz
6. MANUFACTURER ei ae SUPPLIER aan DESCRIPTION RESISTORS R1 Anchor 10M ohm 1 8W 5 carbon resistor RP1 RP2 Anchor 10K x 9 10 pin SIP CAPACITORS C1 C11 C12 C12 C14 C15 C16 C20 Anchor 0 1uF ceramic monolithic bypass capacitor 0 1 LS C2 Anchor 10uF 6V tantalum capacitor C3 C4 Anchor 22pF ceramic monolithic capacitor SEMICONDUCTORS D1 1N4734 Anchor 5 6V 1W DO 41 Zener diode D2 D6 1N914 Anchor Small signal switching diode DISP1 2 Dialight 555 4403 Digi Key 350 1371 Quad LED indicator with integral resistors U1 Intersil CDP1802ACD3 STG 8 bit microprocessor U2 27C256 Anchor 32K 8 bit EPROM U3 Hitachi HM62256LP Digi Key 32K 8 bit low power SRAM 150ns U4 U6 74HC373 Anchor Octal D Latches U5 Dallas 05123377 JDR 5V 10 TO 92 EconoReset U7 Atmel ATF22V10CQZ Digi Key Flash GAL quarter power U8 Dallas DS275 Digi Key RS 232 transceiver U9 Dallas DS1210 Digi Key Nonvolatile SRAM controller MISCELLANEOUS Y1 Anchor 3 000 MHz HC18 crystal 1 CR1225 Mouser Lithium coin cell 27 Don t use the DS1233M 10 1 2006 4 23 PM Page 101 Spare Time Gizmos COSMAC Elf 2000 User s Manual m ES MANUFACTURER oL SUPPLIER OE DESCRIPTION BH1225 Digi Key 500K 1225 coin cell holder PB1 Panasonic EVQ PADOS5R Digi Key P10890S PCB mount push button switch J1 CommConn 1184 24G2 24 pin dual row
7. Donee 5 2 3 OPTIONAL 5 5 5 5 88 4 7 2 4 SOCKETS AND tris eren rie rene sese tres ren 9 2 5 ASSEMBEY FINTS ee idee 10 2 6 eee 10 2 7 CC 12 2 8 MOUNTING RAILS ea ae 14 2 9 Fal AES E eio ERRORI 14 3 HARDWARE DESCRIPTION cel abel 16 3 1 GONNEGTORS cond aa ee 16 3 2 NIU 5 RT 17 3 3 BOOTSTRAP b ox um unt a ene enero ae 19 3 4 RECONFIGURING THE 6 s ese terere 19 3 5 cc 20 4 SOFTWARE ree er 21 4 1 MONITOR EEAT RES 06 42425 01 244210 221220061 0 50 4122644844242 21 4 2 SETTING THE JUMPERS FOR THE MONITOR 0 21 POWER ON SELF 22 4 4 SERIAL GONSOLE AUTO
8. MANUFACTURER oS SUPPLIER DESCRIPTION D4 Dialight 555 2301 Digi Key Green 2mm LED right angle PCB mount U1 Atmel ATF22V10CQZ Digi Key Flash GAL quarter power U2 74HC245 Anchor Octal bus transceivers U3 74 174 Anchor Hex D flip flops w clear U4 Dallas DS12887A Jameco Nonvolatile RAM and Real Time Clock U5 Maxim MAX232 Anchor RS232 Line Driver Receiver U6 unused U7 16C450 Anchor Asynchronous Communication Element UART U8 74 04 Hex Inverter MISCELLANEOUS Y1 Anchor 2 4576Mhz HC 18 crystal J1 CommConn 1184 24G STG 24 pin stacking bus connector J2 GC Waldom 53856 5010 Digi key WM18505 CF connector SMT right angle top mount J3 Anchor DB9M DB9 male PCB mount J4 Anchor 40 pin 0 1 shrouded header IDE Anchor DIP16 machined pin IC socket Anchor DIP20 machined pin IC socket 0 300 Anchor DIP24 machined pin IC socket 0 300 Anchor DIP24 machined pin IC socket 0 600 Anchor DIP40 machined pin IC socket JP1 JP5 Anchor 2 pin 0 1 header jumper Anchor Shorting plugs STG ELFDISK 1B Printed circuit board Table 44 Disk UART RTC NVR Parts List 26 You can also use the Dialight 555 2303 LED this LED has an integral dropping resistor for operation on 5V If you use the 2303 LED replace resistor R2 with a wire link 10 1 2006 4 23 PM Page 100 Spare Time Gizmos Embedded Elf Parts List COSMAC Elf 2000 User s Manual
9. 31 5 10 SHOW COMMANDS n acuta ecce erat siet 31 5 11 SET COMMANDS 34 5 142 COMMANDS eure 35 tual eet paa Neha 36 Mc adt 36 5 15 LOADING INTEL HEX 36 TIN EPICURI NCC ERU MODO IO VENERE 36 6 EDITOR AND 5 lt reser rest esee sire 39 6 1 EDITOR 39 6 2 ASSEMBLER LINE FORMAT 0 000000 10 39 6 3 EE E E 40 ad aS ta Rt Eek ah 41 7 1 INTRODUGTION te ea eese dah sas 41 7 2 ENTERING 65 4114 214 rese rine rese rine sisse rsen renun 41 7 3 EXPRESSIONS ee sie oes uiii 43 7 4 5 52 e ERR EE 44 CONTENTS 7 5 PROGRAM STATEMENTS hiet 46 7 6 AD
10. 67 10 2 lt elt e LEE E oO VE v go 12010251 67 10 3 INSTALLATION 5 t eec cete ne 68 10 4 PROGRAMMER S 40 0 68 11 THE DISK EXPANSION 0000000 0 000 69 11 1 25502554 69 17 27 ASSEMBLY A bee EN Ed ee Re de 69 14532 INSTALLATION NERA solid Leia Nash 70 11 25 5 JUMPERISETTINGS est fi 71 11 52 PROGRAMMER S REFERENGE head 72 11 6 PROGRAMMING TIPS AND 8 2 4 8 74 12 THEM T1802 VIDEO BOARD iA 77 12 1 77 12 2 ASSEMBLY 5 77 12 3 INSTALEATION AND SETUP de ula 78 12 47 VIDEO TIMING its ct
11. Dur es MANUFACTURER ie SUPPLIER Rec DESCRIPTION RESISTORS R1 Anchor 330 ohm 1 8W 5 carbon resistor R2 R3 R4 Anchor 4 7K ohm 1 8W 5 carbon resistor R5 Anchor 470K ohm 1 8W 5 carbon resistor R6 R7 Anchor 10K ohm 1 8W 5 carbon resistor CAPACITORS C1 C2 Anchor 22pF ceramic monolithic capacitor C3 Anchor 0 0022uF Mylar capacitor C5 47uF 6V tantalum capacitor C13 Anchor 3 3uF 16V aluminum electrolytic capacitor 6 11 0 1uF ceramic monolithic bypass capacitor 0 1 LS SEMICONDUCTORS D1 D2 1N914 Anchor Small signal switching diode U1 Atmel 89C2051 Digi Key Microprocessor U2 U4 74 245 Anchor Octal bus transceivers U3 Intel 82C55A Jameco 52425 CMOS Programmable Peripheral Interface 5 2 U5 Atmel ATF22V10CQZ Digi Key Flash GAL quarter power U6 Atmel ATF16V8CQZ Digi Key Flash GAL quarter power U7 Intersil 7555 Anchor CMOS Timer MISCELLANEOUS 10 1 2006 4 23 PM Page 104 Spare Time Gizmos COSMAC Elf 2000 User s Manual poets n us MANUFACTURER SUPPLIER DESCRIPTION LED1 Dialight 555 2301 Digi Key Green 2mm LED right angle PCB mount F1 F2 Littelfuse 473 500 Digi Key F1200CT 0 5A picofuse SP1 PCB mount dynamic speaker Y1 Anchor 11 0592MHz HC18 crystal J1 CommConn 1184 24G2 24 pin dual row stacking header J2 Cui Stack MD 60SM Digi Key CP 2260 6 pin female right angle PCB mount DIN connector J3 Anchor
12. 242416 22423 22 4 5 VIDEO CONSOLE EMULATION 12 23 4 6 MONITOR DATA 5 5 23 4 7 STARTUP OPTIONS 24 4 8 USING THE MONITOR BREAKPOINT FEATURE 0 1 24 4 9 CROSS ASSEMBLING AND DOWNLOADING 65 6 25 5 MONITOR COMMAND EREFERENGE Lewes 29 5 1 GOMMAND REFERENGE 29 e i 29 5 3 BAS IC ASM AND aa pen cesis teorie reti cat entrent ete art ate 29 54 lt ADDR gt AND RUN ADDR e tetti 30 DS e o E DER CORN 30 5 6 E XAMINE lt ADDR gt E XAMINE lt gt lt gt 21 30 5 7 D EPOSIT lt ADDR gt lt DATA gt lt gt sada van 31 5 8 IN PUT snae mute da ara 31 5 9 OUTPUT SPORT
13. 80 1225 5 80 12 60 ESCAPE SEQUENGES 5 81 13 m 84 13 1 INTRODUCTION scares ace duns satiate deat conan tae 84 9 2 AS SEMBE AE o tah cos 84 INSTALLATION cota 85 13 45 JUMPER SETTINGS 2 et vote e ec deeem 85 13 5 5 cd oot oce erae oes d ae 85 AC AINSTAUEING EEO S34 ci tne eet eas tan ce ican ie ere eae Nash Gece Cort acute a sla a 89 Bis POST CODES e D M eia ane rta 93 C2 PARTS LIST n 6 ema Menara teo eU ants ool Naser ees ea 94 SWITCH PANEL ARTWORK a 107 E RESOURCES AND 109 Fis S SCHEMATICS 1 oin A VILLE 110 Page ii Spare Time Gizmos COSMAC Elf 2000 User s Manual 1 OVERVIEW The Spare Time Gizmos COSMAC Elf 2000 is a reproduction of the original COSMAC EIf as published in the pages of Popular Electronics magazine August 1976 Although we tried to keep the look and feel of the original we had no hesitation about updating the Elf 2000 with the latest in hard
14. suffix indicates a special version of the DS1233 which has the same pin out as some Motorola parts and because of the different pin out the DS1233M cannot be used directly in the EIf 2000 Electrically the DS1233 and DS1233M are identical so it should be possible to use the M version if you twist the pins around to fit the PC board 2 3 OPTIONAL SUBSYSTEMS Many subsystems of the EIf 2000 are optional and may be omitted without affecting the function of the remaining parts In some cases when optional subsystems are omitted special jumpers or connections may be required to enable the rest of the logic to continue functioning This section discusses the optional subsystems in the Elf 2000 and how to safely remove them You may also want to consider the option of building your first EIf with one or more of these subsystems omitted to save both money and time In this case you can always go back and add the missing parts at any time 2 3 4 Video CDP1861 Pixie If you don t want video from your Elf 2000 you can safely omit U2 CDP1861 D2 R2 R3 R4 J1 and jumpers JP1 JP7 and JP8 To disable video temporarily but leave the hardware installed simply remove jumpers JP1 JP7 and JP8 see section 3 2 1 2 3 2 EPROM You may omit the EPROM U3 so long as you also remove jumper JP4 In this case the CPU will always start executing from address 0x0000 after RESET and you ll need to ensure that the SRAM contains valid data at that
15. 002 2 LHOTYAdOD 3jIXId el 1n Jn g 40170 sata 1 2 1 21 13534 SOA ran a INI fen 5 lt V 10 1 02 2 el 440 4610 ONASA 11 NO 4516 vi fe 1041 02 lt 7 038131 21 90 1 02 10 801415 dSId d 6 2 lt 110 a 1 1 INAS 4403 8I 2 118 Hal f EUM 56 alles 910 4 1 174614 02 3 NO 610 12 5 lt lt 81 17 Ze 9 ce 2 SIRE d 28 vid n E 13535 6 1 gad lt ee 005 91 11 1 a 1 52 21d lt 81 17 en 00 lt en 85 ees 42032H Ska 338VN3 O3QIA _ QNIWIL INIT 440 510 43161934 A 1 x5 DINER P igi lt j 22 ONASH e dE a Sate O30I 6 JE 31157 511 15 4610 lt 6 COW LI 16 8107 8 lt 7 19539 194 8107 1 lt a E 024 ge 9 lt 03014 7 O3HVL re S 8 1041 02 lt gr vet 4216 ly V TONLNOS Ch INAS 11 aie 5 Yas Te 43H ONAS 52 avo lt 8 17 2 2 dd APAM 52 134 ONAS So REP 42012d 01 2231 Pam a E G O3HINI 1 320129 E E SST OHPL 1 934741 20 E en Ge K 20124 FS I 2 7 S 9 i 8
16. 10 1 2006 4 23 PM Page 19 Spare Time Gizmos COSMAC Elf 2000 User s Manual For example suppose you wanted to change the I O address for the switch register from its current default 4 to 3 No problem just reprogram the GAL and it s done Absolutely no wiring changes are required Or maybe your Elf 2000 doesn t have TIL311 displays and you d like to add some extra I O instructions so that the firmware can blink the RUN and or LOAD LEDs Easy just add the new I Os to the GAL and you re done No need to even warm up the soldering iron Or for another example currently the BOOTSTRAP flag is cleared by the first I O any I O after a RESET Suppose you wanted to change the system so that the BOOTSTRAP flag could be cleared only by an I O to a specific port Or maybe you d rather not have it cleared by any I O but instead by the first real memory reference to an address 2 8000 You guessed it just reprogram the GAL Or for one more example currently SRAM is mapped from 0000 to 7FFF and EPROM from 8000 to FFFF Suppose you wanted to change that around Yep no problem just reprogram the GAL If you have a particular piece of software that you want to run on your EIf 2000 then the GAL gives you tremendous flexibility in changing the hardware configuration to accommodate the software all without changing a single wire 3 5 SERIAL PORT The DS275 chip used in the Elf 2000 provides true EIA i e 15V si
17. RUN A BC 10 PRINT A 20 PRINT B RUN A B 10 PRINT A 20 PRINT B RUN AB 10 PRINT A 20 PRINT B RUN A B 7 5 17 RANDOM This statement allows the random number generator to be reseeded The user will be prompted for a value to reseed the generator with The same seed value will always generate the same string of random numbers 10 1 2006 4 23 PM Page 51 Spare Time Gizmos COSMAC Elf 2000 User s Manual 7 5 18 READ variable variable variable The READ statement will read values from the current DATA pointer into the specified variables It is not necessary to match the number of variables in the READ list to a specific DATA statement For all practical purposes it does not matter how many DATA statements the data is spread over it is all considered linear to the READ statement If an attempt to read a data element beyond the last DATA statement is made then an error 9 will occur The READ DATA set of statements makes it easy to initialize variables For example 10 DATA 5 10 15 20 25 30 20 READ A B C 30 PRINT A B C 40 READ A B 50 PRINT A B 60 READ A 70 PRINT A 80 READ A RUN 5 10 15 20 25 30 ERROR 9 in line 80 7 5 19 REM remarks This statement marks everything else on the same line as being a remark Remarks are ignored by BASIC and program execution will continue with the next line of the program 7 5 20 RESTORE line The RESTORE command will reset the DATA point
18. an ER xi Tra 80 A s uc rLEN 80 2 1 g er Tubs ETE VIGN 72 2 2 1 b er gt Blar ed3 143 1 VION 1 43 1 1 LdnHH31NI x 19 E des s lt I ELA ad H Oxy 4 Ydl 2 21 5 67 ox DG pees axl via 6 lt EA m 8 1 71 PIGNIT 8 16 e er Do OXY i Po IN axa 13 111 6 16 2 lt 250 8 1 T er sn 0 Pii 11 ey ec 51 6 1 777 0 a c 4 el 11 1404 1 3M Ei 6 80 1 4510 viva X79 81 8 TN 2B Sc See 1 NON 52 61 L aN ear S2 y E Sly 1 1 dYNISIO08 1214 lt 1 dvNISI008 42 on CIs ad NOISNVdX3 E H NAY 197 99 I 21 841 in 1 I 2 y T 5 9 CU JO 1 L33HS sna sa 60 11 22 9 S1vi30 X04 3114 3SN3017 01 X343 03A3838 SLHIIE 5 3715 804719 3411 3NVdS AG 9002 2 LHOTYAd 5610 M2413 lt Li 109g ez in SYSA1SOSNVYL sna 79120 84014 4114 g 8Y 88 11 17 35 n 8 e 9d 512 054 51 21121448 es 80 154 21 g pg v08
19. zsa 01 eq Lit 688 S ME esa 112 sq 216 a pigs 154 S p 198 KE salle contin 054 2 t 20406 aaa gai ad 12 5 n V wna be 110 14 2 ES 10 1 10 en 99 2 5018 C Ion dr INI X72 NOTSNVdxX4 1 13 15 OI 8114 1 1 OI 1112 2 lt 1214 S3 8 acis q DAI MSIG 3 2 1 1840 52 6116 L Edt pee 1G 1 4652 02 0 vdl 17 123189 Te bv 1 cau Bp 081 215 5 2 NMOl 22 lt o 9 17 ed 1401 62 pean av A 4 TENI 4197 01 2241 in 11383 S3 12634 1 13634 21 1 7 ue 33 2 3 a 387 2 2 C Hosess ai V2OHvL 38N I c 5 V S V S8 9 2 8 2 13385 90 e enez 2 511 130 3114 35 3211 01 N3434 Q3AN3S34 51 91 01 3715 804719 1 5 002 2 IH9IMAd 5610 M28473 vOOHVL asn A 9 3 ar br 5 QE vn 92 A dd 0 en 133 y E 8I v 38N 2 17281123 1352 mer 01 80 AYO 7 Lav dsvd
20. 230121 ayn A 54014 114 avn c 90 p 26 48 INVI an 0 a 51 10 43102N3 SS we 5 246 AIII dad 28d ae 250 pus Y vA O O Sus ee Sys COS 2 884 vad 686 84d LYS aki 0255349 ei M O 0 Ji ul EX Fg Lad 98d Sad vd 2 ex 0 XT Oc Oc S650 edd 28 184 in EX ZX IX y 4 9 1 e y S 1 8 40 2 13395 e qvaA34 90 4 2 6001 2 611 130 504 3114 39N3211 Ol N343M T3ANJS3M SIH9IM Lave 1081 02 3718 504719 AWIL 3HNVdS AG 2 2 IH9INAdOO IVdA3M A 251 1 338 3 2t d338A34 7 dW 13538 1 4 01 1353s AN 21 EI angr eid vy 1 13934 135 0 2 4v 810 cid 527 7 d338A3M A 112 13534 3 _ ES gt Rein a 4 01 13534 1 dW ITA gt 1 al 13534 13538 6 gt N d338A3M H d31 dH QUA 610 8 1187 dW 13538 gt FEN sa S x qvO 135 gt 080184 1 11534 135 PISNI IIET 91 18 gt d 2 H NOM L3S3M 9 _ d338434 5 5 lt dW 13538 gt 248 2 7 1 01901 1353 gt 13533894 135
21. 49 7 4 2 CHR numeric expression This function takes the expression and produces a 1 character string that is the ASCII character for the specified expression For example 10 A CHR 65 20 PRINT 5 RUN A 7 4 3 FLG This function will read the four CDP1802 EF inputs and produce a merged result with EF1 1 EF2 2 EF3 4 and EF4 8 For example if EF1 and EF3 were active then FLG would return 5 10 1 2006 4 23 PM Page 44 Spare Time Gizmos COSMAC Elf 2000 User s Manual 1 44 FRE This FRE function allows you to determine how much memory is left To be more precise it returns the memory that is above program variable space and below the stack heap space For example PRINT FRE 16274 7 4 55 INP port This function will read the specified input port and return the result The Port number argument must be between 1 and 7 Note that carelessly reading the wrong port may crash your Elf 2000 7 4 6 LEFT string expression length This function will return the specified number of characters on the left side of the specified string expression For example PRINT LEFTS ABCDEFG 3 ABC 7 4 7 LEN string expression This function will return the length of the given string expression For example PRINT LEN ABCD 4 7 4 8 MID string expression start position length This function will extract the middle portion of a string expression The resulting string will start at the specified positi
22. 5 BIOS Copyright 2004 by Mike Riley For help type HELP gt gt gt If the LEDs stop counting at some number before 16 then refer to section 4 3 Power On Self Test POST for help in diagnosing the problem 5 A PC running terminal emulation software e g KERMIT or HyperTerm works fine T Many of the numbers in this sequence including the 99 go by so fast that you can t see them 10 1 2006 4 23 PM Page 15 Spare Time Gizmos COSMAC Elf 2000 User s Manual 3 HARDWARE DESCRIPTION 3 1 CONNECTORS 3 1 4 Power J2 is the main power connector It is a standard 2 1mm ID 5 5mm long coaxial power connector and the center conductor is positive Diode D5 protects against accidental reverse polarity Using a standard 7805 regulator for VR1 the applied power may be anywhere from 9 to 12VDC Use care when applying voltages higher than 12V not to exceed the power dissipation limits of VR1 A fully populated Elf 2000 including all six TIL311 displays and the STG1861 video chip substitute uses approximately 600 Removing the six LED displays and the STG1861 will reduce the current requirements to only about 100mA 3 1 2 Console J4 is a standard DB9 female connector The wiring of this DE9F is such that it can connect directly to a standard PC serial port which uses a DB9 9 pin male connector using a straight thru i e not a null modem cable Note that only TXD RXD and ground are connected Pin
23. 8 INPUT NC to pin 20 GND Since J5 is not needed if you aren t installing a switch panel or keypad you can solder these two jumpers directly to the pads reserved for J5 These two jumpers ensure that the INPUT and LOAD signals remain inactive at all times You may find that your Elf 2000 runs without them but it s not recommended You may also wish to jumper J5 pins 3 5 7 9 11 13 15 and 17 to ground as well pin 12 will do this will ensure that an INP 4 instruction always reads all zero bits however this is not really necessary Of course if you do this you ll also need to keep U14 as well Another tip if you want to use your Elf 2000 sometimes with a switch panel keypad and sometimes without then go ahead and install the header for J5 anyway When you are using the EIf without a keypad you can use a wire wrap tool to jumper the necessary pins and then later remove the wire when you want to connect a switch panel 2 3 5 Address Display To delete the address display omit DISP1 thru 4 and also U12 Note that U13 is still required 2 3 6 Data Display To delete the data display omit DISP5 6 and U13 Before you decide that you don t need the data display remember that the power on self test in the standard EPROM software uses the data display to show test results 2 3 7 RS 232 Port If you don t want the onboard RS 232 port if for example you have a UART on an I O expansion daughter board then you can s
24. 8 and 8 design rules which means that the traces are only 8 mils that s 0 008 inches wide and in some places there is only 8 mils of air gap between adjacent traces or pads The Elf 2000 is definitely not a learn to solder project if you ve never soldered a board like this before then it d be a good idea to find something cheaper to practice on When it comes to soldering having the proper tools makes all the difference A temperature controlled soldering station with a 30 mil tip will can be purchased for about 100 and will make the job much more pleasant The right solder is important too 63 37 solder is preferable to the traditional 60 40 because it has a slightly lower melting point and requires less heat You should not be using anything larger than 31 mil 0 031 inch diameter solder And finally you ll want a nice pair of wire cutters for trimming the leads on components after you ve soldered them Get the kind that s made for trimming wires on PC boards they have a special cutting face that cuts flush with the PC board without leaving any wire stubs sticking up You ll want to wash the bare PC board before you start soldering to remove any grease or oils from fingerprints If you don t wash them off these oils will make the solder take longer to flow and will require more heat and flux to get a good solder joint prefer to use a mildly abrasive cleaner such as a Brillo pad or Comet cleans
25. 23 There is no escape sequence for a normal scroll up operation but it s invoked by the standard ASCII LF line feed code 10 1 2006 4 23 PM Page 81 Spare Time Gizmos COSMAC Elf 2000 User s Manual lt 5 gt lt fac gt Store Field Attribute Code lt gt Store Line Drawing Code Table 30 VT 1802 Extended Escape Sequences The Home Cursor and Erase Screen lt ESC gt E function is equivalent to the two escape sequences lt ESC gt H and lt ESC gt J Home Cursor and Erase to End of Screen The lt ESC gt Q sequence should be followed by a single printing character and the cursor is then moved to the home position and the entire screen is filled with this character The lt ESC gt N sequence stores 8275 field attribute byte into screen memory It should be followed by a single ASCII character the lower six bits of which are the desired field attributes code Field attributes are used to select video features such as blink underline and reverse Table 31 summarizes some of the common 8275 field attribute codes and their corresponding ASCII character for this escape sequence for more complete information refer to the 8275 data sheet lt fac gt Attribute Normal lt space gt Underline P Reverse B Blinking Table 31 Field Attribute Codes Field attribute codes be together to select more than one attribute at the same time
26. C PARTS LIST mos COSMAC Elf 2000 User s Manual Elf 2000 Main Board Parts List id MANUFACTURER SUPPLIER ER DESCRIPTION RESISTORS R1 R5 R6 R7 R8 Anchor 330 ohm 1 8W 596 carbon resistor R2 Anchor 1K ohm 1 8W 5 carbon resistor R3 Anchor 200 ohm 1 8W 5 carbon resistor R4 Anchor 3 3K ohm 1 8W 5 carbon resistor RP1 RP3 Anchor 10K x 9 10 pin SIP RP2 Anchor 10K x 7 8 pin SIP RP4 Anchor 10K x 56 pin SIP CAPACITORS C1 Anchor 1000uF 16V radial lead aluminum electrolytic capacitor C2 Anchor 10uF 6V tantalum capacitor C3 Anchor unused C4 C24 Anchor 0 1uF ceramic monolithic bypass capacitor 0 1 LS SEMICONDUCTORS D2 D3 D4 D6 1N914 Anchor Small signal switching diode D5 1N4001 Anchor power diode D1 unused VR1 7805 Anchor 5 0V fixed output TO 220 regulator U1 Intersil CDP1802ACD3 STG 8 bit microprocessor U2 RCA CDP1861D video co processor U3 270256 Anchor 32K 8 bit EPROM U4 Hitachi HM62256LP Digi Key 32K 8 bit low power SRAM 150ns 10 1 2006 4 23 PM Page 94 Spare Time Gizmos COSMAC Elf 2000 User s Manual bene me ES MANUFACTURER eR SUPPLIER DESCRIPTION U5 Dallas DS1210 Digi Key Nonvolatile SRAM controller U6 74HC373 Anchor Octal D Latches U7 Atmel ATF22V10CQZ Digi Key Flash GAL quarte
27. EXAMINE or BASIC Some commands require one or more parameters usually but not always hexadecimal numbers Parameters are separated from the main command and each other by spaces for example gt gt gt 0 100 If you make mistake while typing command you rub out erase previous characters with the backspace key and you can abort the entire command line by entering CONTROL C Command lines are always terminated with a CR carriage return character In general command names may be abbreviated to their shortest unique length For example you may enter any one of CONT CONTI CONTIN CONTINU or CONTINUE for the CONTINUE command in the following command descriptions this would be shown as to signify this Occasionally some commands allow ambiguous abbreviations for example is always BOOT E is always EXAMINE and is always DEPOSIT 5 2 B oor The BOOT command what else attempts to boot a disk operating system from the primary IDE device gt gt gt BOOT Booting primary IDE Starting 1 05 Ready 5 3 BAS ic ASM AND FOR TH The BASIC command invokes the BASIC interpreter and the ASM and FORTH commands invoke the Editor Assembler and FORTH languages In all three cases simply typing the command and a carriage return invokes the prompt gt gt gt BASIC NEW OR OLD which you should answer
28. Signal 2 TXD 3 RXD 5 GND Table 2 RS 232 Connector 3 1 3 Expansion J3 is a general purpose expansion connector which can be used to connect to one or more daughter boards mounted on top of the Elf 2000 Four mounting holes for 84 40 swage standoffs to support the daughter board are also provided on the Elf 2000 Note that these daughter boards are intended for I O expansion only J3 does not contain any memory address or control signals There s hardly any need since the EIf 2000 already contains 64K of memory Table 3 shows the pin out of the I O expansion header Pin Signal Type Pin Signal Type 1 vcc PWR 2 VCC PWR DO TRE 4 N2 5 D1 TRI 6 N1 7 D2 TRI 8 NO O 9 D3 TRI 10 MRD L 11 D7 TRI 12 EF4 L OD 13 D6 TRI 14 TPA 15 D5 TRI 16 TPB 17 D4 TRI 18 RUN 19 Q 07 20 INTREQ L OD 8 Tri State 10 1 2006 4 23 PM Page 16 Spare Time Gizmos COSMAC Elf 2000 User s Manual Pin Signal Type Pin Signal Type 21 21 OD 22 L 23 GND PWR 24 GND PWR Table 3 I O Expansion Header J3 3 2 JUMPERS 3 2 1 JP1 JP7 and JP8 Jumpers JP1 JP7 and JP8 are used in conjunction with the CDP1861 video generator chip JP7 connects the 1861 DMA REQ to the CPU s DMA OUT input JP8 connects the 1861 INT REQ output to the CPU s INT REQ input and JP1 conne
29. to 7 bit ASCII is checked Click OK here and then click OK again in the elf2k Properties window ASCII Receiving E Play sound when connecting or disconnecting Figure 3 elf2k Properties Be sure to save these settings File gt gt Save so C Append line feeds to incoming line ends that you won t have to do it again next time Once gt 5 you ve completed this setup to send a HEX file to Force deed one 2 the Elf 2000 first be sure that the monitor is ready Wrap lines that exceed terminal width press ENTER and you should receive the gt gt gt prompt and then use Transfer gt gt Send Text File to send the HEX file to the Elf Note that the HyperTerminal Send Text File Dialog defaults to Figure 4 ASCII Setup 10 1 2006 4 23 PM Page 26 Spare Time Gizmos COSMAC Elf 2000 User s Manual showing only TXT files and so to see HEX files you ll have to select All Files from the Files of Type drop down list WARNING Be sure that the HEX file you are sending is in MSDOS text format that is each line ends with both a carriage return and line feed character Files that are in UNIX text format i e lines end with a line feed only and no carriage return will not transmit correctly 10 1 2006 4 23 PM Page 27 Spare Time Gizmos COSMAC Elf 2000 User s Manual 5 MONITOR COMMAND REFERENCE 5 1 COMMAND REFERENCE The Elf 2000 monitor understands simple one word commands such as
30. 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 LAO FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FE 0 FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 9 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FE 00 nnn 100 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF 0 FF 00 FF 00 FF FF 00 FF 00 FF FF 00 FF IFO 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 nn n SEDIT gt Q gt gt gt OO OO OO OO o oo Table 6 summarizes the SEDIT commands IMPORTANT SEDIT currently only understands upper case commands 10 1 2006 4 23 PM Page 36 Spare Time Gizmos COSMAC Elf 2000 User s Manual Command Action L Show Low 256 bytes of loaded sector H Show High 256 bytes of loaded sector Rsect Read specified sector sect is in hex N Load the Next sector P Load the Previous sector D Display current sector number Eofs byte byte Enter bytes into sector at specified offset W Write sector back to disk Aau Load first sector of specified AU Cau Show AU Chain for specified AU Q Quit return to the EIf 2000 monitor Table 6 SEDIT Commands 10 1 2006 4 23 PM Page 37 Spare Time Gizmos COSMAC Elf 2000 User s Manual 6 EDITOR AND ASSEMBLER The Elf 2000 Monitor EPROM contains a simple text editor along with a load and go assembler both
31. Once selected a field attribute continues until the end of the screen unless a Normal attribute is written some where after it Finally note that field attribute codes occupy a character location in screen memory just as do ordinary characters this location will be blanked so that nothing is shown on the screen in that spot but no other character can be written to that location either Field attribute codes can also be used to select one of three alternate character sets in the VT1802 character generator EPROM however the standard character generator supplied by Spare Time Gizmos contains only the default character set You re always welcome to add your own Note that the JP1 2 jumpers see section 12 3 1 on the VT1802 must be set to select the 1 outputs before alternate character sets be used The lt 5 gt write line drawing code sequence works much the same way however instead of a field attribute it stores an 8275 line drawing code The character generator EPROM must be programmed for the 8275 line drawing codes before this option can be used and sadly the default character generator image supplied by Spare Time Gizmos does not support line drawing You are of course welcome to add it Note that the JP1 2 jumpers see section 12 3 1 on the VT1802 must be set to select the LAO 1 outputs before alternate character sets can be used 12 6 3 VT52 Escape Sequences not Supported by the VT1802 Table 32 summarizes the VT52
32. and there is a small beeper that generates a short key beep whenever any key is pressed Photo 4 shows an Elf 2000 keypad assembled by Ken Rother There are three different types of pushbuttons which may be supplied with the keypad kit One has a white insert inside the button one has a gray insert and the last has a red insert Some of the kits are supplied with all white buttons and some supplied with a mix of white and gray or red Since these surplus switches the selection is limited to the supply on hand and Spare Time Gizmos doesn t have enough of any one type to fill all the orders with the same buttons Photo 4 Elf 2000 Keypad All the buttons accept a printed insert for a legend and after you ve installed the insert the button color won t show any more Notice that the gray and red buttons have their pins is a different location than the white buttons The PC board is designed so that each switch position has two sets of pads to accommodate either type of button Also notice that only the white buttons have a hole in the back for a LED or lamp don t use gray or red buttons for any of the five function keys unless you intend to forgo back lighting them 10 1 2006 4 23 PM Page 12 Spare Time Gizmos COSMAC Elf 2000 User s Manual Two tips for installing the legends in the buttons First look closely at the buttons there s a small slot on the side just underneath the top of the cap The sli
33. command ok A 4 CR 5 ok B 4 CR 10 ok A a4 B 8 CR 15 To immediately print the value in a variable you can use the SEE command ok SEE A 5 ok Note that the SEE command provides its own CR LF ok SEE A SEE B 5 10 ok The real power of forth is that it allows you to define your own commands Commands are defined using the command and are terminated with the command Note that Forth requires the entire command to be created in one input cycle Try this one ok STARS O DO 42 EMIT LOOP ok If you look at the WORDS now you will see another new name STARS You can also use the SEE command on functions to see their definitions ok SEE STARS STARS 0 DO 42 EMIT LOOP This command can now be used just like any other forth command ok 5 STARS CR ek ok Custom functions can even be used inside other custom functions ok PYRAMID 1 DO I STARS CR LOOP ok Now run it ok 5 PYRAMID kk kkk 10 1 2006 4 23 62 Spare Time Gizmos COSMAC Elf 2000 User s Manual 8 10 DEFINITIONS OF EXTENDED FUNCTIONS This section reproduces the exact definitions in Forth of course of the extended functions described in section 8 8 1 1 1 2 2 0 2 gt 0 DUP IF 32768 AND 0 ELSE 1 THEN ELSE DROP 0 THEN 0 DUP IF 32768 AND 1 ELSE 0 THEN ELSE DROP 0 THEN gt DUP IF 32768 AND IF 0 ELSE 1 THEN ELSE DROP 0 THEN lt DUP IF 32768 AND IF 1 ELSE
34. execution will resume at the next instruction after the SEP R1 Note that the monitor prints the contents of all sixteen registers after a breakpoint however one more time the values printed for RO and R1 have no significance 10 1 2006 4 23 PM Page 24 Spare Time Gizmos COSMAC Elf 2000 User s Manual Since this break point feature requires some cooperation from your program unlike other more powerful CPUs which can implement a completely transparent break point it s worth while to go over once again the requirements for making it work To use the break point feature your program must gt Not use or care about the contents of RO gt Not change the contents of R1 gt Keep a valid stack pointer R2 gt Ensure that there are at least three free bytes on the R2 stack So long as it meets these conditions your program can contain any number of break points and you ll be able to continue execution of your program after it hits one WARNING The break point feature requires the use of registers RO and R1 which is incompatible with the VT1802 video card If the VT1802 is installed the break point feature and all related commands are disabled 4 9 CROSS ASSEMBLING AND DOWNLOADING PROGRAMS There are several cross assemblers for the 1802 which run on the IBM PC and other systems Two particularly useful examples are TASM and rcasm refer to Appendix E for links to both of these Since the EIf 2000 ROM monitor has
35. started The CALL command invokes the program using the SCRT RCA s standard call and return technique subroutine linkage this effectively makes your machine language program subroutine of the monitor In particular the program counter will be R3 and R4 R5 and R6 will be set up with their usual call return and argument list pointers R2 will point to a valid stack in the monitor s data page A machine language program invoked this way can return to the monitor by executing a SEP i e subroutine return instruction On the other hand the RUN command simulates the action of a hardware reset before invoking the machine language program For programs started with RUN the program counter will be RO and the contents of the other registers will be undefined The only way a machine language program invoked with the RUN command can return control to the monitor is by executing a long branch LBR to address 8000 the monitor s cold start entry point 5 5 CONT INUE The CONTINUE command is used after a break point see section 0 to restore the original CPU state and register contents Execution continues at the next instruction after the break point WARNING Remember that the monitor break point feature does not preserve or restore registers RO or R1 and cannot be used with code that depends on these registers That includes any code that uses interrupts or DMA 5 6 E XAMINE lt ADDR gt AND E XAMINE lt ADDR gt ADD
36. unused YELLOW 15 D1 GREEN 16 RUN RESET BLUE 10 1 2006 4 23 PM Page 11 Spare Time Gizmos COSMAC Elf 2000 User s Manual Switch Color PIN Switch Color 17 DO VIOLET 18 MP GREY 19 GND WHITE 20 GND BLACK Table 1 Switch Wiring The LOAD and INPUT switches both SPDT have a common terminal both connected to ground in this circuit and normally closed NC and normally open NO terminals The normally closed terminal corresponds to the OFF state of the switch i e LOAD mode off or INPUT not pressed In the case of a push button this generally isn t an issue but if you use a momentary toggle for the INPUT switch then you ll have to be sure get it the right way around The same thing is true for the LOAD switch which is always a toggle If you re unsure of the internal wiring of your switches an ohmmeter will give a quick answer WARNING SPDT toggle switches invariably have the common terminal in the center but push buttons frequently do not Generally the switch will be labeled but if there s any doubt dig out your ohmmeter 2 HEX KEYPAD A push button hexadecimal keypad may also be used as an alternative to the toggle switch panel The keypad consists of 21 dida total sixteen hexadecimal keys and five function keys RESET hemes GO RUN LOAD MEMORY PROTECT and INPUT The five function keys are illuminated from behind by T1 LEDs
37. v v Return 1 if TOS gt 0 else 0 0 v v Return 1 if TOS 0 else 0 gt a b v Return 1 if a gt b else 0 lt a b v Return 1 if a b else 0 gt a b Return 1 if a gt b else 0 lt a b v Return 1 if a lt b else 0 2 5 2 Display entire contents of stack 2 a gt Display value at address NEG v v Negate a number MAX a b v Return largest of 2 numbers MIN a b v Return smallest of 2 numbers DUP Duplicate TOS if nonzero ABS v v Return absolute value of a number BL 32 Place a blank on the stack SPACE 2 Display a single space NIP baa Drop 2nd item from stack TUCK Place copy of TOS before 2nd on stack TRUE 1 Place true value on stack FALSE 0 Place false value on stack CLS 2 Clear screen MOD a b v Get remainder of a b INVERT Invert the bits of TOS TYPE av Display v bytes from address a SGN v v Return sign of number 2DUP ba baba Duplicate top 2 stack values PICK a v Duplicate a th element of stack on top MOD abrq Perform both mod and remainder functions Table 18 Extended Forth Functions 8 9 A BASIC FORTH TUTORIAL Forth is primarily a stack based language Arguments for functions are first pushed onto the stack and then the instruction is executed Pushing a number onto the stack is done merely by mentioning the number ok 5 This instruction will leave 5 on the to
38. 0 THEN ELSE DROP 0 THEN gt DUP IF 32768 AND IF 0 ELSE 1 THEN ELSE DROP 1 THEN lt DUP IF 32768 AND IF 1 ELSE 0 THEN ELSE DROP 1 THEN CLEAR DEPTH WHILE DROP DEPTH REPEAT FREE MEM U CR SPACES O DO 32 EMIT LOOP DUP ROT SWAP SWAP DUP ROT SWAP SWAP SWAP DUP ROT SWAP SWAP DUP ROT SWAP SWAP SWAP NOT IF O ELSE 1 THEN DUP SWAP 2 SWAP S 8206 8 1 DEPTH 1 0 DO DUP 2 LOOP DROP 3 NEG 0 SWAP DUP ROT DUP ROT gt IF SWAP DROP ELSE DROP THEN MIN DUP ROT DUP ROT gt IF DROP ELSE SWAP DROP THEN DUP DUP IF DUP THEN ABS DUP 0 IF 0 SWAP THEN BL 32 SPACE 32 EMIT NIP SWAP DROP TUCK SWAP OVER TRUE 1 FALSE 0 CLS 27 EMIT 91 EMIT 50 EMIT 74 EMIT MOD DUP ROT DUP ROT ROT LSHIFT DUP WHILE SWAP 2 SWAP 1 DUP REPEAT DROP RSHIFT DUP WHILE SWAP 2 SWAP 1 DUP REPEAT DROP FILL SWAP DUP IF 0 DO OVER OVER 1 LOOP ELSE DROP THEN DROP DROP INVERT 1 DUP IF 0 DO DUP C EMIT 1 LOOP ELSE DROP THEN DROP SGN DUP IF 32768 AND IF 1 ELSE 1 THEN THEN 2DUP OVER OVER PICK DUP DEPTH 1 lt IF 2 8206 1 Q ELSE DROP 1 ERROR THEN MOD OVER OVER MOD ROT m E DM ONNE 10 1 2006 4 23 PM Page 63 Spare Time Gizmos COSMAC Elf 2000 User s Manual 9 THE STG1861 VIDEO BOARD The Spare Time Gizmos CDP1861 emulator aka the STG1861 is built on a sm
39. 2 LOOP CR 02468 10 0 DO 3 LOOP CR 0369 The next two loop types are uncontrolled these loops are executed so long as the top of stack is non zero at the time of test The BEGIN UNTIL loop has its test at the end and therefore just like DO loops the loop will always be executed at least once ok 5 BEGIN DUP 1 DUP UNTIL CR 54321 ok Notice we used the DUP command here first to make a duplicate of our counter for the command and then a second DUP before the UNTIL UNTIL takes the top of the stack in order to determine if another loop is needed The second uncontrolled loop is the WHILE REPEAT loop This loop has its test at the beginning therefore if WHILE finds a O on the stack the loop will not even execute the first time ok 5 DUP WHILE DUP 1 DUP REPEAT CR 54321 ok 0 DUP WHILE DUP 1 DUP REPEAT CR ok Variables can be created with the VARIABLE command Notice that variables should not be given the same names as built in commands Here are some example variables 10 1 2006 4 23 PM Page 61 Spare Time Gizmos COSMAC Elf 2000 User s Manual ok VARIABLE A ok VARIABLE B If you execute a WORDS command you will see that your new variable names now appear in the list To store a value in a variable we use the command First we push the value we want to store on the stack and then mention the variable ok 5 A ok 10 B This stores 5 into A and 10 into B To retrieve the values of variables use the
40. 3000000 2 or 3MHz The result is especially interesting if the VT1802 video card is installed because the SHOW CPU command does not turn off the 13 The RTC is needed so we have a time base with a known frequency that s independent of the CPU clock speed 10 1 2006 4 23 PM Page 33 Spare Time Gizmos COSMAC Elf 2000 User s Manual video during the measurement The CPU speed reported in that case is the effective CPU speed after the video refresh overhead is taken out 5 11 SET COMMANDS 5 11 1 5 The SET Q 1 and SET Q 0 commands set and reset the Q output respectively These commands cannot be used if the Elf 2000 onboard bit banged serial port is used for the console 5 11 2 SET DA time The SET DATIME command will set the current time and date stored in the real time clock chip If no disk expansion card or no RTC chip is installed then an error message is printed instead gt gt gt set datime 3 14 2005 17 22 00 03 14 2005 17 22 00 Note that the format of the argument for SET DATIME is exactly the same format that SHOW DATIME uses to print the current time and date 5 11 3 SET RES tart If your EIf 2000 system has some form of non volatile memory either in the form of battery backup for the mother board SRAM or in the form a NVR chip on the disk expansion card then it is possible to select one of three different Monitor actions on a power up or reset gt gt gt set restart none gt g
41. 4 pin SIP 0 1 header J4 unused J5 J6 J7 Anchor 10 pin dual row 0 1 shrouded header Anchor DIP8 machined IC socket Anchor DIP20 machined pin IC socket Anchor DIP24 machined pin IC socket 0 300 Anchor DIP40 machined pin IC socket STG ELFGPIO 1B Printed circuit board Table 47 GPIO Card Parts List 28 You can also use the Dialight 555 2303 LED this LED has an integral dropping resistor for operation on 5V If you use the 2303 LED replace resistor R1 with a wire link 10 1 2006 4 23 PM Page 105 Spare Time Gizmos COSMAC Elf 2000 User s Manual D SWITCH PANEL ARTWORK Print this page onto a sheet of self adhesive label stock and then carefully cut out Figure 5 It should measure exactly 5 by 2 Paste Figure 5 onto a similarly sized piece of 1 8 thick ABS plastic stock and then drill as shown The remaining text stays behind to label your control panel o LOAD Spare MP RUN Time ee 4 Gizmos 7 6 5 4 3 2 1 0 o Oo oo OG EG COSMAC ELF 2000 d Figure 5 Switch Panel Artwork Figure 6 shows the actual size legends used for the keycaps on the Elf 2000 keypad Print it on regular paper cut out each individual squares and slide the slips of paper under the corresponding keycaps C DEF 8 9 45167175 PROTECT RUN S s 8 s a S e 8 8 8
42. 50 80 11 7 10 00 EO 74 65 73 74 20 64 61 74 61 20 2D 20 31 2C test data 1 7 20 20 32 2C 20 33 20 2D 20 42 6F 62 20 41 72 6D 73 2 3 Bob Arms 7030 gt 74 72 6F 6E 67 20 30 32 FO 32 33 2 30 35 75 1E trong 02p23 05u 7 40 02 00 17 00 11 00 02 OF 03 21 20 07 00 80 FF 11 7050 00 EO 74 65 73 74 20 64 61 74 61 20 2D 20 31 2C test data 1 7060 gt 20 32 2C 20 33 20 2D 20 42 6F 62 20 41 72 6D 73 2 3 Bob Arms 7070 gt 74 72 6F 6E 67 20 30 32 FO 32 33 2 30 35 75 1E trong 02p23 05u 5 10 3 SHO w REG isters The SHOW REGISTERS command will display the contents of application program s registers saved at the last break point If no break point has been encountered then these values are meaningless See section 4 8 for more information on the monitor s break point feature gt gt gt show registers BREAKPOINT XP 23 D AA DF 1 R0 0000 R1 0000 R2 7F7D R3 0102 R4 FA7B R5 FA8D 82 0 R7 7FA8 R8 0000 R9 82DE RA 8CF7 RB FEFF RC 7FAF RD 0100 RE 1100 RF 7FB7 5 10 4 SHO w IDE The SHOW IDE command will probe the IDE bus for attached devices Each device there are a maximum of two master and slave is reset and then its size and identification printed For example gt gt gt show ide IDE Master 122Mb SanDisk SDCFJ 128 IDE Slave Fail 5 10 5 SHO w MEM ory The SHOW MEMORY command shows the SRAM size in bytes as returned by the BIOS f freemem function Notice that the res
43. 8 8 8 8 8 Figure 6 Keycap Legends 10 1 2006 4 23 PM Page 107 Spare Time Gizmos COSMAC Elf 2000 User s Manual E RESOURCES AND REFERENCES Spare Time Gizmos Elf 2000 home page http elf2k SpareTimeGizmos com COSMAC ELF and 1802 Micro Computing Group http groups yahoo com group cosmacelf Spare Time Gizmos User s Group http groups yahoo com group sparetimegizmos TASM Cross Assembler http home comcast net tasm EIfOS Disk Operating System http www elf emulation com elfos html Rc Asm cross assembler http www elf emulation com rcasm html HyperTerm http www hilgraeve com htpe Kermit http www columbia edu kermit 10 1 2006 4 23 PM Page 109 Spare Time Gizmos COSMAC Elf 2000 User s Manual F SCHEMATICS This section contains the schematics for the Spare Time Gizmos COSMAC Elf 2000 and various options Spare Time Gizmos Product PCB Revision COSMAC Elf 2000 1 Embedded Elf 1B Disk UART RTC daughter card 1B Hexadecimal Keypad 1 STG1861 Pixie replacement 1B VT1802 80 column video card 1D GPIO General Purpose I O card 1B 10 1 2006 4 23 PM Page 110 S8 9 2 8 9 40 1 133H
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46. S e H 5 4 6 12 0 34 2 1 2413 13120 2479 nr 7066 28 x21 222 e YL Y leeoHeL 8H 7 9H 9n wes yes ES 1 m 527 33 Sh 15193 ar 4 1 97 lt 0301 311504402 521 L4IHS 1188 0 4 HNI 96 A O30IA VINIS 43 INH INAS 311504402 81 28 Is 0301 311504402 SI H INASA gt 4 150 H N311 SI is H ONASH A S PERET T3AV130 H dS 5o 5 8 8 2 1 30 81 1 ONASH 92 420323 61 L 1 INASA 0 1 3 4 USA 4 01 02 3 9 28 1207 E ar 5 25221 INASA 92 9 80 e Oo vO 62120 4 H INASA QVO 14185 Hay MEM S 000 21 0 250 22516 T yS MI sn 1250 9912 914561845 viu on DOA 1 8 420712d 1 XSA QVO OA 2 7 S 9 L 8 S g 2 8 2 0 1 13385 90 120 1 06 66 61 2 611 130 04 3114 3SN39I7 01 N3434 Q3AN3S34 SLHITY 17 5 3715 804719 AWIL 5002 2 1H9IMAd 0149 SH3AI3OSNVML SH A 7 11 01 91 0 Idd sng 19120 RY
47. VIDEO GAL U5 If you are installing your VT1802 card on the COSMAC Elf 2000 you will need to solder four short pieces of wire approximately 3 4 long to J2 Solder a single pin to the other end of each wire and insert them into the proper holes of the CDP1861 socket U2 on the Elf 2000 This table summarizes the connections Signal CDP1861 Socket U2 DMA OUT Pin2 SCO Pin 21 SC1 Pin 22 EF1 Pin 9 Table 25 Video Connections Be sure to also install jumpers JP1 and JP7 on the EIf 2000 board If you are lucky enough to have one of the Embedded Elf 2000 board then you ll notice that the Embedded Elf PC board has a four pin header conveniently located directly under J2 on the VT1802 video board Using a combination of a 2x2 female header and some extra long wire wrap pins it s possible to rig up a direct connection between the two similar to the one used to install the STG1861 PC board see chapter 9 Of course this connection will not stack as the main bus connector does but it s unnecessary since the video card is the only one which requires these extra connections WARNING For a number of reasons the VT1802 video card is incompatible with the CDP1861 Pixie graphics chip At any time you can have one or the other installed but never both 12 3 1 Jumper Settings Table 26 summarizes the jumpers present on the VT1802 card Note that none of these jumpers affect the interface to the 180
48. about power consumption you ll want to use an Atmel suffix part this device uses approximately 1 4 the power of a conventional 22V10 10 1 2006 4 23 PM Page 6 Spare Time Gizmos COSMAC Elf 2000 User s Manual 2 26 LED displays Six TIL311 hexadecimal LED displays are used to display the current address and data Either or both address and data of these displays are optional and may be omitted without harm refer to section 2 3 6 Note that the TIL311 devices are bipolar logic not CMOS and use a tremendous amount of power Eliminating them from your EIf can easily reduce the power consumption by a factor of 10 2 2 7 Oscillator The EIf 2000 uses one half sized can TTL crystal oscillator to generate the clock for both the CPU and the Pixie chip Notice that the oscillator frequency is divided in half before it is applied to the CPU that would mean that a standard CDP1802ACE could tolerate a maximum oscillator frequency of 6 MHz a 3 MHz CPU clock If you intend to use the CDP1861 video generator or the STG1861 clone you must use a crystal oscillator with the frequency 3 579545 MHz in order to generate the correct NTSC video timing In this case the CPU clock will be 1 7897725 MHz You ll find that crystals for this rather arcane looking value are actually quite easy to obtain since it is the standard NTSC color burst frequency 2 2 8 051233 There is some confusion between the 051233 part and the DS1233M The
49. after a RESET clears the bootstrap flag This works well with the current EPROM code since one of the first actions after a reset is to load POST code 99 into the displays and the I O output instruction that loads the data display will also clear BOOTSTRAP as a side effect The entire BOOTSTRAP mechanism may be defeated by removing jumper JP4 see section 3 2 2 which prevents the BOOTSTRAP flag from getting to the GAL in the first place If JP4 is removed then RAM is always addressed from 0 0000 to Ox7FFF and the processor will be executing instructions from RAM immediately after a RESET This is most useful when you intend to hand toggle in programs using the switches however it can also be useful if the backup battery is installed and the RAM contents are known to be valid 3 4 RECONFIGURING THE GAL The 22V10 GAL is responsible for most of the random logic address and I O decoding in the Elf 2000 In particular the GAL is responsible for gt Decoding the EPROM and SRAM chip selects gt Decoding the I O select for the switch register and data display gt Decoding the I O select for VIDEO ON and VIDEO OFF gt Handling and clearing the BOOTSTRAP flag see section 3 3 gt Deciding when the RUN and LOAD LEDs are illuminated Besides the simple fact that it saves a handful of discrete logic chips the other really wonderful thing about this is that it is possible to change the way the ELF 2000 operates simply by reprogramming the GAL
50. dental pick to gently push on each and every pin If the pin moves then you need to fix it a pin that s firmly solder in place won t budge when you poke it Checking for shorts requires that you use an ohmmeter or continuity tester to check every pair of adjacent pins for a short Note that pins 13 and 38 are both connected to Vcc and these two pins are adjacent Don t panic when they show up as shorted There are no other instances of adjacent pins that are connected together 11 3INSTALLATION The Disk daughter board is physically attached to the Elf 2000 main board by four solder in swage standoffs four 72 stand offs and four 84 40 screws The swages should be soldered directly to the EIf 2000 PC board in the four large mounting holes provided One hole is on the rear edge immediately to the right of the power connector another hole is immediately to the left of the DB9 serial port connector the third hole is just above VR1 and just below J3 and the final swage mounts immediately below the GAL U7 If you have any doubts use the expansion card as a template to ensure that you ve found all the right spots Note that the swages require a considerable amount of heat to solder properly and your regular iron probably won t be enough 20 goes without saying that there should be no CF card in the socket when you perform this test and this also assumes that there are no other components installed on the PC board If there are other compo
51. e Basic memory examination and modification commands e A program break point feature including a register dump and the ability to continue execution after the break e A bootstrap for the ElfOS disk operating system Asimple command line interpreter 4 2 SETTING THE JUMPERS FOR THE MONITOR The monitor requires that some of the COSMAC Elf 2000 be configured properly before it can run Table 4 summarizes the jumper settings required to run the EPROM monitor NOTE The photos shown in section 3 2 all depict the jumpers in the correct positions for the EPROM monitor 10 1 2006 4 23 PM Page 21 Spare Time Gizmos COSMAC Elf 2000 User s Manual Jumper Expected seiting for Monitor EPROM JP1 Installed if you have a CDP1861 STG1861 Otherwise removed JP2 Installed JP3 Unused doesn t exist JP4 Installed automatically start the monitor JP5 As required by your CPU chip JP6 RxD to EF3 JP7 See JP8 See 4 RxD invert JP10 TxD invert Table 4 Jumper Settings for Monitor EPROM 4 3 POWER ON SELF TEST POST Immediately after a RESET provided that jumper JP4 is installed see section 3 2 2 the CPU begins executing instructions from the EPROM and the first thing the EPROM code does is to execute a simple test of the Elf 2000 components This power on self test aka POST displays a different two digit number on the data display for each test i
52. external 5 volt regulated power supply Finally the Embedded Elf lacks the CDP1861 Pixie circuit and cannot be used with either the CDP1861 chip or the STG1861 module however the Embedded Elf will work with the VT1802 80 column video card The Embedded Elf does have the same non volatile memory and bit banged serial port with EIA level shifter as the Elf 2000 LF2K V60 2005 STG 10 2 ASSEMBLY Assembling the Embedded Elf is very straight forward but here is some additional information that may be useful JP5 is actually shorted by a small trace on the back of the PCB If you don t need JP5 and you probably don t then it s not necessary to install anything there Conversely if you do want to use JP5 you d better cut the small trace between the two pins J4 the 4 pin female header is there for the 80 column video card see Chapter 12 You don t really need to install it unless you intend to use that card F1 the picofuse is shown on the schematic but isn t on the PC board The 0 1uF bypass capacitors aren t labeled on the PC board but they are shown on the schematic as C11 C16 Note that the schematic shows seven however only six are actually used on the PC board You don t need to install the bypass above the SPARE chip location 10 1 2006 4 23 PM Page 67 Spare Time Gizmos COSMAC Elf 2000 User s Manual Dallas Semiconductor doesn t recommend a bypass capacitor on the output of the 05121019 because it can cause i
53. just poke your ML subroutine into the string space The advantage of using dynamic strings is that the original program source is not affected by the poking of the ML subroutine The disadvantage is that the ML subroutine must be loaded into the string every run Here is an example of a program using the dynamic string technique 10 8 20 M VARPTR AS 25 M PEEK M 256 PEEK M 1 30 FOR I 0 TO 4 READ N POKE 40 I USR M 50 DATA 227 100 174 226 221 In the static string technique you want strings that are fixed into the program space Normally when a string is assigned as a constant in the program the string in the program code is used as the string space for the variable and it is not allocated on the heap The advantage of this method is that once the strings are loaded with the ML routine you need not load them again between runs When the program is saved it will be saved with the ML routines intact in the strings The disadvantage is that you usually end up with unprintable characters in the strings which when the program is listed can cause havoc with the terminal Here is an example of using the static strings method 10 A 20 M VARPTR AS 25 M PEEK M 256 PEEK M 1 30 FOR 1 0 4 READ N POKE M I N NEXT 50 DATA 227 100 174 226 221 10 1 2006 4 23 PM Page 54 Spare Time Gizmos COSMAC Elf 2000 User s Manual Notice the difference in the definition of A in this version since the a
54. length up to the maximum available memory The storage for string variables does not need to be allocated before use they are dynamically created on the heap 10 1 2006 4 23 PM Page 42 Spare Time Gizmos 7 3 EXPRESSIONS COSMAC Elf 2000 User s Manual In nearly all places where numbers are expected you can use arithmetic expressions in place of the numbers even in the destinations of GOTO and GOSUB Relational operators may also be used in expressions When a relational operator evaluates true its result is 1 otherwise it results 0 The following operators and relations are valid in expressions Operator Operation Multiplication Division Addition Subtraction amp Logical AND Logical OR Equality lt gt Inequality lt Less than gt Greater than lt Less than or equal gt Greater than or equal Table 8 BASIC Operators 7 3 1 Order of Precedence Expressions are evaluated with a given precedence to the operators Operators that have the same precedence level are processed from left to right BASIC follows the standard convention for operator precedence Operator Precedence 1 Functions and variable references 2 e 3 4 AND OR amp 5 lt gt lt gt lt gt 3571 7 75 Table 9 BASIC Operator Precedence Precedence can be altered by th
55. machined pin IC socket 0 300 Anchor 12 pin female header strip Anchor 12 pin wire wrap header strip 25 At the moment there is no known retailer for the lighted push buttons You can always use the unlighted ones and omit the LEDs 10 1 2006 4 23 PM Page 98 Spare Time Gizmos COSMAC Elf 2000 User s Manual ES MANUFACTURER ee SUPPLIER DESCRIPTION Anchor Shorting plugs Keystone 1560A Mouser 534 1560 4 40 swage stand offs 0 125 high 0 250 diameter Olander 4 40 1 2 hex nylon M F standoffs Olander 4 40 1 4 Philips pan head nylon screws STG PIXIE 1B Printed circuit board Table 43 STG1861 Parts List Disk UART RTC NVR Daughter Board Parts List Pu d 2 MANUFACTURER m SUPPLIER sd DESCRIPTION RESISTORS R1 Anchor 10M ohm 1 8W 5 carbon resistor R2 Anchor 330 ohm 1 8W 5 carbon resistor RP1 Anchor 4 7K 6 pin 5 resistor SIP CAPACITORS C1 C2 Anchor 22pf 0 1 50V mono ceramic capacitor C3 C6 Anchor 1uF 35V tantalum capacitor C7 C8 47uF 6V tantalum capacitor C9 C10 unused C11 C17 Anchor 0 1uF ceramic monolithic bypass capacitor 0 1 LS SEMICONDUCTORS D1 D2 D3 1N914 Anchor Small signal switching diode 10 1 2006 4 23 PM Page 99 Spare Time Gizmos COSMAC Elf 2000 User s Manual
56. monolithic bypass capacitor 0 1 LS C9 unused C10 Anchor 10uF 6V tantalum capacitor SEMICONDUCTORS D1 D22 1N914 Anchor Small signal switching diode LED 1 5 Anchor T1 LEDs Q1 Q5 2N2222 Anchor GP NPN switching transistor U1 74C9222 Digi Key 16 Key Encoder U2 74C175 Anchor Quad D Flip Flops U3 CD4011 Anchor Quad 2 Input NAND Gates U4 74014 Anchor Hex Schmitt Trigger MISCELLANEOUS BZ1 RadioShack 273 0074 Mini PC mount Piezo Beeper 3 12V 10 1 2006 4 23 PM Page 97 Spare Time Gizmos COSMAC Elf 2000 User s Manual iE es MANUFACTURER DUE SUPPLIER E DESCRIPTION PBO PBF Grayhill 82 101 71 Jameco 472948 Unlighted Push Button PBINPUT PBMP PBLOAD PBRUN Grayhill 82 150 38 Unknown Lighted Push Button PBRESET Anchor DIP14 machined pin IC socket Anchor DIP16 machined pin IC socket Anchor DIP18machined pin IC socket 0 300 STG KEYPAD 1C Printed circuit board Table 42 Hexadecimal Keypad Parts List STG1861 Parts List x 28 MANUFACTURER SUPPLIER Seat DESCRIPTION CAPACITORS C1 C4 Anchor 0 1uF ceramic monolithic bypass capacitor 0 1 LS SEMICONDUCTORS D1 D2 1N914 Anchor Small signal switching diode U1 U2 Atmel ATF22V10CQZ Digi Key Flash GAL quarter power U3 74HC4040 Anchor 12 bit counter U4 74HC165 Anchor 8 bit parallel in serial out shift register MISCELLANEOUS Anchor DIP16 machined pin IC socket Anchor DIP24
57. of general purpose non volatile RAM that can be used for any purpose EIf OS and the BIOS use these bytes to save setup and configuration information such as the console port baud rate The DS12887A supports a reset CMOS memory feature To use this first remove power from the Elf 2000 and the Disk board then install jumper JP5 on the Elf 2000 Disk board count to ten and then remove JP5 This action will reset all 114 general purpose RAM locations to OxFF not zero and can be used to clear the current configuration By the way the only difference 10 1 2006 4 23 PM Page 74 Spare Time Gizmos COSMAC Elf 2000 User s Manual between the DS12887A and the DS12887 is that the latter does not support the reset jumper A DS12887 no A may be used in this circuit and everything will work except for jumper JP5 And the only difference between the DS12887 and the DS1287 is that the latter only contains 64 bytes of NVR RAM addresses 0x40 to Ox7F are not implemented with the DS1287 The DS1287 and its equivalent the Motorola MC146818A were very commonly used in PC AT machines and within their limitations any of these chips will work in the EIf 2000 Disk board If jumper JP2 is installed and the software enables the 1802 interrupt system the DS12887A can be programmed to generate periodic interrupts over a wide range of intervals ranging from milliseconds to hours Refer to the DS12887A DS12887 DS1287 or MC146818A data sheet for mo
58. stacking header J2 Mode Electronics 37 6302 0 2 pin right angle PCB mount header J3 3M 2510 5002 Digi Key MHD10K 10 pin low profile right angle shrouded header Anchor DIP8 machined IC socket Anchor DIP20 machined pin IC socket 0 300 Anchor DIP24 machined pin IC socket 0 300 Anchor DIP28 machined pin IC socket 0 600 Anchor DIP40 machined pin IC socket STG EELF 1B Printed circuit board Table 45 Embedded Elf Parts List VT1802 80 Column Video Card Parts List MANUFACTURER eesti SUPPLIER DESCRIPTION RESISTORS R1 R2 R3 R8 Anchor 10K ohm 1 8W 5 carbon resistor R4 unused R5 R7 R9 Anchor 2 2K ohm 1 8W 5 carbon resistor R6 Anchor 4 7K ohm 1 8W 5 carbon resistor R10 Anchor 680 ohm 1 8W 5 carbon resistor R11 R14 R15 R16 Anchor 1K ohm 1 8W 596 carbon resistor R12 Anchor 47 ohm 1 8W 5 carbon resistor R13 Anchor 150 ohm 1 8W 5 carbon resistor TR1 TR2 Anchor 50K PCB mount trimmer resistor CAPACITORS C1 Anchor 470pF ceramic monolithic capacitor 10 1 2006 4 23 PM Page 102 Spare Time Gizmos COSMAC Elf 2000 User s Manual Bae Es MANUFACTURER LR SUPPLIER eae DESCRIPTION C2 Anchor 0 001uF ceramic monolithic capacitor C3 Anchor 0 047uF ceramic monolithic capacitor CA Anchor 0 1uF ceramic m
59. text gt Print specified text on the terminal INP gt v Read port and push the value OUT p v Write value v to I O port P EF v Read the 4 EF inputs BYE 2 Return to the Elf 2000 Monitor Table 17 Other Forth Functions 8 8 EXTENDED FUNCTIONS These extended functions are implemented as pre loaded Forth programs As such they can be viewed with the SEE command and removed with the FORGET command 1 v v Add 1 to the top of stack 1 v v Subtract 1 from the top of stack 2 v v Add 2 to the top of stack 2 v v Subtract 2 from the top of stack FREE 2 Display free memory LSHIFT vc Left shift value v by c bits 10 1 2006 4 23 PM Spare Time Gizmos COSMAC Elf 2000 User s Manual RSHIFT vc Right shift value v by c bits FILL ad ch cn gt Fill cn bytes with ch starting at ad CLEAR gt Clears the stack of all entries SPACES v gt Display specified number of spaces va Add value to specified variable address 2 gt Subtract value from specified variable address va 2 Multiply specified variable address by value NOT v v Return 0 if TOS lt gt 0 otherwise 1 0 v v Returns 1 if TOS is zero otherwise 0 a v Like except preserve address incremented by 2 gt 0
60. that all switches should be mounted so that they are ON with the lever in the down i e zero position except for the MP switch This includes the RUN switch the MP switch alone should be installed so that it is ON with the lever in the UP position Please don t solder your 1802 chip or your 1861 chip to the board And of course you always want to socket the GAL and EPROM chips so that you can reprogram them if need be 10 1 2006 4 23 PM Page 10 Spare Time Gizmos COSMAC Elf 2000 User s Manual Mount a SPDT toggle switch in the LOAD position and either an SPDT push button or a SPDT momentary toggle switch in the INPUT position If you use momentary toggle switch for INPUT mount it so that the momentary position is UP ot e e La LA The switches are wired using a short piece of 20 conductor ribbon cable terminated with a 20 pin IDC female connector This connector plugs into J5 the main board which you should Photo 3 Switch Panel Rear View have installed the bottom of the PC board It s recommended that you use rainbow colored ribbon cable for the switch panel connections and install the connector so that the BROWN wire corresponds to pin 1 of J5 RED to pin 2 of J5 and so on Remember that pin 1 of J5 is the one with the square pad and remember to count the pins of J5 while looking at it from the bottom of the PC board If you hold the Elf 2000 PC board upside
61. with either the word NEW or OLD If you answer NEW then memory will be initialized for a new program but if you answer OLD BASIC ASM Forth will attempt to recover any existing program that may be left in RAM Of course if there is no program in RAM it will most likely crash Note that all three languages work exactly the same way in this respect The OLD option is especially useful when your Elf 2000 has the battery backup option for SRAM in this situation you can enter a long program into SRAM turn your Elf off and then later turn it on and recover your original program by using the OLD option Optionally you can shorten this dialog to a single command e g gt gt gt FORTH OLD Currently it is not possible to boot from an IDE slave device 10 1 2006 4 23 PM Page 29 Spare Time Gizmos COSMAC Elf 2000 User s Manual 5 4 CALL lt ADDR gt AND RUN lt ADDR gt Both of these commands are used to transfer control to a machine language program that you have loaded into RAM presumably by downloading it from a PC see section 4 9 or possibly by entering it directly into RAM with the DEPOSIT command Both commands require a single hexadecimal argument to indicate the starting address of the machine language program for example gt gt gt RUN 100 begins running the machine language program at location 0100 The difference between these two commands is in the way the machine language program is
62. write device register select Port 3 read selected device register write selected device register Table 20 Disk Board I O Ports 11 5 1 Status Register Reading the status register returns 8 bits as shown in Table 21 IMPORTANT Disk Expansion PC Boards revision B and later do not implement the status register This includes the vast majority of boards shipped to customers On these boards reading the status register returns all 1 bits regardless of the expansion board status The EIf 2000 Monitor and EIOS BIOS do not use this register EIf 2000 Disk Board Status Register Bit 7 Bit 6 Bit 5 Bit4 Bit 3 Bit 2 Bit 1 Bit 0 UART RTC DISK X X CD1 CD2 DASP IRQ IRQ IRQ X Unused bits state is indeterminate Table 21 Disk Board Status Register CD1 CD2 Card detect inputs from the Compact Flash card socket Normally these bits will both be zero when no CF card is inserted and both will be one when a CF card is inserted DASP This bit reflects the state of the DASP output from the selected IDE disk or CF card This bit is normally one while the disk is busy and zero when it is idle This same bit also controls the disk activity LED located next to the CF card socket UART IRQ This bit will be zero if the 16450 50 is requesting an interrupt and one if it is not Note that the sense of this bit is backwards from the RTC and DISK IRQ bits This bit always reflects the state of t
63. written by Mike Riley The text editor allows the user to type simple assembly language programs into memory and then when you re ready the assembler assembles the program directly to memory hopefully a different part of memory and starts it The rest of the chapter documents the Editor Assembler and was contributed by Mike Edt Asm is a basic editor with integrated in memory assembler Edt Asm was designed so that it could be run from ROM with the text editor buffer at 1000 In this configuration programs can be assembled in the space from 0000h to 0FFF 6 4 EDITOR COMMANDS A Assemble the program B Move to bottom of buffer D Move down one line Move down lines Itext Insert text at current location nltext Move to line n then insert text Enter multi line insert mode end with lt CTRL gt lt C gt Enter multi line insert mode starting at line n end with lt CTRL gt lt C gt nG Make line n the current line K Kill delete the current line nK Move to line n and then delete line Kill n lines starting from current line n mK Kill m lines starting from line n n becomes current N New file clears buffer P Print the current line nP Print line n P Print n lines starting from current line n mP Print m lines starting from line n R Run program T Move to top line of buffer U Move up one line nU Move up n lines Table 7
64. 0 00 00 00 00 00000 7 gt 00 00 00 00 00 00 00 00 6 11 00 03 0E 21 155 gt 11 16 00 00 00 00 00 00 00 00 01 00 73 68 6F 77 show gt 20 64 70 00 74 61 72 74 00 6F 6E 65 00 30 30 00 dp tart one 00 7 0 gt 20 31 37 32 32 30 30 00 00 00 00 00 00 00 85 7FE0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 7 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 5 10 9 SHO w DA time The SHOW DATIME command prints the current date and time of day according to the RTC chip on the disk expansion card If the expansion card is not installed or if the RTC chip is not installed then an error message is printed instead gt gt gt show datime 03 14 2005 17 24 07 5 10 10 SHO w EF The SHOW EF command prints the current state of all four EF inputs For example gt gt gt show ef EF1 0 EF2 0 EF3 1 EF4 0 This command prints the logical state of the EF inputs as the programmer would see it Thus EF 120 implies that the EF1 input is HIGH and EF3 1 implies that the EF3 input is LOW 5 10 11 SHO w CPU The SHOW CPU command reports the type either CDP1802 or CDP1804 5 of the CPU chip in use Better yet if the RTC option part of the Disk RTC NVR card is installed SHOW CPU will also compute and report the CPU clock speed gt gt gt show cpu CDP1802 SPEED 3000000 In this case the CPU clock speed is
65. 0 600 Anchor DIP28 machined pin IC socket 0 600 Anchor DIP40 machined pin IC socket 4 40 mounting hardware for VR1 Digi Key HS104 1 Heat sink for VR1 STG ELF2K 1C Printed circuit board Table 40 Elf 2000 Parts List Switch Panel Parts List 5 22 MANUFACTURER DE SUPPLIER DESCRIPTION DO 7 RUN MP Jameco 76523CR SPST toggle switch LOAD Jameco 21936CR SPDT toggle switch INPUT Jameco 28062CR SPDT toggle switch momentary or push button Anchor 20 pin 0 1 dual row header Anchor 20 pin IDC connector Anchor 6 20 conductor ribbon cable Tap 5 1 2 x 2 x 3 16 ABS switch panel Tap 6 3 4 x 1 x 3 8 Acrylic side rails STG Front panel decal see Appendix D Table 41 Switch Panel Parts List 10 1 2006 4 23 PM Page 96 Spare Time Gizmos Hexadecimal Keypad Parts List COSMAC Elf 2000 User s Manual REFERENCE PART STOCK MANUFACTURER NUMBER SUPPLIER NUMBER DESCRIPTION RESISTORS R1 R2 R8 R10 R11 Anchor 4 7K ohm 1 8W 5 carbon resistor R3 R5 R6 R12 Anchor 150 ohm 1 8W 5 carbon resistor R4 Anchor 10K ohm 1 8W 5 carbon resistor R7 Anchor 47K ohm 1 8W 5 carbon resistor RP1 Anchor 10K x 5 6 pin SIP CAPACITORS C1 Anchor 0 1uF ceramic monolithic capacitor C2 C11 Anchor 2 2uF 6V tantalum capacitor C3 Anchor 1uF 6V tantalum capacitor C4 C8 Anchor 0 1uF ceramic
66. 00 10 1 2006 4 23 PM Page 50 Spare Time Gizmos COSMAC Elf 2000 User s Manual Note that just as in the standard GOTO the line numbers may be computed 7 5 14 OUT port value The OUT command allows you to write the specified value out to the specified port The port number must be a value from 1 to 7 Note that carelessly writing to the wrong port may crash your Elf 2000 7 5 15 POKE address value POKE will write the specified value into the specified address in memory Care must be taken when using POKE if you POKE a value into a critical location it could crash your Elf 2000 and require a reset 7 5 16 PRINT expression list The print command allows a program to output values to the terminal The expression list may consist of no elements or multiple elements When no expressions are given PRINT will just move the cursor down a line on the terminal and when multiple expressions are provided each expression must be separated by either a or 5 character Whenever a is encountered character is sent to the terminal which will tell the terminal to move the cursor to the next tab stop When 5 is used no cursor movement will occur Either or 5 may also be the last character of the expression list and will have the effect of preventing the automatic carriage return at the end of the PRINT statement Here are a few examples of PRINT 10 PRINT ANSWER 5 7 RUN ANSWER 12 10 PRINT
67. 03 04 2005 00 00 00 90 STAT 03 04 2005 00 00 00 139 HEXDUMP 03 04 2005 00 00 00 218 COPY 03 04 2005 00 00 00 212 RENAME 03 04 2005 00 00 00 75 TYPE 03 04 2005 00 00 00 149 EDIT 03 04 2005 00 00 00 1361 EXEC 03 04 2005 00 00 00 34 INSTALL 03 04 2005 00 00 00 274 MKDIR 03 04 2005 00 00 00 90 RMDIR 03 04 2005 00 00 00 93 CHDIR 03 04 2005 00 00 00 127 PATCH 03 04 2005 00 00 00 553 VER 03 04 2005 00 00 00 287 ASM 03 04 2005 00 00 00 3489 SAVE 03 04 2005 00 00 00 338 1 05 Ready COSMAC Elf 2000 User s Manual 10 1 2006 4 23 PM Page 90 Spare Time Gizmos COSMAC Elf 2000 User s Manual Once you ve built a system disk in the future you can boot EIfOS directly from the Elf 2000 monitor EPROM using the BOOT command COSMAC ELF 2000 EPROM V50 CHECKSUM 024B SRAM 32K INITIALIZED Copyright C 2004 2005 by Spare Time Gizmos All rights reserved 1 5 BIOS Copyright 2004 by Mike Riley IDE Master 122Mb SanDisk SDCFJ 128 03 14 2005 16 55 16 For help type HELP gt gt gt BOOT Booting primary IDE Starting E1f OS Ready Even better you can use the auto restart feature of the Elf 2000 Monitor EPROM to automatically boot ElfOS any time the system is reset or power is applied To enable automatic booting type this Monitor EPROM command gt gt gt SET RESTART BOOT 10 1 2006 4 23 PM Page 91 Spare Time Gizmos B POST CODES COSMAC Elf 2000 User s Manual
68. 1 5 Option 4 Initialize the hard disk Option 1 IDE Disk Initialization Utility lt Q gt uick or lt F gt ull 7 q formating Sectors 54272 Complete 5 Initialize the file system Option 2 IDE File System Gen Utility Total Sectors 54272 AU Size 8 Total AUs 31360 10 1 2006 4 23 PM Page 89 Spare Time Gizmos Master Dir Sector 144 File system generation complete 6 Install the operating system kernel Option 3 System copied 7 Install system utilities Option 4 Binary utilities installer nstall DIR y Installing nstall DUMP y Installing nstall MINIMON y Installing nstall LOAD y Installing nstall FREE y Installing nstall DEL y Installing nstall STAT y Installing nstall HEXDUMP y Installing nstall COPY y Installing nstall RENAME y Installing nstall TYPE y Installing nstall EDIT y Installing nstall EXEC y Installing nstall INSTALL y Installing nstall MKDIR y Installing nstall RMDIR y Installing nstall CHDIR y Installing nstall PATCH y Installing nstall VER y Installing nstall ASM y Installing nstall SAVE y Installing 8 And then boot Option 5 Starting E1f OS Ready 5 DIR S DIR 03 04 2005 00 00 00 500 DUMP 03 04 2005 00 00 00 307 MINIMON 03 04 2005 00 00 00 201 LOAD 03 04 2005 00 00 00 180 FREE 03 04 2005 00 00 00 226 DEL
69. 1 0 Idd 11 DG ad 0 A34 11 gd N vivd 144 21 54 Sue 1 A3M el 8 2 VIVI Idd 61 ag By 2 viv gt L 2 t VIV Idd vl VIVO A34 vl 8 E y VIVO Idd SI y VIVE SI 5 S Viva 144 91124 Sd S A34 91 5 Sd 9 vi Idd Ll 9 LI Ta 91 VIVI 144 81 Ug 11 VIVI 811 1 Sue 210 11 IMET 29 YIT Idd SreoHvL 8 8 E EN 4 28 CL Old W2T 9 x 7300 c r VIVO SN 0 VIVO 2 301 LS 51 IIO 5 0 Lea cm H HOLSYLS 91 Ql 1054 i Sel 4 2 8 8 1 213415 11 ny 6 gdl MM 144 81 8 0 co ax ur 6 169 1 Idd 61 a ZN 9 IN gt 52s axe re 2905 Ade VIVO Te E gt 2216 NS 7 13535 2 2 5 SIE le ee 13 11 ddee z3 L 2640 11 Jazz A 2n Vx 1 WLX Ed TlNI V 23 12 58 1 AQH 138 oe Lu 1va H ETE 1 8 2 s AS 42012 aay 9 4 O 2 lt ee 5 1 33 ven G 6 1 Lasay E S3 2 584 11 52522 1 243 1502268 i gt 2 1 ONL v SL v S ace d OUI I rane 5 euS 1 5018 NOISNVdX3 c S g L 8
70. 10 1 2006 4 23 PM Page 87 Spare Time Gizmos COSMAC Elf 2000 User s Manual SP1 SPO Speaker 1 1 Table 39 Speaker Control Bits Speaker Off state 00 is just that no sound will be heard Speaker On 11 causes a click and the software can toggle between the Off and On states at audio frequencies to generate arbitrary tones and play simple music State 10 is essentially the same except that the software can toggle the speaker on and off with the 1802 s Q bit output This is a little easier and is compatible with many simple music playing programs for the 1802 Needless to say this mode should only be used if you aren t using the Q bit for something else WARNING Remember that the Elf 2000 mother board serial port uses Q to transmit serial data The fixed frequency tone state 01 is determined by the 7555 oscillator on the GPIO card This state generates a continuous tone without any need for software bit toggling and the tone continues indefinitely until the software changes the speaker state to something else A hardware reset will clear both SPO and SP1 and turn the speaker off regardless of its current state 10 1 2006 4 23 PM Page 88 Spare Time Gizmos COSMAC Elf 2000 User s Manual A INSTALLING ELFOS Mike Riley s has written an excellent disk operating system for the COSMAC Elf microprocessor called ElfOS see Appendix E for more information The Elf 2000 monitor ROM already conta
71. 142 9e 2 9 IN H2I3IS 01 e o S ON 921 ENS H HOLSNLS 01 22 D H NO O3CIA IV lt 5 lt lt 0 5 121 E ev 22 8 207 Et aiy S 12 L 022 ae H 3AILOV MOM WE 122 aes Qi Nee TIA 11 ques S23 7 y 229 NAS x LN e 722 1 22 te bas 8v 622 dd T XS 220 82 555 oud dees 2 1 HONd3 8 8 ve 922 Bei H 081 2189 243 ae 92 2 S 081 2182 en L2 420199 E 7 54 sng NOISNVdX3 c y 9 L 8 y S 9 2 8 2 0 2 13385 O301 90 120 1 29 91 2 611 130 3114 35 3211 01 343 Q3AN3S34 SLHIIY OTIA 3715 604719 WIL 8002 2 2 0341 YLYGAT LIAM YLYGAT LIN 111 YW ten 338v LSONOW 318v LSONOW 180 eg 18 at S y 21 31 18 ev To S INAS 311S0dMW02 i i FAAR 124 oy 30170 SI 4nigg g SI 2 x nga 2 x 0341 311504402 ge LONE E SNARE i ag reo m9 E ALY Ly ye 2 6y 2 22 12 eiu 2 oz 1 9NASA l Ly 1 2 5 el INASA
72. 2 CPU and so the COSMAC Elf 2000 Monitor EPROM BIOS and EIfOS disk operating system don t care how any of them are set Jumper Default Function JP1 Removed Selects GPA or LA to address character generator JP2 Removed Selects GPA or LA to address character generator JP3 Negative Selects the polarity of the vertical sync pulse JP4 Positive Selects the polarity of the horizontal sync pulse JP5 Removed When installed connects the video output to J5 pin 7 Table 26 VT1802 Card Jumpers The 2764 EPROM used for the character generator U3 has enough room for four complete 256 glyph character sets Normally if JP1 and JP2 are both removed the upper two address bits for this EPROM are always zero and only the first character set is used These jumpers may be installed to allow either the 8275 General Purpose Attribute GPAO0 1 outputs or the 8275 Line 10 1 2006 4 23 PM Page 78 Spare Time Gizmos COSMAC Elf 2000 User s Manual Attributes outputs LAO 1 to provide the upper two address bits With careful programming of the character generator EPROM this feature could be used to implement the 8275 line drawing functions or it can be used to implement three alternate character sets 9 12 3 2 Adjustments Trimmer TR1 adjusts the horizontal position of the video on the screen and TR2 adjusts the vertical position You can use these along with the controls on your monitor to position the video c
73. 2 internal registers X P IE R 0 0 and then the processor begins executing instructions at location 0 with R 0 as the PC If we want to start executing code directly from the EPROM after a RESET it s necessary to trick the processor somehow into starting at location 0x8000 rather than 0x0000 The 22V10 GAL U7 is responsible for decoding the chip selects for both RAM and EPROM Ordinarily is uses A15 to do this A15 0 selects the RAM and A15 1 selects the EPROM The hardware also contains a special bootstrap flag implemented by U9 section C this flag is always set i e BOOTSTRAP 1 by a RESET condition This BOOTSTRAP flag is also an input to U7 and when BOOTSTRAP is 1 the GAL modifies its chip select decoding so that the EPROM is always selected regardless of the state of A15 Once again as long as the BOOTSTRAP flag is set the EPROM will be selected for all memory references Address bit A15 becomes a don t The RAM can never be selected under these circumstances This combination causes the processor to execute instructions from the EPROM after a reset even though the PC 0x0000 As soon as possible after RESET the EPROM code should execute a long branch to the correct Ox8xxx address and then clear the bootstrap flag Clearing the BOOTSTRAP flag is also up to the GAL via the CLR BOOTSTRAP output The current GAL programming will assert this output any time N 0 thus the first I O instruction of any kind
74. 2887A chip is used This jumper has no effect any other RTC NVR chips including the 0512887 To erase the NVR first remove power from the Elf 2000 computer and then install jumper JP5 Wait a second or two remove JP5 and re apply power JP5 works only when the DS12887A is 18 More or less 10 1 2006 4 23 PM Page 71 Spare Time Gizmos COSMAC Elf 2000 User s Manual operating on battery power not when Vcc is applied Do not attempt to operate the Elf 2000 and disk card with JP5 installed 11 5 PROGRAMMER S REFERENCE To the programmer a standard IDE disk interface appears as sixteen separately addressable registers although not all of these are implemented Likewise the 16450 550 UART contains ten addressable internal registers and the DS12887A RTC has 128 addressable registers 14 of which track the current date and time and the remaining 114 are general purpose non volatile memory cells Needless to say cramming all this into the 1802 s I O space which can support at most seven yes seven addressable devices requires a few compromises The EIf 2000 Disk board uses a two level I O scheme in which the programmer first outputs a device register select code to one port and then accesses the selected device and register with another port Any pair of 1802 ports may be used by reprogramming the EIf 2000 Disk board GAL but by default these two are used Input Output Port 2 read status register
75. 3 Page 30 Spare Time Gizmos COSMAC Elf 2000 User s Manual The EXAMINE command may also be used with a single argument in which case only one byte is displayed always in hex this time For example gt gt gt e 100 0100 gt 79 5 7 D EPOSIT lt ADDR gt DATA lt DATA gt The DEPOSIT command what else deposits one or more bytes of data in memory It requires a minimum of two arguments the memory address to change and the byte to be deposited For example gt gt gt d 100 7f gt gt gt e 100 0100 7F Additional arguments may be given to change sequential bytes after the first one For example gt gt gt d 1011234567 gt gt gt e 100 10f 00 2 72 136 Be 06 Ie Bis Ge RB CD Gm F 0100 7F 01 02 03 04 05 06 07 FF 0000 FF 0000 FF 00 5 8 IN PUT lt PORT gt The INPUT command reads a data byte from the specified I O port and prints the data obtained For example gt gt gt in 4 Port 4 8C reads the console switches 5 9 OUT PUT lt PORT gt lt DATA gt The OUTPUT command writes the specified data byte to the I O port given For example gt gt gt out 4 a5 displays A5 on the data LEDs 5 10 SHOW COMMANDS 5 10 1 SHO w TERM inal The SHOW TERMINAL command prints the current console port terminal settings BAUD1 contains the software baud rate used by the mother board bit banged serial port The LSB of BAUD 1 also contains the terminal echo flag this wi
76. 38 N 1 11534 135 13534 135 gig YEN O 01 7 aq ay 339431 61 ue 1 dH 135 eM 39 7 y 1 8 S 9 2 6 133H IvdA34 9g uer 28 vI eO 01 2 611 130 504 3114 39N3211 Ol N343M T3ANSSS3M SIH9IM 17V Lave 4338 0131 3718 504719 AWIL 45 A8 002 2 IH9INAdOO IVdA3M v HOTVINVI A9 anzz wazzng arn a s x g 11 124 125917 2 aLr J ven asn Ly mien JOA G37 INNI C33 0407 131 NnH 501 141 T x 431 lt ig 031 13833 X N A L r MO113A 11 CA M0733A TL 7 9 IIN Ql N vran A A 091 l aie ats N3339 LOD 1 VM VM 061 251 091 asl 218 68 SH ou 7 7 c D y m 9 L y 2 9 1 8 1 40 13395 31XId_ 0 2901 9 11 91 2 511 130 X04 3714 35 3211 OL N343H 5 SIHOIN 17V INSH3OV383H 19814602 A 3715 604719 WIL
77. 4 23 PM Page 79 Spare Time Gizmos COSMAC Elf 2000 User s Manual 12 4 VIDEO TIMING The actual timing is strictly a function of the software and except for the pixel clock can easily be changed Table 27 summarizes the video timing used by the standard Monitor EPROM for 80x24 VT52 terminal emulation Character Timing Pixel Clock 12 00000 MHz Pixel Time 83 33 ns Pixels per Character 8 pixels Character Clock 1 50 MHz Character Time 666 7 ns Line Timing Characters per line 80 characters Retrace Time 16 characters Horizontal Total 96 characters Active Scan Time 83 Line Time 64 00 us Horizontal Frequency 15 63 kHz Error 0 79 from 15 750 kHz Frame Timing Lines per Row 10 scan lines per character row Rows per Frame 24 character rows Retrace Time 2 character rows Vertical Total 26 character rows Vertical Total 260 scan lines Active Scan Time 92 Frame Time 16 64 ms Vertical Frequency 60 10 Hz Error 0 16 from 60 00 Hz Table 27 Default 80x24 Video Timing 12 5 PROGRAMMER S REFERENCE Table 28 lists the 1802 I O ports used by the VT1802 video card in addition to these ports it also uses the EF1 status flag The CRTC parameter status and command registers all directly access the internal registers of the 8275 CRTC and if you wish to program the video card directly you ll want a copy of the data sheet for that chip Input Output Port 1 read CRTC parameter write CRTC parameter Port 5 read CRTC
78. B AON LT 92 68 90 2 611 130 3114 35 3211 01 343 GSANaSaY SLHITY 3715 604719 FWIL 002 I IH9INAdOO yess CL 1V lt 1 4 EPEN NOSSIIONdONIIW S 118 8 SONO 8 lt S 420 L 9d gr 243 34 9 ia 8 ea wi an ar ON be gt IN et LN 2 qWLx AOT Jen ga 24 o 75 oL uM 2012 7 5 0 125 SE 42012 ISO 1 440 4510 1 2 ev 34 AV1dSIG OJIA m SV m 202 mE 2 T 1143 cy i T 1 2 3 5305 28 y 2 17 ANS 0301 110 180 ino D Sa eT TS ae E EE c glia M LAAA INAS dWOD 2 va 5 g L 0 4 03 0 C2 TO X 51 gat 181 8 5 2 16 9 2 avo 8 INAS 3 29 lt m 5 Vc Vd lt ma gt 1 yal Lan Ht MNCS as g ps 105 0 lt lt 2 655 fee 125 026 8 x O 038 INI 1 IdnHH3lNI SR er JH SOA J ino WW ST 6 one T 490018 z 9 r ve NI 13838 1981442 c y 9 L 8 032 0 WOSd3 X
79. BY 10 1 2006 4 23 PM Page 2 Spare Time Gizmos COSMAC Elf 2000 User s Manual SPARE TIME GIZMOS EMPLOYEES OR OTHERWISE WILL BE DEEMED TO BE A WARRANTY FOR ANY PURPOSE OR GIVE RISE TO ANY LIABILITY ON THE PART OF SPARE TIME GIZMOS THE WARRANTIES AND CORRESPONDING REMEDIES AS STATED IN THIS SECTION ARE EXCLUSIVE AND IN LIEU OF ALL OTHERS WRITTEN OR ORAL SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF IMPLIED WARRANTIES SO THE ABOVE EXCLUSION MAY NOT APPLY TO YOU THE LIMITED WARRANTIES AND CONDITION REFERENCED ABOVE GIVE YOU SPECIFIC LEGAL RIGHTS YOU MAY HAVE OTHERS WHICH VARY FROM JURISDICTION TO JURISDICTION IN NO EVENT SHALL SPARE TIME GIZMOS OR ITS EMPLOYEES BE LIABLE FOR ANY COSTS OR DIRECT INDIRECT PUNITIVE INCIDENTAL SPECIAL CONSEQUENTIAL DAMAGES OR ANY OTHER DAMAGES WHATSOEVER INCLUDING WITHOUT LIMITATION DAMAGES FOR COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES LOST PROFITS LOSS OF DATA INTERRUPTION OF BUSINESS OR LOSS OF USE ARISING OUT OF OR IN ANY WAY CONNECTED WITH THE USE OR PERFORMANCE OF THE ELF 2000 OR YOUR RELIANCE ON THE ELF 2000 OR RESULTS FROM MISTAKES OMISSIONS INTERRUPTIONS DELETION OF FILES ERRORS DEFECTS DELAYS IN OPERATION OR TRANSMISSION OR ANY FAILURE OF PERFORMANCE WHETHER BASED ON CONTRACT TORT STRICT LIABILITY OR OTHERWISE EVEN IF SPARE TIME GIZMOS HAS BEEN ADVISED OF THE POSSIBILITY OF DAMAGES BECAUSE SOME STATES JURISDICTIONS DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILI
80. Editor Assembler Commands 6 2 ASSEMBLER LINE FORMAT label OPCODE ARGUMENTS Comments Labels and comments are optional and not all opcodes have arguments In addition to the 1802 instruction set Edt Asm provides these 4 pseudo opcodes ORG addr Specify address for assembly DB b1 b2 bn Define a list of bytes in memory DW W1 W2 wn Define a list of words in memory END start End of assembly also specifies start address 10 1 2006 4 23 PM Page 39 Spare Time Gizmos COSMAC Elf 2000 User s Manual Edt Asm currently only supports simple arguments arithmetic expressions cannot be used When specifying registers the register number may but need not begin with R for example LDN R8 The high byte of a value can be obtained by adding 1 to the end of a label for example LDI STACK 1 will load the high byte of the address of STACK In the same way 0 will obtain the low byte of a value for example LDI 5 0 6 3 EXAMPLES be added 10 1 2006 4 23 PM Page 40 Spare Time Gizmos COSMAC Elf 2000 User s Manual 7 BASIC 7 1 INTRODUCTION The Elf 2000 EPROM contains a very powerful BASIC Language Interpreter written by Mike Riley and in addition to the software Mike has contributed this chapter which documents his BASIC language BASIC is an acronym for Beginners All purpose Symbolic Instruction Code BASIC was developed in the early 70s in order to provide an easy means for writin
81. I O decoding memory mapping and other control functions are implemented in a 22V10 GAL so they can be easily changed without any wiring modifications Six TIL311 displays for a full address and data display Switches mounted on a separate piece of plastic or aluminum like the original ELF that connect to a header on the Elf 2000 PC board If you don t like toggle switches the Elf 2000 can also accommodate a Super Elf style hex keypad and push button controls automatic bootstrap to allow the Elf 2000 to be used without any switches or keypad On power up it can wait for download from a PC or automatically begin running a program stored in EPROM or non volatile RAM A Vcc low voltage monitor in the Elf 2000 ensures that the CPU is reset on power up and power down regardless of the switch settings A circuit that works with either the original CDP1802 chip or any of the later CDP1804 1805 1806 chips The classic Elf load mode of course requires a genuine 1802 chip 1 1 REGULATORY WARNING In the United States the Federal Communications Commission requires that devices that use and radiate radio frequency energy be certified in accordance with CFR Title 47 Parts 2 and 15 Other countries will have different requirements The COSMAC Elf 2000 design is not in finished product form and has NOT been approved by the FCC or any other regulatory agency worldwide The user understands that approvals may be required prior to the o
82. Operators 8 4 VARIABLES VARIABLE name Create a variable not allowed in functions 8 v Retrieve value from address va 2 Store value at address v Retrieve byte value from address 10 1 2006 4 23 PM Page 57 Spare Time Gizmos COSMAC Elf 2000 User s Manual gt Store byte value at address ALLOT n gt Increase the last defined vars storage space Table 14 Forth Variables 8 5 FUNCTION DEFINITION name 2 End of function definition Table 15 Forth Function Definitions 8 6 STACK OPERATORS KEY DUP a aa Duplicate top stack value DROP a gt Drop top stack value SWAP abba Swap top 2 stack entries OVER a b a b a Copy 2nd stack value to top ROT abc bca Rotate 3rd stack item to top ROT abc cab Rotate top of stack to 3rd position DEPTH a Get number of items on stack a gt Print top of stack as signed integer U a gt Print top of stack as unsigned integer EMIT a gt Print top of stack as ASCII character v Read a char from the keyboard and place on stack Table 16 Forth Stack Operators 8 7 OTHER FUNCTIONS CR 3 Print a CR LF pair MEM a Return amount of memory WORDS 2 Display vocabulary words SEE name 2 See what is bound to a name FORGET name 2 Remove a variable or function
83. P1 JP7 and JP8 be installed Photo 11 STG1861 installed on the ELF 2000 see section 3 2 1 It s probably easiest if you install these before mounting the STG1861 for the last time If you are lucky enough to have a real CDP1861 Pixie chip and you want to use it with your Elf 2000 then install a standard 24 DIP socket at U2 and plug in your chip It ll work just fine Be sure you also install jumpers JP1 JP7 and JP8 see section 3 2 1 10 1 2006 4 23 PM Page 66 Spare Time Gizmos COSMAC Elf 2000 User s Manual 10 THE EMBEDDED ELF 10 1 INTRODUCTION The Embedded Elf is a slightly simplified and much smaller version of the EIf 2000 The Embedded EIf is exactly the same size and form factor as the Elf 2000 daughter cards such as the Disk UART RTC card the VT1802 80 column video card or the GPIO General Purpose card The Embedded Elf has the same expansion bus as the EIf 2000 and stacks perfectly with the daughter cards to form a cute little cube The Embedded Elf can run the same software as the EIf 2000 and in fact uses the exact same monitor firmware EPROM as the EIf 2000 The primary differences between the Elf 2000 and the Embedded Elf are that the latter lacks the switch interface and the TIL311 displays although the Embedded Elf does have eight LEDs that are used to display the POST results The Embedded Elf also lacks an on board voltage regulator Photo 12 Embedded Elf requires
84. R The EXAMINE command is used to display the contents of one or more memory bytes in both hex and ASCII For example the command gt gt gt e 8000 80ff produces this output 0 22 2 8000 gt 0 80 8010 0 OA 43 8020 30 20 00 8030 20 32 30 8040 69 6D 65 CO 80 0 CO FF 06 CO FF 6C E2 CO FF 4E 1b N 4 4 3 2 8050 20 72 69 6 4 6 2 0 4 3 0 53 4 41 43 20 45 4 46 20 32 30 30 COSMAC ELF 200 3 6 70 79 72 69 67 68 74 20 28 43 29 0 Copyright 0 34 20 62 79 20 53 70 61 72 65 20 54 2004 5 0 47 69 7 6D 6F 73 2 20 20 41 6C 6 ime Gizmos All 7 68 74 73 20 72 65 73 65 72 76 65 64 rights reserved 5 6 66 53 20 42 49 4 53 20 43 6 1 5 BIOS Co 9 67 68 74 20 28 43 29 20 32 30 30 34 pyright C 2004 0 4D 69 6B 65 20 52 69 6C 65 79 2E OD by Mike Riley A 8060 gt 2 OD OA 8070 gt 70 79 72 8080 gt 20 62 79 8090 gt OA OD OA 46 6F 72 20 68 65 6C 70 20 74 79 70 For help typ 80A0 65 20 48 45 4C 50 2E OD OA 00 EO 64 99 71 00 EO HELP d q 80B0 64 98 F8 80 BF F8 00 AF F8 00 BD AD EF 8D F4 AD d x x X o t 80C0 gt 9D 7 00 BD 60 9 3A BD EO EO 64 97 8 FF BF F8 541 154 04 2 800 FE AF EF 9D F7 D5 60 8D F7 DA EO EO 64 89 O W U w Z d 80E0 00 BF AF EF FO AD FB FF 5F 8D F4 01 F5 80F0 8D 1F 30 E5 2F EO EO 64 88 9F FB 7F FD 8F o 0eyt A 10 1 2006 4 2
85. Spare COSMAC ELF 2000 Time Gizmos UsER S MANUAL rms TETT L ae ue FE a 4 Gizmos 5 dM 8 2 ELF 2000 ici ap Ax FE a NW o y ptt JP AM ie 0 Sixth Edition Copyright 2004 2006 by Spare Time Gizmos Visit our web site at www SpareTimeGizmos com Permission is granted to copy distribute and or modify this document under the terms of the GNU Free Documentation License Version 1 1 published by the Free Software Foundation with no invariant sections with the front cover text Portions Copyright 2004 2006 by Spare Time Gizmos and our URL and with no back cover text A copy of this license may be obtained from http www gnu org licenses fdl txt CONTENTS 1 OVERVIEW se tenia 1 1 1 REGULATORY 1 1 4 eset eser rine rss terne rie rese renes esr 2 1 2 SAFETY WARNING ERO viene ee eR cape desee awe dee nua ei ce E ave aeree indes a 2 1 3 MAP ARIES ORTUS UE 2 2 5 E 5 2 1 5 2 2 PART SELECTION
86. TN Ld 1 UMW SE sss 32012 i 27 SV E C 143 7 243 01 a 1 33 2 3 00 SI a 7 vd3 ID vl i 1 1010 vig BRL Sa ree NI 0 el 1 71 18088311 80 0 244 3 90 LG 8 ddl E 8 7 Vdl ve 7 amp e 4 158 5 135 O3 1 avon 9 5 2 Py 035 9 ues FE NAY By 51 6 20814412 DO 29 2 1 6 9 18d 8 4 DA 3 gt gt 2 lt Lasay 3 lt 2 154 2 2 215 1 4 Sag alt 1 dSid 1 0 wag l pu 7 poe 4 ELEOHVL Ky 555 14510 c y 9 8 C 2 REFER V 7 9 JO 6 133H 1041 02 80 21 12 02 O 511130 BO 3014 348321100 8345 cAB3S3H 514018 dw 1041 02 3715 804710 SuvdS AS 4002 2 1H91BAd00 413 3003843 2 lt gr 113 13 ETI 9 S13 SI2 023 angi Ae gal qe ale 55 i v veL oN LH 133 vn 235 2 7 13 dun 198 99 1 1n 110
87. TY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES THE ABOVE LIMITATION MAY NOT APPLY TO YOU IN NO EVENT SHALL SPARE TIME GIZMOS LIABILITY IN THE AGGREGATE EXCEED THE SUMS ACTUALLY PAID BY YOU TO SPARE TIME GIZMOS AND ACCEPTED BY SPARE TIME GIZMOS FOR THE USE OF THE ELF 2000 10 1 2006 4 23 PM Page 3 Spare Time Gizmos COSMAC Elf 2000 User s Manual 2 ASSEMBLY Many thanks to the Elf 2000 builders who have contributed their experiences suggestions and frustrations to this chapter 2 1 ERRATA There are no known errors in Revision C and later of the COSMAC Elf 2000 board To determine the revision of your PC board look for the text ELF2K 1x printed in copper along the edge of the PC board You ll find it near the video CDP1861 section In this text the x is the revision of your PC board for example ELF2K 1C for revision 2 2 PART SELECTION The complete parts list for the EIf 2000 is contained in Appendix A and with the exception of the CPD1802 CPU and the CDP1861 Pixie all parts are common modern devices that should be readily available Most part values are non critical and substitutions should not be a problem however when changing connectors or switches use care that the replacements will fit the footprint on the PC board 2 2 1 CPU Selection The EIf 2000 is intended to use the CDP1802CE CPU however this chip comes in many variations that will also work In particular the ACE and the ACD and even t
88. VANCED 53 7 7 ERROR GODES c oboe 55 8 oA 57 8 1 STACK 57 8 2 ARITHMETIC 57 8 3 GONTROL Pear i 57 8 4 MARIABEES bt cca hander 57 8 5 FUNCTION DEFINITION eene et e coa ehe deoa cea Pee Pat c bees pte a e Fee eee etd 58 8 6 STACK OPERATORS ns dedere LER e edo eee 58 8 7 OTHER F UNCTIONS 62 ie Se eee 58 8 8 EXTENDED F NCTIONS e ee e Gael E e Pe ed ee dade dd 58 8 9 ABASIC FORTHCTUTORIAE rtc te ieee salves e et eu bed e Ee Dx beet 59 8 10 DEFINITIONS OF EXTENDED 8 2 04 4 04 00 0 63 9 THESTG1861 VIDEO BOARD etie eroe 65 10 THE EMBEDDED ELF onore oed eco Ec Ee e e e LEE E E POE AVENUE e e eee epe 67 10 1 INTRODUCTION 2250 he cer E
89. ad not used Keypad lt ESC gt P VT52 F1 BLUE key Keypad VT52 F2 RED key Keypad lt ESC gt R VT52 GRAY key Keypad ENTER lt ESC gt M Table 37 Application Keypad Escape Sequences The four arrow keys always send the corresponding VT52 escape sequences shown in Table 38 regardless of the keypad application mode option Key 7 0000 UP ARROW lt ESC gt A DOWN ARROW lt ESC gt B LEFT ARROW lt ESC gt C RIGHT ARROW lt ESC gt D Table 38 Arrow Key Escape Sequences All the remaining keys do nothing This includes the function keys F1 thru F12 the Windows keys left right and menu the editing keypad INSERT DELETE HOME PAGE UP PAGE DOWN and END NUM LOCK SCROLL LOCK PAUSE BREAK and PRINT SCREEN The keyboard LEDs are not used including CAPS LOCK 13 5 4 Programming the PPI The 8255 PPI is a very versatile device and entire books have been written about using it to interface with all manner of peripherals This manual won t even attempt to cover all the things that can be done the reader is referred to one of the many books or web pages on the topic 13 5 5 Programming the Speaker The two speaker bits SPO and SP1 in the GPIO control register see section 13 5 1 control the speaker state as shown in Table 39 0 m 0 1 Fixed frequency tone 1 0 Follows the 1802 Q output
90. afely omit parts D16 J4 D6 JP6 JP9 and JP10 2 3 8 Status LEDs The status LEDs LED1 5 may be omitted simply by removing the LEDs and the associated resistors R1 R5 R6 R7 and R8 2 3 9 Expansion Bus Connector If you don t plan on adding any daughter cards you can omit the expansion bus connector J3 10 1 2006 4 23 PM Page 8 Spare Time Gizmos COSMAC Elf 2000 User s Manual 2 3 10 Power Supply Regulator If you always plan to use your Elf 2000 with an external regulated 5V power supply then you can omit VR1 along with any heat sink Be sure to solder a jumper wire between the input pin 1 and output pin 3 pins of VR1 to provide continuity for the power If you use an external regulated supply you must also replace D5 with a wire jumper otherwise the drop in Vcc across D5 would be excessive If you eliminate VR1 you can also get by without C1 however it is recommended that you keep C2 in all cases WARNING If you make this change your Elf will have no protection against reverse or over voltage inputs Connect the wrong power supply just once and you can easily fry all the chips in your Elf 2000 You have been warned 2 4 SOCKETS AND SOLDERING The instructions for every kit that have ever built all the way from the legendary Heathkit on down have always said that 90 of the kits that don t work after they re assembled fail because of the soldering The Elf 2000 PC board was laid out with
91. ain and it will be replaced If you specify a line number without any command then that line will be deleted from the program 10 PRINT HELLO 20 PRINT BYE LIST 10 PRINT HELLO 20 PRINT BYE 10 LIST 20 PRINT BYE As in the example above it is customary not to number each line right after another but rather to leave space between the line numbers This way if you need to insert something between two lines of your program there will still be line numbers available for the new line BASIC allows you to put multiple commands on the same line Each command needs to be separated by the character For example 10 FOR I 1 TO 10 PRINT I NEXT I The length of any line is limited to 252 characters 7 2 3 Numbers BASIC uses 16 bit integers for numeric computation The range of numbers allowed is from 32768 through 32767 When numbers are used in expressions if there is no leading sign the number is considered positive A sign is not needed before positive numbers 7 2 4 Variables BASIC allows two types of variables integers and strings BASIC allows for multiple character names which must start with A through Z and then can use A through Z as well as 0 9 Variable names are limited in length to 248 characters but for performance reasons should be kept to shorter lengths String variables must have a appended to the variable name for example A String variables can hold strings of characters of up to any
92. all daughter card that fits on top of the main EIf 2000 board and plugs into the U2 socket You should build and test the Elf 2000 first before beginning construction on the STG1861 It s necessary to do a trial fitting of the STG1861 daughter board to the EIf 2000 main board in order to get the pin length correct and this is much easier to do before you ve assembled the STG1861 When you are using the STG1861 do not install a conventional DIP socket at U2 instead install a pair of twelve pin 0 1 female header strips These strips are not part of the Elf 2000 kit but are included in the STG1861 full kit The female header strips mount on the top side of the Elf 2000 PC board and point up just as you d expect The STG1861 daughter board is physically attached to the Elf 2000 main board by three solder in swage standoffs three 72 stand offs and three 4 40 screws All of these parts are included STG1861 full kit You should solder the swages directly to the Elf 2000 PC board in the three large holes surrounding the U2 Socket The swages are installed with the threaded Photo 10 The STG1861 Board part on the top component side of the PC board and are soldered on the bottom solder side Photo 9 The Classic Pixie Demo 10 1 2006 4 23 PM Page 65 Spare Time Gizmos COSMAC Elf 2000 User s Manual Note that the swages require a considerable amount of heat to solder properly and your regular iron probably
93. ard the GPIO Disk board uses a two level I O scheme for accessing the PPI The programmer first writes a device register select code to one port and then accesses the selected register with another port Input Output Port 6 Read PPI data Write PPI Data Port 7 Read Keyboard data Write GPIO Control Register Table 35 GPIO Board I O Ports 10 1 2006 4 23 PM Page 85 Spare Time Gizmos COSMAC Elf 2000 User s Manual 13 5 1 GPIO Control Register The GPIO control register is used to control the speaker and select the 8255 PPI port Elf 2000 GPIO Board Control Register Bit 7 Bit 6 Bit 5 Bit4 Bit 3 Bit 2 Bit 1 Bit 0 X X SPEN SP1 SPO PPIEN PPI 1 PPI AO Table 36 GPIO Control Register This bit must be a 1 to enable loading the SPO 1 bits If this bit is a zero during and output instruction then the current SPO 1 values will not change This allows the firmware to change the PPI address without affecting the speaker state SPO0 1 These two bits select the current speaker state according to Table 39 PPIEN This bit must be 1 to enable loading the PPI 0 1 bits If this bit is a zero during and output instruction then the current PPI 0 1 values will not change This allows the firmware to change the speaker state without affecting the PPI address PPI 0 1 These two bits select the PPI port addressed by 1802 port 6 X don t care bits sh
94. ccessfully decoded the monitor prints OK and another prompt For example gt gt gt 1802000090B1B2B3B4F82DA3F 8F 8A2F811A1D37270C422782252F80009 OK gt gt gt In case you ve forgotten the standard format for a HEX record is i llaaaattdddddddddddddddddddddddddddddddddddd cc where 11 is the number of data bytes in this record aaaa is the loading address of the data tt is the record type dddd dd are the actual data bytes and cc is the checksum of the entire record Currently the only two record types recognized by the monitor are 00 normal data and 01 end of file It s possible to download entire programs to the Elf 2000 this way refer to section 4 9 5 16 SEDIT The SEDIT command invokes Mike Riley s disk Sector Editor which is resident in EPROM gt gt gt sedit SEDIT gt RIA SEDIT gt H 100 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF OO 110 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FEF FF 00 FF L20 EP ER EP 00 EP EF 00 PE ORR 00 BP EP OO BR EP 44 444445 ARR 130 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 140 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF 150 FF 00 FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 160 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FE 00 170 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FF 180 FF 00 FF FF 00 FF FF 00 FF FF 00 FF FF 00 FE FF 190
95. ch call the VT52 emulator firmware in the Elf 2000 EPROM directly and use that to display text on the VT1802 4 6 Monitor DATA The monitor reserves one page of RAM memory from 7F00 to 7FFF Modifying bytes in this page with the DEPOSIT command may cause unpredictable results including system hangs and monitor crashes Any machine language programs you write should avoid this page of memory and naturally you should not attempt to download any data to it If you do manage to corrupt the monitor s data page and you happen to have the battery backup option then even a reset or power cycle may not clear the problem In this case you can try setting the switch register to 0100 0011 see section 4 7 and rebooting this will force RAM to be cleared If that doesn t work or if you don t have a switch register then the only other option is to turn the power off remove the Lithium backup battery wait a few minutes for the RAM to discharge and then turn the power back on again Any time the VT1802 video card is installed whether or not the GPIO is also installed the monitor also reserves 2048 bytes of RAM memory from 7700 to 7EFF for use as a frame buffer and to hold local variables for the VT52 emulator code Any programs you write should also avoid using this area of memory if you plan to use the VT1802 The BIOS f freemem function see Appendix E for the EIf 2000 knows about the monitor s data page at 7F00 and always adjusts the amount o
96. cified it will be printed before the program queries for input Multiple variables may be input at the same time and the BASIC expression evaluator is used when reading input values so you can specify expressions for input values If not enough values were given for the number of variables specified in the INPUT command then multiple queries will be made of the user If the user gives more values than INPUT is expecting remaining values will be read by the following INPUT commands For example 10 B 5 20 INPUT VALUE A 30 PRINT A RUN VALUE 10 10 RUN VALUE B 5 25 10 INPUT VALUES A B 20 PRINT A B RUN VALUES 4 5 4 5 RUN VALUES 4 2 4 5 10 INPUT VALUE 1 20 INPUT VALUE 2 B 30 PRINT A B RUN VALUE VALUE NPR 1 4 0 RUN VALUE VALUE Ry NOR 1 1 10 1 2006 4 23 Page 49 Spare Time Gizmos COSMAC Elf 2000 User s Manual 7 5 10 LET variable value The LET statement assigns values to variables however the use of the LET keyword is optional in BASIC For example LET A 5 2 7 10 7 5 11 LIST This command will list the entire program memory usage LIST line will list only the specified line number If the specified line number does not exist then an error will be generated The longer form of this statement LIST start end will list all lines between the specified starting and ending line numbers Neither the starting
97. cts the 1861 s DISPLAY STATUS output to the CPU s EF1 input Normally all three of these jumpers would be installed if the CDP1861 chip is being used and all three would be removed if the 1861 is not installed or not used Photo 5 shows the position of jumpers JP1 JP7 and JP8 3 22 JP4 Jumper JP4 enables the auto bootstrap feature of the Elf 2000 If JP4 is installed then the CPU begins executing instructions at address Photo 5 JP1 JP7 and JP8 0x8000 after a hardware reset Since 0x8000 is the first location in the EPROM installing this jumper has the effect of causing the CPU to execute the EPROM bootstrap after a reset If jumper JP4 is not installed then the 1802 CPU begins executing instructions at location 0x0000 after a reset This Photo 6 JP4 address is normally mapped to the first location in the SRAM Needless to say it s your job to ensure that the RAM contents are meaningful either by using the toggle switch bootstrap or some other means before using this option Photo 6 shows the position of jumper JP4 3 2 3 JP5 Jumper JP5 is used to select the type of CPU installed in the EIf 2000 JP5 must be installed for a CDP1802 CPU If a CDP1805 or CDP1806 chip is being used for the CPU instead JP5 must be Photo 7 JP5 removed Output driven by the ELF 2000 board Open Drain with a 10K pull up resistor on the ELF 2000 PC board 10 1 2006 4 23 PM Page 17 Spare Time Giz
98. d the software can read or write the addressed memory location by reading or writing 1802 I O port 3 WARNING A quirk of the clock calendar chip requires that the address register be rewritten after every RTC NVR access For example it is not possible to load the address write a byte and then read that byte back You must load the address write a byte reload the same address and only then can you read back the same byte 11 6 PROGRAMMING TIPS AND OBSERVATIONS 11 6 4 IDE To be added g n Spare po dedii 4 7779 Photo 14 Disk Board Installed on Elf 2000 11 6 2 UART The 16450 550 UART features an internal baud rate generator which the software must program before the UART can be used In the case of the Elf 2000 Disk board the baud rate clock used is 2 4576Mhz not the 3 072MHz that s shown on some 16450 550 data sheets 2 4576 MHz will give an integral baud rate divisor for all standard baud rates from 300bps thru 153 600bps The only difference between the 16450 and the 16550 UART is that the 16550 contains an internal 16 byte FIFO and the 16450 does not Either can be used in this circuit so long as the software supports it Refer to the 16450 550 data sheet for more information 11 6 3 RTC NVR The DS12887A NVR RTC chip internally uses addresses 0x00 to OxOD to address real time clock and calendar registers Addresses 0 0 to Ox7F address 114 bytes
99. deo output from your EIf 2000 then there s no reason why you need either the CDP1861 or the STG1861 replacement Just leave these parts unpopulated and your EIf will work just fine without them 2 2 3 SRAMs If you intend to use a battery backup for your Elf 2000 be sure to use an LP low power suffix SRAM chip The standard 62256 SRAMs chips have stand by currents 100 times that of the low power versions and will drain the Lithium cell in a few hours If you do not intend to use battery backup then any 62256 SRAM may be used 2 2 4 EPROM A 27C256 EPROM is used to hold the monitor program power on self test diagnostics programming languages and disk operating system BlOS bootstrap The EPROM is optional and may be omitted if you intend to only toggle in programs with the switches If the EPROM is installed be sure to insert jumper JP4 to force execution to begin at address 0x8000 the first byte in the EPROM after a RESET If the EPROM is not used remove JP4 so that execution will begin at 0x0000 the first byte in RAM after a RESET Refer to section 3 2 2 for more information on JP4 2 2 5 GALS One GAL is used in the Elf 2000 to decode I O addresses memory addresses and some of the status LEDs Not only does this save a great deal of random logic but it also makes reconfiguration of I O addresses and or the memory map a simple matter Refer to section 3 4 for more information on reconfiguring your GAL If you are concerned
100. down i e solder side up with the DE9 serial RCA video and coaxial power connectors pointing away from you then the ribbon cable attached to J5 should have a BROWN conductor at the far right side and a BLACK wire on the far left side If you do it this way then wiring the switch panel is easy Table 1 summarizes the wiring between the switches and J5 you may also wish to refer to the Elf 2000 schematic page 3 for more detailed information Notice that there are three ground connections in J5 normally pin 19 is used as a ground for the eight data switches pin 12 for the LOAD and INPUT switches and pin 20 for the RUN and MP switches There s no magic to this though and you can assign the grounds any way you wish The RUN switch is upside down because the associated function is really RESET i e NOT When the RUN switch is down the RUN RESET input should be grounded i e the switch is ON and when the RUN switch is UP i e processor running the RUN RESET input should be open i e the switch is OFF MP memory protect works the way you d expect when the MP switch is UP the MP input is grounded i e switch ON and memory is protected PIN Switch Color PIN Switch Color 1 BROWN 2 N C Vcc RED 3 D7 ORANGE 4 LOAD NC YELLOW 5 D6 GREEN 6 LOAD NO BLUE 7 D5 VIOLET 8 INPUT NC GREY 9 D4 WHITE 10 INPUT NO BLACK 11 D3 BROWN 12 GND RED 13 D2 ORANGE 14 N C
101. ds 7 2 ENTERING PROGRAMS 7 2 1 Direct Mode BASIC has two modes of operation direct and stored program In direct mode BASIC will attempt to execute what you type immediately PRINT HELLO WORLD HELLO WORLD Direct mode can also be used for doing calculations in other words it can be used as an elaborate calculator Here are some more examples PRINT 5 4 20 A 10 B 20 PRINT A B 200 In direct mode you can use variables in addition to numbers It is important to know however that any values stored in variables will be cleared whenever a program is RUN 10 1 2006 4 23 PM Page 41 Spare Time Gizmos COSMAC Elf 2000 User s Manual 7 2 2 Program Mode In stored program mode lines that are entered are not immediately executed but are stored into program memory as part of a whole program To store a line into memory you just add a line number in front of the command 10 PRINT HELLO This line would then be added to the stored program The numbers in front of the command specify where in the program this line should be inserted The lower the number is the more towards the beginning of the program So for instance line 10 will be executed before line 20 If a line already exists with the same line number then it will be overwritten 10 PRINT HELLO LIST 10 PRINT HELLO 10 PRINT BYE LIST 10 PRINT BYE This is how your programs are edited If you have a mistake in a line all you have to do is type the line ag
102. e use of parentheses 7 3 2 Expression Examples Here are some expressions and their results to help illustrate these rules Table 10 Examples of BASIC Expressions Expression Result 2 5 3 13 2 5 3 16 2 7 5 AND 3 1 5 3 lt 4 5 5 3 4 0 3 lt 4 5 lt 6 1 10 1 2006 4 23 43 Spare Time Gizmos COSMAC Elf 2000 User s Manual In addition to numbers and variable references the following functions can also be utilized in expressions ASC FLG FRE INP LEN PEEK RND USR VAL and VARPTR These functions are described in section 7 4 7 3 3 String Expressions The only valid operator for string expressions is the concatenation operator which is the symbol The concatenation operator will create a new string that consists of both strings that are arguments of the concatenation For example 10 AS ABC 20 BS DEF 30 5 5 5 40 PRINT C RUN ABCDEF In addition to the concatenation operator there are the following string functions which may be used in string expressions CHR LEFT MID RIGHT and STR These functions are described in section 7 4 For example 10 AS ABCDEF 20 B XYZ 30 CS LEFTS A 3 40 PRINT C RUN ABCXYZ 7 4 BUILT IN FUNCTIONS 7 41 ASC string expression This function will return the ASCII value for the first character in the specified string expression For example PRINT ASC ABC 65 PRINT ASC 1
103. easonable size for SP1 and the board contains several holes for this device to accommodate different lead spacings If you use a piezo speaker be sure that it is of the passive variety and doesn t already contain a built in oscillator Be aware that piezo speakers have limited frequency response and are loudest around their resonant frequency you may wish to adjust the value of C3 to change the 7555 oscillator frequency to match I 4 1 LI 4 Lu 4 4 a LI LU 4 4 1 Photo 16 Elf 2000 GPIO Card 10 1 2006 4 23 PM Page 84 Spare Time Gizmos COSMAC Elf 2000 User s Manual the piezo speaker you use If you intend to play music you ll be much happier with a miniature dynamic loudspeaker 13 2 1 Optional Subsystems If you don t want the PS 2 keyboard interface you can omit U1 U2 LED1 J2 and the associated passive components R1 3 F1 C1 2 1 etc from the GPIO If you don t want the PPI you may omit U5 and the associated headers J5 7 Note that you still need U4 and U6 even if you don t have the PPI unless you also intend to omit the speaker too If you don t need the speaker you can omit SP1 and U7 along with the associated passive components R4 5 and C3 You still need U4 and U6 unless you intend to omit the PPI also If you don t need either the PPI or the speaker i e you want a PS 2 keyboard interface only then you can also omit U4 and U6 in addition to t
104. ed below the state of the stack is shown in parentheses Symbols before the represent the stack before the instruction is executed symbols after the represent the stack after execution The top of stack is to the right Example 1 2 3 This shows that 2 is on the top of the stack and 1 is 2nd from the top after the instruction is executed 3 will be on the stack the 1 and 2 will be consumed 8 2 ARITHMETIC OPERATORS ab Add top 2 stack entries Subtract top 2 stack entries Multiply top 2 stack entries Check equality 1 equal O unequal ab c Check inequality 1 unequal O equal Logically and top 2 stack values Logically or top 2 stack values Logically xor top 2 stack values Table 12 Forth Arithmetic Operators 8 3 CoNTROL OPERATORS BEGIN Beginning of BEGIN UNTIL loop UNTIL gt Ending of BEGIN UNTIL loop WHILE gt Beginning of while repeat loop REPEAT End of while repeat loop DO TS Start of DO LOOP I Put current loop count onto stack LOOP End of DO LOOP LOOP v End of loop with specified increment IF gt Beginning of IF ELSE THEN structure ELSE 2 ELSE portion of IF ELSE THEN THEN End of IF ELSE THEN gt R a Move top of data stack to return stack R gt a move top of return stack to data stack Table 13 Forth Control
105. en sq 11052 asoa 2 6 eG 2100 Ld lt 4 no 9 sa a ca za usd n 1 usd 711 LE I 111 axl LL 1I a 2 2 SM 66 50 92 ZS 9 ELE 15 8 6 4 4723 8c 0S 2 gn axa vI3 5 ibi el lavn 52 We vis 22 ey ee es 81 7 n 211 1 le 11 01 _ 21 1 ala A LI 1 ce T YH H3 lt LN ZHW9LSv 2 01 YW 690 SN PEE JE 401 uc 1H 1S2 eUco SMH 5 9 291 099 5 ant ee 301 z 1701X 1 z ui 259291 CUIR gn 2 I 2 y T 5 9 L 8 e y S E 40 I 13395 TdvdAsy 90 2 88 60 01 2 81710130 40 3714 38 4011 OL 83458 3AH3838 018 dV Java IVkIJJTVXJH 3715 504719 S8vdS A8 9002 9 1 015 IVdA 3M 21 2 ABS 30170 ANY SHOLIOVdVO SSVdAG 08 11 A 61 1 21 2762 92 L9 82 e IP 100 pap 55 H LAdNI 21 3 lt LMdNI 5 1 1 A9 NI 100 110 62 asn 1 LNdNIGd ere 9s 6 AS 223121 arn J lt 1 d338A34 1 0355359 11 1 d338A3
106. enced outer loop will cease to exist and execution continues with the referenced loop Here are some examples of the FOR NEXT statement 10 FOR I 1 TO 10 20 PRINT I 30 NEXT I RUN L2 3 4 56 T 8 amp 9 10 10 FOR I 1 TO 10 STEP 3 20 PRINT I 30 NEXT I RUN 147 10 This next example may require a bit of explanation so that you will understand why the results are the way they are In line 40 we are testing for J 2 and if so we execute NEXT At this point loop J is the innermost nested loop but by using NEXT this will terminate the J loop right where it is and start the next iteration of the loop When the loop finishes the END following the NEXT is the next executed statement which ends the program so the print at line 60 will never be Seen 10 1 2006 4 23 PM Page 47 Spare Time Gizmos COSMAC Elf 2000 User s Manual 10 FOR I 1 TO 5 20 FOR J 1 TO 10 30 PRINT I J 40 IF 2 2 NEXT I END 50 NEXT J 60 PRINT WILL NEVER SEE THIS 70 NEXT I 40 0 A 7 5 6 GOSUB line number The GOSUB command allows normal program execution to be interrupted so that a subroutine could be executed Like GOTO BASIC allows for computed GOSUB for example GOSUB B 100 If the target line of GOSUB does not exist then an error 3 will result When a RETURN command section 7 5 21 is encountered program execution will continue with the statement following the GOSUB 7 5 7 GOTO line number The GOTO command chan
107. er a name for the connection e g elf2k and pick an icon elf 2k Properties Connect Settings from the list Click OK Function arrow and ctrl keys act as 3 In the Connect To Dialog Terminal keys Windows keys select the PC COM port from the Connect Using drop Backspace key sends down list Leave the other Del Space fields e g area code phone number etc blank Click p Emo m 4 In the COMx Properties Dialog see Figure 2 pick 2400 Bits per Second 8 Telnet terminal ID Data Bits None sic Parity 1 Stop Bits and None Flow Backscroll buffer lines 500 control Click OK 5 At this point the main HyperTerminal window opens Before proceeding Pick File gt gt Properties from the HyperTerminal menu bar 6 In the elf2k Properties window see Figure 3 that appears be sure the Backspace key sends Ctrl H radio button is selected set the terminal emulation to TTY and click the ASCII Setup button ASCII Setup 7 n the ASCII Setup Dialog see Figure 4 ASCII Sending under ASCII Sending ensure that Send Sond ine ands wih ina laai line ends with line feeds and Echo typed characters locally are both unchecked L_ Echo typed characters locally Enter 150 in the Line delay edit box and 15 Line delay 150 T millisecond for the Character delay For ASCII Receiving ensure that Force incoming data milliseconds
108. er in R2 a break point can be placed in your program with this two byte sequence MARK 79 SEP R1 5 1 When a break point occurs the monitors break point routine will save the CPU s context including X P D DF and registers 2 thru F into the monitors data segment This process requires three bytes on your stack before control can be transferred to the monitor s stack Registers R1 and RO are not saved by the break point routine Presumably this is not a problem in the case of R1 since you were using it for the break point program counter anyway but you might regret the loss of RO And in particular this precludes the use of the break point feature with any code that uses either interrupts or DMA or both WARNING Let s say that again the monitor s break point feature does not save and hence the CONTINUE command cannot restore the contents of registers RO or R1 All other CPU state is saved After saving the CPU state the monitor s break point routine will print out the entire CPU status BREAKPOINT XP 23 D AA DF 1 RO 0000 R1 0000 R2 7F7D R3 0102 R4 FA7B R5 FA8D R6 82A0 R7 7FA8 R8 0000 R9 82DE RA 8CF7 RB FEFF RC 7FAF RD 0100 RE 1100 RF 7FB7 and then a command prompt You can use the EXAMINE and or DEPOSIT commands to poke around in what your program is doing and you can also use the CONTINUE command to restore the CPU s state and continue execution of your machine language program If you do elect to continue
109. er used by the READ statement If no line is specified then the DATA pointer will be set to the first data item of the first DATA statement in the program If a line number is specified then the DATA pointer will be set to the first item of the first DATA statement line that is on or later than the specified line Note that it is not necessary to specify the DATA line number exactly however the line referenced by the RESTORE command must exist even if itis not a DATA line If the line does not exist at all an error 3 will result For example 10 DATA 1 2 3 4 5 20 DATA 10 11 12 13 30 READ A B C 40 PRINT A B C 50 RESTORE 60 READ A B C 70 PRINT A B C 80 RESTORE 20 90 READ A B C 100 PRINT A B C RUN 1 2 3 1 2 3 10 11 12 7 5 21 RETURN This command will return execution back to the statement following the last executed GOSUB command If there are no more GOSUB targets left on the stack then an error 4 will result and the program will be terminated For example 10 1 2006 4 23 PM Page 52 Spare Time Gizmos COSMAC Elf 2000 User s Manual 10 PRINT A 20 GOSUB 100 30 PRINT C 99 END 100 PRINT 110 RETURN RUN A B G 7 5 22 RUN RUN begins execution of the program in memory Execution always starts with the lowest line number and all variables and heap space is cleared This command may be used inside of a program in order to restart the program from the cleared state 7 6 ADVANCED TECHNIQUES 7 6 1 Usin
110. er with a sponge for cleaning They do a better job removing oils but remember to rub ever so gently heavy scrubbing will remove the silkscreen the solder mask and even the plating Just one light wipe with a wet and soapy Brillo pad is all it takes Lastly and most importantly make sure the board is completely dry before you start soldering Even a tiny amount of water left in a hole will turn to steam when soldering heat is applied and blow the solder right out of the hole If you have it canned air is ideal for removing water from the holes and can be used to accelerate the drying process Use care to avoid solder bridges to adjacent traces and pads Some of the bypass caps are also very close to traces and when you nip the leads on these check that your cutters cut cleanly and don t cause shorts And finally be careful not to use too much solder on the pins excessive solder can wick up the pin to the top side of the board and cause invisible because they re hidden under the IC socket shorts there 1 Yes I m old enough to have built one or two missed their golden years though 10 1 2006 4 23 PM Page 9 Spare Time Gizmos COSMAC Elf 2000 User s Manual strongly advise using good high quality machined pin sockets for all ICs These sockets admittedly expensive a 16 pin DIP socket might cost 50 cents and a 40 pin DIP more than dollar but they re worth it if you ever need to replace an IC Some people
111. escape sequences that are not implemented by the VT1802 These will all be ignored if sent to the VT1802 Escape Sequence Function lt ESC gt Enter Alternate Keypad Mode lt ESC gt gt Exit Alternate Keypad Mode lt 5 gt 2 Identify Table 32 Unsupported Escape Sequences 10 1 2006 4 23 PM Page 82 Spare Time Gizmos COSMAC Elf 2000 User s Manual 12 6 4 Standard ASCII Control Characters Recognized by the VT1802 In addition to the escape sequences the VT1802 firmware recognizes many standard ASCII control characters Table 33 summarizes these characters and their actions Code Character Function 0x00 NUL ignored Ox7F DEL ignored 0x07 BEL Ring the Bell on the GPIO card 0x08 BS Backspace same as Cursor Left 0x09 Horizontal Tab Ox0A LF Line Feed OxOB Vertical Tab same as Line Feed 0 0 FF Home Cursor and Erase Screen Same as lt ESC gt E OxOD CR Carriage Return OxOE SO Select Graphics Character Set Shift Out OxOF SI Select Normal Character Set Shift In 0 1 ESC Escape Sequence Prefix Table 33 Standard Control Characters All other control characters not listed in this table are ignored 10 1 2006 4 23 PM Page 83 Spare Time Gizmos COSMAC Elf 2000 User s Manual 13 THE GPIO CARD 13 1 INTRODUCTION The Spare Time Gizmos Elf 2000 General Purpose I O board GPIO in
112. f 2000 has no provisions for doing this If you have an actual CDP1804 chip that you re willing to part with please contact Spare Time Gizmos and we ll see what can be done about making it work 2 2 20 CDP1861 Pixie Chi The CDP1861 is the standard video generation chip used by the original COSMAC EIf and by a generation of video games powered by the 1802 CPU including the RCA VIP Unfortunately CDP1861 chips have become quite scarce in recent years and you may have difficulty finding one If you do happen to have a real CDP1861 chip then by all means use it it s intended to work in this circuit However if you don t have a CDP1861 then there s no need for despair Spare Time Gizmos makes a replacement for the 1861 which consists of a small daughter PC board that plugs directly into the 1861 socket on the EIf 2000 The STG1861 as it s called contains two GALs and two 74HC parts and is functionally equivalent to the original CDP1861 The software cannot tell the difference If you use either the CDP1861 or the STG1861 be sure to install jumpers JP1 JP7 and JP8 see section 3 2 1 to enable the DMA INTERRUPT and EF1 outputs from the Pixie WARNING If you don t have a CDP1861 chip and you plan to use the STG1861 at some point in the future then do not install a socket at U2 The STG1861 uses a special header to make connections and can not be used if a standard DIP socket has been installed Of course if you don t want vi
113. f a particular test fails the processor will halt leaving the code for that test visible on the display Thus it s easy to identify the cause of a failure from the two digit POST code shown Appendix B gives a list of the current POST codes and their meanings These are current as of EPROM monitor version 76 Note that many of these codes are not necessarily errors they simply show progress thru the sequence of tests A POST code is only a problem if the system halts while it is displayed 4 4 SERIAL CONSOLE AUTO BAUD After the majority of the POST is completed the monitor will attempt to determine the console terminal port and baud rate by waiting for you to type either a carriage return CR or a line feed LF character A carriage return will also enable monitor echo of all future input a line feed does not In the latter case it s presumed that your terminal has a local echo feature The data display POST code will show 16 while the monitor is waiting for you to type CR or LF Either the serial port on the main board or the UART serial port on the Disk Expansion card may be used for the console terminal and during the auto baud phase the Elf 2000 will respond to which ever port receives a CR character first With a 3 579545 MHz clock the Elf 2000 mother board serial port is able to support any baud rate up to 2400bps The UART serial port supports any standard baud rate from 2400bps thru 19 200bps regardless of the CPU clock T
114. f free memory accordingly Better yet the BIOS is also able to determine whether the VT1802 option is installed and if it is adjust the amount of 10 1 2006 4 23 PM Page 23 Spare Time Gizmos COSMAC Elf 2000 User s Manual free memory downward to allow for the VT1802 frame buffer Thus the safest and most portable option is to always use the BIOS f_freemem function to determine the amount of available RAM 4 7 STARTUP OPTIONS During the power up sequence the monitor can recognize several special patterns of the toggle switches in the switch register and perform special startup actions Currently three such special patterns are recognized SWITCHES Startup Action 1000 0001 special CHM startup mode 0100 0010 force SRAM to be initialized 0100 0011 force SRAM and NVR both to be initialized Table 5 Special Startup Options To use one of these options the switches must be set to this pattern before the CPU is reset or power applied For a normal startup sequence the switches may be set to any other pattern all zeros are recommended 4 8 USING THE MONITOR BREAKPOINT FEATURE Whenever the monitor starts one of your machine language programs running whether it is with the CALL or the RUN command it will initialize R1 with the address of a breakpoint routine that is a part of the monitor Provided that your program does not change the contents of H1 and provided that your program keeps a valid stack point
115. g VARPTR VARPTR is a function that allows you to determine where in memory something is stored The following sections describe what the VARPTR function returns for the different variable types in BASIC 7 6 1 1 Integer Variable VARPTR A When obtaining the address of an integer variable VARPTR will return the address where the variables value is actually stored Here is an example 10 I 5 20 PRINT PEEK VARPTR I 30 PRINT PEEK VARPTR I 1 RUN 0 5 Integer variables are stored with the MSB first in memory and then the LSB second Using the address you get from VARPTR you can also change the data in a variable 10 5 20 POKE VARPTR I 1 10 30 PRINT I RUN 10 7 6 1 2 String Variable VARPTR A When using VARPTR on a string variable the address returned points to the address of where the string data is stored Unlike integer variables there is one level of indirection in the address For example 10 5 20 M VARPTR AS 30 M PEEK M 256 PEEK M 1 40 POKE M 49 50 PRINT AS 1BC 10 1 2006 4 23 PM Page 53 Spare Time Gizmos COSMAC Elf 2000 User s Manual In this example line 30 is what takes the address that VARPTR returned and then reads the address of the actual string data Just like in integer values address values are stored MSB first Unlike many other BASICs Elf 2000 BASIC does not use a length byte for strings This has the benefit that strings can be longer than 255 characte
116. g software for people new to computers hence Beginners in the name BASIC is a very easy language to learn and is capable of performing a wide range of tasks hence all purpose Early computers were programmed in codes that were difficult to use and required a lot of for thought on the part of the programmer on how data and program code is stored in memory This made early programs difficult to write and very difficult to modify Higher level languages were developed in order to abstract away the specifics on how the computers actually worked and making it easier for programmers to write and maintain their software There are two basic types of higher level languages compilers and interpreters A compiler takes the program that the developer wrote and translates it into the machine code that the computer understands Interpreters typically use intermediate code rather than direct machine language A line of a program is tokenized or converted to the intermediate code and then the interpreter looks at the codes and executes subroutines in the interpreter to handle each token BASIC is an interpreted language It accepts input from the user and either immediately executes the command or stores it in memory for later execution The advantage of an interpreter is that it allows you to quickly see what your commands will do With a compiler you would have the steps of converting your code into machine language before you could see the results of your comman
117. ges the order of execution Normally a program is executed from the lowest numbered line to the highest numbered line When a GOTO is encountered a jump is taken to the specified line BASIC allows for computed GOTO for example GOTO A 1000 If the target line of a GOTO either explicit or computed does not exist then an error 3 will result and program execution will be terminated GOTO can also be used in direct mode in order to start a program from a specified line For example 10 A 5 20 PRINT A RUN 5 100 GOTO 20 100 Note that when GOTO is used to start execution that variable and heap space are not cleared as they are when using RUN to start a program 7 5 8 expression THEN statement The IF command allows for decisions within a program In BASIC the THEN is optional If when the expression is evaluated and results in a nonzero value the statements following THEN will be executed If the results of the expression are zero then execution will follow through to the line following the line containing the IF statement For example 10 1 2006 4 23 PM Page 48 Spare Time Gizmos COSMAC Elf 2000 User s Manual 10 A 5 20 IF lt 10 PRINT A PRINT B 30 PRINT C RUN A B Change line 10 to 10 A 100 RUN Note that IF THEN statements be nested 7 5 9 INPUT variable variable This statement allows a program to get input from the user If the optional prompt is spe
118. gnaling levels for the RS 232 port however it has one significant limitation The DS275 is capable of half duplex operation only That is the serial port can receive characters and it can transmit characters but it cannot do both at the same time Since the serial port in the EIf 2000 is intended to be used with a software UART algorithm in the 1802 CPU this is not a serious limitation Except that is on one situation There are some UART algorithms that implement the echo of characters read at the bit level That is the character read routine attempts to echo each bit back to the Q bit output as each bit is being read That s full duplex and will not work you ll get unexplained garbage characters with the DS275 The solution is to change to a character level echo instead read an entire 8 bit character and assemble all the bits into a byte and then echo the entire 8 bit character affer input is finished This algorithm works fine with the DS275 and the different is imperceptible to the user 10 1 2006 4 23 PM Page 20 Spare Time Gizmos COSMAC Elf 2000 User s Manual 4 SOFTWARE DESCRIPTION You can program a 27C256 EPROM with any 1802 code you like and install it at U3 or you can use the standard EPROM software provided by Spare Time Gizmos The standard EPROM contains several distinct software modules including A monitor written by Spare Time Gizmos which provides hardware diagnostics program debugging and downloading feat
119. h simple variables as well as arrays 10 1 2006 4 23 PM Page 46 Spare Time Gizmos COSMAC Elf 2000 User s Manual For example 10 DIM A 5 20 FOR A 0 TO 5 A A A 2 NEXT 30 FOR 1 0 TO 5 PRINT A I NEXT RUN 0246810 10 DIM 10 10 20 FOR Y 1 TO 10 FOR 1 10 A X Y X Y NEXT NEXT 30 FOR Y 1 TO 10 FOR X 1 TO 10 40 IF lt 10 PRINT 50 IF gt 9 IF lt 100 PRINT 60 IF 100 PRINT 70 PRINT A X Y 80 NEXT PRINT PRINT RUN 3 4 5 6 7 8 9 10 6 8 10 12 14 16 18 20 9 2 15 48 21 24 2 330 2 16 20 24 28 32 36 40 10 20 30 40 50 60 70 80 90 100 7 5 4 END This statement will cause the program to terminate 7 5 5 FOR variable start TO end STEP step and NEXT variable The FOR statement allows you to build controlled loops into your programs FOR requires a variable to store the current loop value in as well as the start and ending values for the loop The loop will end when the value in the loop variable exceeds the end value STEP is optional and if omitted a step of 1 is assumed If STEP is provided then the expression following STEP is added to the loop variable each time through the loop NEXT provides the endpoint of the loop The variable reference in NEXT is optional if the NEXT is referring to the FOR at the same level It is also possible to specify a variable for NEXT that is in an outer loop in this case all loops inside of the refer
120. hat are unsupported 12 6 4 Standard VT52 Compatible Escape Sequences Table 29 summarizes the VT52 compatible escape sequences supported by the VT1802 Escape Sequence Function lt ESC gt A Cursor Up lt ESC gt B Cursor Down lt ESC gt C Cursor Left lt ESC gt D Cursor Right lt ESC gt H Cursor Home lt ESC gt Scroll Up Reverse Line Feed lt ESC gt J Erase to End of Screen lt ESC gt K Erase to End of Line lt 5 gt lt row gt lt gt Direct Cursor Addressing lt ESC gt Select Graphics Character Set Select Normal Character Set Table 29 VT52 Compatible Escape Sequences The lt ESC gt Y sequence is followed by two data bytes which indicate the line and column in that order that the cursor is to move to Both values are biased by 32 so that they appear as printing ASCII characters The line number character should be in the range 32 to 55 decimal and the column number character may range from 32 to 112 decimal If either byte is out of range then the cursor will only move as far as the margin 12 6 2 VT1802 Extended Escape Sequences Table 30 summarizes the extended escape sequences supported by the VT1802 These are not present on the VT52 Escape Sequence Function lt 5 gt E Home Cursor and Erase Screen lt 5 gt R char Raster Test The symbol lt ESC gt refers to the ASCII code 1033
121. he character format used by both ports is 8 N 1 8 data bits no parity and 1 stop bit regardless of the baud rate After recognizing your terminal s port and baud rate the monitor will print a sign on message that looks something like this COSMAC ELF 2000 EPROM V48 CHECKSUM BA24 SRAM 32K INITIALIZED The monitor will remember the console port baud rate in RAM and if your Elf 2000 has the Lithium battery backup option installed on subsequent startups the monitor will skip the auto baud step and re use the last baud rate memorized your Elf has the Disk Expansion card installed with the Non volatile RAM NVR option then the monitor will remember the console port and 11 The line feed no local echo option may be used with the mother board serial port only The UART serial port supports only the CR local echo option 10 1 2006 4 23 PM Page 22 Spare Time Gizmos COSMAC Elf 2000 User s Manual baud rate NVR even if the main memory does not have the battery backup option If this should become a problem set the toggle switches to 0100 0011 see section 4 7 before rebooting to erase the memory see section 4 7 4 5 VIDEO CONSOLE EMULATION If both the VT1802 80 column video card Chapter 12 and the GPIO card Chapter 13 are installed and pass the power on self test then the monitor will automatically use them to emulate a VT52 style terminal as the Elf 2000 console 1802 card provides the display out
122. he CD versions will work just fine with no changes f you are using an 1802 CPU of any type then be aware that jumper JP5 must be installed see section 3 2 3 JP5 is installed by default The enhanced versions of the CDP1802 the CDP1805 and CDP1806 may also be used in the EIf 2000 provided that jumper JP5 is removed see section 3 2 3 The 1805 6 offer many additional extended instructions which were not available in the standard 1802 however the 1805 6 implement IDLE mode in a way which is incompatible with the CDP1861 Pixie chip or the STG1861 replacement This may cause problems for any graphics software which uses the IDL 0x00 instruction Finally the 1805 6 CPUs 3 Hin s 1 ATLETI do not implement the Load Mode of Bilbo the 1802 and this will render the Spar 2 d LOAD toggle switch useless For 2 ec lt d this reason the CDP1805 6 CPUs Gi are recommended for use without the izmos toggle switch panel only 7 8 0 The CDP1804 is CDP1805 with 34 4 5 i incipe 9 __ Sosmac ELF 200 internal program ROM principle a special startup sequence can be Photo 2 Assembled Elf 2000 10 1 2006 4 23 PM Page 5 Spare Time Gizmos COSMAC Elf 2000 User s Manual used with the 1804 to disable the internal ROM and force program execution from external memory however the El
123. he IRQ output from the UART chip however before an 10 1 2006 4 23 PM Page 72 Spare Time Gizmos COSMAC Elf 2000 User s Manual interrupt can actually occur jumper JP3 on the Elf 2000 Disk board must be installed and the software must enable the 1802 interrupt system RTC IRQ This bit is one if the DS12887A RTC NVR is requesting an interrupt and zero if it is not This bit always reflects the state of the IRQ output from the RTC NVR chip however before an interrupt can actually occur jumper JP2 on the Elf 2000 Disk board must be installed and the software must enable the 1802 interrupt system DISK IRQ This bit is one if the IDE or CF card is requesting an interrupt and zero if it is not This bit always reflects the state of the IRQ output from the IDE CF subsystem however before an interrupt can actually occur jumper JP1 on the Elf 2000 Disk board must be installed and the software must enable the 1802 interrupt system 11 5 2 Device and Register Select Bytes written to the device register select port use one of three different formats depending on the device selected To select the IDE or Compact Flash interface use the format shown in Table 22 Elf 2000 Disk Board IDE and CF Register Selection Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 CS1 0 0 ICS3 RS2 RS1 RSO Table 22 Disk Board IDE and CF Register Selection CS1 CS3 If this bit is zero the first IDE register
124. he components listed above 13 3 INSTALLATION Installing the GPIO card on either the Elf 2000 or the Embedded Elf is simple and is pretty much the same as installing any other expansion card Refer to the description of the Disk UART RTC card section 11 2 1 for more details on the standoffs and mounting screws used If you are using the 8255 PPI then notice that the three PPI ports are brought out to three ten pin headers on the left side of the GPIO card Each of these headers has the same pin out and contains the eight data bits from the GPIO port plus ground and Vcc You ll need to make up some ribbon cables to connect these headers to whatever external hardware you have 13 4 JUMPER SETTINGS The GPIO card contains four jumpers labeled JP1 thru JP4 The following table summarizes the function of these jumpers and the proper default setting to work with the Spare Time Gizmos Monitor EPROM Jumper Default Function JP1 EF2 Connects the PS 2 keyboard data available flag to either EF2 or EF4 JP2 Removed Allows the PS 2 keyboard data available flag to interrupt the 1802 JP3 Functionally swaps the CAPS LOCK CTRL keys JP4 Enables PS 2 numeric keypad application mode Table 34 GPIO Card Jumpers 13 5 PROGRAMMER S REFERENCE The GPIO card uses two ports from the 1802 s I O address space The default port assignments and their usage is summarized Table 35 Like the Elf Disk RTC UART bo
125. he shorting block on the two pins towards the edge of the board away from J3 and in JP9 install the shorting block on the two pins closest to J3 The pin out for J3 the serial port and I O connector is such that you can use a standard PC style 10 pin IDC to DB9 cable but be careful that your PC only connects to TXD and ground That s because the Embedded EIf has other signals e g EF1 4 and Q on other pins in this connector and they won t like being connected to RS232 voltages f you use a PC style cable the best thing would be to cut out all the other wires 10 4 PROGRAMMER S REFERENCE With the exception of the missing subsystems switch register TIL311 displays and Pixie video programming the Embedded Elf is exactly the same as the Elf 2000 The monitor EPROM is the same the commands and languages the same and with the exception of the STG1861 all the same daughter cards can be used s Sorry didn t know that when designed the board 10 1 2006 4 23 PM Page 68 Spare Time Gizmos COSMAC Elf 2000 User s Manual 11 THE DiSK EXPANSION BOARD 11 1 INTRODUCTION 11 2 ASSEMBLY If you didn t build your Elf 2000 or if it s been a while since you did it would be a good idea to review the generic construction tips in sections 2 4 Sockets and Soldering and 2 5 Assembly Hints Here are a few assembly tips that are unique to the Disk Expansion Board The serial port connector J3
126. he top socket side it ll fit down into the little hexagonal cutouts in the socket 2 English hex nuts are too large and you ll have to put the nuts on the bottom side of the PC board There are some traces on the bottom of the PC board which run too close to the socket card mounting holes Use nylon washers on the bottom side to ensure that there are no shorts Assemble all the screws CF socket and PC board and tighten the screws finger tight Carefully check the socket pins for the correct alignment with their pads the socket pins and the pads are exactly the same size and all 50 of them should line up perfectly Slide the socket around a little if necessary to fix the alignment and as a last resort use a small probe 10 1 2006 4 23 PM Page 69 Spare Time Gizmos COSMAC Elf 2000 User s Manual to bend one or more of the socket pins You will need a magnifying lens and a good light to make this check When you re happy with the pin alignment tighten the screws and then go back and double check the alignment again to make sure it didn t slip When all is well solder the two metal feet at the front of the socket one on the left and one on the right first Be careful not to melt the socket but apply enough heat long enough for the solder to wick all the way under the socket and cover the pad completely Between the soldered feet and the screws the socket should now be firmly locked into place solder each pin just t
127. hes on one end and one notch on the other end the end with two notches is the top towards the CDP1802 socket side Flip the power on and check the milliammeter the TIL311s are TTL chips and are huge power hogs the current drain will now be something around 600mA Use your voltmeter to double check the VCC one more time and verify that it s still between 4 9 and 5 1VDC If you don t get these results and especially if the current drain is significantly more than predicted then stop and figure out what s wrong before proceeding If well and your Elf 2000 has a switch panel then proceed to section 2 9 1 Switch Panel Checkout f your Elf has no switch panel but you are using the Spare Time Gizmos monitor EPROM proceed with section 2 9 2 EPROM Checkout You did socket all the ICs didn t you Assuming you are using the Atmel Q quarter power GAL specified in the parts list 5 using the STG1861 replacement do not install it at this time 10 1 2006 4 23 PM Page 14 Spare Time Gizmos COSMAC Elf 2000 User s Manual 2 9 1 Switch Panel Checkout Set all switches to the OFF position including DO D7 and flip LOAD to the ON position The LOAD LED should light and the address display should show 0000 the data display will be random Flip press INPUT and the display should read 0000 00 Now set the DO D7 switches to ON and flip press INPUT again the display should now read 0001 FF Next set the data switches t
128. ht CTRL left control only and CAPS LOCK keys work as you would expect Note that CAPS LOCK is a CAPS LOCK and not a SHIFT LOCK i e it affects only alphabetic characters This is standard for PCs but not all ASCII terminals behave this way The right CTRL if your keyboard has one and ALT keys both left and right do nothing If JP3 is installed on the GPIO card see Table 34 then the CAPS LOCK and CTRL key functions will be swapped This is convenient for most modern PS 2 keyboards which have the CAPS LOCK key where the CONTROL key ought to be If JP4 is installed on the GPIO card see Table 34 then keypad Application Mode option is selected then the PS 2 numeric keypad keys send escape sequences that map approximately to the VT52 keypad If JP4 is not installed then the numeric keypad sends normal characters 0 9 and ENTER The escape sequences used in application mode 10 1 2006 4 23 PM Page 86 Spare Time Gizmos COSMAC Elf 2000 User s Manual summarized in Table 37 In either case the NUM LOCK key is not implemented and never does anything Key Escape Sequence Keypad 0 lt ESC gt p Keypad 1 lt ESC gt q Keypad 2 lt ESC gt r Keypad 3 lt ESC gt s Keypad 4 lt ESC gt t Keypad 5 lt ESC gt u Keypad 6 lt ESC gt v Keypad 7 lt ESC gt w Keypad 8 lt ESC gt x Keypad 9 lt ESC gt y Keypad lt ESC gt z Keyp
129. ins the ElfOS BIOS and if you have the Disk Expansion Card you can run ElfOS quite well on the Elf 2000 To install EIfOS on the Elf 2000 you first need to obtain an image of the ElfOS System Builder Utility customized for the Elf 2000 from Mike Riley s web site This file called e fos2k hex is in standard Intel HEX format for downloading to the Elf 2000 as described in section 4 9 Once you have downloaded elfos2k hex you may proceed as follows Note that this example uses a 128Mb compact flash card for the system disk the numbers you see may vary depending on the system device you are using 1 Install the Disk Expansion card in your Elf 2000 either insert a CompactFlash connect a real IDE hard disk and connect your Elf 2000 serial port either one to your PC Power up the Elf 2000 COSMAC ELF 2000 EPROM V50 CHECKSUM 024B SRAM 32K INITIALIZED Copyright C 2004 2005 by Spare Time Gizmos All rights reserved 1 5 BIOS Copyright 2004 by Mike Riley IDE Master 122Mb SanDisk SDCFJ 128 03 14 2005 16 28 43 For help type HELP 2 Download the elfos2k hex file as described in section 4 9 At 2400 baud using the motherboard serial port this will take about twenty minutes 3 After the download has completed start the EIfOS System Builder utility gt gt gt run 3000 Elf Os Installation 1 gt Run hard drive init tool 2 gt Run filesystem gen tool 3 gt Run sys tool 4 gt Install binaries 5 Boot
130. is intended to be a male DB9 and is wired the same as a PC serial port connector Therefore if you want to connect J3 to a PC serial port you ll need to use a null modem cable This differs from the mother board serial port which uses a female connector and interfaces to a PC with a straight thru cable The baud rate oscillator crystal Y1 should be 2 4576MHz Other values will work and are commonly used with the 8250 16450 UARTs however the EIf 2000 firmware calculates baud rates based on 2 4576MHz Photo 13 Disk Expansion Board 11 2 1 Installing the CompactFlash Connector Mounting and installing the CF socket is not a task for the faint of heart but with patience and the right equipment you can get thru it Here are a few tips to help you Mount the CompactFlash socket first before you solder anything else You ll find that it s much more difficult to work on SMD pins when they re surrounded by a forest of taller thru hole parts The CF socket has two little alignment nipples next to the screw holes Unfortunately the Revision 1B PC board dimensions for these holes are incorrect and they will not fit Use an Xacto knife or razor blade to trim off these little nibs Be sure the bottom surface of the Socket is flat and smooth otherwise some of the pins may not touch the PC board 4 You can use 2 English machine screws M1 Metric screws to mount the socket With M1 hardware you can actually fit the hex nut on t
131. istors R3 R5 R6 R9 and R12 with wire links instead Jumper JP1 connects VLED to VCC if you elect to use lamps instead you may wish to break this connection and supply VLED separately with a higher voltage and or higher current supply Needless to say VLED doesn t need to be regulated IMPORTANT Look closely at JP1 and you ll see that there is a trace on the solder side which connects the two pins by default Normally nothing not even a header or shorting block needs to be installed at JP1 If you want to use a separate VLED supply you ll need to cut this trace first Remember that it s going to be difficult to replace one of the back light lamps if it ever burns out So it d be wise to operate these bulbs well below their rated voltage Whether you use LEDs or lamps the LOAD and RUN GO back lights are simply connected to the corresponding LEDs on the main ELF 2000 PC board There is no decoding for the RUN and LOAD states on the keypad PC board and if you want to use these two LEDs lamps you ll need to connect TP1 LOAD on the keypad PC board to U7 pin 16 on the main EIf 2000 PC board Likewise you ll need to connect TP2 to U7 pin 15 on the EIf 2000 board It s not necessary to use the back lighting at all you can simply omit the LEDs lamps and all the associated components if you choose There are also alternate mounting locations for the RESET MEMORY PROTECT and INPUT LEDs in the upper left corner of the keypad PC board The
132. ll be 1 if input should be echoed back to the terminal BAUDO contains the hardware serial port the disk expansion card UART settings as used by the BIOS F USETBD function If BAUDO is zero then the software port is the console and if the upper 7 bits of BAUD1 are zero the hardware serial port is the console gt gt gt show terminal BAUD1 0x11 0 0 00 If the VT1802 and GPIO combination is being used as the console terminal see section 4 5 then the output from SHOW TERMINAL gives the current versions of the VT52 emulator firmware and the GPIO PS 2 keyboard APU firmware For example gt gt gt show terminal VT1802 Video Card Firmware V23 PS 2 Keyboard APU Firmware V2 10 1 2006 4 23 PM Page 31 Spare Time Gizmos COSMAC Elf 2000 User s Manual 5 10 2 SHO w RTC The SHOW RTC command prints the contents of the real time clock and non volatile RAM memory This command is intended for debugging the higher level BIOS functions that access the RTC NVR e g SHOW DATIME SHOW RESTART etc and because of that SHOW RTC performs no error checking of any kind If you use the SHOW RTC command when no RTC is installed all OXFF bytes will be printed If you use SHOW RTC when 64 byte RTC NVR chip e g the DS1287 is installed then the contents of the first 64 bytes will be repeated twice as they are in this example gt gt gt show rtc Qs Z3 45 56 7 82 9 LD 7D00 gt 02 00 17 00 11 00 02 OF 03 21 20 07
133. location One way to do this would be to toggle in a program using the switches 2 3 3 Battery Backup If you don t require non volatile RAM you can safely omit the DS1210 NVR controller U5 and the Lithium coin cell B1 However if you do this you must connect two jumpers to enable the 10 1 2006 4 23 PM Page 7 Spare Time Gizmos COSMAC Elf 2000 User s Manual SRAM First connect a jumper between U5 pin 8 and U5 pin 1 this connects VBAT directly to VCC so that the SRAM will receive power Second connect a jumper between U5 pin 5 and U5 pin 6 this ties SAFE CS RAM L to CS RAM L to enable the SRAM 2 3 4 Toggle Switches The entire switch panel including the eight data switches and the LOAD RUN MP and INPUT switches are completely optional If they are omitted the DS1233 will hold the CPU in the RESET state for approximately 300ms after power up and then release the CPU to RUN mode The CPU will begin executing instructions at either location 0 0000 0 8000 as determined by jumper JP4 see section 3 2 2 If you don t want the switch panel then in addition to omitting all the switches you may also omit U14 and J5 Note that RP4 RP3 and U9 are still required don t be tempted to omit those If you use your Elf 2000 without any switch panel or keypad then you need to solder two short jumpers to the board in place of J5 The first connects pin 4 LOAD NC to pin 19 GND and the second should connect
134. may object to the idea of putting a 25 cent 74 74 IC into a 50 cent socket but it s not the IC you are protecting it s the PC board If you ever fry that 74HC74 a single slip of the scope probe is all it takes then it will require significant skill and equipment to unsolder that dead IC without damaging the board With a socket it takes only a few seconds to pop out the dead one a pop in a new one When soldering IC sockets and connectors especially the larger ones start by holding the part tightly to the board and then soldering only two pins on diagonal corners This will hold the part in place temporarily while you turn the board over and make sure the part is flush against the PC board If it isn t then apply pressure to the part while using your iron to re melt the solder on the closest pin The worst thing is to solder all 40 pins on an IC socket only to turn it over and find that it s skewed It s pretty difficult to desolder all those pins and repair the error at that point Lastly clean the board again after you re finished soldering by using a commercial flux remover or if you ve used a solder with water soluble flux by washing with a toothbrush and warm water Water soluble fluxes are corrosive in the long term and should never be left on the board Traditional rosin fluxes won t actually hurt anything if left behind but the residue obscures the traces and makes it harder to find shorts Make sure everything is co
135. mos COSMAC Elf 2000 User s Manual IMPORTANT As shipped from the factory revision C and later of the ELF2K PC board have a small trace shorting JP5 on the top side of the PC board If you plan to install a jumper at JP5 you must very carefully cut this trace with a small knife first This means that by default your Elf 2000 PC board is wired for an 1802 chip and if you are using an 1802 you don t need to do anything You don t need to install a jumper at JP5 at all If you want to use an 1805 6 CPU then you must first cut the trace between the two pins of JP5 If you want to be able to select between the two CPU types first cut the trace connecting the two pins of JP5 and then install a jumper there Photo 7 shows jumper JP5 3 24 JP2 When installed jumper JP2 connects the INPUT switch to EF4 This is the standard arrangement used by the original EIf however you may remove this jumper if you wish to use EF4 rae for some other Pit UPSDE Jro purpose Note that the INPUT switch stil BC NC CS functions in LOAD mode regardless of this jumper Photo 8 shows the location of JP2 Photo 8 JP2 JP6 JP9 and JP10 3 2 5 9 and JP10 JP9 and JP10 are two position jumpers which determine the polarity of the RS 232 serial input and output signals Remember that a proper RS232 to TTL level shifter inverts the polarity of the signal i e the active or marking RS232 state is the more negative
136. mpletely dry before you begin installing parts in the sockets once again compressed or canned air can be used to accelerate the drying process 2 5 ASSEMBLY HINTS Y Twenty one 0 1uF 50VDC monolithic bypass capacitors are used in the Elf 2000 These are identified by a box only on silk screen Y Notice that capacitors C1 and C2 are polarized devices and must be installed correctly The polarization is shown on the silk screen of all PC boards Y Header J5 should be mounted on the bottom solder side of the PC board with the pins facing down i e on the solder side Because of the limited space available a shrouded header is not recommended for J5 Y Remember to use a heat sink with VR1 Y f you intend to use the STG1861 Pixie emulator then do not install a dip socket at U2 the CDP1861 socket The STG1861 daughter board uses special 0 1 female headers which are included in the STG1861 kit and will not mate correctly with a standard DIP socket 2 6 SwiTCH PANEL The switch panel is not part of the PC board and is constructed on a separate 5 72 x 2 x 1 8 thick piece of ABS plastic Appendix D of this manual contains a full sized template for the switch panel which you can print on a piece of adhesive decal stock and then use as a drilling guide Once you are done drilling leave the decal in place as the remainder serves to label the various switches Mount ten SPST toggle switches for DO thru D7 RUN and MP Note
137. n and also notice that this command has no legal abbreviations You must spell it out exactly as shown 5 12 TES T COMMANDS 5 12 1 TES t RAM This command will perform an exhaustive test on all of SRAM using the Knaizuk and Hartmann algorithm This algorithm first fills memory with all ones FF bytes and then writes a byte of zeros to every third location These values are read back and tested for errors and then the procedure is repeated twice more changing the position of the 00 bytes each time After that the entire algorithm is repeated three more times this time using a memory fill of 00 and every third byte is written with FF Strange as it may seem this test can actually detect any combination of stuck data and or stuck address bits Each pass six iterations requires about 30 seconds for 32K RAM on a 1 7 MHz CDP1802 and produces the following output gt gt gt test ram Testing RAM Pass 1 Errors 0 Testing RAM Pass 2 Errors 0 Testing RAM Pass 3 Errors 0 4 Errors 0 Testing RAM Pass NOTE This test repeats endlessly The only way out is to reset the Elf 2000 5 12 2 TES t PIX ie The TEST PIXIE command attempts to exercise CDP1861 or STG1861 video subsystem The test command first examines EF1 normally the STATUS output from the 1861 for a once per frame square wave If no CDP1861 STG1861 is installed or if it is not working then no change in EF1 will be detected and the monito
138. nents or a CF card present then other spurious low resistance paths may show up 10 1 2006 4 23 PM Page 70 Spare Time Gizmos COSMAC Elf 2000 User s Manual The daughter board electrically connects to the main board with a 24 pins stacking bus connector These connectors are similar to the stacking connectors used on the PC 104 bus and are special order parts but you can order one from Spare Time Gizmos You can undoubtedly improvise some sort of connection using standard male and female 0 100 headers but the stacking connectors will allow you to stack up multiple expansion boards one above the other Note that two stacking bus connectors are required to install the first daughter card one for the daughter card itself and one for the main COSMAC Elf 2000 PC board The pins on the latter will hang down below the Elf 2000 PC board but if you ve mounted your board in the usual way on side rails then these pins shouldn t cause a problem If the extra pin length is a problem you can always cut them off Needless to say do not cut the pins on any of the daughter cards they won t make contact with the mating connector if you do 11 3 1 Connecting an External Drive Connector J4 is a standard 40 pin header that electrically conforms to the standard ATA 3 specification and can be used to attach an external disk drive The hardware is compatible with pretty much any ATA device however the current Monitor EPROM BIOS and EIfOS operating s
139. nstability So don t install C1 either that s the 0 1 bypass above the SRAM chip In the end there are actually eight bypass caps shown on the schematic seven page 3 and one for the SRAM on page 2 but only five are actually installed Of course nothing really bad will happen if you install the extras anyway The official power connector is a Mode Electronics 37 6302 0 2 pin right angle and the mating shell is 37 602 0 from http Awww mode elec com Lots of other 0 1 connectors will also fit If you don t want battery backup for the SRAM you don t need 1 or 99 but you ll have to install a couple of jumpers to bypass U9 so the SRAM still works The instructions are the same as the Elf 2000 and can be found in section 2 3 3 of this manual Unlike the Elf 2000 where the crystal frequency is divided by two the Embedded Elf crystal frequency is the CPU frequency You can use 2 2 3MHz or even 5 2 provided that your 180x chip is fast enough 10 3 INSTALLATION Remember that your Embedded Elf requires a regulated 5 volt power supply The odd jumper designations JP5 JP9 and JP10 are used because their function corresponds to the Elf 2000 jumpers of the same name Refer to sections 3 2 3 and 3 2 5 for a complete description of these jumpers To work with the standard Elf 2000 EPROM the RS 232 polarity jumpers JP10 and JP9 should be set with JP10 pins 1 2 shorted and JP9 pins 2 3 shorted In other words on JP10 install t
140. o 5 D7 ON D6 OFF D5 D4 OFF OFF D2 ON D1 OFF and DO ON flip press INPUT and the display should show 0002 5 Finally set the data switches to 0x5A flip press input and verify that the display shows 0003 Set LOAD to OFF set MP to ON and then flip LOAD back to ON The display will show 0000 5A Flip press INPUT and the display will show the contents of location 0 0000 00 Flip press INPUT three more times and you ll see the next three bytes that you just entered 0001 FF 0002 A5 and 0003 5A If you are also using the Spare Time Gizmos monitor EPROM then proceed with the next section 2 9 2 EPROM Checkout Turn the power off and ensure that all jumpers are set as described in section 4 2 for monitor EPROM compatibility Connect an RS 232 terminal to J4 and set the terminal for 2400 baud 8 N 1 8 data bits no parity and 1 stop bit Set all switches to OFF except RUN which should be set to ON Turn on the power The RUN LED should light if it doesn t make sure you ve set the RUN switch to ON and the data display should show 99 followed by 98 and then gradually count down to 16 This means that the monitor is ready for auto baud press the ENTER carriage return key on the terminal The data LEDs will read 00 and on the terminal you should see something like this COSMAC ELF 2000 EPROM V15 CHECKSUM BA24 SRAM 32K INITIALIZED Copyright C 2004 by Spare Time Gizmos All rights reserved 1
141. on and be the specified length For example PRINT MIDS ABCDEFG 2 3 BCD 7 4 9 PEEK address The PEEK function allows the program to retrieve a 1 byte value from memory 7 4 10 RIGHT string expression length This function will return the specified number of characters on the right side of the specified string expression For example PRINT RIGHTS ABCDEFG 3 EFG 7 4 11 RND range The RND function will generate a random number from 0 to 1 less than the specified range For example if RND 6 were used it would return a random number from 0 to 5 7 4 12 STR numeric expression This function will produce a string representation of a numeric expression This function is used to convert numbers to strings for example 10 AS STR 5 100 20 PRINT A RUN 500 10 1 2006 4 23 PM Page 45 Spare Time Gizmos COSMAC Elf 2000 User s Manual 7 4 13 USR address or USR address expression The USR function is used to call a Machine Language subroutine The address argument is required in both versions and specifies the address of the ML routine to be executed If the second argument is provided this value will be loaded into RF prior to the ML routine being called The return value of this function is the value in RF when the ML routine returns See section 7 6 2 Machine Language Subroutines for more information on using this function 7 4 14 VAL string expression This function will return an integer equivalent fo
142. onolithic capacitor C12 Anchor 47uF 6V tantalum capacitor C14 Anchor 0 0022uF Mylar C5 C11 C13 Anchor 0 1uF ceramic monolithic bypass capacitor 0 1 LS SEMICONDUCTORS D1 D3 1N914 Anchor Small signal switching diode Q1 2N3904 Anchor GP NPN switching transistor U1 U5 Atmel ATF22V10CQZ Digi Key Flash GAL quarter power U2 Intel 8275 Jameco CRT Controller U3 27C64 8K x 8 EPROM U4 74HC166 Anchor 8 bit shift register U6 U7 74 221 Dual Monostable Multivibrator U8 74HC132 Anchor Quad Schmitt Trigger Dual Input NAND Gate OSC1 CTS 45 5 12 0000 Digi Key CTX164 12 000Mhz DIP8 crystal oscillator MISCELLANEOUS J1 CommConn 1184 24G2 24 pin dual row stacking header J2 See section 12 3 J3 Anchor PCB mount phono jack RS 170 Video J5 Anchor PCB mount DE9F connector CGA Anchor DIP8 machined pin oscillator socket Anchor DIP16 machined pin IC socket Anchor DIP14 machined pin IC socket Anchor DIP24 machined pin IC socket 0 300 Anchor DIP28 machined pin IC socket 0 600 Anchor DIP40 machined pin IC socket 10 1 2006 4 23 PM Page 103 Spare Time Gizmos COSMAC Elf 2000 User s Manual REFERENCE PART STOCK DESIGNATOR MANUFACTURER NUMBER SUPPLIER N MEER DESCRIPTION STG ELFVIDEO 1D Printed circuit board Table 46 VT1802 80 Column Video Card Parts List General Purpose I O GPIO Card Parts List
143. or ending lines themselves need to exist The shorthand LIST start will list lines starting from the specified line up to the end of the program The specified line does not need to exist If it does not exist then the first line to be listed will be the next highest line number that does exist The LIST end shorthand will list from the start of the program up to and including the specified line number The ending line number need not exist 7 5 12 NEW NEW clears the program space of the current program Issue this command when you desire to erase the current program and begin a new one If this command is used inside of a program it will cause memory to be cleared and program execution to end 7 5 13 ON expression GOTO line1 line2 line3 This form of the GOTO command will evaluate the given expression to see which of the specified line number to jump to If the expression evaluates to 1 then the first line will be jumped to if the expression evaluates to 2 then the second line will be jumped to and so forth If the expression evaluates to less than 1 or greater than the number of line numbers given execution will fall through to the next statement For example 10 A 2 20 ON A GOTO 100 200 A 100 30 PRINT NONE 99 END 100 PRINT 100 GOTO 99 200 PRINT 200 GOTO 99 300 PRINT 300 GOTO 99 RUN 200 Change line 10 to 10 A 0 RUN NONE Change line 10 to 10 A 4 RUN NONE Change line 10 to 10 A 3 RUN 3
144. orrectly If you are unable to center the video with these controls then you might want to try changing the sync polarity jumper s Jumpers JP2 and JP3 see section 12 3 1 select the polarity of the CGA sync signals Most CGA monitors are happy with positive going horizontal sync pulses and negative vertical sync but if yours is different then you can change these settings Note that these two jumpers have no effect on the composite video J3 output 12 3 3 Video Outputs J5 is a standard CGA compatible video output connector which you should be able to plug directly into any CGA compatible monitor Since CGA is normally a color standard and this card is monochrome the VT1802 card always outputs the same TTL video signal to pins 2 3 and 4 of the DB9 connector These are the normal Red Green and Blue connections for a color monitor and will cause the monitor to display white text on a black background There are monochrome monitors that conform to the CGA standard some of these monitors expect monochrome video to be on pin 7 of the DB9 connector This is a non standard usage however if your monitor is one of them you can make it happy by installing jumper JP5 Color monitors use this pin for intensity modulation so you don t want to install this jumper unless you need it Connector J3 outputs RS 170 compatible composite video Although the video timing is the same as standard broadcast television the video bandwidth required to dis
145. ouch the tip of the iron you are using an ultra fine 0 015 diameter tip right to the pad on the PC board Count to three while it heats up and then touch the solder you are using 0 020 ultra fine solder right to the end of the CF socket pin Try to avoid touching the iron tip with the solder if you can If you do it right the solder will only melt on the one pad pin that s hot and it ll wick up between the pin and the pad f you look carefully at the cut ends of the CF card pins with a magnifier you ll see that each end is copper colored where the pin was cut off after it was tinned When this little copper colored end disappears because it s covered with solder you ve used enough solder f you use too much solder and short to an adjacent pin and you will do this before you re done with all 50 pins take my word for it use your super fine solder wick to remove the excess Solder wick generally leaves enough solder behind for a good connection and you shouldn t need to add more solder when you re done 11 2 2 Testing the CompactFlash Connector After you ve gone to all the trouble of soldering on the CompactFlash socket you really should invest fifteen or twenty minutes in testing it before you proceed The CompactFlash socket is extremely difficult to work on after the other parts have been mounted and if there are any shorts or opens you want to find out now not later To check for opens use a small sharp tool such as a
146. ould be zero for future compatibility 13 5 2 The PS 2 Keyboard Interface From the 1802 side the PS 2 keyboard interface is very simple The microcontroller on the GPIO card handles the PS 2 serial protocol and converts the keyboard scan codes into ASCII When a character is ready the interface asserts either EF2 or EF4 depending on the state of JP1 and then waits The 1802 software can read the current ASCII keystroke by executing an input from port 7 This clears the keyboard data available flag and de asserts EF2 4 and then the whole process repeats with the next keystroke The microcontroller implements a 16 byte buffer for keystrokes to give a little breathing room in the event you can type faster than the 1802 program can read During normal operation LED1 lights whenever there are one or more keystrokes waiting and goes out when the key buffer is empty This gives a visual indication of whether the keyboard and 1802 software are cooperating Resetting the 1802 with the switch panel keypad or the RESET button also resets the PS 2 keyboard microcontroller which clears the keystroke buffer After a reset the microcontroller also executes a simple internal diagnostic if the diagnostic fails then LED1 will flash rapidly 13 5 3 PS2 to ASCII Translation All printing characters on the PS 2 keyboard send their corresponding ASCII codes as do TAB 0x09 ENTER 0 00 BACKSPACE 0x08 and ESC 0x1B The SHIFT both left and rig
147. p of paper with the printing slides that slot Do not try to disassemble the buttons Also it s much easier to insert the legends in the buttons before they re soldered to the PC board The space between the buttons is a little tight once they re in place and they re difficult to work on It s a good idea to do a dry run with the buttons and insert them all into the PC board before you solder anything Make sure that you have the right set of pads for each button type and that all the buttons line up Finally make sure that the back light LEDs or lamps fit in the five function keys The five function keys accept either a T1 LED or a grain of wheat light bulb for back lighting If you use LEDs you ll want to pick colors that complement that color of the button legends l ve found that the LED back lighting is a little disappointing it isn t quite bright enough and the effect is a subtle in a normally lit room It works great in the dark however WARNING Once the push button is soldered into place there s no way to install or change the back light so be sure you insert the LED or lamp first Be sure that the LED or lamp doesn t stick up so far that it interferes with the operation of the push button Each back light has a separate transistor driver that can stand up to 100mA and voltages well above VCC This is especially useful if you use lamps instead of LEDs If you do use lamps you may want to replace the LED current limiting res
148. p of the stack The command will take the top of the stack and display it in signed integer notation ok 5 ok The took the 5 we pushed earlier removed it from the stack and printed it If we execute the command again 10 1 2006 4 23 PM Page 59 Spare Time Gizmos COSMAC Elf 2000 User s Manual ok stack empty ok the interpreter will complain about an empty stack and abort any further processing Commands can be placed multiply on a line with just spaces separating each command ok 54 4 5 ok In this example 4 was the last value pushed onto the stack therefore the first value popped off by the first command To keep the prompt off the line with the answers you can use the CR command ok 5 4 CR 4 5 ok Note also that commands are executed from left to right and there is never any order of operations other than left to right It is also possible to display text using the operator ok HELLO WORLD CR HELLO WORLD ok Arithmetic can be performed as well Try this example ok 5 4 CR 9 ok Again notice all the arguments are pushed onto the stack before the command is executed Equality is tested with the operator ok 5 4 CR 0 ok 5 5 1 Note that when two numbers are equal 1 is left on the stack whereas 0 is left when they not equal The DEPTH command will place onto the top of the stack the number of items on the stack ok 4 5 6 DEPTH CR 3 ok No
149. peration of the Elf 2000 and agrees to utilize the Elf 2000 in keeping with all laws governing its operation in the country of use 1 2 SAFETY WARNING The COSMAC Elf 2000 board uses a Lithium coin cell battery There is a danger of explosion if this type of battery is incorrectly replaced Replace with only the same or equivalent type recommended by the manufacturer Dispose of used batteries only in accordance with the manufacturer s instructions 1 3 WARRANTY SPARE TIME GIZMOS OFFERS NO WARRANTY EXPRESS OR IMPLIED AS TO THE RELIABILITY OR ACCURACY OF THE COSMAC ELF 2000 ELF 2000 DESIGN SPARE TIME GIZMOS OFFERS NO WARRANTY EXPRESS OR IMPLIED AS TO THE ACCURACY OF THE INFORMATION PRESENTED IN THIS DOCUMENT SPARE TIME GIZMOS OFFERS NO WARRANTY EXPRESS OR IMPLIED AS TO THE SUITABILITY OR CORRECTNESS OF ANY SOFTWARE OR FIRMWARE SUPPLIED IN CONJUNCTION WITH THE ELF 2000 SPARE TIME GIZMOS MAKES NO REPRESENTATIONS AS TO THE SUITABILITY OF THE ELF 2000 FOR ANY APPLICATION IT IS SOLELY AND EXCLUSIVELY YOUR RESPONSIBILITY TO EVALUATE THE ACCURACY COMPLETENESS AND USEFULNESS OF THE ELF 2000 AND ALL RELATED DESIGNS SOFTWARE AND OTHER INFORMATION PROVIDED BY SPARE TIME GIZMOS THE ENTIRE RISK AS TO THE USE AND PERFORMANCE OF THE ELF 2000 IS ASSUMED SOLELY BY YOU REPRESENTATION OR OTHER AFFIRMATION OF FACT INCLUDING BUT NOT LIMITED TO STATEMENTS REGARDING CAPACITY PERFORMANCE OF PRODUCTS OR SUITABILITY FOR USE WHETHER MADE
150. play 80 column text is 3 or 4x what a standard television can handle You won t be able to display 80 column video on an ordinary TV even less so with an RF modulator so don t even consider it However if you happen to have a genuine computer monitor with at least 10 to 12 MHz of video bandwidth and a composite video input then you should be able to use it 12 3 4 CPU Clock Selection The standard Elf 2000 uses a 3 579545 MHz crystal so that the CDP1861 Pixie chip can generate the correct NTSC video timing If you re using the VT1802 then you have no need for Pixie compatibility and you can safely increase the clock frequency In fact it s a good idea to do So since the video refresh overhead of the VT1802 would use almost all of the available CPU time How fast you can go depends upon the CPU chip that you have The standard ACE version of the 1802 is rated for 3 MHz operation remember that the Elf 2000 divides the crystal oscillator frequency by two so in this case you could safely use a 6 MHz oscillator 19 The VT1802 firmware has escape sequence hooks for both of these options but the standard character generator EPROM image supplied by Spare Time Gizmos has only one US ASCII character set Sorry but please feel free to add more Remember CGA not EGA or VGA There or were multi standard monitors that could accommodate both EGA and CGA but they are uncommon 2 At least in the United States 10 1 2006
151. put and the PS 2 interface on the GPIO provides the keyboard input Additionally the speaker on the card if it is installed will be used as the console terminal s bell When both cards are installed and working the monitor always uses the VT1802 GPIO combination as the console terminal No serial console auto baud is performed post step 16 will be skipped and both serial ports are ignored by the monitor The POST and initialization for the UART chip is still executed if the Disk UART RTC card is present and you can of course still write your own programs which use the UART NOTE The bit banged motherboard serial port cannot be used when the VT1802 is installed This is because the DMA and interrupt overhead associated with the VT1802 precludes accurate timing for the software serial port emulation Console emulation works only if both the VT1802 and GPIO cards are installed If only one is present then the POST will still execute the self test and initialization for that card however the monitor will attempt to use either the motherboard serial port or the UART as the console If the GPIO card is installed alone you can still write programs which use the PS 2 keyboard port but the monitor will ignore it And if the VT1802 card is installed alone the POST will initialize it and start the screen refresh DMA and interrupts running but the monitor will ignore it You can however still write your own programs whi
152. r power U8 74 04 09 CD4044 Anchor Quad S R Latches U10 T4HC74 Anchor Dual D Flip Flop U11 unused U12 U13 U14 74HC244 Anchor Dual Quad Buffer U15 Dallas DS1233 JDR 5V 10 TO 92 EconoReset U16 Dallas DS275 Digi Key RS 232 transceiver DISP1 6 TIL311 Jameco LED Hexadecimal Display LED1 5 Anchor Red T1 LEDs OSC1 ECS 2100A 035 Digi Key XC235 3 579545Mhz DIP8 crystal oscillator MISCELLANEOUS B1 CR1225 Mouser Lithium coin cell BH1225 Digi Key 500K CR1225 coin cell holder PB1 Panasonic EVQ PADOS5R Digi Key P10890S PCB mount push button switch 51 C amp K T101MH9ABE Digi key CKN1067 SPDT Tiny Toggle Switch PCB Mount Right Angle J1 Anchor PCB mount phono jack Video J2 Cui Stack PJ 102AH Digi Key CP 102AH high current coaxial power jack 2 1 x 5 5mm J3 CommConn 1184 24G2 24 pin dual row stacking header J4 Anchor PCB mount DE9F 45 Anchor 20 pin 0 1 dual row header Anchor DIP8 machined pin IC socket Anchor DIP8 machined pin oscillator socket Anchor DIP14 machined pin IC socket 24 Don t use the DS1233M 10 1 2006 4 23 PM Page 95 Spare Time Gizmos COSMAC Elf 2000 User s Manual m ES MANUFACTURER LR SUPPLIER eae DESCRIPTION Anchor DIP16 machined pin IC socket Anchor DIP20 machined pin IC socket 0 300 Anchor DIP24 machined pin IC socket 0 300 Anchor DIP24 machined pin IC socket
153. r prints gt gt gt test pixie test no CDP1861 detected gt gt gt If a square wave is detected then the monitor measures the period of EF1 and then attempts to display a video test pattern In this case the test pattern is the familiar picture of the spaceship Enterprise gt gt gt test pixie test 466 OK The COSMAC Elf Enterprise Joseph Weisberger P E 1976 Toggle INPUT to continue gt gt gt 5 12 3 TES t VT1802 The TEST VT1802 command displays a test pattern on the VT1802 video screen and it can be used even if the VT1802 is also being used for the console To exit from the test press any key Note that this is a visual test only and it doesn t actually evaluate the VT1802 hardware which is already tested to the best of our ability by the POST 15 Proceedings of the IEEE April 1977 10 1 2006 4 23 PM Page 35 Spare Time Gizmos COSMAC Elf 2000 User s Manual 5 13 HEL P The HELP command prints a short list of monitor commands and their arguments 5 14 CLS The CLS Clear Screen command will clear the terminal screen if the VT1802 GPIO console terminal is in use It has no effect if a serial console is being used 5 15 LOADING INTEL HEx RECORDS The monitor contains a built in loader for standard Intel format HEX records No special command is required simply transmit one or more HEX records to the EIf 2000 and the monitor will decode and load them If the HEX record is su
154. r the specified string expression This is the function used to convert a string representation of an integer to binary integer format For example 10 8 123 20 I VAL AS 30 PRINT I RUN 123 7 4 15 VARPTR variable name This function returns the address of the data field for the specified variable See section 7 6 1 Using VARPTR for more on how to use this function 7 5 PROGRAM STATEMENTS 7 5 1 CLEAR The CLEAR statement will remove all variables variable values strings string values and arrays from the heap Essentially the CLEAR command will leave memory in the same state as if RUN had just been executed For example 10 5 20 PRINT A 30 CLEAR 40 PRINT A RUN 5 0 7 5 2 DATA value value value The data command provides a means to store data values inside your program These values can then be read using the READ command The current version of BASIC only allows for integer values in DATA statements See the READ statement section 7 5 18 for examples and further information on DATA 7 5 3 DIM variable dimension dimension The DIM statement allows you to create integer arrays Multidimensional arrays are allowed Each dim argument specifies the largest valid index for the specified array and axis A dimensioned variable is considered a distinct entity from a scalar variable by the same name therefore A and A do NOT refer to the same entity As such you can use the same name for bot
155. re information 10 1 2006 4 23 PM Page 75 Spare Time Gizmos COSMAC Elf 2000 User s Manual 12 THE 1802 VIDEO BOARD 12 1 INTRODUCTION The Spare Time Gizmos Elf 2000 VT1802 video board is able to generate a real 80 column by 24 line text display on a CGA compatible CRT RS 170 composite video monitor Other display formats including 25 lines are possible by modifying the video timing The hardware supports reverse video underline and blinking video attributes and four different character sets may be selected and simultaneously displayed under software control With the proper character generator ROM the hardware is also capable of displaying simple line and box drawing graphics characters The VT1802 uses the 1802 s DMA system to fetch ASCII characters directly from a 1920 byte 80x24 buffer anywhere in or EPROM Unlike the CDP1861 Pixie video the video timing for the video card is independent of the Photo 15 VT1802 Card CPU clock and any CPU crystal frequency up to the CPU s maximum may be used With a 3 MHz CPU clock the DMA and interrupt service for the 80 column card uses approximately 50 of the total CPU time 215 300 128450 m 2 o m i gt a o m 2 The card outputs include a standard 9 pin female DE9F for connection to CGA monochrome color monitor and a standard RS 170 composite video output for use with a high resolution monochrome monitor Both CGA horizon
156. rs Strings are terminated with a zero byte for example ABC would be stored in memory as 0x41 0x42 0x43 and 0x00 7 6 1 3 An Array Variable VARPTR A 0 When using VARPTR on an array element the address where that element s data is stored is returned Here is an example 10 DIM A 10 20 0 5 30 POKE VARPTR A 0 1 10 40 PRINT 0 RUN 10 7 6 2 Machine Language Subroutines Using USR it is possible to extend the capabilities of BASIC with your own machine language subroutines When writing ML subroutines for use with BASIC you must make sure that all registers modified by the ML subroutine be preserved on return back to BASIC Control will be transferred to the ML subroutine with R3 as the active program counter R2 will point to BASIC s stack R4 R5 and R6 will all have the values for using SRET and SCAL from the BIOS In order to return back to BASIC you must execute a SEP RD Strings make a good place to store small machine language programs Since when the string is created the space in memory is allocated and you no longer need to worry if the subroutine gets clobbered by the stack heap or variable storage There are two basic techniques for doing this dynamic strings and static strings In dynamic strings you want to create space on the heap where the string will be stored if you create the string using a string expression the resulting string is guaranteed to be on the heap After the string is created you
157. se will line up nicely with the LEDs already on the EIf 2000 PC board and you can install these in place of the back lights if you prefer The function buttons RESET GO LOAD and MEMORY PROTECT all light up when the associated condition is true The INPUT button lights when any numeric key is pressed and then goes out when INPUT is pressed Notice that RESET button will also be lit while in LOAD mode This is normal Note that the MEMORY PROTECT button is not a toggle pressing this button always sets the MEMORY PROTECT flip flop This condition is cleared by pressing any one of the RUN LOAD or RESET buttons 10 1 2006 4 23 PM Page 13 Spare Time Gizmos COSMAC Elf 2000 User s Manual The keypad contains a power on clear circuit that should cause it to always power up with RESET on and LOAD GO MEMORY PROTECT and INPUT all off The power on clear also causes a short key beep whenever the power is switched on 2 8 MOUNTING RAILS The original COSMAC Elf was mounted on two strips of wood the Elf 2000 uses two 6 34 x 1 x 3 8 thick strips of clear acrylic plastic instead Drill small pilot holes in your plastic rails to line up with the holes in the EIf 2000 PC board there are four on each side and the plastic switch panel two holes on each side Mount the PC board and the switch panel to the plastic rails using twelve 3 8 self tapping screws If you purchased a kit from Spare Time Gizmos note that the mounting rails are part of
158. set corresponding to IBM PC I O addresses 01 is selected If this bit is one the second IDE register set corresponding to IBM PC I O addresses is selected instead RS2 RSO select an individual IDE register 0 7 X don t care bits should be zero for future compatibility Once an IDE CF register is selected by writing to the device register select port port 2 the software can then read or write the contents of that register by accessing port 3 To select the 16450 550 UART the software should write a byte to the device register select port with the format shown in Table 23 Elf 2000 Disk Board UART Register Selection Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 RS2 RS1 RSO Table 23 Disk Board UART Register Selection RS2 RSO select an individual UART register 0 7 Again once the UART has been selected the software can access the UART register by reading or writing from 1802 port 3 And finally Table 24 shows the format used to access the DS12887A Elf 2000 Disk Board RTC NVR Register Selection Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 A6 A5 A4 A3 A2 Al AO Table 24 Disk Board RTC NVR Register Selection 6 0 address one of 128 internal registers the RTC NVR chip 10 1 2006 4 23 PM Page 73 Spare Time Gizmos COSMAC Elf 2000 User s Manual Once the DS12887A has been selecte
159. ssignment does not involve an expression the string pointer will point to the constant in the program text itself After running this program take a look at line 10 LIST 10 10 A 2 cd b The values now in the string were put there by the POKEs and now constitute the ML subroutine as part of the program code Now delete line 30 and change line 50 30 50 I USR M and you should have this 10 A cd b 20 M VARPTR AS 25 M PEEK M 256 PEEK M 1 40 I USR M This program will now do what the first program did but now you can save this and not ever need to load the ML subroutine again since it is now part of the program 7 7 ERROR CODES Table 11 summarizes the error codes used by BASIC Error Code Explanation Break IN button or Control C 1 Statement not allowed in direct mode 2 Syntax Error 3 Invalid line number 4 RETURN without GOSUB 5 Value of range 7 8 9 INVLP NEXT without FOR No DATA for READ 10 Out of Memory 11 Bad Dimension 12 Unsupported feature Table 11 BASIC Error Codes 10 1 2006 4 23 PM Page 55 Spare Time Gizmos COSMAC Elf 2000 User s Manual 8 FORTH In addition to the Editor Assembler and BASIC the Elf 2000 Monitor EPROM contains an interpreter for the Forth language also written by Mike Riley This chapter documenting the Elf 2000 Forth language was contributed by Mike 8 1 STACK REPRESENTATION In the instructions list
160. status write CRTC command Table 28 Ports used by the VT1802 Normally there s no need to ever access the VT1802 directly support for the VT1802 is fully integrated into Elf 2000 monitor EPROMs version 73 and later If the VT1802 is installed the monitor s power on self test see section 4 3 will both test and initialize the VT1802 hardware If both the VT1802 and the PS 2 Keyboard Interface part of the GPIO card described in section 10 1 2006 4 23 PM Page 80 Spare Time Gizmos COSMAC Elf 2000 User s Manual 13 1 are present the monitor will automatically redirect the Elf 2000 console to these two devices section 4 5 Console redirection is done thru the BIOS and any program which does console I O thru the standard BIOS functions READ and will automatically be redirected to the VT1802 with no software changes This includes all the languages and utilities built into the Elf 2000 EPROM e g Forth BASIC Edt Asm etc as well as the ElfOS disk operating system 12 6 ESCAPE SEQUENCES A programmer would normally interact with the VT1802 in the same way he would with any video terminal connected to the Elf by sending escape sequences The firmware in the Elf 2000 EPROM attempts to emulate the escape sequences of a Digital Equipment VT52 terminal and most of the escape sequences used mimic that terminal however there are a few additional escape sequences unique to the VT1802 as well as a few VT52 sequences t
161. t gt show restart NONE The SET RESTART NONE command disables the auto restart mechanism The Monitor enters the command mode after either a reset or a power up gt gt gt set restart boot gt gt gt show restart BOOT The SET RESTART BOOT command instructs the monitor to attempt an IDE bootstrap after a reset or power up This is equivalent to the BOOT command gt gt gt set restart 100 gt gt gt show restart RESTART 0100 The SET RESTART lt address gt command causes the monitor to transfer control to the address given after the self test completes This command can only be used if the main memory mother board SRAM battery backup option is installed and working To bypass any of the auto restart options and force the monitor to enter command mode after a power up or reset set the console switches to 0100 0011 before resetting Refer to section 4 7 for the complete story 5 11 4 SET NVR DEFAULT The SET NVR DEFAULT command resets the contents of non volatile RAM either battery backed up memory on the motherboard or the NVR chip in the Disk UART RTC option board to 14 trust that it s obvious why this is so 10 1 2006 4 23 PM Page 34 Spare Time Gizmos COSMAC Elf 2000 User s Manual the factory default settings This is useful if you ve somehow managed to screw up your NVR contents and want to get everything back to a known state Note that there are no other SET NVR commands DEFAULT is the only optio
162. tal and vertical sync outputs can be jumper selected for either polarity and an analog one shot delay gives a continuously adjustable horizontal and vertical position for either the CGA or composite output The Spare Time Gizmos EIf 2000 Monitor EPROM contains a VT52 terminal emulator that works with the VT1802 and takes care of all the work necessary for maintaining the display The firmware allows the video display to be used independently of the console terminal or if the PS 2 Keyboard Interface is also present as a replacement for the console terminal The video display works with BASIC Forth Edit ASM or EIfOS 12 2 ASSEMBLY If you didn t build your Elf 2000 or if its been a while since you did it would be a good idea to review the generic construction tips in sections 2 4 Sockets and Soldering and 2 4 Assembly Hints 10 1 2006 4 23 PM Page 77 Spare Time Gizmos COSMAC Elf 2000 User s Manual 12 3 INSTALLATION AND SETUP Installing the VT1802 card is very straight forward and is essentially the same as any other daughter card such as the Disk UART RTC NVR card refer to section 11 3 VT1802 card has one unique problem however because it requires connection to four signals which are not on the standard 24 pin EIf 2000 expansion connector These four signals are DMA OUT SCO SC1 and EF1 On the video card these four signals are brought out to a four pin header J2 just to the left of the 8275 chip and just below the
163. te that the depth command does not include its own answer in the total The top two stack values can be swapped using the SWAP command ok 2 3 CR 32 ok 2 3 SWAP CR 23 ok The top of the stack can be duplicated using the DUP command ok 2 CR 2 stack empty ok 3 DUP CR 3 3 ok 10 1 2006 4 23 PM Page 60 Spare Time Gizmos COSMAC Elf 2000 User s Manual The IF command can be used for conditional execution IF examines the top of the stack to determine what to execute ok 1 IF 1 THEN 2 CR 12 ok 0 IF 1 THEN 2 CR 2 ok When IF finds 0 on the stack execution begins after the matching THEN It is also possible to have an ELSE Try these ok 1 1 ELSE 2 THEN 3 CR 1 3 ok 0 1 ELSE 2 THEN 3 CR 23 If an ELSE is found before the next THEN a failed IF test the ELSE code block will be executed There are looping constructs in FORTH The first is the LOOP This is controlled loop with a specific start and a specific end The I command can be used inside of a loop to retrieve the loop counter ok 100 DO I LOOP CR 0123456789 ok Notice that the loop terminates once the end condition is reached The test occurs at the LOOP command therefore the loop is not executed again when 1 reaches 10 Notice also that a loop is always executed at least once ok 10 15 DO I LOOP CR 15 ok To increment the loop counter by something other than 1 use the LOOP command ok 10 0 DO I
164. tegrates three independent I O functions onto a single card The GPIO contains 4 PS 2 keyboard interface A single chip microprocessor on the GPIO card handles the PS 2 protocol converts the keystrokes to ASCII and presents the data the 1802 as if it were a simple parallel ASCII keyboard An 8255 programmable parallel I O PPI chip 8255 is a very popular general purpose parallel interface chip that provides 24 I O bits The bits can be configured as inputs outputs or as an 8 bit bidirectional port with or without handshaking A speaker for generating tones Arbitrary tones and even simple music be generated by 1802 software either by toggling the Q bit or thru an output port The speaker logic also contains a fixed frequency oscillator that may be used to generate simple beeps without any software intervention These three GPIO subsystems are functionally independent and if you don t require all of them you can easily build your GPIO card and omit the unused parts 13 2 ASSEMBLY If you didn t build your Elf 2000 or if its been a while since you did it would be a good idea to review the generic construction tips in sections 2 4 Sockets and Soldering 2 4 Assembly Hints Note that C4 is normally unused and can be omitted There s a place for it on the PC board and no harm will be done if you install it but it s unnecessary You can use either a piezo or a dynamic speaker of any r
165. the ability to load Intel 70 HEX format records directly see COMS Frnperiies section 5 15 the output from any Por Settings cross assembler in this format can be downloaded directly to the Elf 2000 over the console serial port And because each HEX file record contains its own checksum which is verified by the Elf 2000 monitor this method even provides simple Data bits protection against corrupted files or downloads Downloading HEX files to the Elf 2000 is simple with the exception of one caveat since there is no Stop bits handshaking between the Elf and the PC the PC terminal program must ARARA RASANA implement some form of transmit Flow control pacing i e a fixed delay between T characters to prevent overrunning the relatively slow Elf 2000 The HyperTerminal program can do this a free or at least no additional cost version of this program has been shipped with every version of Microsoft Windows since Windows 95 Other communications programs Figure 2 HyperTerminal Port Properties can undoubtedly do the same thing Bits per second Parity To set up HyperTerminal for downloading directly to an Elf 2000 follow these instructions 1 Run HyperTerm START MENU gt gt ALL PROGRAMS gt gt ACCESSORIES gt gt COMMUNICATIONS gt gt HyperTerminal 10 1 2006 4 23 PM Page 25 Spare Time Gizmos COSMAC Elf 2000 User s Manual 2 In the Connection Description Dialog ent
166. the switch panel kit and are not included in the basic EIf 2000 kit 2 9 FINAL CHECKOUT After you finish assembly apply power before installing any ICs Place a DC milliammeter inline with the power supply with no ICs installed the current consumption should be essentially zero Use a DC voltmeter to verify that the voltage between pins 20 negative and 40 positive on the microprocessor CDP1802 socket you should read 4 9 to 5 1V Next remove power and install all ICs except the CDP1802 CDP1861 if you have it and the TIL311 displays Install the TTL oscillator and the 22V10 GAL at this time Turn on the power and check the power consumption it should be 100mA or less The SCO and SC1 LEDs may or may not light or they may glow faintly Don t worry about this If you have access to an oscilloscope check that pin 1 of the CDP1802 has a 1 7897725MHz square wave Turn the power off and install the CDP1802 and if you have it CDP1861 chips Turn on the power and check the milliammeter the power consumption should still be under 100mA and probably more like 50 75mA Ensure that the RUN and LOAD switches are both set to OFF and only the SCO LED should be illuminated Flip the LOAD switch ON and the green LOAD LED should light flip LOAD back to OFF and flip RUN to ON and after a slight pause the RUN LED should light Finally remove power one more time and install the six TIL311 displays Notice that the TIL311s have two notc
167. ult is a few 256 to be exact bytes less than 32K because of the monitor s data page gt gt gt show memory 32512 bytes free 5 10 6 SHO w VER sion The SHOW VERSION command prints the Monitor EPROM version the BIOS version and the BIOS configuration gt gt gt show version Monitor v50 BIOS v1 0 4 BIOS features 0x003D 10 1 2006 4 23 PM Page 32 Spare Time Gizmos COSMAC Elf 2000 User s Manual 5 10 7 SHO w RES tart The SHOW RESTART command prints the current restart settings see section 5 11 3 gt gt gt show restart NONE 5 10 8 SHO w DP The SHOW DP command prints the contents of the Monitor s data page It s just a shorthand for the E 7F00 7FFF command gt gt gt show dp 0 1 2 34 5 6 T7 0 9 A B C PD b E 7 00 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 7 10 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 7 20 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 7 30 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 7 40 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000 7 50 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0000 7 60 gt 00 00 00 00 00 00 00 00 00 00 00 00 00 05 0000 7 70 gt 05 00 00 86 40 86 40 7 86 40 70 C8 84 C8 84 pH H 7 80 gt 72 6C 61 02 4B 00 00 00 00 00 00 00 00 00 00 00 rla K 7 90 gt 00 00 00 00 00 00 00 00 00 0
168. ures AVT52 terminal emulator for use with the Spare Time Gizmos VT1802 80 column video card The video card is described in chapter 12 disk BIOS written by Mike Riley and compatible with the EIOS disk operating system The BIOS contains many useful functions that you are free to call from your own assembly language programs Please refer to Appendix E for references to BIOS and EIfOS documentation Appendix A describes the procedure for installing EIfOS on your Spare Time Gizmos EIf 2000 platform e Asimple text editor and a load and go assembler written by Mike Riley which allows you to type in edit assemble and then run 1802 assembly language programs The Editor Assembler is documented in Chapter 6 e A full featured BASIC interpreter written by Mike Riley BASIC is documented in Chapter 7 Forth interpreter also written by Mike Riley and described in Chapter 8 The remainder of this chapter will describe the Spare Time Gizmos monitor for the EIf 2000 4 1 MoNITOR FEATURES The Spare Time Gizmos monitor is a multipurpose piece of software which lives in the EPROM and adds a number of useful features to the EIf 2000 A power on self test POST that performs a basic test of all Elf 2000 components e Amore extensive diagnostic that performs in depth tests of certain Elf 2000 subsystems e A down loader that can receive Intel HEX format files over the console serial port and load them directly into memory
169. voltage and corresponds to a TTL high level and the normal polarity position of jumpers JP9 and JP10 is used by software that originally expected the CDP1802 Q and EFx signals to be interfaced with a real e g MAX232 RS232 driver However many Elf circuits attempted to interface RS 232 devices directly to the Q and EFx signals without a proper RS 232 level shifter In this case a OV TTL signal corresponded assuming that the external RS232 device was willing to accept it to the active or marking RS232 state and a 5V TTL signal corresponded to a RS 232 space Software written for this kind of interface will expect JP9 and JP10 to be set to the invert position Notice that the two jumpers JP9 and JP10 are flipped with respect to each other that is the invert position on one corresponds to the normal position on the other and vice versa Photo 8 shows the location and the normal invert positions of JP9 and JP10 10 1 2006 4 23 PM Page 18 Spare Time Gizmos COSMAC Elf 2000 User s Manual 3 2 6 JP6 JP6 connects the RS 232 serial input to either EF3 or EF4 To disable the serial port input completely i e to leave both EF3 and EF4 free for other purposes simply remove JP6 completely Photo 8 shows the location of JP2 3 2 7 Other Jumpers Note that jumper JP3 does not exist It was used in an earlier revision of the PC board only 3 3 BOOTSTRAP FLAG Under normal conditions the CLEAR RESET state sets the 180
170. ware Unlike its ancestor the Spare Time Gizmos COSMAC Elf 2000 features An expanded memory to 32K RAM an optional 32K EPROM The EPROM if installed contains a power on self test extended hardware diagnostics an Editor Assembler interpreters for the BASIC FORTH and CHIP 8 languages and a BIOS and bootstrap for the EIfOS disk operating system A jumper is included to allow the CPU to start up at address 0x8000 EPROM rather than the normal 0x0000 RAM An included CDP1861 Pixie chip video display circuit If you don t have an 1861 the Elf 2000 has space and standoffs to mount a daughter board that plugs into the 1861 socket and contains a discrete logic replacement for the 1861 An I O expansion connector and mounting holes for I O daughter cards that fit on top of the main board 31 2473 3117 oe Bernsen eens 12 AMI at goo 8 ree ITI EIYIJG Photo 1 The COSMAC Elf 2000 10 1 2006 4 23 PM Page 1 Spare Time Gizmos COSMAC Elf 2000 User s Manual An optional lithium coin cell and a Dallas DS1210 NVR controller to make the RAM non volatile Any programs you toggle in or download today will still be there tomorrow A true RS 232 compatible serial port using 05275 EIA level shifter and DE9F connector Fully decoded I O ports including the CDP1861 switches and display so there will be conflicts with add on peripherals In addition all
171. won t be enough After the female headers and swages are mounted install the three 72 4 40 standoffs and insert the two 12 pin wire wrap header strips into the female headers Place the STG1861 bare PC board on top component side up of the wire wrap headers and be sure that they re inserted thru the correct holes for J1 You ll find that the wire wrap pins are much longer than needed and that the STG1861 PC board is way above the tops of the standoffs Gently press down on the STG1861 PC board the plastic strips on the wire wrap headers will slide down until the board rests on top of the standoffs The black plastic strips that hold the wire wrap headers together should be flush against the bottom of the STG1861 PC board While you everything arranged just so solder the 24 wire wrap pins to the top of the STG1861 PC board Now you can remove the STG1861 board wire wrap pins and all and cut off the tops of the wire wrap pins flush with the PC board Only now can you solder the rest of the components to the STG1861 and GENE 4 1 111111 1 14112 9g aWvui I IN LOAD Spare Xi MP RUN amp finish assembling it When it s all Time Q done return it to its original See position on top of the Elf 2000 Gizmos board and secure it in place with 3 2 1 0 three 4 40 screws ae ae Note that the 5761861 also MM ELF 2000 gt 4 requires that the Elf 2000 jumpers i J
172. ystem only work with IDE devices that a Support 8 bit transfer mode b Support logical block addressing LBA mode CompactFlash cards except some very very old ones meet these requirements Unfortunately there are very few hard disk drives around that implement 8 bit transfer mode and most of those that do date from the PC XT days and do not implement LBA mode If you are lucky you may be able to find a disk drive which meets these requirements however you ll probably only be able to use this connector to attach an external CompactFlash card ATAPI devices like CDROM drives and ZIP disks have no chance of working with the current firmware and software 11 4 JUMPER SETTINGS Revision 1B of the Disk Expansion card contains five jumpers labeled JP1 thru JP5 The following table summarizes the function of these jumpers and the proper default setting to work with the Spare Time Gizmos Monitor EPROM Jumper Default Function JP1 Removed Enables disk Compact Flash interrupt requests JP2 Removed Enables real time clock interrupt requests JP3 Removed Enables UART interrupt requests JP4 Installed When installed the onboard CF card is the IDE Master When removed the onboard CF is the IDE Slave JP5 Removed When installed erases the NVR see section 11 4 1 Table 19 Disk UART RTC NVR Card Jumpers 11 4 1 Erasing NVR Jumper JP5 can be used to erase the non volatile RAM provided that a DS1

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