The Final Chesscard

The Final Chesscard by TASC was released in 1989 for the Commodore 64/128 and PC. The C64/C128 version plugs into the Expansion(cartridge) slot and the PC version comes with an ISA Card.

The Chesscard forms a stand-alone computer with 32K of ROM, 8K of RAM and an extra CPU running at 5 Mhz. Program software was delivered on disk for the PC and the C64 software is loaded from an additional 32K ROM on the C64/128 cartridge.

The Final Chesscard C64/C128

Unfortunately my Chesscard only displayed a black screen with white stripes, so I began to investigate it.

The C64/C128 Chesscard has two 32K ROMs which I dumped with an eprom reader. One ROM contains software for the external CPU(“brom”) and the other has software for the C64(“crom”). The ROM namings can be found in the Chesscard menues.

The C64-ROM consists of two banks, both 16K at $8000-$bfff. The bank is selected by setting $DE00 to $40 or $41. The Chess-ROM is 32K at $8000-$ffff and boots independently with reset vectors pointing to $FF22.

I needed a way to test the ROMs. The same company was involved in making the “Final Cartridge III” which has 16K sized banks and uses $DE00 for bank swapping. I created a TFC3-type cartridge ROM for emulators(.crt) and wedged in code to set $DE00 accordingly. The Final Chesscard now started up in the Vice emulator, displaying a black screen with white stripes.

Now it became much easier to debug. After examining the code, I could see the “black screen with stripes” was waiting for the extra CPU to acknowledge it was running (possibly these two communicate with each other using zeropages $04-$0e). I removed the checks and had the Chesscard running graphically, the chess engine itself was of course not working.

The Final Chesscard in Vice
It is not playable since there is no support for the extra hardware. I had to patch it to bypass the hardware checks.

I eventually figured out the extra CPU did not start up properly. I took out my desolder gun and removed the CPU. It was tested OK on another equipment. After desoldering the crystal I noticed that one of the legs was broken, and while at it, I decided to clean up the whole PCB for documentation purposes. You will find scans and pictures of the PCB below.

Component list:74LS04 74LS30 74LS32 x 2 74LS74 74LS174 74LS374 x 2 SRAM = 8Kx8 TC5565/MCM6064 CPU = G65SC02P-4 ROM1/ROM2 = 27256 Eprom D1-D6 = Diode 1N4148 ZD1 = Zener diode 2V7 C1-C2 = Tantalum 1uF 35V C3-C6 = Ceramic 0.1uF (100nF /104) C7-C9 = Ceramic 1.0nF (1000pF / 102) C10 = Ceramic 0.56nF (560pF / 561) X1 = Crystal 5Mhz Resistor 2.2 KOhm x2 Resistor 680 Ohm x2 Resistor 330 Ohm Reset button

Everything back in place and all IC:s socketed.

Final mount. The Final Chesscard is now fully functional with english language.

Final Chess Card – CPU information / Compatibility
The co-processor used in the chesscard must have specific characteristics to function.
Original CPU is a CMD G65SC02P-4(MHz) overclocked to 5 Mhz with an extended set of opcodes.
The code for the co-processor utilizes some of the extended opcodes (PHX,PHY,PLY,PLX) which excludes using many 6502-family CPU models.

Beware for relabeled/fake processors, use a known good source for your components.

Compatible processors:
CMOS G65SC02-4 (CMD / California Micro Devices) – Original CPU (178 opcodes, 4 Mhz)
CMOS R65C02P4 (Rockwell) – Straight replacement. (210 opcodes, 4 Mhz)
CMOS W65C02S6TPG-14 (WDC) – (212 opcodes, up to 14 Mhz). Still available from distributors, needs some modifications to work. See link to forum64 below.

Incompatible processors:
NMOS CPUs. MOS6502/SY6502/R6502/UM6502 etc.
Most of these will not run at 5 Mhz and lack the extended instructions.

Links:
W65C02 modification and information by Kinzi at forum64
Information at WDC website

Final Chess Card – Forum64 Edition
With the information above, Freak at forum64.de reproduced and redesigned the chesscard completely, it fits into a standard cartridge case.

You can read about the project at Forum64.de and GitHub.

The Final Chesscard Forum64 edition CPLD core version 1.0 had an issue running the latest ROM on slower speeds (see also Wybren’s comments below) but has been fixed with the latest v2.0 version.

Freak at Forum64.de came up with code and a way to update the CPLD of FCC-Forum64 edition with an userport JTAG-adapter he designed.

I did the update and it took just some minutes, it verifies, erases and programs the CPLD.

Follow the link above to Forum64 for more details and the software.

Awesome work by Freak on the Final Chesscard !

Final Chess Card – Bwack

bwack made an interesting video how to reproduce/trace the PCB using Sprint-Layout and the scans above, well worth a look!

He also released the gerber files which are available on GitHub

Downloads:
The Final Chesscard came in two languages; english and german. The language is hardcoded on the ROM and the english ROM has been quite hard to get hold of (until now). There are demo versions available in both languages on disk but those are incompatible with the ROM version.

By studying the code, I managed to make a C64 tool to extract the ROM and Ratuv at Lemon64 kindly run the tool and extracted the english ROM.

Thanks to DDI for sending the german 1.3 CROM which I disassembled and translated into english.

Note that the RAMDISK feature was removed in the CROM 1.3 (and 1.3e) release.

The Final Chesscard ROM. English ( crom 1.3e / brom 1.5 )

Size: 64.61 KB. 234 downloads

English C64 ROM : crom 1.3e  16-07-90 (Translated by jani@worldofjani.com)

FCC ROM : brom 1.5   22-05-90

The Final Chesscard ROM. English and German ( crom 0.9 / brom 1.0 )

Size: 64.27 KB. 627 downloads

English C64 ROM : crom 0.9   12-10-89

German C64 ROM : crom 0.9   29-11-89

FCC ROM : brom 1.0   05-10-89

The Final Chesscard ROM. German ( crom 1.3 / brom 1.5 )

Size: 43.71 KB. 332 downloads

German C64 ROM : crom 1.3   16-07-90

FCC ROM : brom 1.5   22-05-90

The Final Chesscard - Manual (German)

Size: 5.99 MB. 396 downloads

The Final Chesscard - Extras

Size: 249.76 KB. 368 downloads

The Final Chesscard – Disk

Size: 105.08 KB. 372 downloads

Running The Final Chesscard in an emulator:
The final chesscard is supported by MAME, read more about it at Forum64.

The Final Chesscard (crom 1.3e) - The Final Cartridge 3 .crt image

Size: 129.36 KB. 221 downloads

I made the Final Cartridge III type .crt image to aid in debugging and studying the code during translating CROM 1.3e, perhaps this will also help in developing further support for the Final Chesscard in emulators, it will WILL NOT WORK as intended. Use them only for debugging/developing purposes.

Credits:
Ratuv at Lemon64 for the english ROM.

DDI (http://www.sys64738.net/) for the updated german ROM (crom 1.3 / brom 1.5).

Forum64.de members for the manual, extras and a disk (autoplay, openings, replays etc. available from the File-menu).

Bart (Amon_RA on Twitter) for sending me a reproduced TFCC PCB by bwack. Also thanks for help in testing and verifying the crom 1.3e!

Freak For the The Final Chesscard Forum64 edition and userport JTAG adapter. Thanks!

Kinzi for his great work on investigating and coming up with a solution for the W65C02 CPU !

Update:
2019-12: bwack’s youtube video how to re-draw the PCB using Sprint-Layout and a link to the gerber files.
2020-02: Added The Final Chesscard as The Final Cartridge 3 .crt image for debugging purposes.
2020-02: Added english crom 1.3e, disassembled and translated into english.
2020-03: Updated information about emulation and the missing ramdisk in CROM 1.3/1.3e.
2020-06: Added information about the flash adapter by Freak.
2021-11: Added information about CPU compatibility and replacement

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Comments

Isolde Wieda-Maduschen 33

March 22nd, 2020 at 12:42 AM


The “C64 Final Chesscard” CAN be emulated in M.A.M.E. since about half a year now, cause a new TASC emulator was included in the M.A.M.E. emulation. It works flawlessly.

Jani

March 25th, 2020 at 8:19 AM


Hi, thanks for notifying :). Updated accordingly.

Wybren van Duinen

March 24th, 2020 at 10:01 PM


Hello Jani,

I build the FCC64 and have discovered that with CROM1.3(e) and BROM 1.5 the card only works at 14Mhz and there is no ramdisk option.
With the older CROM 0.9 (german or english) and BROM 1.0 the card works at all speeds 5MHz, 7MHz, 10Mhz and 14Mhz and the ramdisk is fully functional. You can even save you’re preferences and when you save it under the name “BOOT”, it gets automatically loaded each time at start-up or reset.

Just to let you know. Maybe this information is also handy for others who build the FCC64. so they can choose there options for CROM and BROM.

Greetings Wybren

Jani

March 25th, 2020 at 8:20 AM


Hi, thanks for the detailed information :). Updated post with your information.

Wybren van Duinen

March 31st, 2020 at 3:50 PM


Freak had updated his Github (https://github.com/ttahsin-bey/FCC64/tree/master/CPLD) repository with a new version for the CPLD. And this fixes the speed problem. The new ROMS work with the update CPLD core at all selected speeds (5 MHz, 7MHz, 10MHz and 14MHz).

So if you build you’re own FCC64 card. Use the new CPLD core and the new ROM’s will work correctly.

Greetings Wybren

Jani

March 31st, 2020 at 6:54 PM


Thanks for the update 🙂
Regards
Jani

RefriedNoodle

January 30th, 2021 at 3:13 PM


I used to own a FCC back in the 90s. I do recall that I got upgrade roms from TASC at some point, which included the new chesspieces. I’m sure it was in English too, so I’m confident that a genuine English crom 1.3 must exist.

Soldering SMD is beyond my skills, so I am unable to recreate your project. But recently I managed to get a relatively cheap FCC for my Ultimate64 again, and thanks to this site, I upgraded the roms. Thanks!
Jannes

October 10th, 2021 at 11:24 AM


Jani ,

do you still have the clone final chess card ? based on the original design

i tried to reproduce your design with the same processor and the use of 2 27256-10 eproms but it does not function correctly .

can you confirm your configuration works flawlesly

Jani

October 10th, 2021 at 3:59 PM


Hi Jannes,
The reproduction on original design by Bwack works, a trace needs to be cut on version 1.0 (details on GitHub).

Be sure to find a good source for the IC:s, a few have had problems with counterfeit/relabeled CPUs and broken 74xx IC:s.

EDIT: Updated post with information about CPU compatibility

Regards
Jani

Bob

April 24th, 2022 at 12:17 AM


Hi Jani,

really nice article and very good work!

is there any documentation on the usage (in brom) of the “non” NMOS compatible instructions in detail? Or in other words: does a disassembly file, maybe already reworked and with added “human” comments exist already?

I think, it would be interesting to get this thing working with only the commodore built CSG/MOS chips and there are some 3MHz (6502B) and even (a few) 4 MHz 6502C (do not mix up with Atari´s “Sally”) CPUs still available…

You wrote that “probably” the communication between the “HMI”-CPU aka C64/128 and the working CPU in module works with zeropage ram. As the C64/128 timing is rather weird, i think that there must be something like a dualport-ram or at least some registers and a semaphore register too to do this. In the BoM above i see some TTL Chips which could the job, but i am missing any kind of schematics, is one available at all?

Thanks and have a nice sunday!

best regards,

Bob

Jani

May 10th, 2022 at 7:59 PM


Hi Bob, and thanks 🙂
I have disassembled the ROM and it should be possible to replace the illegal operands, there is some free memory for that. I haven’t studied the PCB for how it works, my assumption comes from looking at the code. It waits for some zeropages to change for it to acknowledge the co-processor is active.
Regards
Jani

Charles Gutman

April 11th, 2023 at 12:57 AM


I’d like to purchase a couple of the bare boards for assembly please. Can you please tell me where I could acquire them please? I will gather the components elsewhere and I already have a stock of cartridge cases already.

Thanks so much

Charles

Jani

April 11th, 2023 at 3:51 PM


Hi Charles, Unfortunately I don’t have any spare PCB:s. I believe you can get the gerbers from Bwack’s and Freak’s Github, links are available in the article.
Regards
Jani

Kerim

September 16th, 2023 at 4:56 PM


Hi Jani,

What brand/model fladbed scanner did you use to scan the PCB? Thanks in advance.

Jani

September 16th, 2023 at 5:32 PM


Hi Kerim,
I got an Epson v370 scanner, the backlight/seethrough pictures are photographed with a Canon 7D in full manual mode. The backlight used is from a broken LCD screen.
Regards
Jani

The Final Chesscard

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