Orac Draughts

by orac81

Last edited on 28 Oct 2025 by orac81. See all edits

11 comments

orac81 - 22:34 28 October 2025 #

ORAC is a (fairly) strong open-source 6502 checkers playing program. Its was originally written in 1981 for the PET, then later adapted for the Commodore 64, C16/+4 and VIC20. The unexpanded VIC20 version is just 3300 bytes

Main files in this archive:

orac-c64.prg - Commodore 64 version.
orac-c16.prg - Commodore 16/Plus 4 version.
orac-pet.prg - Commodore PET version. (BASIC 2.0, PET 30xx/2001)
orac-vic8k.prg - Commodore VIC20 8k+ version.
orac-vic5k.prg - Commodore VIC20 unexpanded version (PETSCII only) (just 3300 bytes!).
orac88pet.prg - Original PET version, written and hand-patched on a PET.
orac.s - Source code for above, compiles with CA65 or ASM502. Released as free under GPL3 licence.
orac.txt - Full instructions and quick tutorial on checkers.

Commands:

Cursor up/down/left/right & SPACE - Move cursor and select move. (first the piece to move, then destination)
#-# - Enter your move using square numbers. (ie. 11-15 <RETURN>)
N - Put the square numbers up on the screen. Hit <RETURN> to clear numbers.
I# - Set an intelligence (IQ) level. (ie. I20<RETURN>, range 0 to 39)
H - Show HELP screen. (H <RETURN>)
R - Resign and Restart a new game.
A - Auto play, tells ORAC to play ORAC. To stop this feature, hit RETURN.

https://github.com/orac81/Orac-Draughts#orac-draughts

Enjoy!

dipswitch - 22:36 28 October 2025 #

@orac: can you please enter a correct release date? it's surely not 1981.

dipswitch - 22:41 28 October 2025 #

@orac: so, _YOU_ released it on 1 june 1981?

orac81 - 22:42 28 October 2025 #

It is! First version adverised in PCW magazine June 1981. page 145.

https://www.worldradiohistory.com/Personal_Computer_World.htm

Thus my handle, orac81
:-)

dipswitch - 22:43 28 October 2025 #

but how is this a valid scene release then? what exactly is the scene-produced aspect of it? or did you do the ports? then the ports are the actual release, and have to be dated accordingly.

orac81 - 22:45 28 October 2025 #

Yes, I wrote it on an 8k PET 2001. A lot of hand assembly.
(ORAC88PET.PRG) is the original version. The c64 version came later of course.

orac81 - 22:49 28 October 2025 #

Well ok the last edit of orac523.zip was last year, if you want use that as the date. But the 1981 version is in the zip.
We did have a "scene" in 1981, ie cursor tape magazine! I had a few type ins published then.

dipswitch - 22:50 28 October 2025 #

OK, fair enough! Thanks for the clarification!

orac81 - 22:50 28 October 2025 #

If u want me to change it thats ok.

orac81 - 22:53 28 October 2025 #

no worries!

orac81 - 22:58 28 October 2025 #

I suppose the "scene" part might be hacking it down to 3.3k to run on an unexpanded vic20, which is in there..