Both the ZX80 and 81 have had a full FIDE 1k chess for about five years now. I did a lot of play testing for Stefano of both versions and whilst the ZX81 version is quite excellent in my opinion, the ZX80 version is problematic from a gameplay point of view which I find surprising as I believe they have the same game code though happy to be corrected.
The ZX81 has three main versions of the program( also a couple of prototypes): "weak" (faster) "Strong" (slower 5-8 mins per move but stronger play) and "Flexi" which allows you to make a few strong opening moves for the zeddy before letting the AI take over. Constant pressing of the enter key allows this version to play itself and or play a move for you.
All versions are FIDE compliant insofar as they allow castling en passant and under promotion and whilst the grandmasters won't lose any sleep over it I have to say the gameplay after setting up the zeddy with a good opening is quite good and tentatively ELO rated at around 1200 or novice level.
I have had the strong game play against other computer/consoles chess programs and whilst losing to stronger up to date PC's it wiped the floor with Saga and Atari chess at equivalent levels and can hold its on on some occasions against 16k ZX81 chess.
The ZX80 gameplay is strange insomuch as it seems to just want to repeatedly move a rook side to side on concentrate on solely advancing its queens rook pawn at the expense of everything else but I do believe this is still a work in progress.
None of the versions have any kind of book opening or end game strategy but hey we are talking 1k here and I have to say in my very humble but honest opinion that these chess programs are a staggering feat of programming for such a humble machine and Stefano has my full admiration and support for all his hard work.
Information can be found here..
viewtopic.php?f=6&t=2290&hilit=fide+zx80+chess
viewtopic.php?f=6&t=1841&p=18959&hilit= ... ess#p18959
The Micro chess page with versions for different platforms
http://smmax.sourceforge.net/
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