"The current "shrinking level" of this version is around 670 bytes." ...
"Later on this version has been extended to allow playing with full FIDE rules, meaning including the management of en-passant, castling and under promotion. This new version is around 750 characters (35 lines of codes when pretty printed)."
https://smmax.sourceforge.net/
Written in C:
"The current "shrinking level" of this version is around 670 bytes." ...
"Later on this version has been extended to allow playing with full FIDE rules, meaning including the management of en-passant, castling and under promotion. This new version is around 750 characters (35 lines of codes when pretty printed)."
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full FIDE version assembly 583 bytes .COM
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ZX81 1K version