Smallest ever chess program: 487 bytes

BootChess has smashed the record for the smallest computer implementation for chess, held since 1983, with a total size of only 487 bytes

Rudolph Muller 

January 28, 2015

BootChess is now the smallest computer implementation of chess on any platform at a size of only 487 bytes.

BootChess was coded by Olivier Poudade, with assistance from Peter Ferrie, and is a 512-byte x86 boot sector program for Windows, Linux, OS X, DOS, BSD, DOSBox, and Bochs.

The program beats the previous record held by the 672-byte 1K ZX Chess program, which was created by programmer David Horne.

1K ZX Chess was first published in Your Computer Magazine in 1982 when Artic Computing started selling the program.

Poudade wrote that 1K ZX Chess implemented most chess rules – castling, queening, and en-passant capture were missing – as well as artificial intelligence and a user interface.

The screenshot from the February 1983 edition of Your Computer Magazine shows the code for 1K ZX Chess.

1K ZX Chess
487 bytes BootChess

Red Sector Inc. and Poudade have significantly reduced the memory requirements of BootChess when compared to 1K ZX Chess – down from 672 bytes to 487 bytes.

Full codes here:
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