AttoChess: A Complete Playable Chess Program in Just 278 Bytes for DOS

AttoChess, a complete, playable chess program for 16-bit x86 DOS in 278 bytes

I present AttoChess, a fully functional chess engine for 16-bit x86 DOS that fits into a mere 278 bytes, breaking the previous record. This program draws the board, accepts keyboard moves, and searches four plies deep using optimized assembly techniques. Building on the legacy of LeanChess and BootChess, I achieved this by eliminating render buffers and folding arithmetic constants directly into memory addresses.

"AttoChess is not a byte-count stunt that only sets up a board. It boots, draws the position, reads your move from the keyboard, searches with real 4-ply recursion, replies with a legal move, and loops."