A chess program for the Acorn Atom released in 1981 by Acornsoft on cassette. Atom Chess was an improved version of Chessnut by Geoffrey Bulmer which competed at the 2nd European Microcomputer Chess Championship. Atom Chess recognizes all legal chess moves, including castling, en passant, and promotes to queen only. The program uses pure coordinates for game notation and entering moves, allows to manually set up positions, and features 6 levels of play.