Keys "s"=save "l"=load "b"=back once
Pieces promote upon being moved. A maximum of four rooks, four bishops, and four knights are allowed in play at any time. I take this to mean for each side. Mate any king to win. I ignored en passant. V.R. Parton, 1961.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!
