Darren Branagh shared a link via F.book recently about what might be the smallest chess playing program ever at just 487 bytes - see http://arstechnica.com/gaming/2015/01/s ... 487-bytes/.
That article links to a 1K ZX81 chess listing article in Your Computer magazine http://archive.org/stream/your-computer ... 9/mode/2up
I thought we'd done quite well getting chess into a 25K SuperBASIC program on the QL - look for Wedgie on the games page on my website.