Sinclair ZX81 – ZX Chess in 672 bytes of RAM #Retrocomputing

How do you squeeze the gameplay and graphics of chess into 672 bytes of RAM? Very carefully! Back in the early 1980s, the base model Sinclair ZX81 was affordable but limited to 1K RAM. Developer David Horne discussed 1K ZX Chess and published the full source code in a series of articles in Your Computer in 1982 and 1983.

You can get the source code from zx81stuff.co.uk if you’d like to see the magic yourself.