[bananamogul]

We had a Fidelity Chess Challenger 7 when I was a kid.

I was a horrible chess player but painstakingly worked out a way to win as white, keeping a detailed log of my experiments in a notebook. The first couple moves were wildly out of book (because I didn't know book), and the computer with its limited Z80 processor always computed the same moves after that. Some googling [1] shows the board's Elo is 1300ish.

To illustrate the state of the art in 1979, the manual [2] explicitly calls out that it understands en passant and castling.

[1] https://www.spacious-mind.com/html/chess_challenger_7.html

[2] https://ia902902.us.archive.org/20/items/mame0.211manualsful...

[mrandish]

From the same time period there's also Atari Video Chess for the VCS (aka 2600). It had to fit in 4K of ROM and 128 bytes of RAM yet also had en passant, castling and prevented illegal moves.

It plays well enough that it beat ChatGPT 4o last year. https://en.wikipedia.org/wiki/Video_Chess

[a_t48]

I love that the TEST PROGRAM at the end to verify the computer is working is to basically scholars mate yourself.