[t0mek]

Programming a chess program was an important challenge for the "first generation of hackers" working on the mainframe machines like TX-0 and PDP-1 in '50 and '60, as described in "Hackers: Heroes of the Computer Revolution" by Steven Levy. I highly recommend this book, I think a lot of people here can recognize their own passion and interests in the stories described there.

Also, there's interesting implementation for the ZX-81, created over 20 years later and fitting in just 1024 bytes: https://users.ox.ac.uk/~uzdm0006/scans/1kchess/

[sloucher]

Not even 1024 bytes. There were 1024 bytes available to the computer, but some of that was required to store what was displayed on the screen. Exactly how much depended on how much of the screen was used(!).

Different times...