Impressive, as is the recent smaller program from a French programmer. Note, however, that both have sacrificed some rules. I believe they have both left out en passant, which is rare enough that it won't be missed most of the time. It's rare enough that if you use it against a casual player, there is a good chance they will accuse you of making it up. Castling, however, which is also omitted, is much more serious. G…
There's a rather ahistoric perspective at work here. I wonder if there's a generational thing. ZX81 chess was so impressive because it was impossible (at least, I'd have bet real money on it). It was the thing programmers namechecked as the kind of thing you couldn't do on these newfangled cheap home computers. You need a 'real' computer to do it. There's just no way. I was writing programs for the ZX81, and the kind…
http://uknet.com/gallery2/d/16341-2/076_Sinclair_ZX81_Manual...
(Paintings by John Harris. He sells prints! http://www.alisoneldred.com/thumbsJohnHarris-Prints-3-1.html)
However, you will be frustrated with the ZX81; the built in BASIC was utterly appalling and also didn't have a tokeniser --- instead each key (plus modifiers) produced a different keyword. And it was stateful, so the keys did different things depending on what you were typing. This made typing on it horribly frustrating even when you had the keywords written on the keyboard, which you won't have with an emulator.
It may be of interest to check out the Jupiter Ace --- it's basically the same machine, made by some ex-Sinclair staff, except running Forth instead of Basic; you can at least type on that, and using Forth means you're much closer to the machine. (Plus, Sinclair's Basic was seriously horrifying. Any alternative is better.) There's a bunch of emulators. But it's a much more esoteric machine, so there'll be very limited resources around.
There are Javascript emulators for all the above, but they're pretty naff.
