First commercial chess programs

[Colin]

Hi, I was wondering how the very first chess programs worked.
There was a chess game for the 48k spectrum, I forgot the name, Colossus I think.
I don't see how it could search deep enough to play reasonably, but I believe it could play quite well.

How did they do this?

[Bill Rogers]

I may be mistaken but I think the first commercial chess program was written by Peter Jennings and it was caled Microchess. It could only search to a depth of 3 plys and was rated at about 600 elo.
Originally written for the Kim handheld computer Peter had it cross assembled for the 'Big' three at that time, ie. Radio Shacks Model 1, Apple and Commador Pet. In an extremely short period of time it had sold over 1,000,000 copies all on cassette.
Bill

[Mike S.]

I am no programmer, but I think even the oldest chess programs used a quiescence search extension, at least. By that, a 3 plies search can spot combinations deeper than 3 plies. I had Colossus for the Amstrad (Z80 8 bit cpu@4 MHz) and I think it played roughly at ~1600 level. As far as I can remember, a depth of 4 was typical at medium time controls.



Since a few years, there is a new Colossus version aviable as a UCI engine, from the same programmer:

http://www.colossus.demon.co.uk/chess/c ... essuci.htm

[IanO]

Yes, Microchess was not just the first chess program sold. It was the first game of any kind sold (released December 18, 1976). Even on the tiny, splintered markets of the day, Microchess sold a million copies. This provided the seed money for VisiCorp, which went on to develop the pioneering spreadsheet VisiCalc.

The 6502 assembly source is available if you wish to see how much it did in 1K of RAM.

http://www.benlo.com/microchess/microchess.html

The author used a Scientific American article and Nimzovitch's My System as the basis of the search and evaluation functions.

http://www.benlo.com/microchess/microchess4.html

Ian

[fern]

Incredible: those extremely weak programs got sold by the millions and sometime enriched his authors; now a guy create a GM level engine and he is lucky if he sell enough to get a coffee in Starbuck.

Life is such and such a miserable thing sometimes regards
fernando