Belle (chess machine)

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Belle is a chess computer that was developed by Joe Condon (hardware) and Ken Thompson (software) at Bell Labs. In 1983, it was the first machine to achieve master-level play, with a USCF rating of 2250. It won the ACM North American Computer Chess Championship five times and the 1980 World Computer Chess Championship. It was the first system to win using specialized chess hardware.

In its final incarnation, Belle used an LSI-11 general-purpose computer to coordinate its chess hardware. There were three custom boards for move generation, four custom boards for position evaluation, and a microcode implementation of alpha-beta pruning. The computer also had one megabyte of memory for storing transposition tables.

At the end of its career, Belle was donated to the Smithsonian Institution. The overall architecture of Belle was used for the initial designs of ChipTest, the progenitor of IBM Deep Blue.^[1]