Symbolics 3600

The Symbolics 3600 was a Lisp machine, a workstation built specifically to run the Lisp programming language efficiently, introduced by Symbolics in 1983 during the 1980s boom in commercial artificial intelligence research. It used a 36 bit word architecture split into tag and data components, 44 bit memory words with error correcting code, a stack machine instruction set and 4,096 hardware registers, with an original processor running at about 5 megahertz that could execute many Lisp operations in a single clock cycle, alongside a Motorola 68000 front end processor for startup and peripheral handling and an Ethernet interface for networking. The original 3600 was roughly the size of a refrigerator, while later models such as the 3640, 3645, 3620 and 3650 shrank progressively as disk technology improved, and the series became a leading platform for artificial intelligence research and commercial AI applications through the 1980s.