Control Data Corporation (CDC)

Contribution to AI

Speed was the whole proposition, and for a decade nobody else could sell it. The 6600 that shipped in September 1964 ran at roughly three megaflops, about three times the IBM 7030 Stretch, and stayed the fastest machine anywhere until CDC's own 7600 displaced it in 1969. Seymour Cray reached that by subtraction: a small load-store instruction set, ten peripheral processors absorbing all input and output so the central processor did nothing but arithmetic, and Jim Thornton's scoreboard, the first hardware to issue instructions to parallel functional units and let them complete out of order. Dynamic scheduling in every processor since descends from it. For artificial intelligence the machines mattered as the place where the search-versus-knowledge argument was tested rather than debated. Slate and Atkin's Northwestern chess programme began on a CDC 6400, moved to the Cyber 175 and then the Cyber 176 with help from CDC's David Cahlander, and the 1973 rewrite threw out selective search for full-width alpha-beta; the iterative deepening and transposition tables that came with it became standard equipment for everyone afterwards. By 1977 it was winning open tournaments against rated human players. CDC also commercialised PLATO from Illinois, which had started on a 1604 the company supplied, giving computer-assisted instruction a real installed base for tutoring research to build on.

Drafted with AI and edited by hand (claude-opus-5, reviewed 2026-08).