CDC 6000 series

The CDC 6000 series was a family of mainframe computers manufactured by Control Data Corporation in the 1960s. It consisted of CDC 6400, CDC 6500, CDC 6600 and CDC 6700 computers, which all were extremely rapid and efficient for their time. Each was a large, solid-state, general-purpose, digital computer that performed scientific and business data processing as well as multiprogramming, multiprocessing, time-sharing, and data management tasks under the control of the operating system called SCOPE (Supervisory Control Of Program Execution).

The CDC 6000 series computer is composed of four main functional devices: the central memory, one or two high-speed central processors, seven to ten peripheral processors (Peripheral Processing Unit, or PPU), and a display console. The four computer types differ primarily in the number of and kind of central processor. It had a distributed architecture and was a reduced instruction set (RISC) machine many years before such a term was invented.

The first member of the CDC 6000 series was the first supercomputer CDC 6600, designed by Seymour Cray and James E. Thornton in Chippewa Falls, Wisconsin. It was introduced in September 1964 and performed up to three million instructions per second, three times faster than the IBM Stretch, the speed champion for the previous couple of years. It remained the fastest machine for five years until the CDC 7600 was launched. The machine was Freon refrigerant cooled. Control Data manufactured about 100 machines of this type, selling for $6 to $10 million each.

The next system to be introduced was the CDC 6400, delivered in April 1966. The 6400 central processor was a slower, less expensive implementation with serial processing, rather than the 6600's parallel functional units. All other aspects of the 6400 were identical to the 6600. Then followed a machine with dual 6400-style central processors, the CDC 6500, designed principally by James E. Thornton, in October 1967. And finally, the CDC 6700, with both a 6600-style CPU and a 6400-style CPU, was released in October 1969.

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