CDC 6600

Control Data Corporation
Clock Speed: 
Dates Used: 
Thursday, December 30, 1965 to Sunday, May 1, 1977
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In 1962, Seymour Cray opened a Control Data Corporation laboratory near Chippewa Falls, Wisconsin, where he led the design of the CDC 6600 computer. This machine, which was announced in 1964, sold for around $7 million and was the first computer designed in the Chippewa Falls area.

The CDC 6600 is believed to have been the first computer to be designated as a "supercomputer," offering the fastest clock speed for its day (100 nanoseconds). It was one of the first computers to use Freon refrigerant cooling and was also the first commercial computer to use a CRT console. (CDC checkout engineers created computer games such as Baseball, Lunar Lander, and Space Wars, which became incentives for getting the machines operational. These are thought to be the first computer games that used monitors.)

NCAR accepted delivery of a CDC 6600 in late December 1965. The machine was operated for nearly a year at the 30th street location in Boulder until the Mesa Laboratory was ready in December 1966.

The CDC 6600 was a large-scale, solid-state, general-purpose computing system. It had a distributed architecture (central scientific processor supported by ten very fast peripheral machines) and was a reduced instruction set (RISC) machine many years before such a term was invented.

Input to the computer was by punch cards or seven-channel digital magnetic tape. Output was available from two line printers, a card punch, a photographic plotter, and standard magnetic tape. An interactive display console allowed users to view graphical results as data were being processed.

The CDC 6600 had 65,000 60-bit words of memory. It was equipped with a large disk storage device and six high-speed drums as storage intermediate in speed and accessibility between the central core storage and magnetic tapes. The 6600 supported the FORTRAN 66 compiler and a program library.

The CDC 6600 was decommissioned in 1977.