Computers and Programming

UC Berkeley CDC 6400

Sixteen Years of Service!
(December 1966 to August 1982)

UCB 6400 Memories

CDC References

CDC 6400 Hardware Diagram UCB CDC 6400 Job Card

The Berkeley Control Data 6400 system was put into operation in December of 1966 as the primary system for academic computing on the Berkeley campus. Its final configuration as of January 1969 was a 10 MHz 60-bit processor, 64k of 60-bit core memory, 500k of extended core memory, and about 10M words of disk storage. The initial operating system was Control Data Chippewa OS but the system was heavily modified by the Computer Center systems staff over time.

In 1968, the Remote Terminal System (RTS) was installed. RTS used locally developed hardware and systems software, and connected remotely located Teletypes for 110 Baud batch input-output. At its peak, there were 160 lines at 110 to 9600 baud, and some 110/300/1200 Baud dialup modems.

In 1971, the Remote Computer System (RCS) was installed. RCS used locally developed hardware and systems software, and provided remotely located medium-speed reader-printer workstations, eventually including the campus UNIX systems and peaking at 24 stations, including several 4800 baud dialups.

In 1971, the CALIDOSCOPE Operating System was installed. CAL's Improved Design of SCOPE 3.2 was an extensive revision featuring substantial improvements in job turn-around, performance, and reliability. Also major work was done on the Fortran libraries, and a Fortran debugging interpreter and a SNOBOL 4 compiler were implemented.

In 1973, a locally developed disk-pack subsystem was installed, adding 39 million words of disk storage in 6 drives. This allowed some users to keep files permanently available on the system for the first time.

After 1973, numerous refinements and adjustments were made but the system was essentially frozen until its final shutdown on August 31, 1982.

In its 16 years of service, the CDC 6400 ran about 10 Million jobs averaging 8 hours per day of central processor time. 7200 jobs were run on each of the peak days, December 4th and 5th, 1974.



  • University of California at Berkeley to Purchase Control Data Dual 6400 System, November 14, 1966 (Box 2, folder 3)

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