Varian Data Machines

Varian Data Machines was a division of Varian Associates which sold minicomputers. It entered the market in 1966, but met stiff competition and was bought by Sperry Corporation in 1977.

The 620i and 620/L series were parallel, binary 16-bit general-purpose digital computers with core memory expandable to 32,768 words. An 18-bit word length was optionally available. A basic machine cycle took 1.8 microseconds, and the core memory read time was 700 nanoseconds. The computers uses two's complement arithmetic and had four main registers - accumulator A, accumulator extension B, an index register X and a program counter register. Addressing modes were direct, immediate and indexed. The instruction set had more than one hundred artihmetic, logic and control instructions and supported microprogramming. These models used a hardware front panel console that allowed starting and stopping the machine, examinging memory and registers and changing memory or registers with front-panel switches. The processor was made with integrated circuittransistor transistor logic from the 7400 series. The system was packaged in a 19 inch rack and used 340 watts of power at 120 V AC. The 620/F was a variation with a faster machine cycle time of 750 nanoseconds. The 620/L 100 was released in 1973. It had a cycle time of 950 nanoseconds and a more compact system chassis than the 620/F. The 70 series had semiconductor memory but also supported core. Various models were released between 1972 and 1977.