Varian Data Machines  From Wikipedia, the free encyclopedia Jump
to: navigation, search For other uses of "Varian", see Varian
(disambiguation).  Varian Data Machines was a division of Varian
Associates which sold minicomputers. It entered the market in
1966,[1] but met stiff competition and was bought by Sperry
Corporation in 1977.[2]  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 st