【Fujitsu】 FACOM 230-15

This was a small general-purpose computer from Fujitsu -- the lowest-end model of the FACOM 230-5 Series. This machine was announced in April 1970 as a small general-purpose computer to cover the gap between the FACOM 230-10 small computer for office use, and the FACOM 230-25 mid-size general-purpose computer. At the time, information processing was entering a new era due to the advent of the computerization age, and this FACOM 230-15 achieved a low cost/performance performance ratio by using new technology. The features of this machine were as follows:

  1. High-speed processing capability
    ICs were used to achieve a high-speed machine cycle time of 750ns.
    The information format was based on the 16-bit word, and the system could be optionally equipped with high-speed arithmetic based on 4-digit 2-byte parallel arithmetic for business calculations, and double-length (32-bit) arithmetic and binary multiplication/division for scientific calculation.
    High-speed paging was achieved using a high-speed built-in drum (capacity 131/262KB, access time 10.0ms (50Hz)/8.5ms (60Hz), transfer speed 218KB/S (50Hz)/262KB/S (60Hz)).
  2. Outstanding file capabilities
    In addition to the built-in drum, the machine had outstanding file capabilities based on features like a magnetic tape and magnetic disk pack.
  3. Easy communication line connection was achieved by developing a dedicated channel for line control.
  4. Superior economy
    Modularized CPU with two options (one for business computation, and one for scientific computation)
    Greater compactness and lower cost were achieved by greatly reducing the component count. This was done by developing a channel integrating the functions of input/output control unit.
Comparison between FACOM 230-15 and Machines Existing at the Time
Model name FACOM 230-10 FACOM 230-15 FACOM 230-25
Announcement date March 1965 April 1970 August 1968
Main memory unit Memory element Magnetic core
Cycle time 2.0microsec./1byte (1byte=10bit) 1.5µs/2B 1.5µs/2B
Capacity 4-8KB 8-32KB 8-64KB
Arithmetic speed Binary addition/subtraction
None 3.0µs 3.0µs
Decimal addition/subtraction 144.2microsec.
(5 digits + sign)
(5 digits + sign)
(6 digits + sign)
Floating point addition/subtraction none none 16.5microsec.
Instruction word length 1-5 bytes, variable 2/4/6 B 2/4 B
Max. number of channels 2 6 6

FACOM 230-15