• 1954

Hardware Description

This was Japan's first practical relay-based automatic computer. It was developed in October 1954 by Fuji Tsushinki Manufacturing Corporation (currently Fujitsu). The main unit of the FACOM 100 was comprised of approximately 4,500 relays. Circuit control was asynchronous, and programs were executed by reading from 60-unit paper tape (non-combustible film was used for repeatedly used programs). For numerical values, the system used the floating point number which could handle a range from positive/negative 99-digit integers to 99 digits after the decimal point (with 8 significant digits), and arithmetic was done using the binary coded decimal method. Arithmetic speed performance for 8 digits was 0.35 seconds for addition and subtraction, 1.8 seconds for multiplication and 5.0 seconds for division.