【Fujitsu】 Software for FACOM 222

Fujitsu shipped the relay computers FACOM 100, FACOM 128A and FACOM 128B between 1954 and 1958. However, Fujitsu did not provide their software, and users created programs in machine languages. The company initiated research on programs in conjunction with the start of development of the large general-purpose computer FACOM 222 in 1958, and prototyped a FORTRAN programming system (FACOM 222P FAST), an assembler programming system (FACOM 222P FASP)(*), an IOCS (Input Output Control System) and a SORT/MERGE program for FACOM 222P. Because the main memory of FACOM 222P consisted of a 400-word core memory and a 9,600-word magnetic drum, the company took various measures to achieve control similar to today’s virtual memory.

In 1963, following these prototypes, the company provided a FORTRAN programming system (FACOM 222 FAST), an assembler (FACOM 222 FASP), an IOCS and a SORT/MERGE program as software for FACOM 222A.

This FORTRAN programming system was a closed system that contained a relocatable binary loader (FACOM 222 FAST LOADER), a subroutine during execution and a small monitor. In addition, the assembler itself also constituted one system, and the object program used the IOCS and SORT/MERGE program.

(*) FASP: FACOM Automatic Symbolic Program