【Fujitsu】 Operating Systems for Early FACOM M Series Computers

 For the FACOM M series, Fujitsu changed the architecture for general-purpose computers to M series architecture based on IBM S/370. The company therefore needed to develop three new operating systems (hereinafter “OS”) as the OSs for the FACOM M series: super-large general-purpose OS OSIV/F4, large-scale general-purpose OS OSIV/X8, which achieved a high price/performance ratio, and medium-scale general-purpose OS OSIV/F2, which was optimal for medium-scale business applications. These OSs had the following features:

(1) Adopted various virtualization technologies, including a virtual memory, virtual access method, and a channel DAT mechanism specific to the FACOM M series hardware, based on a design concept common to the three OSs.
(2) Introduced the new-age database/data communication program package AIM (Advanced Information Manager), developed under an innovative concept for all three OSs.
(3) Achieved upward compatibility and international compatibility from the company’s existing OSs, in addition to compatibility among the FACOM M series OSs.

 The following table gives an overview of the functions of the OSs.

Table Overview of the functions of the FACOM M series OSs
Applicable computer model M-190M-160S M-190M-130
(multi CPUs not supported)
(multi CPUs not supported)
Processing type Batch X X X
Remote batch X X X
Interactive remote batch X X *1
TSS X X *1
Virtual memory control Level Multi virtual Multi virtual Single virtual
Address space size
(Max. of job multiplexing number)
16 MB
16 MB
16 MB
Channel DAT X X X
Multiprocessing X X -
Virtual access method Virtual storage access method(VSAM) X X X
Communication access method(VTAM) X X X
*1: Supported by OSIV/F2 AIF, which was announced in 1979.
*2: Initially, up to 5 when announced; later extended to 8, and then 12.