OS/VS1

OS/VS1
DeveloperIBM
Written inAssembler (XF), PL/S (nee BSL)
Working stateHistoric
Latest releaseOS/VS1 Basic Programming Extensions (BPE) Release 4 / March 1984 (1984-03)
Marketing targetIBM mainframes
PlatformsSystem/370
LicenseProprietary
Preceded byOS/360

Operating System/Virtual Storage 1, or OS/VS1, is a discontinued IBM mainframe computer operating system designed to be run on IBM System/370 hardware. It was the successor to the Multiprogramming with a Fixed number of Tasks (MFT) option of System/360's operating system OS/360. OS/VS1, in comparison to its predecessor, supported virtual memory (then called virtual storage). OS/VS1 was generally available during the 1970s and 1980s, and it is no longer supported by IBM.


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