On 17 March 2014 13:51, John Eells <ee...@us.ibm.com> wrote: > MVS was the prior name of what has become z/OS. What was started out as MVS > in 1974 was renamed to: [...]
Although the name MVS was around in 1974, IBM chose, for the usual marketing reasons of the day, to sell it as OS/VS2 Release 2, presumably to emphasize continuity with the very different OS/VS2 Release 1 (aka SVS), which was essentially MVT virtualized into a single 16 MB address space. It took a long time for the names MVS (and SVS, for that matter) to appear in official publications; many if not most pubs still had titles with "OS/VS2 Release 3.7" and no mention of MVS into the late 1970s. There is some evidence that the product was going to be called MVM (Multiple Virtual Memories) at one time. For quite some time after release of OS/VS2 Release 2, the IEHDASDR program printer a heading line containing "MVM DASDR". There is a different sense of "MVS", and that is, as John Chase said 'MVS is the "kernel"; z/OS is the "whole package"'. This, though, came about only when MVS/XA appeared with the non-optional Data Facility Product (DFP) in addition to the core operating system. Two labs, east coast, west coast, etc... These were re-integrated only with the OS/390 bundling. I doubt any one present -- even Lynn Wheeler -- knows all the politics behind all these changes. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
