On Mon, 10 May 2021 12:56:42 +0000, Seymour J Metz <sme...@gmu.edu> wrote:
>CMS originally ran on a real S/360 or on a S/60 virtual machine under CP-67. >The CMS for VM/370 through VM/SP ran > on a virtual S/370. When did CMS stop requiring S/370 mode and when did it > stop supporting S/370 mode (if it did)? I worked on that project as I was in CMS Development at the time, the owner of a lot of I/O-related code. VM/XA SP2.1 shipped CMS 5.5, the "converged" CMS that made CMS bimodal (dual-pathed for 370 and 370-XA) and replaced all of the I/O instructions DIAGNOSE calls to CP. Prior to that, CMS Release 5 (VM/SP 5) required 370 mode, though you never noticed because VM/SP (and the VM/ESA 370 feature) didn't have any other kind of virtual machine. Both the ESA and 370 features of VM/ESA 1.0 and 1.1 had the same CMS (level 7 and 8, respectively). z/VM 3.1 was the last release to support 370 mode virtual machines, including CMS. z/VM V4 (all releases) tolerated virtual machines defined with MACHINE 370, but would not instantiate them. (This was done in case of sharing a directory with z/VM V3 or earlier.) The 9672 G3 was the last machine with 370 microcode, and z/VM 3.1 was the last release to support the G3. CMS today would probably run in a 370 mode virtual machine. There are still BC/EC-mode dual paths, too, but let's not get carried away. :-) Sir Alan Lord of the Protocols Order of the Knights of VM ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
