I have a copy of the manual "Amdahl MVS/SP Assist Release 1.0 Software Logic Manual" L1020.0-02A from October 1982. I recall we used this to run MVS/SP 1.3 on old 370/158 machines. It would simulate the entire set of "new" cross-memory services instructions, such as MVCP, MVCS, PC, PT and so on.
Lennie Dymoke-Bradshaw Consultant working on contract for BMC mainframe Services by RSM Partners ‘Dance like no one is watching. Encrypt like everyone is.’ -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Seymour J Metz Sent: 03 September 2020 19:40 To: [email protected] Subject: [EXTERNAL] Re: Architectural Level Sets It was probably some model of the 470V and MVS/SP 1.3. -- Shmuel (Seymour J.) Metz https://urldefense.proofpoint.com/v2/url?u=http-3A__mason.gmu.edu_-7Esmetz3&d=DwIGaQ&c=UrUhmHsiTVT5qkaA4d_oSzcamb9hmamiCDMzBAEwC7E&r=3UDd4E9ydP_Wheb7d5gow6pPKEFAD7WOFgBGu4v30s8&m=DwUZghnVEGFYge0Hwm727-6uVlyQZd1XOH27IzXGMOw&s=hj2QtB60QvQBtZlTl5N1yW2GEhq71FA9myBvSWmf4GA&e= ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Jesse 1 Robinson <[email protected]> Sent: Thursday, September 3, 2020 1:56 PM To: [email protected] Subject: Re: Architectural Level Sets It's almost Friday. Back in the day when IBM had competitors in the hardware game, I worked at TRW Credit Data, ancestor of Experian. We had an Amdahl something-or-other. I was a baby sysprog at the time, so some details are fuzzy. A new iteration of MVS arrived that was designed *not* to run on an alien machine. (I believe it was MVS-SP1 circa 1980.) Trying to IPL it on Amdahl gear resulted in instant death because of new instructions. So Amdahl to the rescue. They developed an ingenious usermod that replaced unexecutable instructions with either NOPs or invocations of Amdahl-supplied routines that simulated the function of the new instructions. These routines were initially invoked in response to 0C1 abends, but each offending instruction was then replaced in memory with a direct branch to the simulation routine. In effect as time wore on, the OS became more efficient. I have no idea how IBM felt about this clever workaround, but it was certainly welcomed by Amdahl customers. . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-543-6132 Office ⇐=== NEW [email protected] -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Peter Relson Sent: Thursday, September 3, 2020 9:16 AM To: [email protected] Subject: (External):Re: Architectural Level Sets CAUTION EXTERNAL EMAIL <snip> I was thinking more along the lines of things that prevented earlier operating systems from even IPLing on newer boxes. Such as z13 is the last processor to have ESA/390 mode </snip> It depends how much earlier you are thinking of. A z/OS prior to OS/390 R10 would not work on a machine that is z/Arch-only. A z/OS prior to z/OS 1.12 would not work on a machine that begins the IPL in z/Arch mode. I don't happen to know what about the z990 would have caused an earlier release of the OS not to work. In almost all cases, an old enough OS (specifically, one for which toleration support for a new machine was not provided) will not work properly because there are machine-related definitions that need to be accommodated and those would not have been provided. But it might well IPL. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
