None of the MVS-SP1 releases required new instructions. They did exploit new instructions if they were available.
More likely, you are thinking of SE1 or SE2. That was where various required assist (Lock, SVC, SETFRR) instructions were added. Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY "Seymour J Metz" <[email protected]> wrote on 09/03/2020 02:39:30 PM: > > It was probably some model of the 470V and MVS/SP 1.3. > > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > > > ________________________________________ > 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] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
