Yes, local mods could always exploit facilities that the shipped operating system did not. But the only IBM operating system that used DAS, with the possible exception of TPF, was MVS/SP. I don't know about MTS.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Joe Monk <joemon...@gmail.com> Sent: Wednesday, September 2, 2020 12:26 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Architectural Level Sets "WTF? DAS requires MVS/SP." Nope. :) It is available via USERMOD in MVS 3.8J. Joe On Tue, Sep 1, 2020 at 7:01 PM Seymour J Metz <sme...@gmu.edu> wrote: > WTF? DAS requires MVS/SP. > > That said, MVS/SP ran just fine on a 4341. > > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > > > ________________________________________ > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf > of Joe Monk <joemon...@gmail.com> > Sent: Tuesday, September 1, 2020 5:55 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Architectural Level Sets > > 370 supported DAS (the code is in MVS3.8J). > > 43XX running MVS supported DAS also. 4381 could have up to 64M of main > storage... > > Joe > > On Tue, Sep 1, 2020 at 4:26 PM Mike Schwab <mike.a.sch...@gmail.com> > wrote: > > > Well, XA+ machines only supported 4K pages / 1M segments and not 2K > > pages / 64K segments. Then DAS and Access register additions. The > > 43xx series only supported a single virtual address space, like > > DOS/VSE. 3090s were the only processors to support Vector > > instructions, and op codes were re-used in z series. > > > > On Tue, Sep 1, 2020 at 4:20 PM Tony Thigpen <t...@vse2pdf.com> wrote: > > > > > > 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. I also have it in my head that at > > > some point there were changes to the page size and virtual storage > > > tables that caused havoc. > > > > > > Tony Thigpen > > > > > > Seymour J Metz wrote on 9/1/20 3:30 PM: > > > > Typically the new features reqiured by a level set were added over > > several generations, and each generation added more than one feature. > > > > > > > > > > > > -- > > > > Shmuel (Seymour J.) Metz > > > > http://mason.gmu.edu/~smetz3 > > > > > > > > > > > > ________________________________________ > > > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on > > behalf of Tony Thigpen <t...@vse2pdf.com> > > > > Sent: Tuesday, September 1, 2020 3:25 PM > > > > To: IBM-MAIN@LISTSERV.UA.EDU > > > > Subject: Architectural Level Sets > > > > > > > > IBM has had several Architectural Level Set points where there were > > > > significant changes to the CPU that prevented earlier operating > systems > > > > from running on them. > > > > > > > > What CPU's were involved with each level, and what was the real > > > > underlying item changed on the CPU that forced a new level? (Let's > keep > > > > it limited to z990 and newer.) > > > > > > > > > > > > Tony Thigpen > > > > > > > > > ---------------------------------------------------------------------- > > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > > send email to lists...@listserv.ua.edu with the message: INFO > IBM-MAIN > > > > > > > > > ---------------------------------------------------------------------- > > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > > send email to lists...@listserv.ua.edu with the message: INFO > IBM-MAIN > > > > > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > > > > > -- > > Mike A Schwab, Springfield IL USA > > Where do Forest Rangers go to get away from it all? > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
