[Default] On 1 Sep 2020 14:26:32 -0700, in bit.listserv.ibm-main mike.a.sch...@gmail.com (Mike Schwab) 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. The 4341 and 4381 could and did run MVS. I was responsible for MVs on them at my site. Clark Morris > >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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
