According to this guide, the 3090 could still start in BC mode when in 370 mode. See page 7-6.
http://vtda.org/docs/computing/IBM/Mainframe/Hardware/System/SA22-7121-6_3090ProcComplexFunctionalCharacteristics.pdf Joe On Wed, Sep 9, 2020, 16:07 Lennie Bradshaw < 0000032fff1be9b4-dmarc-requ...@listserv.ua.edu> wrote: > I think this happened with the move to MVS/XA as XA does not recognise a > BC mode PSW. > So I guess it was the first machine which did not support architectures > earlier than MVS/XA. > I suspect that was the 3081. > > All my conjecture of course. Let's see what the IBM oracles tell us. > > Lennie Dymoke-Bradshaw > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf > Of Mark S Waterbury > Sent: 09 September 2020 18:35 > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Architectural Level Sets > > To add to this thread ... > > I would like to know at what point during the evolution from S/370 to > S/370-XA to S/390 to zSeries, did the architecture stop supporting IPL of > any OS that runs in "BC mode" or that starts out in BC mode, before setting > up page and segment tables and control registers and then enabling DAT? > > In other words, what processor family(s) and specific models in that > family, if need be, can no longer IPL and run any of the "public domain" > operating systems from the 1970s to early 1980s? (DOS/360, OS/360, DOS/VS, > OS/VS1, OS/VS2, VM/370, TSS/370, etc.) > > Thanks in advance. > > Mark S. Waterbury > > ---------------------------------------------------------------------- > 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
