Not confused. Just didn't remember the hardware correctly. But, I do remember the complaints for 4K out of an entire HIPERSPACE.
-teD Original Message From: Jim Mulder Sent: Friday, February 26, 2016 02:15 To: IBM-MAIN@LISTSERV.UA.EDU Reply To: IBM Mainframe Discussion List Subject: Re: Prefix save area - confused > With ESA it was 'absolute' zero. > I remember because we had users complain about the unusable portion > of a HIPERSPACE which was the PSA. > > -teD You are indeed confused, teD. 3090E processors did not have the necessary hardware to implement the Private-Space Control(P) bit, which overrides low-address protection and fetch-protection override. For that reason, MVS/ESA did not map addresses 0-4095 in data spaces on 3090E processors. This had nothing to do with prefixing. The Private-Space Control(P) bit was implemented on 3090S and subsequent processors, so MVS/ESA did map addresses 0-4095 in data spaces on those processors. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- 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
