Under MVS/ESA we had expanded storage. Expanded storage allowed each page to be addressed using a 32 bit address. As each page held 4096 (2**12) bytes the effective addressing was 32bits + 12bits = 48bits.
Is this what you were thinking of? Lennie Dymoke-Bradshaw Consultant working on contract for BMC mainframe Services by RSM Partners ‘Dance like no one is watching. Encrypt like everyone is.’ -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Pommier, Rex Sent: 09 December 2020 18:19 To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: does anyone recall any details about MVS/XA? Somewhere in the past, there was an article printed where somebody was gazing into a crystal ball. I have (maybe had) it on paper but can't find it right now. They were conjecturing on IBM's next OS and they called it MVS/ESB. They were pretty convinced that IBM's next move from 31 bit was going to be to 48 bit. Unfortunately I can't find the paper right now. Ranked right up there (without the massive publicity) of Steward Alsop's prediction of the last mainframe being unplugged in 1995. Does anybody else recall ever hearing anything like this? Rex -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Mike Wawiorko Sent: Wednesday, December 9, 2020 8:55 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: [External] Re: does anyone recall any details about MVS/XA? I remember an IBM SE presenting XA to us saying 31 bit addressing and 2GB memory would serve every need. Now how long since 64 bit? How long before everything fully supports 64 bit though? 128 bit next? Mike Wawiorko The information contained in this message is confidential, protected from disclosure and may be legally privileged. If the reader of this message is not the intended recipient or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any disclosure, distribution, copying, or any action taken or action omitted in reliance on it, is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by replying to this message and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. ---------------------------------------------------------------------- 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