On Sun, 27 Dec 2015 13:21:23 -0800, Anne & Lynn Wheeler wrote: >later, newer memory for 370/168 was less expensive ... and started to >see four mbytes as much more common ... aka four mbytes as 370/165 would >have met that typical MVT customer could have gotten 16 regions ... w/o >having to resort to virtual memory ... but the decision had already been >made.
Sure, but even before you got to 16 regions, you had the problem of different regions having to use the same storage protection key. As a result, the system could no longer ensure that one region was isolated from other regions. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
