The following message is a courtesy copy of an article that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
gahe...@gmail.com (George Henke) writes: > Yes, I believe it was some how connected to Preferred Machine Assist (PMA) > where page 0 was actually owned by MVS not VM. preferred machine assist could be considered step on the way to LPARs ... since part of it involved the virtual machine pages being mapped to fixed real storage. the earlier version of this (preferred V=R guest) had been done for vm370 at the science center circa mid-70s on a "csc/vm" base. There was then a joint study with AT&T ... which was provided a copy of the (complete) system. One of the enhancements that AT&T put into vm370 kernel was support for virtual devices operating over network (could mount a tape in one datacenter and read it from a different machine in a different datacenter). It somewhat propogated around internal AT&T ... where they made some number of enhancements and migrated the source code to new machines as they came out. In the 80s, the AT&T national marketing rep tracked me down about possibly helping AT&T move off the platform. The "csc/vm" base they had didn't include SMP/multiprocessor support ... and the 3081 strategy was still multiprocessor only ... before TPF customers forced the company into doing 3083 uniprocessor (at the time, TPF still didn't have multiprocessor support). AT&T was being forced to going with clone processor vendor that had single processor products (for the again vm370 system). That old csc/vm system included my dynamic adaptive resource manager ... so I made a point of it being able to dynamically adapt across a broad range of processors & processor generations ... with nearly two orders magnitude range in performance. 3083 finnally announced http://www-03.ibm.com/ibm/history/exhibits/mainframe/mainframe_PP3083.html above also has mention of preferred machine assist being supported. trivia ... 3083 involved removing one of the processors in 3081 in the frame. unfortunately, "processor 0" was physically at the top of the box. there was concern that the simplest, straight-forward removal of "processor 1" would make the box dangerously top-heavy. past posts in this thread: http://www.garlic.com/~lynn/2010d.html#58 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#59 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#60 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#61 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#62 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#63 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#66 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#69 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#70 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#71 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#72 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#73 LPARs: More or Less? http://www.garlic.com/~lynn/2010d.html#78 LPARs: More or Less? -- 42yrs virtualization experience (since Jan68), online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
