re: http://www.garlic.com/~lynn/2013b.html#72 One reason for monocase was Re: Dualcase vs monocase. Was: Article for the boss
IBM ASCII reference also mentions getting collating sequence wrong in STRETCH IBM Stretch references: http://en.wikipedia.org/wiki/IBM_7030_Stretch http://www.brouhaha.com/~eric/retrocomputing/ibm/stretch/ and http://people.cs.clemson.edu/~mark/stretch.html for other drift there is also ACS reference http://people.cs.clemson.edu/~mark/acs.html ending with ACS-360 http://people.cs.clemson.edu/~mark/acs_end.html the above mentions investigation into making ACS-360 multithreaded. In summer 1968, Ed Sussenguth investigated making the ACS-360 into a multithreaded design by adding a second instruction counter and a second set of registers to the simulator. Instructions were tagged with an additional "red/blue" bit to designate the instruction stream and register set; and, as was expected, the utilization of the functional units increased since more independent instructions were available. ... snip ... and finally cancellation: After the cancellation a large number of ACS engineers wanted to stay in California. Several chose to work on disk drive systems at the IBM San Jose facility, including Mooney. Robelen and Galtieri left IBM to form Mascor (Multi Access Systems Corp.), and Beebe, Buelow, Clements, Tobias, Zasio, and others left IBM to join Mascor. Amdahl resigned in September of 1970 and formed his own company shortly thereafter. Many of the former ACS engineers at Mascor joined Amdahl after Mascor closed, due to Mascor being unable to obtain the necessary additional venture capital to stay afloat. The S/360 Model 195 was announced in August 1969 after the ACS cancellation, and a vector processing task force was started in Poughkeepsie that same month. ... snip ... I got sucked into some of this later in the 70s (nearing the death of FCS) when 370/195 people were looking at multithreaded simulated two-processor implementation ... and wanted me to help with multiprocessor software support. The issue was 195 pipelined stalled on conditional branches on most code ran at half 195 processing rate. Feeding the execution units from two independent instruction streams had chance keeping the execution units 100% busy. The above also claims ES/9000 design being influenced by ACS-360 Amdahl says he knew nothing about Future System effort when he was doing his clone processor company. However at a seminar he gave at MIT in the early 70s (large auditorium, standing room only), a student asked how did he make the case for investment money. His reply was that IBM customers had already invested an enormous amount of money in 360 software development and even if IBM was to completely walk away from 360 (possibly veiled reference to Future System killing off 360/370), that body of 360 software would keep him in business through the end of the century. To large extent the company nearly killed itself off in the early 90s ... and its mainframe business lingers on based on that same body of 360 software ... mentioned earlier in this thread: http://www.garlic.com/~lynn/2013b.html#57 Dualcase vs monocase. Was: Article for the boss... past posts mentioning Future System (including references about continuing to work on 360/370 and periodically ridiculing FS activity) http://www.garlic.com/~lynn/submain.html#futuresys other STETCH drift ... HARVEST http://en.wikipedia.org/wiki/IBM_7950_Harvest -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
