R.S. wrote: > It was called 'OEMI' I forgot what I stands for, presumably Interface. > This book descibes Bus&Tag infterface, including plug construction, > signal characteristics, voltage levels etc. See GA22-6974
other equipment manufactureinterface ... or something similar ... synonym for pcm ... plug compatible manufacture. somewhere along the way, there had been some litigation by pcm vendors. when i was an undergraduate, some guys from the science center (4th flr, 545tech sq, cambridge) http://www.garlic.com/~lynn/subtopic.html#545tech had come out and installed cp67 at the university. i got involved in rewritting large portions of the kernel ... creating dynamic adaptive, feedback scheduler (later customers would refer to it as fairshare scheduler ... since one of the resource management policies was fairshare), new paging algorithms, chain record, ordered seek queueing, fast path, etc. i gave a presentation on some of the work at aug. 68 share meeting in boston (presentation also included extensive work done on os/360 mft14) ... part of that presentation: http://www.garlic.com/~lynn/94.html#18 CP/67 & OS MFT14 cp67 shipped with 2741 and 1052 terminal support but the university had these m33 teletypes (ascii) terminals ... so i added tty/ascii terminal support. the cp67 2741/1052 support had dynamic terminal identification ... i.e. it would play sending various commands and playing with the 2702 sad command to dynamically identify the terminal. i figured what the heck, i could add tty/ascii support in similarly ... so that cp67 could do dynamic terminal identification for 2741/1052/tty. i had this grandiose idea that you could have a single number on phone rotory and let all kinds of terminals dial the same number ... and the system would dynamically determine terminal type. well, it turned out that the dynamic terminal identification worked fine for 2741/1052 ... but there was a problem adding ty. while 2702 supported being able to associate any line-scanner with any port/line ... it had a restriction that the oscillator setting the baud rate for each line/port had to be hired-wired. this sort of kicked off a project at the univ. to reverse engineer the 360 channel interface, build our own channel interface board and program an interdata/3 to emulate a 2702 controller (somebody even wrote an article blaiming four of us for originating the pcm controller market). one of the things that was implemented in the interdata/3 was dynamic buad rate in the software line-scanner ... i.e. the software would strobe the signal rise/lower on the line to dynamically figure out the terminal baud rate. misc. past posts about 360 oem/pcm http://www.garlic.com/~lynn/subtopic.html#360pcm later, supposedly a major motivating factor for FS was oem/pcm controllers http://www.garlic.com/~lynn/subtopic.html#futuresys specific article mentioning future system project by somebody that worked on it (The rise and fall of IBM, Jean-Jacques DUBY Scientific Director of UAP, Former Science & Technology Director of IBM Europe) http://www.ecole.org/Crisis_and_change_1995_1.htm quote from above: IBM tried to react by launching a major project called the 'Future System' (FS) in the early 1970's. The idea was to get so far ahead that the competition would never be able to keep up, and to have such a high level of integration that it would be impossible for competitors to follow a compatible niche strategy. However, the project failed because the objectives were too ambitious for the available technology. Many of the ideas that were developed were nevertheless adapted for later generations. Once IBM had acknowledged this failure, it launched its 'box strategy', which called for competitiveness with all the different types of compatible sub-systems. But this proved to be difficult because of IBM's cost structure and its R&D spending, and the strategy only resulted in a partial narrowing of the price gap between IBM and its rivals. ... snip ... by that time, i had gone to work at the science center ... and i would make some sarcastic comments about the similarity between FS project and a long-playing "cult" film playing down in central sq. (something about the inmates being in charge of the institution). basically FS was going to completely replace 360 ... and was as radically different from 360 than 360 had been from prior generations. the focus on replacing 360 with FS somewhat dried up projects for 360 follow-ons ... so when FS was eventually killed there was a mad scramble to re-invigerate work on 370 products. by that time, you were starting to see plug-compatible processrs in addition to plug-compatible controllers. i remember a seminar that amdahl gave at mit to a large audience in the early 70s. one of the questions was how did he justify getting investment for his company. he described an analysis of the hundreds of billions that customers had already invested in developing 360 software and stated that even if ibm was to totally walk away from 360 architecture, there would still be enough customer 360 software until at least the end of the century to keep him in business (at the time, the end of the century was still almost 30 years away). ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
