The following message is a courtesy copy of an article that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
[EMAIL PROTECTED] (Rick Fochtman) writes: > That increased instruction set allows for vastly increased capability, > in spite of the perceived complexity. Simple applications can still be > coded using simple instructions, but more complex requirements can be > met more simply and efficiently by using some of those "added > instructions" that seem to lead to complexity. > > Complexity is far too often used as an excuse for incompetence or > laziness; not always or even most of the time, but still far too > often. You don't let a carpenter into your house if he doesn't know > how to use his tools, do you???? re: http://www.garlic.com/~lynn/2007i.html#25 Latest Principles of Operation http://www.garlic.com/~lynn/2007i.html#26 Latest Principles of Operation well, i remember the hassle to get compare&swap instruction into the 370 architecture. Charlie had invented compare&swap instruction when he was working on smp knerel fine-grain locking for cp67 at the science center http://www.garlic.com/~lynn/subtopic.html#545tech the "redbook" 370 architecture owners claimed that everybody (namely the POK favorite son operating system people) thot that test&set was totally adequate for all multiprocessor support. in order to justify getting compare&swap instruction into 370 architecture, we had to come up with a whole boatload of justifications for compare&swap instruction that wasn't specific to multiprocessor operation. thus was born the stuff in principle of operations about using compare&swap instruction for application multithreaded operation (regardless of whether or not it was multiprocessor environment). lots of past posts mentioning multiprocessor support and/or compare&swap instruction http://www.garlic.com/~lynn/subtopic.html#smp it is sometimes relative. i've claimed that John came up with risc/801 as part of going to the opposite extreme after the extremely complex future system project failed ... misc. past posts mentioning failed future system project http://www.garlic.com/~lynn/subtopic.html#futuresys and lots of past post mentioning 801, romp, rios, iliad, fort knox, somerset, power/pc, etc http://www.garlic.com/~lynn/subtopic.html#801 and old email with 801 references http://www.garlic.com/~lynn/lhwemail.html#801 Supposedly future system project was a countermeasure to clone controllers ... something I got (at least partially) blamed for from a project that I worked on as undergraduate in the 60s producing our own clone controller http://www.garlic.com/~lynn/subtopic.html#360pcm also some "FS" quotes referenced in this post http://www.garlic.com/~lynn/2007f.html#28 The Perfect Computer - 36 bits? from article by former executive here http://www.ecole.org/Crisis_and_change_1995_1.htm The FS effort and subsequent failure ... can also be considered as contributing to the uptake of clone processors (in part because of the dearth of items in the 370 product pipeline) a few recent posts http://www.garlic.com/~lynn/2007g.html#55 IBM to the PCM market(the sky is falling!!!the sky is falling!!) http://www.garlic.com/~lynn/2007g.html#57 IBM to the PCM market(the sky is falling!!!the sky is falling!!) http://www.garlic.com/~lynn/2007g.html#59 IBM to the PCM market(the sky is falling!!!the sky is falling!!) and after the failure of the FS project ... there was a rush to get stuff back into the 370 product pipeline. Recent post attributing that as big part of the reason that the product group shipped so much of my code (since I continued to develop 370-based software all thru the FS activity) http://www.garlic.com/~lynn/2007i.html#21 John W. Backus, 82, Fortran developer, dies and another recent posting touching on some stuff that went on in the FS era http://www.garlic.com/~lynn/2007i.html#20 Does anyone know of a documented case of VM being penetrated by hackers? http://www.garlic.com/~lynn/2007i.html#29 Does anyone know of a documented case of VM being penetrated by hackers? another stop-gap effort to try and quickly fill the 370 product pipeline was 3033x (after failure of FS project) was 303x. The standard processor development cycle was 7-8yrs ... and they needed to get something out much quicker than that ... since starting the 370-xa/3081 wouldn't be out before the early 80s. So they took they 370/158 microcode engine ... and stripped out the 370 microcode support ... leaving just the integrated channel microcode and packaged it as the 303x "channel director". Then the 3031 was a 370/158 microcode engine with just the 370 microcode support (and no integrated channel microcode) paired with a "channel director". The 3032 was a 370/168-3 repackaged to work with "channel director". The 3033 started out simply being 168 wiring diagram mapped to newer chip technology. Recent posts about enormous effort to hurry up and get 303x out the door after failed FS project: http://www.garlic.com/~lynn/2007d.html#21 How many 36-bit Unix ports in the old days? http://www.garlic.com/~lynn/2007d.html#62 Cycles per ASM instruction http://www.garlic.com/~lynn/2007e.html#32 I/O in Emulated Mainframes http://www.garlic.com/~lynn/2007e.html#40 FBA rant http://www.garlic.com/~lynn/2007f.html#28 The Perfect Computer - 36 bits? http://www.garlic.com/~lynn/2007f.html#73 Is computer history taught now? http://www.garlic.com/~lynn/2007g.html#17 The Perfect Computer - 36 bits? http://www.garlic.com/~lynn/2007g.html#23 The Perfect Computer - 36 bits? http://www.garlic.com/~lynn/2007g.html#29 The Perfect Computer - 36 bits? http://www.garlic.com/~lynn/2007g.html#57 IBM to the PCM market(the sky is falling!!!the sky is falling!!) http://www.garlic.com/~lynn/2007h.html#1 21st Century ISA goals? the other aftermath of the FS project failure was that POK lab convinced corporate to shutdown the VM development group, decommit the product, and transfer all the people to POK in order to work on MVS/XA ... also attempting to shorten the typical development time. Endicott was eventually able to salvage the product mission and one or two of the people. ---------------------------------------------------------------------- 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
