Processes' memory
in [Unix Programming]
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From: Peter Dickerson on 27 Jan 2010 06:22 <nmm1(a)cam.ac.uk> wrote in message news:hjp78l$v6p$1(a)smaug.linux.pwf.cam.ac.uk... > In article <hjp6nq$tid$1(a)news.eternal-september.org>, > Peter Dickerson <first.last(a)tiscali.invalid> wrote: >> >>>>>> 370 instruction set chip. In 1984 IBM had a PC/370 but decided it >>>>>> would eat mainframe revenue and limited software licenses to machines >>>>>> connected to mainframes thus killing their attraction. >>>>> >>>>> Did they? Despite being VERY close to IBM, I never tracked that down, >>>>> and think that it was an urban myth. Yes, there was a design, and it >>>>> may even have reached silicon, but (as far as I know) it never reached >>>>> the stage of actually running a full-blown System/370 operating >>>>> system, >>>>> even in-house. >>>> >>>>Huh? >>>> >>>>I clearly remember a big Byte article showing how it worked, afair it >>>>had two 68K cpus, one of them with heavily modified microcode. >>>> >>>>Are you saying this article must have been written while the product was >>>>still a lab design? >>> >>> As far as I could discover, yes. >>> >>> IBM being IBM, that doesn't mean I was right. During my time with >>> them, I frequently was telling one group what another was up to, >>> and the history of various products that appeared like mushrooms is >>> well known. But I completely failed to track down any hard evidence >>> that there was such a product, or even a pre-product. >> >>I distinctly recall handling an IBM PC card which ran 370 code and OS. As >>I >>recall it was supposedly based on a modified 68K - don't know about two >>though. When I had it in the mid 80s, say 1986, it was considered scrap. > > Yes. I know about that one, though never saw it. As I understand > it, it could run some 370 code but not a 370 operating system, and > was regarded as the prototype for the putative "370 on a chip". > > Do you have any definite evidence that it ran a real 370 operating > system, rather than a special lookalike one of its own? Only that it came with some disks with OS-like words on. I can't say that it ran an unmodified OS. Its a long time for me to remember anything. Peter
From: nmm1 on 27 Jan 2010 06:30 In article <hjp7mf$4vp$1(a)news.eternal-september.org>, Peter Dickerson <first.last(a)tiscali.invalid> wrote: > >>>I distinctly recall handling an IBM PC card which ran 370 code and OS. As >>>I >>>recall it was supposedly based on a modified 68K - don't know about two >>>though. When I had it in the mid 80s, say 1986, it was considered scrap. >> >> Yes. I know about that one, though never saw it. As I understand >> it, it could run some 370 code but not a 370 operating system, and >> was regarded as the prototype for the putative "370 on a chip". >> >> Do you have any definite evidence that it ran a real 370 operating >> system, rather than a special lookalike one of its own? > >Only that it came with some disks with OS-like words on. I can't say that it >ran an unmodified OS. Its a long time for me to remember anything. My understanding was that it wasn't even a modified 370 OS, but a major and unmaintainable hack, omitting a large proportion of the important features. But that was second-hand information. Regards, Nick Maclaren.
From: Anne & Lynn Wheeler on 27 Jan 2010 09:01 "Mike" <mike(a)mike.net> writes: > I have often wonder how modern systems would have evolved in an > alternate universe where IBM did not fund MicroSoft and OS/2 but > instead chose to implement Presentation Manager to provide a GUI on > top of VM/CMS and compete in the micro and workstation arena with a > 370 instruction set chip. In 1984 IBM had a PC/370 but decided it > would eat mainframe revenue and limited software licenses to machines > connected to mainframes thus killing their attraction. > > Your suggestion of a portable version of CMS is an intriguing > alternate especially if combined with a portable GUI. Just think, an > industrial strength GUI on 370, 801, and S/38 and on PC's to compete > with Windows 3.1. re: http://www.garlic.com/~lynn/2010c.html#4 Processes' memory http://www.garlic.com/~lynn/2010c.html#5 Processes' memory PC/370 had severe useability ... design point of CMS had gotten somewhat bloated so real-storage required (minimum virtual pages) and disk intensive operations ... resulted in poor human factors. original pc/370 was to ship with 384k of 370 memory ... i showed that with only 384k ... system exhibited severe page thrashing behavior. I then got blamed for six month slip in schedule while they retrofitted another 128k (for 512k) for 370 memory. CMS filesystem was emulated on DOS PC/XT harddisk ... which had 100ms access ... and became excruciatingly slow compared to what people were used to with mainframe disks. CMS applications directly ported to DOS tried to be a lot more efficient with their use of storage and disk activity ... old email of somebody ported the CMS (script) document formating to TRS80: http://www.garlic.com/~lynn/2007.html#email801016 in this post http://www.garlic.com/~lynn/2007.html#1 other post/reference http://www.garlic.com/~lynn/2004l.html#74 CMS document formating had been done in mid-60s ... sort of port of ctss runoff command. then GML (precursor to SGML, HTML, XML, etc) was invented at the science center in '69 and CMS document formater was upgrade to support GML tag commands (in addition to original "dot" commands). I had some work with my cms paged mapped file system for pc/370 to help offset the slowness of the disks (i.e. on mainframe 3380s disk ... I measured about a factor of three times improvement in moderately disk limited applications). for other drift ... recent references to high-end mainframe organization (POK) trying to cut in half component allocation for mid-range 43xx production (to limit mid-range eating into high-end revenue) http://www.garlic.com/~lynn/2010b.html#87 "The Naked Mainframe" (Forbes Security Article) http://www.garlic.com/~lynn/2010b.html#99</a> "The Naked Mainframe" (Forbes Security Article) http://www.garlic.com/~lynn/2010c.html#1 "The Naked Mainframe" (Forbes Security Article) also old email reference: http://www.garlic.com/~lynn/2010b.html#email790429 old reference (early '85) to proposal to pack a whole lot of processor chips into single rack ... arbitrary mix of 370 & 801 (although I'm not sure I had worked out all the heat issues): http://www.garlic.com/~lynn/2004m.html#17 mainframe and microprocessor so it was sort-of natural when medusa came along (801 only) ... lots of old email http://www.garlic.com/~lynn/lhwemail.html#medusa project was transferred and we were told we couldn't work on anything with more than four processors ... and nearly immediately after the transfer ... announced; 2/17/92 reference http://www.garlic.com/~lynn/2001n.html#6000clusters1 another http://www.garlic.com/~lynn/2001n.html#6000clusters2 some conjecture that the ease of the transfer was partially because of the threat of RDBMS scaleup to mainframe ... implied here http://www.garlic.com/~lynn/95.html#13 some more discussed here: http://www.garlic.com/~lynn/2010b.html#71 Happy DEC-10 Day -- 42yrs virtualization experience (since Jan68), online at home since Mar1970
From: Anne & Lynn Wheeler on 27 Jan 2010 09:18 "Peter Dickerson" <first.last(a)tiscali.invalid> writes: > I distinctly recall handling an IBM PC card which ran 370 code and OS. As I > recall it was supposedly based on a modified 68K - don't know about two > though. When I had it in the mid 80s, say 1986, it was considered scrap. re: http://www.garlic.com/~lynn/2010c.html#14 Processes' memory it did 370 really slow ... and problem-state only (no privileged state) instructions. ran cms with a highly modified version of vm370 ... i.e. virtual machine privileged instructions interrupted into vm370 kernel. vm370 kernel handled things like i/o and misc other stuff with transfers between "cp/88" running on the PC processor. misc. past posts mentioning cp/88 http://www.garlic.com/~lynn/2001f.html#28 IBM's "VM for the PC" c.1984?? http://www.garlic.com/~lynn/2001i.html#19 Very CISC Instuctions (Was: why the machine word size ...) http://www.garlic.com/~lynn/2001k.html#24 HP Compaq merger, here we go again. http://www.garlic.com/~lynn/2002b.html#43 IBM 5100 [Was: First DESKTOP Unix Box?] http://www.garlic.com/~lynn/2004m.html#7 Whatever happened to IBM's VM PC software? http://www.garlic.com/~lynn/2005f.html#6 Where should the type information be: in tags and descriptors http://www.garlic.com/~lynn/2005f.html#10 Where should the type information be: in tags and descriptors http://www.garlic.com/~lynn/2006m.html#56 DCSS http://www.garlic.com/~lynn/2007j.html#41 z/VM usability http://www.garlic.com/~lynn/2008r.html#46 pc/370 http://www.garlic.com/~lynn/2010.html#2 Happy DEC-10 Day later there was the a74 (7437) ... which was much more like a real 370 in small form factor (with several press/news articles from 1988): http://www.garlic.com/~lynn/2002d.html#4 IBM Mainframe at home some a74 changes I tried to get released (including paged mapped filesystem): http://www.garlic.com/~lynn/2003f.html#56 ECPS:VM DISPx instructions -- 42yrs virtualization experience (since Jan68), online at home since Mar1970
From: Anne & Lynn Wheeler on 27 Jan 2010 09:42
nmm1(a)cam.ac.uk writes: > If anyone had delivered a viable form of Unix at an affordable price, > that would have eliminated Windows 3.1. They didn't, until far too > late, and that was marketing and not technical. I doubt that IBM > could have moved fast enough to convert CMS to such a very different > style of use. re: http://www.garlic.com/~lynn/2010c.html#4 Processes' memory http://www.garlic.com/~lynn/2010c.html#5 Processes' memory http://www.garlic.com/~lynn/2010c.html#14 Processes' memory http://www.garlic.com/~lynn/2010c.html#15 Processes' memory recent post http://www.garlic.com/~lynn/2010c.html#12 Happy DEC-10 Day with an old email discussion of "affordable unix" (and diskless workstations): http://www.garlic.com/~lynn/2010c.html#email871115 -- 42yrs virtualization experience (since Jan68), online at home since Mar1970 |