mash@mips.UUCP (John Mashey) (12/07/87)
In article <2326@killer.UUCP> elg@killer.UUCP (Eric Green) writes: >In article <1006@winchester.UUCP> mash@winchester.UUCP (John Mashey) writes: >>In article <2581@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes: >>>Another trend which might doom the idea is that towards individual >>>(single-user) computers. The future of multi-tasking on such machines is >>>very much in question; if it becomes a big thing, there is no problem. (me): >>Hopefully, multi-tasking will some year come to single-user computers :-) >Actually, multi-tasking single-user computers have been available for years. >OS-9 on the TRS-80 Color Computer, for example, and AmigaDOS on the Commodore >Amiga. Just because the IBM PEE-CEE and Apple Macintosh don't have a >multitasking oprating system, doesn't mean that the rest of the world is stuck >with single tasking (and note that both IBM and Apple intend to introduce >multitasking OS's Real Soon Now). >I think that we'll see the demise of ancient CP/M-derived operating systems >Real Soon Now (as Marketing would say :-). My comment was intended to display humor and amazement that there could be doubt about the future of multi-tasking, especially in this newsgroup. It is clear that the posting was not crisp enough, as I got numerous pieces of mail urging me to look at AmigaDOS and others to assure myself that multi-tasking was indeed possible on a single-user computer. Given that PCs were hardly the first single-user computers, and that multi-tasking on single-user systems has existed almost as long as the systems have, I'd guess that the current prevalence of single-tasking systems is just an anomoly of the cost/performance & feature (i.e. lack of builtin memory-mapping) combinations of late 70s / early 80s microprocessors. For many years, each successive generation of computers (mainframes, minis, micros) seemed to repeat most of the mistakes of the earlier ones. Now that current micros have: a) useful addressability (32-bits) b) on-chip MMUs (hence no cost-cutting reason to omit them) c) reasonable design for use with high-level languages d) more-or-less reasonable design for use with multi-tasking OSs and given that DRAMs are getting big enough that it's almost HARD to build tiny-memory systems, the original reasons for this aberration are rapidly going away, leaving only the software legacy [unfortunately]. Anyway, sorry for the lack of clarity in my original comment. -- -john mashey DISCLAIMER: <generic disclaimer, I speak for me only, etc> UUCP: {ames,decwrl,prls,pyramid}!mips!mash OR mash@mips.com DDD: 408-991-0253 or 408-720-1700, x253 USPS: MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086
lipp@hpindda.HP.COM (Roger Lipp) (12/10/87)
Hey, Mash, long time no see (this is really Herb Gellis logged in as somebody else).... Nothing brilliant to say, needless to say, I vote for multitasking on PEE CEE's.... just a matter of time and a drop in price for it to be more commonplace. Windows-386 will help out the rich folk who can afford 386 machines and want to run the plethora of DOS applications today, etc. etc.
peter@sugar.UUCP (Peter da Silva) (12/27/87)
In article <1062@winchester.UUCP>, mash@mips.UUCP (John Mashey) writes: > Given that PCs were hardly the first single-user computers, > and that multi-tasking on single-user systems has existed almost as long as > the systems have, I'd guess that the current prevalence of > single-tasking systems is just an anomoly of the cost/performance & > feature (i.e. lack of builtin memory-mapping) combinations of late 70s / > early 80s microprocessors. I'd say that the reason was that IBM dived into the market with a machine that was at most a slight improvement over existing single-tasking systems just as multitasking CP/M derivitives (MP/M, CP/M 3.x) and reasonable micro-based UNIX boxes (Onyx, etc...) were just getting into the water. IBM's entry swamped them and they never came up again. The industry is just now beginning to recover from the advent of the IBM-PC. > For many years, each successive generation of > computers (mainframes, minis, micros) seemed to repeat most of the mistakes > of the earlier ones. Now that current micros have: > a) useful addressability (32-bits) Multitasking doesn't require a large adress space. UNIX *used to* run fine in 256K with a user or two. > b) on-chip MMUs (hence no cost-cutting reason to omit them) Multitasking doesn't require an MMU. VenturCom has been selling UNIX for the IBM-PC for years. Or look at the Coco... > c) reasonable design for use with high-level languages 6809, anyone? Back to the Coco. > d) more-or-less reasonable design for use with multi-tasking OSs Please explain what you mean by this. > and given that DRAMs are getting big enough that it's almost HARD to build > tiny-memory systems, the original reasons for this aberration are rapidly > going away, leaving only the software legacy [unfortunately]. The original reason for this abberation is still around, but it's working hard to catch up. -- -- Peter da Silva `-_-' ...!hoptoad!academ!uhnix1!sugar!peter -- Disclaimer: These U aren't mere opinions... these are *values*.
farren@gethen.UUCP (Michael J. Farren) (12/31/87)
In article <1314@sugar.UUCP> peter@sugar.UUCP (Peter da Silva) writes: >I'd say that the reason [for the dominance of single-tasking PC systems] >was that IBM dived into the market with a machine that was at most a >slight improvement over existing single-tasking systems just as >multitasking CP/M derivitives (MP/M, CP/M 3.x) and reasonable micro-based >UNIX boxes (Onyx, etc...) were just getting into the water. IBM's entry swamped >them and they never came up again. The industry is just now beginning to >recover from the advent of the IBM-PC. I would think that it was much more the fact that, for the first time, the corporate users had a machine from a company that they knew (IBM), and which wasn't so complex as to overwhelm the first-time computer users. The IBM PC was, IMHO, a significant improvement over the boxes available at the time, which, for business, tended to be CP/M systems put together by relatively unreliable and unsupportive houses such as Godbout or Morrow. When the corporate types saw a machine which would meet their small computer needs, with the full corporate clout of IBM behind them, they went for it full bore. Just now beginning to recover from the advent of the IBM PC? I'd rather think that it was the IBM PC, warts and all, which opened the door to corporate computing for small computers. Once the users gained sufficient ease with the whole idea of computing, a concept which very few of them had ever been exposed to before, the possibility of more powerful systems, with more powerful operating systems, became something they were willing (and, in many cases, ready) to consider. You have to crawl before you can walk, and I think the IBM PC made a pretty good set of training wheels. Of course, one must cast aside one's training wheels sometime, and I think that the majority of business computer users are rapidly approaching the point where a stock IBM with MS-DOS will no longer do the jobs they need to have done. -- Michael J. Farren | "INVESTIGATE your point of view, don't just {ucbvax, uunet, hoptoad}! | dogmatize it! Reflect on it and re-evaluate unisoft!gethen!farren | it. You may want to change your mind someday." gethen!farren@lll-winken.llnl.gov ----- Tom Reingold, from alt.flame
mash@mips.UUCP (John Mashey) (01/03/88)
In article <1314@sugar.UUCP> peter@sugar.UUCP (Peter da Silva) writes: >In article <1062@winchester.UUCP>, mash@mips.UUCP (John Mashey) writes: >> Given that PCs were hardly the first single-user computers, >> and that multi-tasking on single-user systems has existed almost as long as >> the systems have, I'd guess that the current prevalence of >> single-tasking systems is just an anomoly of the cost/performance & >> feature (i.e. lack of builtin memory-mapping) combinations of late 70s / >> early 80s microprocessors. Peter adds some various notes to this: I don't think there is any fundamental disagreement, but I'll explain more what I meant: >I'd say that the reason was that IBM dived into the market with a machine that >was at most a slight improvement over existing single-tasking systems just as >multitasking CP/M derivitives (MP/M, CP/M 3.x) and reasonable micro-based >UNIX boxes (Onyx, etc...) were just getting into the water. IBM's entry swamped >them and they never came up again.... Apples were this way too, so one can't just blame IBM. > >> For many years, each successive generation of >> computers (mainframes, minis, micros) seemed to repeat most of the mistakes >> of the earlier ones. Now that current micros have: >> a) useful addressability (32-bits) >Multitasking doesn't require a large adress space. UNIX *used to* run fine in >256K with a user or two. Well, at one time it ran OK in 64K total, split between kernel and user, and for years, it ran OK in 124K total real memory, with 64KB I & 64KB D space per user. They were wonderful at the time, but I sure wouldn't want to go back. The compromises got pretty painful towards the end. The point is that micro addressability is in the same league as supermini and mainframe. >> b) on-chip MMUs (hence no cost-cutting reason to omit them) >Multitasking doesn't require an MMU. VenturCom has been selling UNIX for the >IBM-PC for years. Or look at the Coco... Of course it doesn't require it, but it sure makes life easier for certain styles of multi-tasking, especially UNIX's. As a percentage of the market, I suspect UNIX on PCs is a fairly low number; it is clear that 386s will make life easier. ... >> d) more-or-less reasonable design for use with multi-tasking OSs I.e., designed to support kernel + multiple user processes, each in their own address space if they want to be, allow paging, and having no oded quirks that let user programs unduly affect the state of the machine, plus enough performance that one can burn some of it supporting the extra scheduling, protection, paging, etc. [some of this has nothing to do directly with multi-tasking, maybe I should have been more specific and added some of the rest of these things, i.e., not just multi-tasking, but "reasonably modern OS that can support multiple processes, some of which might be larger than real memory, can support complex networking environments, and does not run into arbitrary small limits in physical memory, disk sizes, virtual memory, or number of processes." >Please explain what you mean by this. > >> and given that DRAMs are getting big enough that it's almost HARD to build >> tiny-memory systems, the original reasons for this aberration are rapidly >> going away, leaving only the software legacy [unfortunately]. >The original reason for this abberation is still around, but it's working hard >to catch up. Again, I don't think we fundamentally disagree, except I think blaming it all on IBM is a little strong, but that's a matter of opinion. -- -john mashey DISCLAIMER: <generic disclaimer, I speak for me only, etc> UUCP: {ames,decwrl,prls,pyramid}!mips!mash OR mash@mips.com DDD: 408-991-0253 or 408-720-1700, x253 USPS: MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086