Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cmcl2!rutgers!lll-lcc!pyramid!prls!mips!mash From: mash@mips.UUCP (John Mashey) Newsgroups: comp.arch Subject: Re: Horizontal pipelining [really: multi-tasking is alive and well] Message-ID: <1062@winchester.UUCP> Date: Sun, 6-Dec-87 20:06:06 EST Article-I.D.: winchest.1062 Posted: Sun Dec 6 20:06:06 1987 Date-Received: Sat, 12-Dec-87 06:13:46 EST References: <201@PT.CS.CMU.EDU> <388@sdcjove.CAM.UNISYS.COM> Reply-To: mash@winchester.UUCP (John Mashey) Organization: MIPS Computer Systems, Sunnyvale, CA Lines: 49 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: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