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Path: ...!3.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: anton@mips.complang.tuwien.ac.at (Anton Ertl) Newsgroups: comp.arch Subject: Re: Byte ordering Date: Sun, 06 Oct 2024 13:04:15 GMT Organization: Institut fuer Computersprachen, Technische Universitaet Wien Lines: 70 Message-ID: <2024Oct6.150415@mips.complang.tuwien.ac.at> References: <uigus7$1pteb$1@dont-email.me> <uvl5hj$q0so$1@dont-email.me> <550600971b1a36b4b630c496cb21b96b@www.novabbs.org> <vdhkcs$2s651$1@dont-email.me> <0194054dac788f7e3a163726e84d72ac@www.novabbs.org> <vdi152$2u3v4$1@dont-email.me> <vdkolv$3ed1r$3@dont-email.me> <vdlgl9$3kq50$2@dont-email.me> <2024Oct3.113903@mips.complang.tuwien.ac.at> <vdn55j$3ssv4$11@dont-email.me> <vdoc76$5cna$2@dont-email.me> <2024Oct4.193007@mips.complang.tuwien.ac.at> <vdtmv9$16lu8$1@dont-email.me> Injection-Date: Sun, 06 Oct 2024 16:03:44 +0200 (CEST) Injection-Info: dont-email.me; posting-host="9f5fea38e9806ac24398be8213ac3035"; logging-data="1307821"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18AaAbzcGzJzb7hlSnq8M5Z" Cancel-Lock: sha1:wxk95BrJli6ZERrxtwVpdBph9Xs= X-newsreader: xrn 10.11 Bytes: 4865 David Brown <david.brown@hesbynett.no> writes: >On 04/10/2024 19:30, Anton Ertl wrote: >> David Brown <david.brown@hesbynett.no> writes: >>> On 04/10/2024 00:17, Lawrence D'Oliveiro wrote: >>>> Compare this with the pain the x86 world went through, over a much longer >>>> time, to move to 32-bit. >>> >>> The x86 started from 8-bit roots, and increased width over time, which >>> is a very different path. >> >> Still, the question is why they did the 286 (released 1982) with its >> protected mode instead of adding IA-32 to the architecture, maybe at >> the start with a 386SX-like package and with real-mode only, or with >> the MMU in a separate chip (like the 68020/68551). >> > >I can only guess the obvious - it is what some big customer(s) were >asking for. Maybe Intel didn't see the need for 32-bit computing in the >markets they were targeting, or at least didn't see it as worth the cost. Anyone could see the problems that the PDP-11 had with its 16-bit limitation. Intel saw it in the iAPX 432 starting in 1975. It is obvious that, as soon as memory grows beyond 64KB (and already the 8086 catered for that), the protected mode of the 80286 would be more of a hindrance than even the real mode of the 8086. I find it hard to believe that many customers would ask Intel for something the 80286 protected mode with segments limited to 64KB, and even if, that Intel would listen to them. This looks much more like an idee fixe to me that one or more of the 286 project leaders had, and all customer input was made to fit into this idea, or was ignored. Concerning the cost, ther 80286 has 134,000 transistors, compared to supposedly 68,000 for the 68000, and the 190,000 of the 68020. I am sure that Intel could have managed a 32-bit 8086 (maybe even with the nice addressing modes that the 386 has in 32-bit mode) with those 134,000 transistors if Motorola could build the 68000 with half of that. >It is fair enough to target the existing market, but they were also slow >(IMHO) to take advantage of new opportunities in hardware, re-enforcing >the situation. They introduced Windows/386 in 1987. >I think MS and their monopoly on markets caused a >stagnation - lack of real competition meant lack of progress. Monopoly? These were the times with lots of competition from different hardware and software manufacturers. Apple with the Apple II, Lisa and MacIntosh, Atari with their 8-bit line and ther Atari ST line, Commodore with their 8-bit line and their Amiga line, and, on the software side, Digital Research with CP/M(-86/68K) and GEM, and various Unix offerings, including Xenix. Were they all no real competition? Not in my book. It's just that Microsoft eventually won, maybe accidentially (as it happens in a winner-takes-all market). >IBM were famous for poor (and perhaps cowardly) decisions at the time, >and MS happily screwed them over again and again in regards to OS/2. Another interpretation is that MS went faithfully into OS/2, assigning not just their Xenix team to it (although according to Wikipedia the Xenix abandonment by MS was due to AT&T entering the Unix market) and reportedly also assigned the best MS-DOS developers to OS/2. They tried to stick to OS/2 for several years, but eventually were fed up with all the bad decisions coming from IBM, and bowed out. - anton -- 'Anyone trying for "industrial quality" ISA should avoid undefined behavior.' Mitch Alsup, <c17fcd89-f024-40e7-a594-88a85ac10d20o@googlegroups.com>