Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site watcgl.UUCP Path: utzoo!watmath!watcgl!jchapman From: jchapman@watcgl.UUCP (john chapman) Newsgroups: net.micro Subject: Re: ANOTHER 32-BIT MACHINE??? Message-ID: <1588@watcgl.UUCP> Date: Thu, 28-Mar-85 10:27:32 EST Article-I.D.: watcgl.1588 Posted: Thu Mar 28 10:27:32 1985 Date-Received: Fri, 29-Mar-85 00:02:27 EST References: <9254@brl-tgr.ARPA>, <543@intelca.UUCP> <5337@utzoo.UUCP>, <1549@watcgl.UUCP> <5355@utzoo.UUCP> Organization: U of Waterloo, Ontario Lines: 78 > > > > ... all I can say about the 386 is that it is a full 32 bit > > > > microprocessor, (with four gigabyte segments) which is totally binary > > > > compatible with the iAPX86 family. > > > > > > That statement is self-contradictory. Binary compatibility with the > > > 8086 is fundamentally incompatible with a full 32-bit architecture. > > > > why is it contradictory? the 386 could have a compatability mode > > to execute iAPX86 programs (similar to vax compatability mode - > > or does being able to run pdp-11 programs mean the vax isn't a > > true 32 machine?). > > When it's running in compatibility mode, the VAX is most assuredly not a > 32-bit machine; it acts like a 16-bit machine, to wit the pdp11. Or > rather, a pdp11 subset. > > Besides, "totally binary compatible" doesn't sound like a compatibility > mode to me. Much more likely, especially considering the source (Intel), > is that it's the same old sickening story of backward compatibility > with all previous mistakes, right back to the 4004. (Really. The new > x86 chips are 8086 compatible, the 8086 had a lot of 8080 compatibility, > the 8080 was source-compatible with the 8008, and the 8008 was pretty > much an 8-bit 4004. Isn't it thrilling to know that you're programming > a machine descended from a souped-up calculator? Such roots, such a > sense of history, such a feeling of nausea...) > -- > Henry Spencer @ U of Toronto Zoology > {allegra,ihnp4,linus,decvax}!utzoo!henry Well this seems a bit picky to me, but .... Your'e statement was that binary compatability with an 8086 is funda mentally incompatible with a full 32 bit architecture. I don't see any difference between this and the vax-pdp11 example I made and I seriously doubt that because the vax occasionally executes binary code (which is my understanding of compatibility mode {please correct me if I'm wrong} - i.e. "totally binary compatible") from a 16 bit architecture that very many people would claim it is not a true 32 bit architecture. Does 32 bit mean you're not allowed to execute 16 bit instructions or something? I mean it seems reasonable to me that a 32 bit machine would also have a complete set of 16 bit instructions as well! Personally I think the 8086 resembles a 360 in architecural style as much as an 8080 (maybe that's why IBM liked it so much :-> ). Why if the 8086 is so poor are their so many of them? - because intel delivers a LOT faster than the other companies. 5 years ago I was shopping around for a replacement for my z80 and the 68000 was only promises (trying to order one from my local dealer was very interesting - they had been announced). Similarily with the 16032 - I was drooling when that was announced; I went out and bought the programmers manual and really liked what I saw - but could I gt a working system? On the other hand the 8086 was available, I could get the cpu and other support boards and there was software available - an off the shelf system that works, has software, and is readily available is preferable to a superior system that is unavailable and unsupported (from the individuals point of view). Where can I get a 68020/32032 system today for a reasonable price, including some system and support software? Sure the architecture doesn't show much imagination, I don't like it myself, but how many people program in assembler - I would expect that the architecture (with the possible exception of 64k segments for data) would have zero noticable impact on most people - they are either programming in HLLs or running application packages. I can get msdos (not a great system but it works), an assembler, linker, pascal compiler, fortran compiler, modula compiler and a screen editor for under $1000 - what will software support for other machines cost? John Chapman Computer Graphics Lab University of Waterloo ....!watmath!watcgl!jchapman Disclaimer: the above does not represent the views of anyone important, institutional, or otherwise worth harrassing for fiscal recompense.