Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!comp.vuw.ac.nz!actrix!templar!jbickers
From: jbickers@templar.actrix.gen.nz (John Bickers)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: 8-bit death
Message-ID: <3404.tnews@templar.actrix.gen.nz>
Date: 9 May 91 07:11:28 GMT
References: <1991Apr28.122439.13393@sugar.hackercorp.com> 
 <1991Apr28.162045.15585@daffy.cs.wisc.edu> 
 <1991Apr30.112820.2451@sugar.hackercorp.com> <1991May1.064455.3058@kessner.denver.co.us> <2945.tnews@templar.actrix.gen.nz>
 <69VT02ZW07LF01@JUTS.ccc.amdahl.com>
Organization: TAP, NZAmigaUG.
Lines: 42

Quoted from <69VT02ZW07LF01@JUTS.ccc.amdahl.com> by kls30@duts.ccc.amdahl.com (Kent L Shephard):
> In article <2945.tnews@templar.actrix.gen.nz> jbickers@templar.actrix.gen.nz (John Bickers) writes:

> >    When one calls an MS-DOS "interrupt" (haw, reminds me of the C= 64),
> >    isn't the interrupt number a byte?
> >
> >    That's a fundamental part of the OS that is only 8 bits.
> 
> WRONG.  The Intel 80x86 limits you to 256 vectors for interrupts.  That

    Which part is "WRONG"? That this is a fundamental part of the OS, or
    that it's only 8 bits?

> does not mean that the OS is eight bits.  The hardware only supports that
> many vectored interrupts.  So since the hardware only supports a vector

    Who cares how many damned interrupts the hardware supports? As someone
    pointed out, 680x0 chips provide similar sorts of numbers too. My
    point is that the "OS", MS-DOS, the thing we are talking about,
    uses these "interrupts" as the interface to applications run on it.

    That limits things to 8 bits worth of hooks into the OS. More than
    enough for a tinny little thing like MS-DOS, running on 640K
    application RAM PClones, but nevertheless, only 8 bits.

    I believe (and my Usenet feed is at home, so I don't have manuals
    and things on hand, sorry) that MS-DOS does things like have 1
    vector for a particular range of functions, and when you call one
    of that range, you have to stuff another byte-sized value into
    a register and then invoke the interrupt for that range.

> of 1 byte, you'll say that the 80x86 machines are only 8 bit because that
> is how long the interrupt vector is.

    Well, if Unix implementations on these widgets used the same crankpot
    OS interface that MS-DOS uses, I'd certainly be willing to claim that
    they are 8-bit implementations of Unix.

> /*   Kent L. Shephard  : email - kls30@DUTS.ccc.amdahl.com   */
--
*** John Bickers, TAP, NZAmigaUG.        jbickers@templar.actrix.gen.nz ***
***         "Endless variations, make it all seem new" - Devo.          ***