Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!pro-angmar.UUCP!m.tiernan
From: m.tiernan@pro-angmar.UUCP (Michael Tiernan)
Newsgroups: comp.sys.apple2
Subject: Re: Building a NEW computer
Message-ID: <10895.apple.net@pro-angmar>
Date: 6 Dec 90 10:08:03 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 42

In-Reply-To: message from $CSD211@LSUVM.BITNET

Mr Shekhel is dead right, the basic problem with the Apple II line
is/has-been/will be that it lacks a few required instructions at the processor
level to allow it to be a competative force.  This has been the problem since
way back in the days of the Apple ][+ when they decided that no one will ever
need an inerrupt line so they took them out of the card slots.  I'm not too
sure that I agree that it's largest lack of abilities revolves around the
concept of multiply and devide, yea it takes memory to do that with software
but memory is cheaper than microcode.  The Apple II line has a history of lack
of support of the concept of interrupts.  ProDOS is really the first OS that
actively supports it.  The UCSD p-system allowed it but didn't support it. 
ProDOS does provide you with methods of hooking your routines in using a very
nice clean manner but then at EVERY interrupt, ProDOS runs a little ditty
before handing off control to your code.  (I grant you, they did it for the
right reasons, to return the machine to a known state before you get control)
but hell, that's not their judgement to make beyond the absolute minimum.

Aside from all that, the II line lacked a non-preempt style of instruction
that would allow you to run (cleanly) multiple tasks.  Even the oldest IBM-PC
had an instruction to increment a memory word that blocked all attempts at
prememption until it completed.  Using this, you could signal tasks into and
out of a run/ready state.  We ain't got it.  HOLD IT!  Before the flames get
turned on, I am not saying I should be able to run a uucp transfer while I
recompile the great American program in the background, but even little things
like clean print spoolers, alarm clocks and the such are hindered in their
abilities without such a thing.

Oh well, time to move on.

Thanks for the use of the soapbox, "NEXT!"


<< MCT >>

GEnie       : M.Tiernan
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"God isn't dead, he's only missing in action."
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