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From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac,comp.sys.amiga
Subject: Re: Mac Multitasking? Hee-hee!
Message-ID: <2758@hoptoad.uucp>
Date: Sat, 15-Aug-87 22:14:22 EDT
Article-I.D.: hoptoad.2758
Posted: Sat Aug 15 22:14:22 1987
Date-Received: Sun, 16-Aug-87 12:15:10 EDT
References: <6565@eddie.MIT.EDU> <2742@hoptoad.uucp> <3638@cit-vax.Caltech.Edu>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Centram Systems, Berkeley
Lines: 45
Xref: mnetor comp.sys.mac:5593 comp.sys.amiga:7469

In article <3638@cit-vax.Caltech.Edu> walton@tybalt.caltech.edu.UUCP (Steve Walton) writes:
>>In any case, since Mac programs are so heavily interface-driven,
>>time-slicing is not a particularly great requirement.
>
>You mean if I want to do some editing while Mac C Kermit is downloading
>a 150K file for me at 1200 baud, I have to go to another machine?  I
>can't type "make" in a CLI window and then go off and play a game?
>Humph...

Well, as long as the downloading loop cedes control of the processor every
time through, a trivial code change, then synchronous multitasking will
serve this end quite well.  I'm not clear on how MultiFinder handles modal
dialogs (the documentation we've been seeded with is rather deficient), but
I believe it will let you change context during them.  Anyway, it's pretty
easy to make the download run in the background.  The same goes for any
other special-purpose long-lived operation, like Save; but most of what you
do on the Mac doesn't make any sense in the background.  That's why I said
that time-slicing is not such a big deal.

By the way, since games consume most of the CPU on the Mac, I really doubt
that you particularly want to slow down your compiles and screw up your
game's timing that way.

>   Look, can we all agree that it was unfair of Gary Samad to tweak the
>Mac owners about their lack of multitasking, AND that the Mac
>defenders' postings so far (Tim Maroney's and Pierce Wetter's) show little
>understanding of the Amiga's capabilities?  Let's nip this thing in the
>bud before the net explodes with another religious war.

I understand multitasking perfectly well, having rewritten a synchronous
multitasking system on the Mac, gotten a good way into writing an
asynchronous one before my boss insisted I do something useful, and munged
around extensively in the UNIX kernel.  I don't think you understand the Mac
very well, frankly.  You don't need time-slicing with a notebook and pen,
and for 95% of the things on the Mac you don't need it, either.  For the
remaining 5%, MultiFinder makes it pretty easy to write them so they can run
in the background, even in current versions.  No coroutines, asynchronous
notifications, or other weird code structures, just periodically giving up
control of the processor.  For something like a download or save, it ought
to be nearly trivial.  For computation-intensive processing, presumably you
don't want to slow things down to that extent anyway, whether through
synchronous or asynchronous interruptions.
-- 
Tim Maroney, {ihnp4,sun,well,ptsfa,lll-crg,frog}!hoptoad!tim (uucp)
hoptoad!tim@lll-crg (arpa)