Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!usc!apple!claris!peirce
From: peirce@claris.com (Michael Peirce)
Newsgroups: comp.sys.mac
Subject: Re: Hey Apple Mac engineers, answer->Ma
Message-ID: <10483@claris.com>
Date: 13 Aug 89 19:58:14 GMT
References: <14845@dartvax.Dartmouth.EDU> <46100321@uxe.cso.uiuc.edu>
Reply-To: peirce@claris.com (Michael Peirce)
Organization: Claris Corporation, Santa Clara CA
Lines: 48

In article <46100321@uxe.cso.uiuc.edu> mcdonald@uxe.cso.uiuc.edu writes:
>
>>In article <21857@dcatla.UUCP> mclek@sunb.UUCP (Larry E. Kollar) writes:
>...
>>     This not a fault of the Mac, but of the programmer who programmed
>>the dialog.  Mac dialogs can be set up to be totally modal, as you
>>describe, or to be modeless, i.e. just like any other window.  It is
>>more work for the programmer to write programs which use modeless
>>dialogs, not much more work, but a little more.  It is modal dialogs,
>>not dialogs per se, which lock you out under MultiFinder, and 99% of
>>the time, you have some lazy application programmer to thank for it.
>
>It is a fault of the operating system. In a true multitasking 
>system, it is IMPOSSIBLE for one program to lock up the system,
               ^^^^^^^^^^
>whether intentionally or because of a bug.
>
>Doug McDonald

Sigh...

Of course it's possible to lock up a "true multitasking" system.  Ever
heard of priorities?  Back in my Vax days we used to lock up Vaxes all
the time by having some of the software we were developing
run amuck at an elevated prioprity.  System also freeze up temporarily 
when you get I/O storms.  And for may other reasons.

EVERY system can behave in ways that some users might not like all the time.
EVERY system is a compromise between myriad design constraints.

Multitasking ("true" or otherwise) is not a panacea. It also takes time and
effort to impliment.  Personally I'd rather see an async SCSI manager, among
other things, before they tackle "true" multitasking...

Claris Corp. | Michael R. Peirce
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I use quotes around "true" because there really isn't such a thing.  There 
are LOTS of kinds of multitasking.  I wrote a nice multitasking OS for a
4K 6809 based machine a long time ago.  It was even "true" multitasking,
but I'd rather have MultiFinder any day :-)