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From: baumgart@esquire.dpw.com (Steve Baumgarten)
Newsgroups: comp.sys.mac.system
Subject: Re: PPC, IAC, and True Multitasking (tm)
Message-ID: <2215@esquire.UUCP>
Date: 6 Aug 90 16:33:48 GMT
References: <1990Aug3.040513.14844@d.cs.okstate.edu>
Sender: news@esquire.UUCP
Reply-To: baumgart@esquire.dpw.com (Steve Baumgarten)
Organization: Davis Polk & Wardwell
Lines: 44
In-reply-to: norman@d.cs.okstate.edu (Norman Graham)

In article <1990Aug3.040513.14844@d.cs.okstate.edu>, norman@d.cs (Norman Graham) writes:
>Obviously, if you don't have true multitasking you can't possibly have
>true IAC: After all, what can a process communicate with if no other
>process is truly running at the same time? Is some Apple marketing type
>trying to pull the wool over our eyes or what? Come on ye keepers of the
>true multitasking faith,let's rise up and squash this IAC propoganda.
>
>Many :-)'s
>Norm

Assuming you meant the smileys for the "rise up" part of your message,
and not necessarily the first part...

One of the most overlooked features of System 7 is its ability to
handle IPC without requiring both programs to be running at the same
time.  For people who just want to get their work done in the best and
most convenient way (i.e., people working in groups, each contributing
something to a final document, or various people receiving live
updates from a spreadsheet that's maintained in another department),
this is a major advance in OS design.

Being able to have a socket or shared memory under Unix, or taking
advantage of DDE under Windows is fine -- assuming that you want to
keep all the relevant programs running at the same time.  But Apple's
publish/subscribe method of IPC makes much more sense, since it allows
documents to make available certain parts of themselves to anyone on
the network who is interested in making use of them.  The application
that created the document does not have to be running or even present
on the system for this to work.

There's nothing like this (that I'm aware of) in the Unix world, and I
don't think there's any support for it under Windows or OS/2 (please
correct me if I'm wrong).  

Although the Mac still doesn't support "true" multitasking or "true"
IPC, it seems that the multitasking and IPC it *does* offer provides
real benefits to real users -- even though Apple's definitions of
multitasking and IPC may not make CS majors happy.

--
   Steve Baumgarten             | "New York... when civilization falls apart,
   Davis Polk & Wardwell        |  remember, we were way ahead of you."
   baumgart@esquire.dpw.com     | 
   cmcl2!esquire!baumgart       |                           - David Letterman