Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!batcomputer!cornell!vax5.cit.cornell.edu!umh
From: umh@vax5.cit.cornell.edu
Newsgroups: comp.sys.mac.system
Subject: Re: Turning off time slices in S7
Message-ID: <1991Jun3.232340.5237@vax5.cit.cornell.edu>
Date: 3 Jun 91 23:23:40 EDT
References: <0E010021.82xzfh@gla-aux.uucp> <1991Jun1.070626.2853@spool.cs.wisc.edu> <1991Jun3.015035.5222@vax5.cit.cornell.edu> <1991Jun3.142717.103@magnus.acs.ohio-state.edu>
Distribution: comp
Organization: CIT, Cornell University
Lines: 69

In article <1991Jun3.142717.103@magnus.acs.ohio-state.edu>,
scasterg@magnus.acs.ohio-state.edu (Stuart M Castergine) writes: 
> In article <1991Jun3.015035.5222@vax5.cit.cornell.edu> umh@vax5.cit.cornell.edu writes:
> 
>>And this brings us into the brave new world of multithreaded programs and real
>>operating systems.
> 
> Sigh. Another "what a terrible operating systeem is MacOS" message. :-)

This dow not really deserve a reply except that I keep seeing this kind of junk
and it irritates me.
THE USER-INTERFACE IS NOT THE OPERATING SYSTEM !!!!!! Repeat 1000 times.

The operating system is the guts of the machine never seen by the users. It
is the software that handles how system resources (CPU time, disk space,
network access, memory, screen space etc) will be allocated among different
contenders, ie among different processes, DAs, INITs etc (in the Mac context).
The Mac OS is considered superior to DOS as an OS because it does a superior
job of such resource management- it has a more flexible file scheme, better
handling of the screen, better memory management etc.

The Mac Toolbox is software that gives the Mac its look and feel. This is *not*
whate we are arguing about. Neither are we arguing about whether or not
MultiFinder is "real" multitasking.

What I am pointing out is that, by the standards of modern operating systems,
the Mac OS is severly deficient. It does not offer protected memory- if one
program crashe, it can crash the entire machine. It does not offer threads-
allowing you to do other thing *in the Finder* while disk copying is going on,
for example. It does not offer support for multiple users on one machine- this
is useful *even if* you are the only user of that machine, to ensure that you
don't do something rash by mistake. It does not offer support for parallel
processing etc etc.

Now a whole bunch of people are going to say that we, common users, don't need
that. This is a load of bull. It doesn't matter what you dow ith your computer-
everyone benefits form a robust environment where the crash of one program does
not affect anything else. Everyone benfits from an environment where time
intensive jobs are shuffled to the background in a separate thread while the ap
you're using remains interactive. Everyone benefits from the extra CPU
performance parallel processing can bring. Have you ever tried to manipulate 2
page 24bit graphics? Wouldn't it be nice if that took half a second instead of
30 seconds. Have you ever tried editing sound? Printing out to a quickdraw
printer?

Even things the MacOS does like multi-tasking could be speeded up a great deal
if the OS were changed in some way. Context switches on a Mac are *slow* by the
stanadards of many other OSs.

Now, what of the competition. Everyone shrinks back at the thought of UNIX.
Dammit- we are interested in UNIX the OS here, not UNIX the shell. The fact is
that as an operating system, UNIX is fundamentally more powerful than the
MacOS. Mach is a kernel based on networking/parallel processing concepts that
is rather more powerful than UNIX, can be customized rather more easily for a
certain task, and can be made to look like UNIX to a programmer- and like UNIX,
to look like anything you want including a Mac, to the user.

Look at AIX. When AIX runs, it takes over the machine- the MacOS is killed.
That doesn't stop you running Mac programs that behave just like always- just
they're using UNIX as their OS, not the native Mac OS, but they still use the
Mac Toolbox.

There are a few innovative features in the MacOS. Things like resources and
parts of Quickdraw. But most of it is not nearly as good as what is available,
and it makes no sense to claim either that it is, or that we do not need the
improvements.

Maynard Handley