Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!easy!lron (Dwight Hubbard)
Newsgroups: comp.sys.amiga
Subject: Re: Multitasking at home (Was Reality check: ....)
Message-ID: <186801ce.ARN0872@easy.UUCP>
Date: 23 Dec 90 04:29:50 GMT
References: <54.27730FA6@ijcr.fidonet.org>
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In article <54.27730FA6@ijcr.fidonet.org>, Darin Arrick writes:

>
>  The Amiga lets you do anything concurrently with anything else,  as
> long as the programs are well-behaved (i.e. the programs go through the
> operating system calls to hardware instead of direct access, don't
> allocate un-needed memory, etc.).

The program doesn't have to be well behaved.  It just shouldn't go accessing
the hardware without getting exclusive access first.  The operating system
can switch tasks at any time.  I.E. if a program is in the middle of playing
with some hardware the operating system is using as well there can be some
serious problems.  On systems like the Mac the actual task switch is
controlled by the program, which means if a program doesn't want to give the
CPU back all other programs will stop, it also means programs on the Mac have
to be well behaved in order for them to multitask.  Same is true for windows
on a 286 PC as well.

And even MS-Dos programs should dealocate unneeded memory.

If a program is written to print the words "hello world" in an endless loop
and was compiled without changes on a Mac, 286 PC, and an Amiga.  The only
machine that would multitask with that program running would be the Amiga.
The Mac and the PC would stop dead as soon as that programs window is selected
because it isn't written to multitask on those systems.
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| Dwight Hubbard,                                       |-Kaneohe, Hawaii   |
| USENET: lron@easy.hiam or uunet!easy!lron             |-GT-Power: 029/004 |
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