Path: utzoo!attcan!uunet!mcvax!hp4nl!phigate!philmds!leo
From: leo@philmds.UUCP (Leo de Wit)
Newsgroups: comp.sys.atari.st
Subject: Re: Multitasking on the ST
Message-ID: <1066@philmds.UUCP>
Date: 10 Aug 89 10:58:38 GMT
References: <8908021826.AA05333@ucbvax.Berkeley.EDU> <15627@watdragon.waterloo.edu> <652@opal.tubopal.UUCP> <471@tw-rnd.SanDiego.NCR.COM>
Reply-To: leo@philmds.UUCP (Leo de Wit)
Organization: Philips I&E DTS Eindhoven
Lines: 29

In article <471@tw-rnd.SanDiego.NCR.COM> johnl@tw-rnd.SanDiego.NCR.COM (John Lindwall) writes:
|In article <652@opal.tubopal.UUCP> alderaan@tubopal.UUCP (Thomas Cervera) writes:
|>
|>  What's all this about MultiTasking on the ST ? You don't have a MMU (not
|>really and I think that's the worst failure in the ST's hardware architechture),
|>so you are definetely not able to run a *secure* multitasking on this machine
|>even if you want to - basta. 
   []
|
|Amen to that! Amiga owners have suffered with the lack of an MMU.  The
|usefulness multitasking is a given, IMO.  The security of Amiga's multitasking
|is poor due to the lack of memory protection supplied by an MMU.  Those of
|you who agree multitasking is useful, and would like to see it on an Atari:
|Demand it from Atari and demand MMU support as well.

I think two issues are being confused here, the need for per process
memory protection, and the possible to run processes 'simultaneously'.
Why should memory protection be a hotter item when parallel processes
are involved? In the current situation it is just as well feasible for
instance by an application program to thrash the space of the shell it
was invoked by. So if you insist on security, you should insist on it
right now already.

An MMU alone probably won't hack it; you will probably want a 680x0
(x >= 1) to be able to page in new memory (a 68000 doesn't maintain
enough internal information to be able to restore correctly from a
BUSERR).

   Leo.