Xref: utzoo comp.sys.amiga:33778 comp.sys.mac:31898 Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!pprg.unm.edu!hc!lll-winken!uunet!intercon!amanda@intercon.UUCP From: amanda@intercon.UUCP (Amanda Walker) Newsgroups: comp.sys.amiga,comp.sys.mac Subject: Re: Re: Apple System 7.0 Message-ID: <13-May-89.212039@192.41.214.2> Date: 14 May 89 01:12:23 GMT References: <17183@usc.edu> <17148@usc.edu> <24279@agate.BERKELEY.EDU> <18268@cup.portal.com> Sender: news@intercon.UUCP Reply-To: amanda@intercon.UUCP (Amanda Walker) Organization: InterCon Systems Corporation, Sterling, VA Lines: 29 In article <17183@usc.edu>, papa@pollux.usc.edu (Marco Papa) writes: > ... Apple can try to fool end-users into thinking that > MultiFinder provides multitasking, but I don't think anybody on Usenet > will ever believe that. If you do, may I suggest you pick up ANY Operating > Systems book. It might be very educational. > > -- Marco Papa 'Doc' Oh, come off it. If you actually *read* a good OS textbook, you'll discover that (listen carefully now) multitasking is a general concept, and has nothing to do with either providing separate address spaces for each process, or providing preemptive task switching. Both of these are useful techniques in many contexts, but they are not necessary conditions for multitasking. There are machines that provide one, both, or neither of these services, while still doing multitasking. There are machines that provide preemptive task switching in one big happy address space (some Lisp machines, for example). There are some that provide both heavyweight (protected) and lightweight (non-protected) processes at the same time (can you say "threads"? I knew you could). Memory protection and preemptive task switching would help the Mac in one basic way: they would enhance reliability, since a bug in a program would only kill that particular process. This is not the same issue as whether or not MultiFinder is "real" multitasking. Grumble. -- Amanda Walker