Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!iuvax!bsu-cs!mithomas From: mithomas@bsu-cs.bsu.edu (Michael Thomas Niehaus) Newsgroups: comp.sys.amiga Subject: Re: Commodore, Amiga, Apple, and MAC Message-ID: <11052@bsu-cs.bsu.edu> Date: 9 Apr 90 01:55:12 GMT References: <23800@pasteur.Berkeley.EDU> Reply-To: mithomas@bsu-cs.UUCP (Michael Thomas Niehaus) Organization: CS Dept, Ball St U, Muncie, Indiana Lines: 45 David Navas writes: > Now, when do *I* use multitasking? > WHen I'm doing downloading and/or playing music [on my computer, silly] while > programming, etc. > > Under these circumstances, MultiFinder doesn't cut it for the obvious reasons. What are these obvious reasons? I download in the background all the time, while checking my hard drive for viruses and talking to our VAX host. (I have two serial lines.) Heck, even MS-DOS can do things like this (with Windows or various other TSRs). > I think that it's not so much that multitasking programs don't need preemptive > multitasking, but that the current manner of programming doesn't teach you to > think in concurrent ways, and so preemptiveness isn't so obvious. Huh? The only time that programming needs to make you think in concurrent ways is when you are working on a parallel processing machine. What we are talking about here is the possibility of two distinctly separate programs running simultaneously. Since there is no interaction between the two, multitasking is not taken into account when writing the programs (assuming of course that the operating system has some multitasking abilities). You are referring to a concept that really isn't related (although it is dependent on the availability of multitasking). Separate "threads" are the concept that most programmers do not consider when programming. They are not taught to think concurrently in this case. You can have preemptive multitasking without such threads being feasible (take VMS for example -- takes to long to create the thread, unless you "pre-create" it and use some type of IPC to send it commands). Unix has the ability to do this partially (with forks), but the only operating system that I have seen that does this well is OS/2. (PageMaker is the first application that I have seen that really takes advantage of this by reformatting in the background while the user continues to edit.) -Michael -- Michael Niehaus UUCP: !{iuvax,pur-ee}!bsu-cs!mithomas Apple Student Rep ARPA: mithomas@bsu-cs.bsu.edu Ball State University AppleLink: ST0374 (from UUCP: st0374@applelink.apple.com)