Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!martens From: martens@cis.ohio-state.edu (Jeff Martens) Newsgroups: comp.sys.amiga Subject: Re: Multiprocessing-Multitasking Message-ID: <43384@tut.cis.ohio-state.edu> Date: 14 Apr 89 03:02:46 GMT Sender: martens@tut.cis.ohio-state.edu Lines: 57 In article <397@bnr-fos.UUCP> Keith Hanlan writes: >In article <42406@tut.cis.ohio-state.edu> Jeff Martens writes: :>In article <12700@louie.udel.EDU> DAVEA%CERNVM.BITNET@cunyvm.cuny.edu (David Almond) writes: :> :>:: In that the amiga has dedicated processers for graphics etc it is, to some :>:: degree multitasking, but not in any sophisticated, scheduled sense. :> :>::::The Amiga is FULLY multitasking, in the sense that the processor is time :>::::sliced among many processes. Much in the same vein as UNIX, OS/9, Aegis, :>::::VMS, etc. :> :>:to burn precious space, is that the though the Amiga is multitaskingfor :>:all the reasions you outlined is not fully multitasking beause there :>:is no scheduler which controls overall running of tasks. So that it :>:would no how much spare capacity exists on each intelligent processing :>:device, as it processes, and thus be able to dispatch the next processing :>:task in the most efficent manner. > I think the confusion is that Mr. Martens is talking about > *multi-processing* but calling it multi-tasking. > Yes the amiga is a multi-processing computer in that it has multiple > processors but it is not multi-processing in the same sense as a > multi-CPU machine. This is hardly surprising. The co-processors are > dedicated function chips. > Does this clear things up? > Keith Hanlan {uunet!attcan!}utgpu!bnr-vpa!bnr-fos!atreus!keithh > Bell-Northern Research > Ottawa, Canada No, this muddies it up. Although none of my posting was repeated (so I think you were attributing to me what soemone else said), I was talking about multasking, as was the person quoted above who pointed out that Unix, VMS, etc. multitask in the same sense as the Amiga (and vice-versa). Multiprocessing is the use of multiple processors; the Amiga does this in a very asymmetric sense since there are processors inside dedicated to screen handling and the like. Symmetric multiprocessing would require more than one 68000, which my Amiga doesn't have. Multitasking, on the other hand, just means there can be more than one thread of control at a time. See any intro undergrad OS text, like Deitel's. My main objection was to the person who claimed that the Amiga doesn't have a scheduler; this is clearly false. On a second read through keithh's posting, perhaps he meant that the person I was responding to (the person quoted above as claiming the Amiga isn't fully multitasking) was confused between multitasking and multiprocessing. If so, maybe he should just pay more attention to who said what. -- -- Jeff (martens@cis.ohio-state.edu) ....and on Wall St., the Tao is unchanged in moderate trading...