Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!cs.utexas.edu!rutgers!cbmvax!martin From: martin@cbmvax.commodore.com (Martin Hunt) Newsgroups: comp.sys.amiga Subject: Re: Multitasking at home is great!! (Was Reality check: ....) Message-ID: <17482@cbmvax.commodore.com> Date: 12 Jan 91 22:09:00 GMT References: <1990Dec13.155848.8152@maytag.waterloo.edu> <1990Dec22.082240.2443@news.iastate.edu> <26060@uflorida.cis.ufl.EDU> Reply-To: martin@cbmvax.commodore.com (Martin Hunt) Organization: Commodore, West Chester, PA Lines: 63 In article mwm@fenris.relay.pa.dec.com (Mike (My Watch Has Windows) Meyer) writes: >In article <26060@uflorida.cis.ufl.EDU> cr1@beach.cis.ufl.edu (Anubis) writes: > > I've heard Amiga's multitasking defined in so many ways it makes my > head spin. Now, I have a general idea of how things work, but could > someone with a good grasp on the topic please explain to me exactly > how Amiga's multitasking works, and why it can be given the honored > term 'true multitasking' ? > >Sigh. The term "true multitasking" was born of immature Amiga users >being worried that their machine would lose some of it's "superiority" >over other machines that had been single tasking before, but recently >acquired a non-preemptive multitasking. The term "true multitasking" did not originate with Amiga users. >It's use implies that non-preemptive multitasking is somehow "fake" or >"false". This is no more true than the claim that the Isetta isn't a >car because it uses a motercycle engine. Non-preemptive multitasking >is every bit as much "true multitasking" as preemptive multitasking. Yes and the Issetta is every bit as much a "true" sports car as a Ferrarri. > >The world would be a better place - and the image of Amiga users would >improve - if Amiga users forgot the phrase "true multitasking", and >used the correct one: "preemptive multitasking". > > -- Every multitasking OS has at least one of the following characteristics: A. The ability to have multiple tasks loaded in memory. B. The ability to switch rapidly between tasks. C. The processor controls which task gets the CPU. There are many different scheduling algorithms that may be used. Generally, some type of priotity scheme is implemented. When a task does not need the CPU (such as when waiting for I/O), it will immediately give up the CPU. The Amiga, Unix, OS/2, VMS, OS9, etc. have all of these. They are generally considered "true" multitasking systems. Because MeSSyDOS and the MAC OS were not designed to multitask, they cannot be easily be made to do A,B, and C. However, many different companies produced kludges that at least allowed them to do A. Now the problem is that MSDOS users were told that they now had "multitasking". Unix, Amiga, and other users cried foul. That isn't truly multitasking, they said. It's just a kludge. So, don't criticize others just because they aren't using the current popular jargon. At least Amiga users know there is a difference, even if they have problems describing exactly what it is. Martin Hunt Commodore-Amiga martin@cbmvax.commodore.com "Windows 3.0 is hot because it's really fun. It has brought some excitement back into the PC industry" - Microsoft I wonder who took the excitement out in the first place?