Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!rutgers!ucla-cs!cit-vax!tybalt.caltech.edu!wetter From: wetter@tybalt.caltech.edu (Pierce T. Wetter) Newsgroups: comp.sys.mac,comp.sys.amiga Subject: Re: Mac Multitasking? Hee-hee! Message-ID: <3632@cit-vax.Caltech.Edu> Date: Thu, 13-Aug-87 22:15:41 EDT Article-I.D.: cit-vax.3632 Posted: Thu Aug 13 22:15:41 1987 Date-Received: Sat, 15-Aug-87 11:56:10 EDT References: <6565@eddie.MIT.EDU> Sender: news@cit-vax.Caltech.Edu Reply-To: wetter@tybalt.caltech.edu.UUCP (Pierce T. Wetter) Organization: California Institute of Technology Lines: 59 Xref: mnetor comp.sys.mac:5518 comp.sys.amiga:7410 In article <6565@eddie.MIT.EDU> gary@eddie.MIT.EDU (Gary Samad) writes: >I just came back from MacExpo here in Boston and saw their new "Multifinder" >"first generation multitasking" system. They really have no right to call >this thing multi-tasking. It gives you print-spooling (even the lowly PeeCee >has print-spooling) and the ability to have several programs open at once >(if they're compatible with Multifinder) but they do NOT run at the same time >unless the program makes "give-up-the-CPU calls" frequently! That's right, ^^^^^^^^^^^^^^^^^^^^^ This is otherwise known as Dosystick which is called when the current program is idle i.e. when a background process is waiting for input it doesn't take up time. Personally, since most mac programs require so much feedback I can't see where MultiTasking would be useful except in printspooling and telecomm stuff. Presently, I am running on a multitasking system and I acutally wish it wasn't since it annoys me to have to wait while the computer catches up with my typing. Additionally, because of the large quantities of information which have to be swapped around (namely all the lowmemory globals) multi tasking is impractical without an MMU (Unix gets around this by swapping things off and on the hard disk KLUDGE!!!!!!). When Apple releases MultiFinder as a full MultiTasking system it will probably only time-slice on the MacII with a PMMU. >There are no provisions whatsoever for process spawning, inter-task >communication, or, it appears, even dynamic memory allocation (it appeared >that each program was allocated a fixed ammount of memory, out of which it >could allocate what it needed). InterTask communication in a graphical interface? Not practical for two programs to communicate with each other that way. However, if a program wants to spawn subprocesses the mac has always had that capability it's called the vertical retrace queue. Actually the Mac does have intertassk comm. Read Inside Mac volume V, specifically the Notification Manager. Again dynamic memory allocation is impractical without an MMU unless you wish to have processes writing into each others memory (wouldn't it be lovely if every time a program in Unix crashed it brought down everyone else too?) >I wonder if Apple is really going to pull the wool over its user's eyes by >advertising "The new Mac multitasking operating system." > Well, since it won't be out until September we'll have to see won't we. However, isn't allowing print-spooling and telecomm in background multi-tasking? What is the practical purpose in running dark castle and MacDraw at the same time since they both require continuous input? FLAME ON I notice in the message header that you are posting to both the amiga and mac newsgroups. Why? If you are a Mac user why are you bothering the amiga owners with mac news? if you are an amiga user why are you posting mac news since you probably don't know enough about the mac for your comments to be relevant anyways? Regardless why do amiga people care about MultiFinder? FLAME OFF PIerce Wetter Brooke's Law: Whenever a system becomes completely defined, some damn fool discovers something which either abolishes the system or expands it beyond recognition. -------------------------------------------- wetter@tybalt.caltech.edu --------------------------------------------