jb10320@uxa.cso.uiuc.edu (Desdinova) (11/06/90)
In article <9736.apple.net@pro-angmar> kgreen@pro-angmar.UUCP (Kevin Green) writes: >In-Reply-To: message from hzink@alchemy.UUCP >I will concede, now, that the Mac line does not multitask. However, if we are >to judge which machines _do_ multitask, then only machines such as the >"Connection Machine" which use multiple processors, can actually multitask. >All other 'multi-tasking' is actually splitting the processing cycles of a >single CPU among several 'processes'. By that definition, I'd say even the >Multifinder 'multi-tasks'. Okay, well that's not exactly the definition of "multitasking". My CS classes are getting the best of me right now, so I'll throw out the accepted definitions of terms. multiprogram (multitask) - one CPU splitting execution time between different programs. preemptive multitasking- the operating system very specifically controls which programs run when, and for how long, using interrupts for switching, and having many other additions to increase CPU usage. multiprocess - two or many CPUs executing different programs (usually each CPU is multiprogrammed) Now, by the very first definition, the Mac AND the GS multitask. By the second, neither. MultiFinder is NOT preemptive (which is assumed these days when talking about multitasking). The Mac has no control over programs that blow up, or decide to hog all CPU time, or whatever. Therefore, neither the MacOS or GS/OS multitask (yet). >And if you _really_ want to get technical, there is still only one CPU that >can multitask: an organic brain. (And I know of some of those that aren't too >good at it...maybe they need System 7 :) ) Ahh.. actually, multi-process. The brain is indeed the greatest machine ever to exist on this earth. My goal is to duplicate it someday... so I can have it write all the NDA's I think of! :-) -- Jawaid Bazyar | Blondes in big black cars look better wearing Senior/Computer Engineering | their dark sunglasses at night. (unk. wierdo) jb10320@uxa.cso.uiuc.edu | The gin, the gin, glows in the Dark! Apple II Forever! | (B O'Cult) Comp.Sys.Apple2- Home of the Unofficial Apple II Developer Support Team (DST)
gwyn@smoke.brl.mil (Doug Gwyn) (11/06/90)
In article <1990Nov6.013239.7125@ux1.cso.uiuc.edu> jb10320@uxa.cso.uiuc.edu (Desdinova) writes: >Now, by the very first definition, the Mac AND the GS multitask. Assuming supportive operative software. Even the existence of "desk accessories" is a form of multitasking, although a rather sick one. >By the second, neither. MultiFinder is NOT preemptive (which is assumed >these days when talking about multitasking). The Mac has no control >over programs that blow up, or decide to hog all CPU time, or whatever. >Therefore, neither the MacOS or GS/OS multitask (yet). While I was happy to see you cite some reasonable definitions, why in the world didn't you stick to them?? It's correct that these systems do not implement PREEMPTIVE multitasking. Neither does the AT&T 630 terminal, which is (correctly) marketed as a "Multi-Tasking Graphics" terminal. It is implemented so slickly that it is unusual for the user to notice that the various layer (window) processes are not really executing concurrently. Voluntary task switching is simpler by far than preemptive scheduling, and it works well if done properly. >>And if you _really_ want to get technical, there is still only one CPU that >>can multitask: an organic brain. (And I know of some of those that aren't too >>good at it...maybe they need System 7 :) ) Now you're getting really ridiculous. I'm surrounded by multitasking computer systems, but a large number of human brains I encounter don't perform even one conceptual task very well, let alone concurrent ones.
kgreen@pro-angmar.UUCP (Kevin Green) (11/08/90)
In-Reply-To: message from jb10320@uxa.cso.uiuc.edu Jawaid wrote "My goal is to duplicate it someday..." (talking about the brain. It can be done now...go to any obstetrician and they will explain the basics to you. ;-) <---very, very big grin