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From: ccant@brolga.cc.uq.oz.au (Anthony Murdoch)
Newsgroups: comp.windows.ms
Subject: Re: Why Windows can't Multitask DOS
Keywords: info
Message-ID: <1990Jul2.000340.27198systhvu@brolga.cc.uq.oz.au>
Date: 2 Jul 90 00:03:40 GMT
References: <1990Jul1.193551.6345@sunee.waterloo.edu>
Organization: Prentice Computer Centre, University of Queensland, Australia.
Lines: 36

In <1990Jul1.193551.6345@sunee.waterloo.edu> gpsteffl@sunee.waterloo.edu (Glenn Patrick Steffler) writes:

>Many people have posted with all sorts of wild ideas about why
>Windows can't multitask, or how it DOES multitask.

>It's a very simple idea really (but the application is much more
>difficult).  DOS was written such that it will only allow one task to
>use it's resources at any one time.  The DOS calls like read/write etc
>busy wait until they complete.  Absolutely NO concurrent operations are
>allowed.  Thus, formatting a floppy disk and reading from the hard
>drive, although they are independent tasks, they still must be executed
>serially.  Even allowing processor time to a task while another is
>waiting for a DOS operation to complete is infeasible.  Windows must
>make sure all of it's accesses to DOS are single threaded.  Therefore,
>background DOS windows in enhanced mode will seem to multitask, but
>Windows must wait for the application to complete a DOS operation
>before it can "switch" the task away.  This is as good as it gets
>unfortunately.

Then why don't they provide a more reasonable version of DOS along with
windows itself.  Everything that DOS does can be done in a multitasking
environment.  I have seen heaps of TSR utilities that do DOS-functions (like
formating etc) while allowing you to continue working.

Does anyone know if the version of DOS that is to be shipped in Microsofts
planned "merging of DOS and Windows" will allow Windows to multitask it ?
If it isn't planned now, maybe someone in Microsoft should seriously start
considering it.

Ant

--
  V   ant                       "It's great to be young and insane"
 \o/  ccant@brolga.cc.uq.oz.au                    - Dream Team
 -O-  Anthony Murdoch           Prentice Computer Centre
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