Path: utzoo!censor!geac!yunexus!maccs!cs4g6ag
From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Is the XT dead?
Summary: 286/386 100% compatible version of MS-DOS
Message-ID: <2525775F.6304@maccs.dcss.mcmaster.ca>
Date: 1 Oct 89 02:33:03 GMT
References: <446@crash.cts.com>
Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Organization: McMaster University, Hamilton, Ontario
Lines: 30

In article <446@crash.cts.com> jca@pnet01.cts.com (John C. Archambeau) writes:
$ As long as MS-DOS is around, the 8086/8 will be around.  MS-DOS is designed
$ around the 8086/8 address space.  There is big money for a company that
$ designs a 100% implementation of MS-DOS that runs in 286/386 protect mode,
$ but I have yet to see such an implementation.

   I, for one, don't see such a thing happening, if for no other reason than
that most applications wouldn't run in such an environment.

   You see, the concept of segments is different in 286 protected mode from
8086 mode.  In general, MS-DOS software is written under the assumption that
it will be running on an 8086 platform with the 8086's concept of what
segments are.  Since MS-DOS is an 8086 operating system, this is a perfectly
reasonable and valid assumption.  Were these programs to be run in 286
protected mode, their assumptions about segments would most likely be ren-
dered invalid --> crash.

   What someone could do would be to come up with a 100% compatible
version of MS-DOS running in the 386's multiple virtual 8086 mode, which
allows multiple programs to multitask, each one believing it has an entire
8086 to itself.  Such a program may well already exist - I'm not familiar
with any of the 386 multitasking DOS-like operating systems; one of
them might be compatible.


-- 
Stephen M. Dunn                         cs4g6ag@maccs.dcss.mcmaster.ca
        = "\nI'm only an undergraduate!!!\n";
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TORONTO BLUE JAYS - 1989 AMERICAN LEAGUE EAST CHAMPIONS!  GO JAYS GO!!