Message-ID: <36AE3229.881FA855@lycosmail.com>
Date: Tue, 26 Jan 1999 16:22:49 -0500
From: Adam Schrotenboer <ajschrotenboer AT lycosmail DOT com>
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To: djgpp AT delorie DOT com
Subject: Re: Some Systems Defined
References: <3 DOT 0 DOT 1 DOT 16 DOT 19990126113745 DOT 1fe79d02 AT shadow DOT net> <78l0vd$fcq$1 AT antares DOT lu DOT erisoft DOT se>
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Reply-To: djgpp AT delorie DOT com

This may be more of a technicality, but as far as I know, command.com is loaded
to run the autoexec.bat, then unloaded, then the GUI is loaded. Unless MSDOS.SYS
has a line BootGUI=0

Therefore, though IO.SYS is loaded, which is real mode, and a part of MS-DOS, it
is bypassed for the most part when the GUI is loaded. So it could be said that
Win98 is running on top of MS-DOS, but DOS is bypassed, unless real-mode drivers
are in use. Even then, command.com is still bypassed, and calls to IO.SYS are
minimal.

The GUI is NOT (AFAIK) loaded on top of DOS, if we say that command.com is DOS.
IO.SYS loads the GUI, and then IO.SYS remains largely dormant. This is not true
in the case of running a DOS prompt, but otherwise this should be valid.

Yes, Win NT is much more of an independent OS than Win9X, but it is a great leap
past Win3.xx/MS-DOS.
Also, WinNT has some disadvantages, DOS programming under WinNT is near to
impossible, due to the fact that direct device access is disallowed. This is
(AFAIK) due to the fact that NT was intended to be cross-platform, and each
platform requires it's own drivers. You get a standardized interface into a
device, but only through a driver.

Martin Stromberg wrote:

> Ralph Proctor (ralphgpr AT shadow DOT net) wrote:
> : Windows 95 ++ is an independent operating system with added GUI features.
> : (Windows 95 ++ is NOT a GUI dependent upon DOS.)
>
> I'd say this isn't true. WINDOZE 4.1 (98) first boots DOZE 7.x and then the
> GUI on that. This can easily be seen by adding the right line to MSDOS.SYS.
> I don't remember exactly how the line looked like, but it was something like
> BootGUI=0.
>
> Right,
>
>                                                         MartinS