X-Authentication-Warning:	acp3bf.physik.rwth-aachen.de: broeker owned process doing -bs
Date:	Thu, 28 Jan 1999 15:45:04 +0100 (MET)
From:	Hans-Bernhard Broeker <broeker AT physik DOT rwth-aachen DOT de>
X-Sender:	broeker AT acp3bf
To:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
cc:	djgpp AT delorie DOT com
Subject:	Re: Some Systems Defined
In-Reply-To:	<Pine.SUN.3.91.990127095755.25202J@is>
Message-ID:	<Pine.LNX.3.93.990128153810.8735E-100000@acp3bf>
MIME-Version:	1.0
Reply-To:	djgpp AT delorie DOT com

On Wed, 27 Jan 1999, Eli Zaretskii wrote:

> 
> On Tue, 26 Jan 1999, Hans-Bernhard Broeker wrote:
> 
> > The only *real* difference is that the DOS part of Win9x has
> > undergone substantial reduction of features and a redesign of some of
> > its behaviour since the previous release, DOS 6.2x.
> 
> There's no reduction in DOS features in DOS 7.x, AFAIK.  

It was the utility programs I had in mind. Unless you install some of them
manually after the Win9x installation, quite a number of DOS 'standard'
utilities are no longer there with DOS 7. For a start, there doesn't seem
to be a 'comp', nor an 'edlin' any longer, IIRC. Defrag, MSBackup and
Undelete are also gone, if I'm not very mistaken. Of course, many of them
had to go because of the LFNs, but some have just vanished into thin air. 

> > The second major difference is that the 'DOS command line' (windowed
> > or fullscreen) inside the running Windows 95 GUI is not really a
> > classical DOS box (Virtual machine running an instance of DOS'
> > command.com) any more. Instead, it now runs Win32 'console mode'
> > executables as well, and starts up a virtual DOS machine only if you
> > actually call a DOS program).
> 
> I don't think this is correct.  I think every DOS window starts a
> virtual machine with a separate instance of command.com.  

I do doubt that, even though I don't have much in the line of technical
details to prove it. *If* it really ist command.com, then that instance of
command.com must have a backdoor to Win32, otherwise I cannot see how it
could possibly surrender its screen to a win32 console mode application,
without losing track of what happened. 

> Otherwise,
> we couldn't have had a separate set of environment variables in each
> DOS window.

For a separate set environment, all that's needed is a separate process. 
The environment is not really global to the VM, after all, but local to
the running program, after all.


Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
Even if all the snow were burnt, ashes would remain.

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