Date: Mon, 25 Jan 1999 09:13:25 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Ralph Proctor <ralphgpr AT shadow DOT net>
cc: djgpp AT delorie DOT com
Subject: Re: DOS Box clear-up
In-Reply-To: <3.0.1.16.19990124133814.1d7f6a6e@shadow.net>
Message-ID: <Pine.SUN.3.91.990125091255.6041A-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Reply-To: djgpp AT delorie DOT com


On Sun, 24 Jan 1999, Ralph Proctor wrote:

> 1. boot up
> 2. bring up windows (and do whatever)
> 3. get out of windows by alt-F4 or the file menu. Window is now OFF!!
> 4. you are now back in DOS.

With Windows 9X, this is impossible to do.  (Well, actually, it's
possible, if you try hard enough, but IMHO it isn't worth it.)  When
you boot the machine, you can boot into plain DOS or into Windows; in
the latter case, you can't exit back to DOS, you can only do one of
these:

      1. shut down the machine;
      2. reboot it;
      3. go to so-called ``DOS mode''.

The last alternative leaves a small Windows module resident in memory,
shuts down all other programs and Windows itself, and dumps you to the
DOS prompt.  When you say "EXIT", the resident module restarts
Windows.

Personally, I suggest to run all DOS programs inside Windows.  Windows
is quite good at running multiple DOS programs (much more stable than
at running Windows programs, actually), so as long as the program will
run under Windows, either in a windowed session or in a full-screen
session, I suggest to stick to that.

If a program such as a flight simulator can only be run in plain DOS,
I suggest to reboot the machine to DOS, and when you are finished,
reboot again into Windows.  I don't know how good the ``DOS mode''
described above is, but you don't lose much (except some time needed
for reboot) by simply rebooting, since going to ``DOS mode'' shuts
down all other programs anyway.

> This problem has been confirmed by other programmers that know more about
> it. I cannot explain it except to say that Windows does not let go of some
> of its memory

Memory is probably not the cause here.

> I am afraid that this will ALWAYS be case with Windows95 whether you
> use a Win95 application or not before you work with your DOS code or
> run your DOS program.

Once again, if you run most of your DOS programs, including DJGPP
development tools, under Windows, you don't need to care too much
about this.  After all, Windows was born as a protected-mode DOS
multitasker, all the GUI mess was added much later.  So the part that
multitasks DOS applications is one of the most proven and stable parts
of Windows.  In fact, I'm running several large DJGPP applications
(Emacs and Info, among others) for days on end without shutting down
the machine, and Windows has never crashed on me.