From: ldlres00@ucs.usl.edu (Lafleur L Dwynn)
Newsgroups: comp.os.msdos.desqview
Subject: Conventional memory available - Desqview vs. Windows 3.1
Date: 3 Oct 92 14:33:55 GMT
Distribution: na
Organization: Univ. of Southwestern La., Lafayette


For a few weeks now, I have been playing with Desqview 386 (v. 2.42) and
Windows 3.1 in order to determine which I favor as a multitasker for DOS
applications.  Conventional wisdom has always been that if one does not wish to
use Windows applications (which I don't), DV is a better multitasker than
Windows.  It's supposedly (1) faster, (2) less prone to system lockup with
straight DOS applications, and (3) less of a memory hog.  I certainly agree
with (1). However, in my experience Windows 3.1 seems just as reliable as DV
with my DOS applications, so I'm not convinced on (2).  My concern in this
posting is point (3).

I've tried working both in DV (without Windows) and in Windows (without
DV).  It seems that whenever I am in Windows, QEMM's MANIFEST program shows
around 20-40 kilobytes more available conventional memory than when I am in
DV.  Realizing this is a complicated function of the CONFIG.SYS, what TSR's are
installed, etc., I ran a two-part experiment with a simplified system
configuration.

First, I booted up with the default CONFIG.SYS  and AUTOEXEC.BAT created by
installing MS-DOS 5.0.  I then installed the Desqview 386 (QEMM 386 plus
Desqview), letting them do what they wanted with CONFIG.SYS and AUTOEXEC.BAT.
Next I ran OPTIMIZE and rebooted the system.  I ran MANIFEST from the DOS
command line and noted 621 KB available conventional memory.  I then ran DV
and, while in DV, MANIFEST showed 587 KB of available conventional
memory.  Since the CONFIG.SYS created by DOS 5.0 contained the DOS=HIGH
statement, I repeated the process without that statement to allow DV to load in
HMA.  The result was 571 KB of available conventional memory.  [In a more
normal system configuration with a disk cache and other TSR's loaded high,
loading DOS in HMA usually yields less conventional memory (about 560 KB, as I
recall) than loading DV there.]

I then returned to the original DOS-5.0-created CONFIG.SYS and AUTOEXEC.BAT and
installed Windows 3.1, letting it modify those files as it wished.  It placed a
statement in AUTOEXEC.BAT installing SMARTDRV.EXE.  For comparison with the DV
experiment (in which no TSR's were installed) I removed that statement, and
rebooted.  I ran MANIFEST from the DOS prompt (outside Windows) and noted
621 KB available conventional memory.  Running Windows and then MANIFEST from
Windows, I observed 616 KB available memory.

Thus, in this experiment, the most available conventional memory I could get
under DV was 587 KB, but I could get 616 KB under Windows 3.1, both according
to MANIFEST.  Is this a legitimate experiment?  Is MANIFEST reading things
correctly?  Does this mean that Windows 3.1 really provides more conventional
memory for DOS applications than does Desqview, or is there a hidden memory
cost involved?

BTW, my system is a 33-MHz 486 with 4 MB ram, if that makes any difference.

I would appreciate any thoughts and criticisms.


L. Dwynn Lafleur
Professor of Physics
University of Southwestern Louisiana
lafleur@usl.edu
Newsgroups: comp.os.msdos.desqview