ID:O2 Quarterdeck Products and OS/2 2.0
Quarterdeck Technical Note #264 Filename: OS2.TEC
by Todd Threadgill CompuServe: OS2.TEC
Last revised: 10/30/92 Category: SW3
Subject: Information on how IBM's OS/2 operating system relates to Quarterdeck
IBM's Operating System/2 version 2.0 (OS/2 2.0) is a protected-mode operating
system that provides some backward compatibility with existing DOS programs.
The purpose of this technical note is to discuss OS/2 2.0's compatibility with
The Quarterdeck Expanded Memory Manager-386 (QEMM-386) is a control program
device driver manages and controls all access to your computer's memory.
Since part of QEMM-386's job involves putting the computer in Virtual 86 mode
(a requirement for 386 expanded memory management), QEMM-386 will fail to load
under OS/2 2.0, since OS/2 has already placed the system in Virtual 86 mode
for running DOS sessions.
Quarterdeck's high-RAM manager (QRAM) is, like QEMM-386, a DOS device driver.
But unlike QEMM-386, QRAM works under OS/2 in specific conditions. While OS/2
itself provides the capability to load DOS device drivers for DOS sessions, our
testing has shown that this method is not as reliable as that of loading QRAM
with the assistance of the DEVICE.COM program included with DESQview.
DEVICE.COM lets you load device drivers (normally only loadable from the
CONFIG.SYS file) from the command prompt. So, in order to use QRAM under
1. Open a DOS Window (or DOS Full Screen) session.
2. Change to your DESQview directory. (DEVICE.COM is only available as
part of the DESQview -- or DESQview 386 -- package.)
3. Type DEVICE C:\QRAM\QRAM.SYS RAM at the DOS prompt. (If QRAM is
installed in a directory other than C:\QRAM on your system, please
make the appropriate changes.)
QRAM will load, converting mappable areas between 640K (address A000h) and
1024K (address FFFFh) into High RAM, which can be used for loading programs by
Quarterdeck's LOADHI.COM program (included in the QRAM package).
The OPTIMIZE program, which automatically calculates your system's usage of
High RAM and configures your DOS CONFIG.SYS and AUTOEXEC.BAT files for optimum
memory usage, is incompatible with OS/2. OPTIMIZE requires that the system be
rebooted twice, so that it can analyze the CONFIG.SYS and AUTOEXEC.BAT files as
they are activated. Under OS/2 this is not possible for OPTIMIZE since the
system boots into OS/2 rather than directly into DOS. As a result, OPTIMIZE
will function properly only when run under DOS.
The Quarterdeck Expanded Memory Manager 50/60 (QEMM-50/60) is a memory manager
for IBM PS/2 Models 50, 50Z, and 60. Since these computers are based on the
80286 processor and OS/2 2.0 requires at least a 386SX processor, QEMM-50/60
and OS/2 2.0 cannot be used on the same machine.
DESQview version 2.42 has been tested with OS/2 2.0 and found to be compatible.
However, our testing has determined that the OS/2 expanded memory manager
(VEMM.SYS) does not currently allow mapping below 4000H in the conventional
memory area. Thus, users are limited to a maximum first DOS window size of
roughly 450K, and subsequent windows (for multitasking) are limited to 384K of
In OS/2, the Alt key brings up the current window's System menu. When using
DESQview inside OS/2, it is suggested that the DESQ key be reassigned to
something else (like Ctrl) in order to call up the DESQview menu more
conveniently. Please consult your DESQview manual for more information: look
for "System keys" in the index. For a more detailed explanation consult
technote #196, "systkeys.tec", "DESQview: Changing the System Keys".
Quarterdeck's Manifest reporting tool (version 1.14) has been found to be
compatible with OS/2 2.0. Since Manifest is a DOS program, it must be run in
a DOS session when used with OS/2.
Our experience has shown that Manifest reports correct information in an OS/2
DOS session; however, there are some things that may appear strange or
inaccurate to users:
* DOS Version: OS/2 reports the operating system version differently
from DOS. The formula is as follows: (VER * 10), where VER is the
version that appears when the user types VER at the DOS or OS/2 command
line. So when using OS/2 version 2.0, the operating system version
reported will be 20.00. This is completely normal.
* First Meg memory timings under OS/2 2.0 are much quicker than those
reported under DOS 5.0, while Expanded Memory timings under OS/2 are
much slower than those of DOS 5.0. This is an accurate representation
of the facts, due to the different operating systems' use of memory.
In short, Manifest continues to report the activity inside the system
accurately, whether under DOS or OS/2 2.0.
*This technical note may be copied and distributed freely as long as it*
*is distributed in its entirety and it is not distributed for profit. *
* Copyright (C) 1992 by Quarterdeck Office Systems *
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