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634.6K free!

When I want to impress people with my computer, I first tell them how many files, buffers, device drivers and TSR (terminate-and-stay-resident programs) are loaded. I then type the DOS command MEM/C and DOS comes back with a message that I have 634.6k free and that the largest executable program can be 634.5k. How can I have that much memory free considering the 640k DOS limit and the fac that the TSRs, the device drivers (including network drivers if you are on one) and DOS features must take a few hundred k of space to load? The secret is Quarterdeck's newest memory manager QEMM which uses the ability of DOS version 5.0 (or higher) to load most of itself into high RAM, that wasteland above 640k at the top of the first Meg.

QEMM comes with a simple installation program. In my case, it tried more than 8 million combinations to get the best memory configuration and that job only too a few seconds. In the process, the AUTOEXEC.BAT and CONFIG.SYS files were modified for future start-ups.

Why would you buy a memory manager when DOS comes with one? The one in DOS is very primitive and not really able to work with large numbers of TSRs or splitting memory between extended and expanded RAM.

With DOS 5.0 alone, the best configuration showed 624.9k free with 612.8k available for the largest executable program. It was unable to handle all the TSRs and if the others or some network drivers were loaded into low RAM, there would not be enough room to load a big program such as WordPerfect 6.0. I also had to tell it how much RAM to assign rather than let it find out for itself an that took about six attempts.

When I tried mixing extended and expanded RAM, most of my attempts ended up wit a system lock-up. QEMM advertises 634k as achievable. With QEMM loaded, both my main system and my notebook did 0.6k better with loads of room for TSRs and drivers.

QEMM comes with a program called manifest, Entering MFT brings up screen after screen of data about memory usage. One thing you quickly realize is that QEMM has options for every idiosyncrasy your software might have. QEMM's Stealth option can adjust on the fly to optimize the memory requirements for each individual program. The manual is good, but if you have anything that is very unusual, you may be required to understand its needs to set the appropriate options.

After installing QEMM, I had a 3-Meg RAM disk in extended memory and set the rest as expanded. I saw only one problem. Printing with WordPerfect 5.1 became very slow, I talked to Quarterdeck's very helpful technical service people. The suggested that the stealth feature might be interacting with WordPerfect's printing routines, especially in my system where it was tied to FaceLift (ACCN, Sept. 1993). I simply deactivated stealth and the printing speed was back to normal. With 634.5k free, I didn't really see the need for it.
TABLE 1. Composite of two memory maps from Manifest showing how DOS allocates
space without a memory manager. This configuration has five TSRs.

Memory Area Size Description

0000 - 003F 1K Interrupt Area
0040 - 004F 0.3K BIOS Data Area
0050 - 006F 0.5K System Data
0070 - 13C7 77K DOS
13C8 - 14DE 4.4K COMMAND
14DF - 14E3 0.1K |Available~
14E4 - 14F4 0.3K COMMAND Environment
14F5 - 14FE 0.2K CAPSLOCK Environment
14FF - 1514 0.3K CAPSLOCK TSR
1515 - 151E 0.2K CARDFILE Environment
151F - 1611 3.8K SNIPPER TSR
1612 - 172A 4.4K SETUP2 TSR
172B - 1F85 33K CARDFILE TSR
1F86 - 28C1 36K |Available~
28C2 - 28CB 0.2K HDILOAD Environment
28CC - 2D7A 18K HDILOAD TSR
2D7B - 9FFF 458K |Available~ FREE SPACE

 Conventional memory ends at 640K

A000 - AFFF 64K VGA Graphics
B000 - B7FF 32K Unused
B800 - BFFF 32K VGA Text
C000 - C7FF 32K Video ROM
C800 - EFFF 160K Unused
F000 - FFFF 64K System ROM


Back in the old days, before memory managers, it was common to load TSRs when they were needed and remove them when they were not. A pair of public domain programs simplified that job and avoided rebooting. MARK inserted a memory marker where the TSR(s) started loading. When they were no longer needed, RELEASE would erase everything above that marker. With QEMM, RELEASE also erase some of the COMMAND.COM loaded into high RAM. Considering the amount of space QEMM frees up, I really don't need to go this route any more.

With the acquisition of the ATI card, it was necessary to load another TSR, HDILOAD to handle 8515/A graphics. I added it to the AUTOEXEC.BAT file and ran it once to check that everything did what it should. A quick look at my memory map showed that HDILOAD required 18k of DOS space. I then asked QEMM to optimiz and it moved HDILOAD into high RAM and I was back to 634.5.

A quick check with MFT showed I still had 61 k free in high RAM, i.e., lots of room for a few more. Needless to say, I was not very happy to remove it from th notebook after testing, but I had agreed to licensing terms that restricted its permanent installation to the one system after the test period.

During the preparation of this review, Quarterdeck made some modifications to accommodate a potential conflict problem. The new version is officially version 7.03. Check that the file creation dates show the time as 0703 h.

QEMM version 7.03: Quarterdeck Canada, 70 York Street, Toronto, ON; Tel: 416-360-5728; Fax: 416-360-4885.

The names of hardware and software mentioned in this review are trademarks of their respective developers.
TABLE 2. Composite of two memory maps from Manifest showing how QEMM and DOS
have located TSRs, Drivers and other DOS functions in conventional and high RAM
regions. This configuration has three device drivers plus five TSRs.

Memory Area Size Description

0000 - 003F 1K Interrupt Area
0040 - 004F 0.3K BIOS Data Area
0050 - 006F 0.5K System Data
0070 - 013D 3.2K DOS
013E - 0144 0.1K COMMAND
0145 - 0155 0.3K COMMAND Environment
0156 - 9FFF 634K |Available~ FREE SPACE

 Conventional memory ends at 640K

A000 - AFFF 64K VGA Graphics
B000 - B7FF 32K High RAM
B000 - B00D 0.2K DOS-UP QEMM
B00E - B158 5.2K DOSDATA QEMM
B15A - B1A3 1.2K RAMDRIVE DRIVER
B1A4 - B2AA 4.1K ANSI DRIVER
B2AB - B639 14K MOUSE DRIVER
B63A - B6BC 2K FILES DOS
B6BD - B6DD 0.5K WKBUFFER DOS
B6DE - B6E9 0.2K CAPSLOCK Environment
B6EA - B6FF 0.3K CAPSLOCK TSR
B700 - B70B 0.2K |Available~
B70C - B7FE 3.8K SNIPPER TSR
B800 - BFFF 32K VGA Test
C000 - C7FF 32K Video ROM
C800 - E7FF 128K High RAM
C800 - C8A1 2.5K QEMM386 QEMM
C8A3 - C926 2.1K QDPMI QEMM
C927 - C940 0.4K SETVER DOS
C941 - C951 0.3K FCBS DOS
C952 - C96E 0.5K LASTDRIV DOS
C96F - C977 0.1K INSTALL
C978 - CA0C 2.3K COMMAND DOS
CA0D - CA11 0.1K |Available~
CA12 - CA1D 0.2K CARDFILE Environment
CA1E - CB85 5.6K SETUP2 TSR
CB86 - D3E0 33K CARDFILE TSR
D3E1 - D3ED 0.2k HDILOAD Environment
D3EE - D89C 18K HDILOAD TSR
D89D - E7FF 61K |Available~
E800 - F7FF 64K Page Frame EXPANDED MEMORY
F800 - FFFF 32K System ROM
HMA 64K First 64K Extended
COPYRIGHT 1994 Chemical Institute of Canada
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1994 Gale, Cengage Learning. All rights reserved.

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Title Annotation:Software Review; memory manager QEMM
Author:Silbert, Marvin D.
Publication:Canadian Chemical News
Article Type:Evaluation
Date:Feb 1, 1994
Words:1236
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