Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : QWAUG92.ZIP
Filename : LARGCONT.TEC

 
Output of file : LARGCONT.TEC contained in archive : QWAUG92.ZIP
ID:LC QEMM-386: Getting large contiguous regions of High RAM
Quarterdeck Technical Note #244
By Greg Goode
Last revision: June 8, 1992

So you want large contiguous regions of High RAM for TSRs and device drivers
that don't have enough space to load high? Well there are many methods for
getting those large High RAM regions.

Use QEMM's Stealth feature. QEMM's Stealth feature is only available with
QEMM versions 6.00 and above. Stealth hides your PC's ROM code and maps High
RAM into the ROM address space, which is then available for loading TSRs and
device drivers. For more information on using QEMM's stealth feature, see your
QEMM manual. If you have trouble using Stealth, get Quarterdeck's Technical
Note #205, "Trouble-shooting Stealth."

This technote gives detailed information regarding the use of QEMM's Stealth
feature, and provides tips for using Stealth on your system. Technotes may be
obtained from the Quarterdeck BBS (310-314-3227), by calling QFAX (our
automated FAX-back service, at 310-314-3214: call and request by number), on
Compuserve (GO QUARTERDECK, library 2), or BIX. Many technotes are also
available on large local BBSs, often in "DESQview" or "multitasking" file
areas.

If you are using a version of QEMM that does not support the Stealth feature,
there are other methods for gaining those large High RAM regions. If the
applications that you use do not need expanded memory, you can disable QEMM's
ability to provide expanded memory. Since expanded memory is accessed via a
64k page frame, by disabling expanded memory you will gain 64k of High RAM.
To disable expanded memory, you must add the NOEMS parameter to the line that
loads QEMM. This line is located in your config.sys file. The line that
would need editing looks something like this:

DEVICE=C:\QEMM\QEMM386.SYS RAM

Disabling expanded memory in the above example would make the line look like
this:

DEVICE=C:\QEMM\QEMM386.SYS RAM NOEMS

Please note that adding the NOEMS parameter to the QEMM line will mean that
your system will be unable to use expanded memory. You will also be unable to
use QEMM's Stealth feature, since this option requires an EMS page frame.

Another method for gaining more High RAM, and potentially larger High RAM
blocks is to run through QEMM's Analysis procedure. Analysis suggests command
line parameters that could be given to QEMM to more efficiently use high
memory. For more information on QEMM's Analysis, refer to Manifest manual
(look in the "Analysis" section of the "QEMM-386" chapter or the QEMM manual
(look in the "Analysis" section of the "QEMM.COM" chapter).

The above 3 methods for getting larger High RAM regions involve increasing the
amount of High RAM available. But you may have plenty of High RAM, but
because it is broken up into different High RAM regions, no one region is
large enough to initialize and load your large TSRs or device drivers. This
may be due to the hardware on your system using high memory addresses for
their own use. Many adapters (such as network cards and disk controllers)
use addresses into which QEMM could map High RAM, and the area that they use
could be right in the middle of what would otherwise be a large High RAM
region.



Fortunately, many adapters have the ability to change which area of High
RAM they occupy. For example, suppose you have a network card that is
configured to use the address space D000-D3FF for its adapter ram. Let us
further suppose that you have 32k of High RAM available from C800-CFFF and
48K of High RAM available from D400-DFFF. If you were to move the network
adapter's 16k of adapter ram to C800-CBFF, the previously used address of
D000-D3FF would become available as High RAM. Hence, the entire 80k region
from CC00-DFFF would become available as one large High RAM block.

Using the techniques described above could potentially give you a single
contiguous High RAM region as large as 191 kilobytes.

************************************************************************
* Trademarks are property of their respective owners. *
*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 *
************************ E N D O F F I L E *************************



  3 Responses to “Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : QWAUG92.ZIP
Filename : LARGCONT.TEC

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

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