From: alheid@sedist.cray.com (Greg Alheid)
Newsgroups: comp.os.msdos.desqview
Subject: Re: Memory allocation question/problem
Date: 11 Nov 92 04:26:28 GMT
Organization: Cray Research, Inc.

In article <1992Nov10.043406.23955@cc.umontreal.ca>, duperval@ERE.UMontreal.CA (Duperval Laurent) writes:
|> Hi all,
|> 
|> I have stumbled upon something I find rather bizarre and annoying.  It's
|> probably something I overlooked or that I don't understand:
|>
|> I'm running DV 2.41.  I use 4Dos as my primary command interpreter.  I've
|> noticed that when I try to open a Big Dos window (512K) and I have more than
|> 512K available, all the memory will be taken from conventional memory.  At the
|> present time, I have 540K available and my window needs 512K.  The problem is
|> that the DOS window gobbles all available conventional memory and leaves me
|> 22K for all other programs.  Needless to say I loose all the rest of the
|> memory.  And it happens with most programs.  For example, Procomm Plus needs
|> 210K memory to run and when I start it, I lose those 210K of memory.
|> 
|> The bizarre part is that if I have less conventional memory available than
|> what the program needs, all the memory is taken from the Expanded memory
|> available.  In other words, if I want to run a DOS window and not lose all my
|> memory, I have to open a small window that leaves slightly less memory than
|> needed to run my DOS window and everything works fine.
|> 
|> What could explain this phenomenon?  How do I fix it?
|> 

   DESQview and QEMM are working correctly and there is no problem. 

  Don't be overly worried about the names being given to the different 
parts of the memory. DESQview was written to use memory provided by the
EEMS or LIM EMS 4.0 (EEMS is Enhanched Expanded Memory Standard and LIM 
EMS is Lotus/Intel/Microsoft Expanded Memory Standard). One of the main
features of these two standards allows "exPanded" memory to be mapped 
into the conventional memory address space if there is no real memory 
there. By doing this one can then "use" multiple copies of "swappable 
conventional memory" to run more programs at the same time. When QEMM 
came out, it also implanted this same LIM EMS 4.0 standard but instead 
of requiring "special" hardware, uses the virtual memory facilities of 
the 386/486 to do the same thing in software. 

  So don't think of exPanded memory provided by QEMM as a place to store 
data for Lotus 123, think of it as "swappable conventional memory" for 
programs that DESQview uses to multi-task with.

  One thing to be concerned about is that if you are using "Big DOS" to 
run a program you may be wasting "some memory" Since "Big DOS" "requests"
512K, that 512K will be taken out of the "available memory" and not be
available for any other use. For example you gave with Procomm Plus. If
you run it in 512K, 302K (512K - 210K) will be unused by Procomm Plus in
that window and no other program can use that memory. When you run Procomm 
Plus in a DV window that has been set up for it, it will use only the memory
allocated to it and the extra 302K will still be for other programs.

-- 
Greg Alheid
alheid@pittpa.cray.com 
QUIT
her programs.

-- 
Greg Alheid
alheid@pittpa.cray.com 
Newsgroups: comp.os.msdos.desqview