[comp.sys.ibm.pc] QEMM and PC-CACHE with memory board

simon@hpspwr.enet.dec.com ("Curiosier and Curiosier...") (04/16/91)

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My 386SX PC has 4 MB RAM -- maximum that can be installed on the 
motherboard.  I added a 2 MB memory board that is configured as all 
extended, starting where the motherboard ends, and let QEMM 5.12 
handle all the memory.  The idea is to use additional memory as a 
disk cache.  The setup screen reports 640K conventional memory and 
5504 extended.  

The problem:

Since the memory on a 16-bit board is considerably slower then the 
motherboard's, I wanted to install a 1024K PC-Cache from the top.  
PC-Cache has a parameter "/EXTSTART=xxxx -- Don't use memory below 
xxxx K" (in my case it is 4480).  However, if I use this parameter, 
PC-Cache reports that it is successfully installed at 4480, and hangs 
solid.  Only the cold boot and a DOS floppy return it back to life.
Removing this parameter lets me install PC-CACHE at 1024, which is what 
I am trying to avoid.

Use of the Manifest revealed that QEMM uses extended memory from *the 
top*, which means that I cannot use the expansion memory board for 
caching.  The Quarterdeck people told me that this is due to DOS 
limitations.  Is there a way around?

Any suggestions will be appreciated.

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Leo Simon			simon@pwrvax.enet.dec.com

Who is not liberal when young, does not have a heart.
Who is not conservative when old, does not have a brain.

				-- Attributed to many