Path: utzoo!utgpu!watmath!att!dptg!rutgers!cs.utexas.edu!uunet!mcsun!sunic!kth!draken!d88-eli
From: d88-eli@nada.kth.se (Erik Liljencrantz)
Newsgroups: comp.sys.ibm.pc
Subject: Memory in Compaq 386
Message-ID: <1538@draken.nada.kth.se>
Date: 31 Aug 89 11:34:02 GMT
Reply-To: d88-eli@nada.kth.se (Erik Liljencrantz)
Organization: Royal Institute of Technology, Stockholm, Sweden
Lines: 29


  When computers are advertised with 1 Mb of RAM you always has to ask
what the not-for-DOS 384Kb are used for. Some computers has shadow RAM,
other turn the extra kilobytes into extended memory, while some 286
motherboards have logic to turn them into 384Kb expanded memory.

  However, in my new Compaq Deskpro 386/20e (no, I didn't spend the money,
my boss did...) the 384Kb are divided into two parts:
    128 Kb Compaq reserved memory
    256 Kb additional memory

  The 128Kb is possibly used for shadowing the BIOS, that's OK. The 256Kb can
be accessed by CEMM (and turned into expanded memory) but I can't use it
as extended memory. The manual mentions that the 256Kb's are mapped just
below the 16Mb boundary (and not just above the 1Mb boundary where I would
like them to be). CEMM is a memory hog. It consumes 33Kb conventional memory
and gives me 256Kb EMS memory. It also degrades the performance of the
CPU (from 33Mhz to 31Mhz according to Landmark).

Well, to my questions:
  Can I turn those 256Kb into normal extended memory?
  What happens if I take out the 1Mb memory module and inserts a 4Mb module?
  Any experiences with Turbo Debugger on this machine? (I mean TD386...)

Do you have the answers? Or more questions? Happy to hear from you! 
Preferably by email, if not of general interest...

  Erik Liljencrantz
  d88-eli@nada.kth.se