Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!decwrl!mcnc!taco!lea.csc.ncsu.edu!bank
From: bank@lea.csc.ncsu.edu (Belgarath the Sorcerer)
Newsgroups: comp.sys.ibm.ps2.hardware
Subject: Re: Why only 3968K OK ?  4096K installed
Message-ID: <1991Apr7.183620.23731@ncsu.edu>
Date: 7 Apr 91 18:36:20 GMT
References: <1991Apr5.062809.1964@brolga.cc.uq.oz.au>
Sender: news@ncsu.edu (USENET News System)
Organization: /etc/organization
Lines: 34

In article <1991Apr5.062809.1964@brolga.cc.uq.oz.au> exnirad@brolga.cc.uq.oz.au (Nirad Sharma) writes:
>
>  I have been having all sorts of problems with my Model 80 recently.
>My 8M memory expansion board was molested and needed resocketing by a
>technician.  This is merely a tale of woe.
>
>  My real question,  however,  is why does my machine with 4M of memory
>on the system board  (forget the before-mentioned memory card - its in a
>workshop somewhere :( )  boot up with only 3968K OK ?  Diagnostics etc
>says that 4096K is installed on the system board.
>-- 
>
>
>Nirad Sharma  (exnirad@brolga.cc.uq.oz.au)		Phone : (61 7) 365 7575
>Systems Programmer					Fax :	(61 7) 870 5080

   This threw me too for a while on my Mod 70 (also w/4 MB). After
tinkering a bit I figured it out.

   The system, when it fonds itself with plenty of memory to play
with (and 4 MB qualifies), automagically does BIOS shadowing (i.e.

reserves a chunk of RAM and copies ROM BIOS into that to improve speed
since DRAM is faster than ROM). So yes you have that memory, but to
improve performance the computer reserves a chunk for itself.
 
Belgarath
       h
   Sorcerer
bank@lea.csc.ncsu.edu

DISCLAIMER: The above Post represents an honest effort by me to impart
            information I know, or reasonably know, to be true. All
            other interpretations are in error.