Path: utzoo!utgpu!watmath!iuvax!rutgers!cs.utexas.edu!steveb
From: steveb@cs.utexas.edu (Steve Benz)
Newsgroups: comp.unix.microport
Subject: Re: NMI in System Mode on System V/386
Summary: Also on 286
Message-ID: <668@dagora.cs.utexas.edu>
Date: 29 Jun 89 20:52:54 GMT
References: <781@cgh.uucp> <143800004@cdp>
Organization: U. Texas CS Dept., Austin, Texas
Lines: 18

In article <143800004@cdp> dfriedlander@cdp.UUCP writes:
> [ NMI in System Mode == memory problem ]
>It's true, diagnostics don't seem to pick up all memory problems.  
...
>
>I wonder if anyone understands why this sort of weirdness happens.

I have some experience with this one on the 286, it seems that
some memory expansion cards -- particularly those which haven't
got dip-switches or circuitry to determine the upper-bound of
memory -- don't work, and display exactly the symptoms that have
been described.

My theory as to why this problem occurs in Unix, but not in DOS
or in the diagnostics is that those two never try and do DMA to the
upper reaches of memory.

				- Steve