*BSD News Article 4547


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Newsgroups: comp.unix.bsd
Path: sserve!manuel!munnari.oz.au!uunet!decwrl!csus.edu!netcom.com!alm
From: alm@netcom.com (Andrew Moore)
Subject: Re: More on NMI problems.
Message-ID: <w9mnsvl.alm@netcom.com>
Date: Sat, 05 Sep 92 01:20:30 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 
Lines: 25

In article <1992Sep2.123248.17492@ponds.uucp> you write:
>Well, I got much advice on my NMI problems; indicating that I probably
>did, in fact, have a bad memory chip on my machine.
>
>So; I grabbed testext.exe from SIMTEL20 and let it have at the machine,
>to determine which chip was bad, etc....
>
>It ran for 38+ hours, without a single error (this program uses
>protected mode read/writes of words and double words, randomly scattered
>through available memory.)  Other people had sent me mail indicating
>this program found their problem, etc...

    If it is a bad chip, it may well not show up after 38 hours
    testing.  I ran (DOS-based) QAPlus _long_ memory test for several
    hours before an error showed up.  The short memory test never
    showed an error.  I.e., it depends on the pattern used to test
    memory.  You might never see an error under DOS, for instance, so
    beware!  On the other hand, the problem I had  was not a bad RAM
    after all, just a bad connection.  I solved the problem by removing
    the chips and spraying both RAM chips and RAM sockets with an
    electronics cleaner/degreaser (but no lubricant!).  This will be
    necessary whenever adding RAM to an old motherboard because of
    oxidation.  Good luck.  
    -Andrew Moore <alm@netcom.com>