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From: baffoni@aludra.usc.edu (Juxtaposer)
Newsgroups: comp.sys.atari.st
Subject: I need help! Bad memory ....
Summary: Which chip is highbank/bit 2??
Keywords: Memory problems
Message-ID: <16039@chaph.usc.edu>
Date: 23 Mar 91 05:04:38 GMT
References: <1991Mar21.065817.1799@convex.com> <352@uqcspe.cs.uq.oz.au> <1991Mar22.100329.25351@convex.com>
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 My ST started flaking out on me just recently.  After warming up, for
1/2 hour to 15 min., it would bomb out or become a nasty blob of random 
speckles.  So I used a memory checker on my memory and it is an intermittant
problem with the high-bank bit 2:  it expected A5A5 and got A7A5, or it 
expected E4BC and it got E6BC.  Anyway, I want to desolder the bad 256k chip,
but I don't know which of the 16 it is.  I have an original 520ST with RF
modulator, and the board is Revision B.  The addresses that it failed at were
0007FF74 to around 0007FD8C.  At present I only have 512k of memory.

 Please, if anyone can tell me the correct chip, and maybe a chart for
future reference, PLEASE EMAIL ME!  I think I'll go nuts without my ST!

 Thank you all MUCH in advance!

-Mike
baffoni@aludra.usc.edu
or
mbaffoni@skat.usc.edu