Path: utzoo!attcan!uunet!cs.utexas.edu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca!neufeld
From: neufeld@physics.utoronto.ca (Christopher Neufeld)
Newsgroups: comp.sys.apple2
Subject: Re: an Idle Apple...
Message-ID: <1990Nov11.125417.16301@helios.physics.utoronto.ca>
Date: 11 Nov 90 17:54:17 GMT
References: <*D$^=0+@rpi.edu> <1990Nov9.195818.26230@helios.physics.utoronto.ca> <14416@smoke.brl.mil>
Organization: University of Toronto Physics/Astronomy/CITA
Lines: 33

In article <14416@smoke.brl.mil> gwyn@smoke.brl.mil (Doug Gwyn) writes:
>In article <1990Nov9.195818.26230@helios.physics.utoronto.ca> neufeld@physics.utoronto.ca (Christopher Neufeld) writes:
>>suddenly it showed seven chips bad out of eight ...
>
>That's too much of a coincidence to be acausal.  There are several causes
>I could imagine, among them static discharge damage from previous handling
>of the chips, or a defective memory addressing support chip external to
>the RAM itself (one of 8 permutations of three bits would be matched by
>a "stuck" chip controlling those chips).

   Well, from the time I got my AE card and began running ][GS specific
applications on it, they were crashing. Usually it began by fouling up
the graphics. On _The Bard's Tale_ it would start to scramble the view
window shapes, starting with random dots appearing on the view of the
city, and progressing to sudden dislocations (bottom half of the shape
shifted thirty pixels to the right), then finally just random noise
filling the window. Usually around then the computer would click a few
times and die completely.
   Anyway, after I replaced the eight RAM chips, it worked fine. No more
problems at all in the three years since then. I doubt that it could be
caused by a chip other than one of the RAMs. I just figured that I'd got
a bad batch of chips which had been mishandled between TI and AE. After
that, though, I recommended to people that they buy their RAM expansions
unpopulated. You have a better chance of a quick replacement if the
local chip store sold you some bad chips than you do if you have to send
it to Texas for a month, and then pick it up after it clears customs.


-- 
 Christopher Neufeld....Just a graduate student  |
 neufeld@helios.physics.utoronto.ca    Ad astra! |  S = k log W
 cneufeld@{pnet91,pro-micol}.cts.com             |    Boltzmann's epitaph
 "Don't edit reality for the sake of simplicity" |