[Coco] RE: 512 Upgrade
devries.bob at gmail.com
Tue Aug 8 22:25:26 EDT 2006
The coco3 service manual is on the maltedmedia ftp site.
Regards, Bob Devries, Dalby, Queensland, Australia
Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.
my blog: http://bdevries.invigorated.org/
----- Original Message -----
From: "Andrew" <keeper63 at cox.net>
To: <coco at maltedmedia.com>
Sent: Wednesday, August 09, 2006 11:42 AM
Subject: [Coco] RE: 512 Upgrade
> Longshot, but check for cold solder joints on the board itself. Also,
> try putting the 128K back in, jumper the caps you removed back in place,
> and make sure the machine still works as a 128K machine. If so, then it
> has to be the board, but if not - your CoCo may have problems of its own.
> Check CoCo3.com and/or Google for the CoCo 3 service manual - it might
> help out.
> Also, check for lifted traces, corrosion on solder joints, possible
> broken connections on the chips themselves and any other hinkyness with
> the board. Boards that old can get flakey. Plus, from what I remember,
> the RS upgrade wasn't the best to begin with.
> You might also try (though I have no clue if this is possible or if it
> can be done with the board?) to pull out 1/2 to 3/4 the memory from the
> board - what I am thinking is that one or more (but only maybe a couple)
> of the RAM chips are bad, and maybe you could get it to run (though
> maybe not perfectly, but enough to boot) as a 256 or 384K "upgrade". If
> so, then maybe swap in one chip at a time in the banks and see when it
> crashes/hangs. If this is even possible, of course (maybe someone here
> can tell us more if this is possible?)...
> -- Andrew L. Ayers
> Glendale (Phoenix), Arizona
> Coco mailing list
> Coco at maltedmedia.com
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