Re: CV Tech Piggy-Back RAM

[dmitton@mulberry.com (Douglas E. Mitton)]

Hi Again Kirk ...

There may also be a fix required on the CV Tech board ...

CV.TECH on GEnie described the fix to me some time ago (Oct. 93) so
that I wouldn't have to return the card via international mail.
Apparently in an attempt to lower the power consumption they used a
driver chip which wouldn't push all the 256x1 RAMs on a full blown
card.

The symptoms are random, frequent and constant memory test failures
and crashing of the GS.

The fix involves replacing the IC chip at location U34 from a 74HCT245
to a 74LS245 (available at Radio Shack).  The chip is soldered in BUT
its through hole technology so "not as complicated as surface mount".

I would temper this with anyone who has replaced an IC before could
fix this ... I installed a socket at the same time ... no real reason,
it just made me feel better.  THAT 20 PIN CHIP SOLVED THE PROBLEM!!!

Later!!!

kmitchel@nyx.cs.du.edu (Kirk Mitchell) wrote:

>Steve Townsend (steve.townsend@rook.wa.com) wrote:
>: Configurations!
>:     

>No, it works fine.  I've got a Sequential 4 Meg card in the pocket of 
>mine, and it works fine (though I got two, one for another GS I have, and 
>it DIDN'T work.  Evidently, Seq. has to make minor modifications to the 
>card to make it work w/ the CV Tech card, and I only had them do that to 
>one.  I couldn't tell which one it was.)

----------------------------------
Doug Mitton
 * In Brockville, Ontario, Canada
   (City of the Thousand Islands!)
EMail: dmitton@mulberry.com
       d.mitton@genie.geis.com
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