GM 2732 won't program

[Programmer]

Yep--shuffle between 27C32B and 27C32 by differing manufacturers seems to
solve it. Verifies "erased" just fine, but won't program passed the first
byte--or second (can't remember how far it gets). If I don't get further
results, they get turfed.

I've had absolutely no luck with the chips in a Fiero--they've got a raised
section on the chip with a window. I've also found a few of these in some
older cars...and they just don't talk to me.

Lyndon.
-----Original Message-----
From: Ludis Langens <ludis at cruzers.com>
To: gmecm <gmecm at efi332.eng.ohio-state.edu>
Date: October 16, 1999 2:50 AM
Subject: GM 2732 won't program


>Has anyone had problems programming GM 2732 EPROMs?  I tried to make
>some minor changes to the EPROM of a 1992 305 TBI.  The EPROM erased
>fine, but my programmer can't write to it.  After several tries, one
>byte programmed:  The byte that should have gone to 0x000 ended up at
>0x800.  I ended up using a 2732A that I had lying around.
>
>I tried programming voltages of both 21 and 25 volts.  Might the chip in
>question need 12.5?  My programmer doesn't support reading out the chip
>manufacturer code.  So I can't check the exact programming needed by
>this chip.  This GM EPROM probably was made by NatSemi.
>
>Incidentally, I have an old 2732B that I've never been able to program
>either.
>
>--
>Ludis Langens                               ludis (at) cruzers (dot) com
>Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
>