Problem erasing & re-using GM Proms

[Ludis Langens]

ECMnut at aol.com wrote:
> 
> Have anyone been able to erase a GM prom & reprogram it?
> I always have to solder a regular 27xxxx eprom on before I can
> re-program..  I can never seem to re-burn the factory original
> prom, which doesn't seem to have meaningful identifiers on it.
> My latest is a 27256 like thing from a '93 L35 4.3 engine.
> Could I be using the wrong programming voltage?

I had a 2732 that didn't program with a $170 (MSRP) programmer.  It
programmed fine with a $17000 (MSRP) programmer.  The EPROM turned out
to be a NatSemi/Fairchild 27C32B.  That chip wants to be programmed with
VCC = 6.25 volts.

Does your problem EPROM have the code 014 on it?  014 means NatSemi or
Fairchild.  It's likely that many of their chips are picky about their
programming conditions.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
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