[Coco] Re: EPROM eraser wanted

[Bruce W. Calkins]

I wire wrapped the "Cooking With CoCo" version of EPROM Burner years ago.
(Hot CoCo Magazine or Color Computer Magazine.)  It worked, I burned several
2764s with it.  I needed to sit down and figure out the pin modifications
needed to burn 27128s half at a time.  As I recall the most expensive chips
were a pair of 6821s.  The most expensive part was the ZIF socket.

Programming voltage was controlled with a set of zener diodes across the
programming input.  Three 9 volt transistor batteries did the "high" voltage
work.

The last time I attempted to use it I had some problems with the software
which was always a bit cantankerous for me.  It insisted that it be loaded
from cassette, along with the file to burn.  (I've forgotten the order, but,
it was fussy about that too.)  I never did get it to load and run from disk
with the MPI as it was supposed to do.

Bruce W.


> Should anyone want to build an EPROM burner for the CoCo we could discuss
> this more and generate a minimal parts board. I would look for the start I
> did if it has not gotten lost for the prototype.
>
> Stephen H. Fischer