13 Dec
2017
13 Dec
'17
7:33 a.m.
My homemade 8080 CPM machine used a number of 2708 and 2716 EPROMs. that was 40 years ago.
This machine is still running and I use it, but since I had trouble with the EPROMs, I
switched to EEPROMs. I would also be interested in hearing about whether or not baking
would work and how to do the baking, exactly. I have a bunch of old EPROMs, that I figured
were dead, but maybe not??Mike Zahorik
From: Holm Tiffe via cctalk <cctalk at classiccmp.org>
To: dwight via cctalk <cctalk at classiccmp.org>
Sent: Wednesday, December 13, 2017 9:17 AM
Subject: Re: EPROM baking
Hmm..I've read about that baking in conjunction with 1702A too..but
don't remember the source of that discussion. I know that ppl suggested
it for proms that would'nt program correctly...
Regards,
Holm
dwight via cctalk wrote:
When I was at Intel, years ago, I recall the baking
was only to repair the retention of the EPROMs. It was not to fix random failures.
It sounds like your EPROMs have various failures that wouldn't be helped by baking.
Each time the EPROM is programmed, there is a slight increase in the leakage of the
floating gate. This was typical after thousands of program/erase cycles. Baking them
repaired the damage to the insulating layer that was damaged.
Dwight
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of william degnan via
cctalk <cctalk at classiccmp.org>
Sent: Wednesday, December 13, 2017 6:18:16 AM
To: Mark G Thomas; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: EPROM baking
On Wed, Dec 13, 2017 at 9:08 AM, Mark G Thomas via cctalk <
cctalk at classiccmp.org> wrote:
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Hi,
I am working on several projects requiring 2708 and 2716 EPROMs, and
am finding some of my chips will not erase, and some will not take
a program. I've also learned more in the past week than I wanted
to know about repairing Data-I/O 29a/b programmers.
I vaguely remember in the 1990s baking such EPROMs in the oven, but
I do not remember temperature or time. I was surprised that Google
didn't turn up anything useful with this info.
I'm sure someone here will have some notes on EPROM baking.
Mark
Mark,
If this is an issue about reviving bad eproms?? I assume you have tried the
regular stuff.
What process are you using now to erase 2708/16's?? I have a simple eraser
unit and it seems to always work.? Some eproms go bad but I never have
issues with erasing them.? My point is that maybe you need a better prom
eraser unit.? I would avoid baking them until you have exhausted other
options.? Not sure what others think.? This topic has come up before here,
about putting them outside and all that.? The erasers are all over ebay,
and the hardware store is full of the correct types of lighting, why not
make a box that will do the job?? ? I assume there is more to it that
simply erasing them.
Bill