[vcf-midatlantic] Good source for eproms?
hjohnson at retrotechnology.info
Mon May 30 12:45:24 EDT 2016
Dave Mc Guire:
> Herb, seriously, I GET IT. I personally do not believe there was ever
> a practical method to erase EPROMs using X-rays. I only asserted that
> it is possible, which we both seem to believe that it is. Possible.
> That's all.
Herb and response:
>> Those interested can do their own research. If anyone finds positive
>> evidence for use of X-rays to erase EPROMS as a matter of approved
>> product use of production EPROMS, please please direct me to that
>> evidence. A weaker assertion, you can do it anyway and not goof up the
>> EPROM - with proof of lack of damage (tough to establish) - would be of
>> interest, too. Thanks for your patience, if you read this far.
> Wow! What's going on here, Herb? I never said it was a production
I'll be brief and answer your question, Dave - the issue is not what's
possible, it's what is practical and productive. I can't prove a
negative, period. And you can't prove the positive when you can keep
saying "I could do this if I wanna, I just don't wanna".
Those interested in rigorous argument, can look up "proving a negative".
So "possible" comes down to "I can put a chip under an X-ray - so I
win". I say, "you win a faulty chip, most likely". And that amounts to
my agreement with your proposition - as brief as I can be.
What's also going on, which is interesting to me, is the early history
of EPROMS, which noted X-rays could erase devices, but would damage the
devices. But UV radiation would erase without damage. It may be - if one
checks the history of developing electric-charge programmed EPROMS -
that their erasure and reprogram-ability was a happy accident, not an
initial research goal. Then it became a product feature.
The way I look at that question of history, goes like this. Many 21st
century people, look back at vintage computing, and ask questions like
"who invented erasable reusable EPROMs?", as though that was some design
goal, something that everyone wanted and was "racing" to achieve, etc.
I'm saying, like many other 1970's computing developments, it could have
been a consequence, not a goal.
I appreciate most don't care about formal argument methods, or early
origins of computing devices. Sorry for the prolonged discussion. But
the myth of X-ray erasure (of unwindowed devices) I consider busted as
"impractical, likely destructive" based on early-development evidence.
Herbert R. Johnson, New Jersey USA
http://www.retrotechnology.com OR .net
preservation of 1970's computing
email: hjohnson AAT retrotechnology DOTT com
alternate: herbjohnson ATT retrotechnology DOTT info
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