My comments and questions. Dave McGuire posted:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice. Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google..... http://www.jmargolin.com/patents/eprom.htm references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent. This suggests that X-rays were not a production nor a customer practice. so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time? That's how UV exposure is cited (when it was cited in detail) in data sheets. I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application. I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you. Herb Johnson -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net
On 05/27/2016 11:02 AM, Herb Johnson via vcf-midatlantic wrote:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice.
There is no accepted practice, but you and I know theory and physics, so we know it's possible. We've also read the documentation you referenced below and know it had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google.....
http://www.jmargolin.com/patents/eprom.htm
references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent.
This suggests that X-rays were not a production nor a customer practice.
Yup. But we already knew that. ;)
so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time?
No. I never said there were commercial products or production parts that were intended to be erased with X-rays. I get the strong impression that you think I asserted that there were production EPROMs which were intended to be erased in the field using X-rays. I made no such assertion.
I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application.
I think we can assume it had been done in the development lab because the developer states that it "caused" a problem. Not "could cause", "may cause", but "caused".
I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you.
I have no idea if anyone has tried it outside of the original development lab. But I have an X-ray system, I could certainly try it in my lab, or facilitate such experimentation here for others who have more free time than I do. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
Oh, hey, somebody need an X-ray machine? Just see Dave! LOL On Fri, May 27, 2016 at 11:46 AM, Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 05/27/2016 11:02 AM, Herb Johnson via vcf-midatlantic wrote:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice.
There is no accepted practice, but you and I know theory and physics, so we know it's possible. We've also read the documentation you referenced below and know it had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google.....
http://www.jmargolin.com/patents/eprom.htm
references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent.
This suggests that X-rays were not a production nor a customer practice.
Yup. But we already knew that. ;)
so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time?
No. I never said there were commercial products or production parts that were intended to be erased with X-rays.
I get the strong impression that you think I asserted that there were production EPROMs which were intended to be erased in the field using X-rays. I made no such assertion.
I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application.
I think we can assume it had been done in the development lab because the developer states that it "caused" a problem. Not "could cause", "may cause", but "caused".
I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you.
I have no idea if anyone has tried it outside of the original development lab. But I have an X-ray system, I could certainly try it in my lab, or facilitate such experimentation here for others who have more free time than I do.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
LOL? But yes, there's an X-ray machine here. (non-dental) I also have two dental X-ray machines, which I'd be more than happy to work out a deal for, if anyone is interested. -Dave On 05/27/2016 01:32 PM, Chris Fala via vcf-midatlantic wrote:
Oh, hey, somebody need an X-ray machine? Just see Dave! LOL
On Fri, May 27, 2016 at 11:46 AM, Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 05/27/2016 11:02 AM, Herb Johnson via vcf-midatlantic wrote:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice.
There is no accepted practice, but you and I know theory and physics, so we know it's possible. We've also read the documentation you referenced below and know it had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google.....
http://www.jmargolin.com/patents/eprom.htm
references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent.
This suggests that X-rays were not a production nor a customer practice.
Yup. But we already knew that. ;)
so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time?
No. I never said there were commercial products or production parts that were intended to be erased with X-rays.
I get the strong impression that you think I asserted that there were production EPROMs which were intended to be erased in the field using X-rays. I made no such assertion.
I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application.
I think we can assume it had been done in the development lab because the developer states that it "caused" a problem. Not "could cause", "may cause", but "caused".
I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you.
I have no idea if anyone has tried it outside of the original development lab. But I have an X-ray system, I could certainly try it in my lab, or facilitate such experimentation here for others who have more free time than I do.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
-- Dave McGuire, AK4HZ New Kensington, PA
There's a package inspection X-Ray machine at a recycler near me in VA. It works... and I bet they would take $50 for it. On Fri, May 27, 2016 at 1:32 PM, Chris Fala via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Oh, hey, somebody need an X-ray machine? Just see Dave! LOL
On Fri, May 27, 2016 at 11:46 AM, Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 05/27/2016 11:02 AM, Herb Johnson via vcf-midatlantic wrote:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice.
There is no accepted practice, but you and I know theory and physics, so we know it's possible. We've also read the documentation you referenced below and know it had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google.....
http://www.jmargolin.com/patents/eprom.htm
references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent.
This suggests that X-rays were not a production nor a customer practice.
Yup. But we already knew that. ;)
so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time?
No. I never said there were commercial products or production parts that were intended to be erased with X-rays.
I get the strong impression that you think I asserted that there were production EPROMs which were intended to be erased in the field using X-rays. I made no such assertion.
I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application.
I think we can assume it had been done in the development lab because the developer states that it "caused" a problem. Not "could cause", "may cause", but "caused".
I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you.
I have no idea if anyone has tried it outside of the original development lab. But I have an X-ray system, I could certainly try it in my lab, or facilitate such experimentation here for others who have more free time than I do.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
-- Jason Perkins 313 355 0085
FYI, at least one "package inspection" X-ray machine is identical, except for the sticker on the front, to a model marketed to assembly firms for weld inspection and PCB inspection. Mine is such a machine. Needless to say it was a very good deal. =) These are awfully, awfully heavy though...much more so than their size would suggest, due to all the lead. Be careful. -Dave On 05/27/2016 01:35 PM, Jason Perkins via vcf-midatlantic wrote:
There's a package inspection X-Ray machine at a recycler near me in VA. It works... and I bet they would take $50 for it.
On Fri, May 27, 2016 at 1:32 PM, Chris Fala via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Oh, hey, somebody need an X-ray machine? Just see Dave! LOL
On Fri, May 27, 2016 at 11:46 AM, Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 05/27/2016 11:02 AM, Herb Johnson via vcf-midatlantic wrote:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice.
There is no accepted practice, but you and I know theory and physics, so we know it's possible. We've also read the documentation you referenced below and know it had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google.....
http://www.jmargolin.com/patents/eprom.htm
references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent.
This suggests that X-rays were not a production nor a customer practice.
Yup. But we already knew that. ;)
so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time?
No. I never said there were commercial products or production parts that were intended to be erased with X-rays.
I get the strong impression that you think I asserted that there were production EPROMs which were intended to be erased in the field using X-rays. I made no such assertion.
I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application.
I think we can assume it had been done in the development lab because the developer states that it "caused" a problem. Not "could cause", "may cause", but "caused".
I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you.
I have no idea if anyone has tried it outside of the original development lab. But I have an X-ray system, I could certainly try it in my lab, or facilitate such experimentation here for others who have more free time than I do.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
-- Dave McGuire, AK4HZ New Kensington, PA
Perhaps we are drifting off topic here... the machine that's local to me is from the late 70s. It has no camera system, you put your face up to a viewing window and peer in (!!!). I'd want to be sure I wasn't irradiating myself before using the machine. On Fri, May 27, 2016 at 1:37 PM, Dave McGuire via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
FYI, at least one "package inspection" X-ray machine is identical, except for the sticker on the front, to a model marketed to assembly firms for weld inspection and PCB inspection. Mine is such a machine. Needless to say it was a very good deal. =)
These are awfully, awfully heavy though...much more so than their size would suggest, due to all the lead. Be careful.
-Dave
On 05/27/2016 01:35 PM, Jason Perkins via vcf-midatlantic wrote:
There's a package inspection X-Ray machine at a recycler near me in VA. It works... and I bet they would take $50 for it.
On Fri, May 27, 2016 at 1:32 PM, Chris Fala via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Oh, hey, somebody need an X-ray machine? Just see Dave! LOL
On Fri, May 27, 2016 at 11:46 AM, Dave McGuire via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 05/27/2016 11:02 AM, Herb Johnson via vcf-midatlantic wrote:
They can be erased with X-rays. EPROMs were originally designed to be erased that way. There are problems with that approach, however. (hence the move to UV).
The notion that one can plop non-quartz PROMs under an X-ray and erase them, has been mentioned here, and elsewhere for decades, as a "could be done". But I'm not aware this has been, or is, any sort of common practice, much less an established procedure. I'm aware of 'theory', I know physics. I'm talking accepted practice.
There is no accepted practice, but you and I know theory and physics, so we know it's possible. We've also read the documentation you referenced below and know it had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Wikipedia....EPROM...citation 6...is a May 10 1971 article from Electonics Magazine by Dov Frohman, who apparently "invented the EPROM". Google.....
http://www.jmargolin.com/patents/eprom.htm
references the article, and interviews the author later in 1993. The text say Intel shipped that 1702 EPROM "with a window because X-rays ....disrupted the structure" of the chip. The Web page has some details. I"ve not (yet) read the article, or checked the patent.
This suggests that X-rays were not a production nor a customer practice.
Yup. But we already knew that. ;)
so: Can you cite a reference I can find also, that shows a product announcement, or a production data sheet, that says specifically that a customer can erase a specific PROM product using X-rays of a particular wavelength and energy for a particular period of time?
No. I never said there were commercial products or production parts that were intended to be erased with X-rays.
I get the strong impression that you think I asserted that there were production EPROMs which were intended to be erased in the field using X-rays. I made no such assertion.
I'll grant the possibility this occurred for some very early product, some early development in the semiconductor lab, or some military or other specialized application.
I think we can assume it had been done in the development lab because the developer states that it "caused" a problem. Not "could cause", "may cause", but "caused".
I'll grant some hackers could borrow a dental X-ray and erase an EPROM - did they do subsequent life-tests? Even that description would be of interest. Thank you.
I have no idea if anyone has tried it outside of the original development lab. But I have an X-ray system, I could certainly try it in my lab, or facilitate such experimentation here for others who have more free time than I do.
-Dave
-- Dave McGuire, AK4HZ New Kensington, PA
-- Dave McGuire, AK4HZ New Kensington, PA
-- Jason Perkins 313 355 0085
On 05/27/2016 01:43 PM, Jason Perkins via vcf-midatlantic wrote:
Perhaps we are drifting off topic here... the machine that's local to me is from the late 70s. It has no camera system, you put your face up to a viewing window and peer in (!!!).
Many (most?) current package inspection X-ray systems are exactly that type of setup, including mine.
I'd want to be sure I wasn't irradiating myself before using the machine.
There's essentially no risk. The dangers of X-ray exposures were known long before the 1970s. If it was built for commercial sale by that time, it's fine. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
I'm persisting, because this "x-rays to erase EPROMS" keeps getting talked about, decade by decade. But it is just - plain - impractical, and never WAS practical, but most certainly was not approved by the manufacturers in products. Please note my qualifiers. But as generally asserted - "you could do it" or "it was done", I believe is improper history in particular, and therefore appropriate to discuss here. Dave McGuire posted a response, but he overlooked my point. Dave's comment can be summarized in this excerpt:
We've also read the documentation you referenced below and know [x-ray erasure] had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Dave, my point is to debunk the idea that X-rays were EVER intended to be a way to erase EPROMS, except as some early lab result or research idea. "Intention for the product" says to me "we are developing a product that will include use of X-rays to restore the product to an unprogrammed state", with the implication that it would be within its *production design* and *approved customer use* to be erased that way. But it wasn't. So X-rays were never recommended or used *in practice*. Practice, Dave, not that someone didn't TRY it at some point. The "erasable" 1702 was designed for production with a quartz window, so the customer or factory could erase the EPROM, by specified light, time, and energy. That's "production", that's "accepted practice". It's on the data sheets! Dave, do you see my point? Conversely, even the references I barely read today - one a second-hand account from the Intel inventor! - suggests the inventor (or one of them) determined early on, that X-rays sufficient to erase the device inside then-conventional packaging (plastic or ceramic I suppose), so disrupted the crystalline structure, that "annealing" was needed (high temperatures which would melt any plastics) to restore the device to some determined condition-for-sale and use. Therefore, the then-unconventional use of a quartz window, to admit UV photons of sufficient frequency to "knock" electrons out of the virtual well of charge (no physics lecture today). http://www.jmargolin.com/patents/eprom.htm reports a 1971 article by Frohman (Intel's designer of the EPROM) is quoted to describe how a "package is sealed, information can still be erased...by X-ray...with commercial X-ray generators". BUT - the above Web page carries an interview - by the Web page author so it's second-hand - with the author in 1993. And Frohman said in 1993 as paraphrased: (quoting the reportage) "they ended up deciding to ship the part with a window because erasing the EPROM with X-rays created surface states in the silicon that required annealing." Annealing is described as a process above 450 degrees Celsius. Need I explain the impact of 450 C upon a plastic package? Or guess the impact upon a sealed ceramic package? the melting temperature of solder, expoxies, etc? Dave, I can probably erase an EPROM with *fire*, but I don't expect it to work afterwards! That's MY "read of the documentation", David. Frohman's patent, filed in 1971: https://www.google.com/patents/US3744036 discusses EPROM structure and programming - not erasure, so it's not helpful. And it could be, Dave, that "erasure" was an afterthought. Most "programmable memories" of the period were not "erasable". While the patent cites many published research papers, I'm not gonna find those papers today, they may be paper-only and not Web accessible; and I have other things to do. But my assertion is: Intel NEVER released the part to be erased by X-ray. I assert nobody else did, either. *That is my point.* Never released. For use. To be erased. By customers. With X-rays. It's possible I'm wrong, but I'll take that bet. I think the burden is on you, to give a positive example. Not on me, to "prove a negative". There's no point in saying "X-rays can in principle can erase EPROMS", if the result of erasure is to so damage the device that it's not reliable, won't meet specification of use it not *lifetime*. Even the patent I referenced gave a "ten year" lifetime for programmed content. Again - programming it once, in the field, may have been considered sufficient for use. ------------------- I"ve posted the same statements twice, so I'm done with the (sub)topic. I've stated and clarified my position. Dave McGuire is welcome to respond, perhaps he misunderstood the limits of my counter-claim. Or has positive evidence. 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. Herb Johnson -- 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
On 05/27/2016 03:23 PM, Herb Johnson via vcf-midatlantic wrote:
I'm persisting, because this "x-rays to erase EPROMS" keeps getting talked about, decade by decade. But it is just - plain - impractical, and never WAS practical, but most certainly was not approved by the manufacturers in products. Please note my qualifiers.
Yup, I think we're all in agreement here.
We've also read the documentation you referenced below and know [x-ray erasure] had been done, and was originally the intention for the product, but the approach had problems, so they moved to an alternative method of erasure.
Dave, my point is to debunk the idea that X-rays were EVER intended to be a way to erase EPROMS, except as some early lab result or research idea. "Intention for the product" says to me "we are developing a product that will include use of X-rays to restore the product to an unprogrammed state", with the implication that it would be within its *production design* and *approved customer use* to be erased that way.
But it wasn't. So X-rays were never recommended or used *in practice*. Practice, Dave, not that someone didn't TRY it at some point.
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. I NEVER said it was a production technique. I NEVER said it was an "accepted" (by whom?!) process. I NEVER said it was a good way to do it. I NEVER said it would help one lose weight, keep away pimples, keep one's dog from crapping on the floor, or anything else. I ONLY said IT IS POSSIBLE. Further, unless Dov Frohman can be reached and simply asked about this (which I will pursue independently), we will never know for sure if it was the INTENTION or PLAN that EPROMs be erased with X-rays. However, we know their team investigated it.
The "erasable" 1702 was designed for production with a quartz window, so the customer or factory could erase the EPROM, by specified light, time, and energy. That's "production", that's "accepted practice". It's on the data sheets! Dave, do you see my point?
I do. But Frohman's description of the process in which they decided to put a window in what we can reasonably assume to have previously considered to be an unwindowed package, like every other IC built up to that point, suggests strongly to me that it was the original intention. Note well, once again, that I never said it was a practical production technique.
reports a 1971 article by Frohman (Intel's designer of the EPROM) is quoted to describe how a "package is sealed, information can still be erased...by X-ray...with commercial X-ray generators".
Yes. Which is exactly what I said originally.
BUT - the above Web page carries an interview - by the Web page author so it's second-hand - with the author in 1993. And Frohman said in 1993 as paraphrased: (quoting the reportage) "they ended up deciding to ship the part with a window because erasing the EPROM with X-rays created surface states in the silicon that required annealing." Annealing is described as a process above 450 degrees Celsius.
Need I explain the impact of 450 C upon a plastic package? Or guess the impact upon a sealed ceramic package? the melting temperature of solder, expoxies, etc? Dave, I can probably erase an EPROM with *fire*, but I don't expect it to work afterwards!
Of course. I don't think anyone ever mentioned plastic packages though.
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 process! -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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 process!
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. The end. herb -- 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
On 05/30/2016 12:45 PM, Herb Johnson via vcf-midatlantic wrote:
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 process!
I'll be brief and answer your question, Dave - the issue is not what's possible, it's what is practical and productive.
Wrong. What was said was what is "possible". Nothing more, and nothing less. After that, you repeatedly attempted to steer the conversation toward what is practical and productive, over and over, and I have said "no" each time.
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".
No. I wanna, but I'm working three contracts right now and don't really have the time to put into it. If anyone here would like to explore it further, I will provide access to my lab for that purpose, which includes all of the equipment necessary to research this topic exhaustively. The only thing I don't have is X-ray crystallography equipment to examine the lattice, but if we have to go that far, we can probably rent that. But further, I never even actually said "if I wanna". I said, as I keep explaining, over and over, that "it is possible". Now that I've clarified this yet again, can we drop it? -Dave -- Dave McGuire, AK4HZ New Kensington, PA
Wow, that was a doosie, and no subject change either. Just sayin' What was that source for eproms anyway?
participants (5)
-
Chris Fala -
Dave McGuire -
Douglas Crawford -
Herb Johnson -
Jason Perkins