Bag-o-chips sorting, storing, testing
I looked at the photos of the donated chips. Most of them are plastic-bagged and labeled when in quantity. Generally, "what to do" is to make a PAPER list of those tags and bags, and keep it with the box o' bagged chips. Then you have a box of bagged chips with catalog. And in this matter, don't use plastic boxes, they generate static. Paper is fine; there's antistat boxes made too but that's excessive in this matter. Problem solved. A couple exceptions: Problem is, all the 4000 series chips that are CMOS, are now damaged by plastic static electricity. I suggest that for the 4000 series, they 1) be rebagged in antistatic bags and 2) tagged as "static damaged". I'm serious. TTL and LS and other non-CMOS chips, leave them in their plastic bags. Some bags had mixed chips embedded in anti-static foam. That foam degrades over decades, so make sure it's not too old (crumbly, melting, etc.) Then rebag in anti-static bags. Label the bags as to kind. If antistat foam is kept from air and moisture, it lasts longer. But it does degrade and should be replaced every decade (!). about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved. In the discussion, it was suggested to 'store these at CDL'. Frankly, I suggest *donating them to CDL*. They will put them to best use, and know how to use them. If VCFed needs chips, I presume they already turn to CDL for assistance. If CDL doesn't want these chips, that's entirely their discretion; if they will store them for VCFed anyway, that is very kind of them. I am not in charge of CDL or VCFed so these are merely policy suggestions. best regards, Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net
Herb, CDL has ESD safe bags - VCF can take as needed for conservation and storage. Martin Sent from my iPhone
On Apr 21, 2021, at 12:38 PM, Herb Johnson via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
I looked at the photos of the donated chips. Most of them are plastic-bagged and labeled when in quantity. Generally, "what to do" is to make a PAPER list of those tags and bags, and keep it with the box o' bagged chips. Then you have a box of bagged chips with catalog. And in this matter, don't use plastic boxes, they generate static. Paper is fine; there's antistat boxes made too but that's excessive in this matter. Problem solved.
A couple exceptions:
Problem is, all the 4000 series chips that are CMOS, are now damaged by plastic static electricity. I suggest that for the 4000 series, they 1) be rebagged in antistatic bags and 2) tagged as "static damaged". I'm serious.
TTL and LS and other non-CMOS chips, leave them in their plastic bags.
Some bags had mixed chips embedded in anti-static foam. That foam degrades over decades, so make sure it's not too old (crumbly, melting, etc.) Then rebag in anti-static bags. Label the bags as to kind. If antistat foam is kept from air and moisture, it lasts longer. But it does degrade and should be replaced every decade (!).
about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved.
In the discussion, it was suggested to 'store these at CDL'. Frankly, I suggest *donating them to CDL*. They will put them to best use, and know how to use them. If VCFed needs chips, I presume they already turn to CDL for assistance. If CDL doesn't want these chips, that's entirely their discretion; if they will store them for VCFed anyway, that is very kind of them. I am not in charge of CDL or VCFed so these are merely policy suggestions.
best regards, Herb Johnson
-- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net
The TL866 device does fault checking rather quickly. No need to guess with in-circuit testing. Drop the chip in the ZIF socket, click on-screen button, read auto-verified chip type passing logic test. Go to next chip. Takes about 10 seconds or less per chip. Easy busy work for someone willing to go through them. If they fail the quick test, just toss them. A positive quick test greatly increases the odds of an end user getting a working copy, and eliminates extra hassle of wondering why a stocked chip from a parts bin doesn't seem to be working. On Wed, Apr 21, 2021 at 12:31 PM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved.
So do we want to stick them in a square of ESD foam, and put the foam into a bag for long term storage? Sent from my iPhone
On Apr 21, 2021, at 1:18 PM, Jeff Salzman via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
The TL866 device does fault checking rather quickly. No need to guess with in-circuit testing. Drop the chip in the ZIF socket, click on-screen button, read auto-verified chip type passing logic test. Go to next chip.
Takes about 10 seconds or less per chip. Easy busy work for someone willing to go through them. If they fail the quick test, just toss them. A positive quick test greatly increases the odds of an end user getting a working copy, and eliminates extra hassle of wondering why a stocked chip from a parts bin doesn't seem to be working.
On Wed, Apr 21, 2021 at 12:31 PM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved.
Foam or antistatic tubes. On Wed, Apr 21, 2021 at 1:23 PM Martin Flynn via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
So do we want to stick them in a square of ESD foam, and put the foam into a bag for long term storage?
Sent from my iPhone
On Apr 21, 2021, at 1:18 PM, Jeff Salzman via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
The TL866 device does fault checking rather quickly. No need to guess with in-circuit testing. Drop the chip in the ZIF socket, click on-screen button, read auto-verified chip type passing logic test. Go to next chip.
Takes about 10 seconds or less per chip. Easy busy work for someone willing to go through them. If they fail the quick test, just toss them. A positive quick test greatly increases the odds of an end user getting a working copy, and eliminates extra hassle of wondering why a stocked chip from a parts bin doesn't seem to be working.
On Wed, Apr 21, 2021 at 12:31 PM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved.
I second the note about static damage. On Wed, Apr 21, 2021 at 12:31 PM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
I looked at the photos of the donated chips. Most of them are plastic-bagged and labeled when in quantity. Generally, "what to do" is to make a PAPER list of those tags and bags, and keep it with the box o' bagged chips. Then you have a box of bagged chips with catalog. And in this matter, don't use plastic boxes, they generate static. Paper is fine; there's antistat boxes made too but that's excessive in this matter. Problem solved.
A couple exceptions:
Problem is, all the 4000 series chips that are CMOS, are now damaged by plastic static electricity. I suggest that for the 4000 series, they 1) be rebagged in antistatic bags and 2) tagged as "static damaged". I'm serious.
TTL and LS and other non-CMOS chips, leave them in their plastic bags.
Some bags had mixed chips embedded in anti-static foam. That foam degrades over decades, so make sure it's not too old (crumbly, melting, etc.) Then rebag in anti-static bags. Label the bags as to kind. If antistat foam is kept from air and moisture, it lasts longer. But it does degrade and should be replaced every decade (!).
about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved.
In the discussion, it was suggested to 'store these at CDL'. Frankly, I suggest *donating them to CDL*. They will put them to best use, and know how to use them. If VCFed needs chips, I presume they already turn to CDL for assistance. If CDL doesn't want these chips, that's entirely their discretion; if they will store them for VCFed anyway, that is very kind of them. I am not in charge of CDL or VCFed so these are merely policy suggestions.
best regards, Herb Johnson
-- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net
One of our friends in low places is providing a bunch of (used) ESD safe, plastic storage boxes with pink ESD foam to CDL. Box is 6" L x 4" W x 1/2" H, we have 20 of them inbound, with the ability to source more if needed. Should facilitate sorting them, so you don't have to paw through the bag to find what you need. Have a p-touch in the makerspace to ID the parts family, and the suggested warning on devices susceptible to static damage. Martin On 4/21/2021 1:48 PM, Chris Fala via vcf-midatlantic wrote:
I second the note about static damage.
On Wed, Apr 21, 2021 at 12:31 PM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
I looked at the photos of the donated chips. Most of them are plastic-bagged and labeled when in quantity. Generally, "what to do" is to make a PAPER list of those tags and bags, and keep it with the box o' bagged chips. Then you have a box of bagged chips with catalog. And in this matter, don't use plastic boxes, they generate static. Paper is fine; there's antistat boxes made too but that's excessive in this matter. Problem solved.
A couple exceptions:
Problem is, all the 4000 series chips that are CMOS, are now damaged by plastic static electricity. I suggest that for the 4000 series, they 1) be rebagged in antistatic bags and 2) tagged as "static damaged". I'm serious.
TTL and LS and other non-CMOS chips, leave them in their plastic bags.
Some bags had mixed chips embedded in anti-static foam. That foam degrades over decades, so make sure it's not too old (crumbly, melting, etc.) Then rebag in anti-static bags. Label the bags as to kind. If antistat foam is kept from air and moisture, it lasts longer. But it does degrade and should be replaced every decade (!).
about testing them. Most are not worth testing. Just use 'em and confirm in circuit that they work. Oscilloscope observation of inputs and outputs will confirm lack of damage at the pin level. If one needs known-good chips - don't use these! problem solved.
In the discussion, it was suggested to 'store these at CDL'. Frankly, I suggest *donating them to CDL*. They will put them to best use, and know how to use them. If VCFed needs chips, I presume they already turn to CDL for assistance. If CDL doesn't want these chips, that's entirely their discretion; if they will store them for VCFed anyway, that is very kind of them. I am not in charge of CDL or VCFed so these are merely policy suggestions.
best regards, Herb Johnson
-- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net
The TL866 device does fault checking rather quickly. No need to guess with in-circuit testing.
Well, I don't "guess". I use, as I said, an oscilloscope if I have any doubts. I have the skills to consider, if a logic level is changing as it ought to; or if the signal suggests there's a pullup or pulldown problem. Likewise on outputs, if I get no change when I should get some changes. And: I can read the circuit logic if necessary, and determine what needs to be seen. This is what we old-people techs did in the era, with circuits of the era. It's still a useful vintage repair skill. I don't trust a microcontroller, as in a TL866 device, to do much beyond some simple, slow logic-testing. It's go/nogo to be sure. And for quote "ten seconds work" on a $30 tester, I would not expect more. But I'm not gonna test a box of loose chips, like some pick-and-place robot. I have all the 74LS00 chips I will ever need, without testing pulled ones. Their functions are easily determined, and they are very cheap. I considered not posting the above. After all, it's about one set of skills versus another set of skills. People do what they are able to do, with tools they have. But I posted, so those who use TL866 class testers can tell me "these are great, they do X Y and Z, really found subtle problems" and so on. Or not. I'd appreciate hearing about actual results. and: I don't hear much posting about "oscilloscopes" - they are surely out of common practice, but they are really useful in my opinion, and should be discussed in the matter of logic-chip-level vintage repairs. One other thing. These chips aren't going into any "parts bins" of unused chips, as suggested. Martin said "...into the VCF box ... long term storage". So no confusion, because they aren't "confused" with new chips anyway. That's a prudent decision, in my opinion. In my shop, old used parts and new parts are kept separate, for reasons already discussed. Also: I haven't seen any accounting of the parts themselves. This may be a lot of fuss, over little. I'll be curious to hear, what is actually found among these chips, what is usefully scarce versus all-too-common. A list in the "VCF box", keeps people from digging through just to find nothing desired. And now that I invested some interest in the matter, I'd like to see what came of it. Regards, Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net
participants (4)
-
Chris Fala -
Herb Johnson -
jsalzman＠gmail.com -
Martin Flynn