# What are these??



## Long Shot (Feb 14, 2016)

Hey All,

I could use some help determining what these are and what they may be worth, i.e. sell as is or scrap.

An Internet search doesn't bring up much - the number on them comes up in reference to Ray Ban sunglasses. There are no other markings on them, no manufacturer, no dates, nada.

Thanks.


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## scrappappy (Feb 14, 2016)

Looks like an eeprom chip to me. Most of them had a glass window in the center that used UV light to erase the memory. I think yours was a higher end chip that would have used a chip eraser. Here's one with the window removed. Hope this helps.


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## Long Shot (Feb 14, 2016)

Yes Sir, thank you, that was my thought too - EEPROM, but as you say, no window. Given what is going on with the price of old chips I am reluctant to scrap these until I know for sure.


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## FrugalRefiner (Feb 14, 2016)

EPROM (Erasable Programmable Read Only Memory) was erased by exposure to UV light through a transparent window. EEPROM (Electrically Erasable Programmable Read Only Memory) is erased by electricity alone, eliminating the need for the window and a UV light eraser.

Dave


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## Barren Realms 007 (Feb 14, 2016)

They are not EPROMS. I'm not finding anything in my search. Go to CPU-world.com and post a picture of it and see what they say. I have a feeling it might be linked to an old 8088 chip. You can put them up for sale there and if there is any intrest in them you might get a sale.


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## Long Shot (Feb 14, 2016)

Thanks Barren Realms, I will try that for sure. I did find some reference to 7511 in relation to 8088s and you may be on to something.

Dave - thanks for clearing that up, something I have forgotten over the years!


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## resabed01 (Feb 14, 2016)

7511 could be a date code, but then so could 1076.


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## Long Shot (Feb 14, 2016)

Resabed01 - yes, I had thought that as well. Working with instruments for a living teaches one something about serial numbers and I thought 1076 would be month and date. You could be correct though, 7511, year and month. I have seen a reference in relation to 7511 and 8088's although it does not firmly link the two. I just posted the pic on CPU-world.com so we'll see what those guys come up with. I will keep this thread updated based on that so if someone else finds these it will be on GRF as well.


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## g_axelsson (Feb 14, 2016)

That is not an eprom (no quartz window) or an eeprom, too early for that technology.

With so little markings I don't think it has anything to do with 8080 series either, those are usually better marked and having maker data too.

My guess is some custom circuit from mid 1970:ies.

Scrapdaddy, that is an EPROM *with the lid still on*. The lid is a clear quartz plate.

Göran


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## macfixer01 (Feb 15, 2016)

g_axelsson said:


> That is not an eprom (no quartz window) or an eeprom, too early for that technology.
> 
> With so little markings I don't think it has anything to do with 8080 series either, those are usually better marked and having maker data too.
> 
> ...



Göran is correct, the 7511 date code means it's way too old to be an electrically eraseable ROM. My guess is a linear chip of some variety with only a partial part number on it? Common part numbers were "AY-3-" or "AY-5-" followed by a four digit number. For example the AY-3-8910 sound generator, the AY-3-1015 UART, or the AY-5-3600 keyboard encoder. On the other hand it may be house-numbered in which case you have no clue what it may be? I wondered about that since there is no manufacturer logo either? General Instruments is a likely manufacturer though. Is there anything printed on the bottom side?


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## mister_rf (Feb 15, 2016)

One question, for such old chips, it is possible to clean up the pins? 8)


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## Long Shot (Feb 15, 2016)

Thanks Guys,

Macfixer01 - your explanation goes hand in hand with what I've been told about these at CPU-world. I acquired these from a guy I used to work with (with a bunch of other stuff) and their origin is thought to be from the now defunct Nortel facility in my town. In house numbers that mean nothing to anyone except them and are now likely to never be known.

Mister_rf - yes, I will do that latter today and post.


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