Are you sure those are the correct names? They don't look anything like correct EPROM part numbers.

I don't see your included photo anywhere...

(Use the picture with circle)

Keith Cress
kcress - http://www.flaminsystems.com

early 70-80's EPROM presumably UV erasable would have had basic part numbers like 1702, 2704 or 2708. which were the Intel part numbers: https://en.wikipedia.org/wiki/EPROM which is consistent with the parts I still have from that era.

It's possible the numbers you refer to are OEM part numbers, but not the original part numbers from Intel

I suggest that in the future you pick the forum more carefully. This really isn't a semiconductor engineering question, and this forum has less than 3000 members, while the two electronics/circuit forums have more than 25000 members.

TTFN
I can do absolutely anything. I'm an expert!
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Sorry about choosing the wrong forum. But these chips look like they have the Intel 'i' and they do say Intel. I'm familiar with Intel's 27 series and SEEQ's 52B series, and XICOR's X28 series, but I'd never seen these chips till I found them in a pile of wires and caps and resistors at a garage sale. The photo was uploaded from Windows Photo Viewer.

Once again, I apologize for using the wrong forum.
David

Sigh.. We wanted to see the picture so we could integrate everything we know/still remember into what the labeling was. Giving us a poorly lit non closeup of the markings doesn't really help.

Keith Cress
kcress - http://www.flaminsystems.com

Machts nichts on the picture. I'm guessing that they're OEM parts with OEM labeling. Nevertheless, the die should have the part number on it somewhere, so find yourself a 50x or 100x microscope and look at the die.

TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers

That works too. Those were some of the only chips that actually had the real part numbers on the dies.

Keith Cress
kcress - http://www.flaminsystems.com

I can see the 8742 die marking through the window with a 20x eyepiece, so any magnification over that should make it pretty easy. Not all manufacturers make the markings that big; Intel's marking for he 8742 about 120 microns tall. The Fujitsu second source of the same part doesn't readily show a die label.

eBay sells a 50x-500x magnifier with 2Mpixel camera for about $12, so if you're doing this a lot, that might be a good investment.

TTFN
I can do absolutely anything. I'm an expert!
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Is this better?

That was a useable picture thanks.

Sorry but you'rescrewed as those are likely OEM numbers as IR speculated. I believe those are pre-programmed EPROMs by Intel and the number is something like the contract, service, or part number to keep track of the fact that they're programmed and who's program it is. The markings are put on by Intel and since the chips are tested then immediately programmed there was no need to identify the type chip only the model/code.

Keith Cress
kcress - http://www.flaminsystems.com

As a wild guess, the 28-pin Intel device is likely a 2764, while the 24-pin Intel device is likely a 2716, judging by die size comparisons on Google images.

TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers

That would explain the strange numbers! I'll plug them in to my old reader/programmer and see what they look like.
I want to thank you all for the input.

Have a great day,
David

Interestingly, this is one of the few times that an unmarked or off-marked part can be identified at all, without destructive examination.

TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers