ID UV erasable PROMS used on an IBM PC board?

dwight dkelvey at
Mon Mar 21 18:49:38 CDT 2022

The dies look to have consistent wire bonding. That would mean they are one of the standard EPROMs made by Intel, just preprogrammed by Intel before shipping. The numbers wouldn't be intel numbers they would be IBMs inventory numbers. My guess is that they are 2732s. You might use a microscope and look at the edges of the dies. They often have the die type in the metal layers around the edge some place. Avoid using florescent ring lights as a large amount of UVC leaks from these. White LED are or incandescent lights.
Also power it up and note which pins look to have signals. if any of the lines have what looks like a constant voltage measure it to the nearest .01 volts if you can. That will help determine if it is driven by a signal or a hard tied wire. Lower left and upper right should be ground and power pins.

From: cctalk <cctalk-bounces at> on behalf of D. Resor via cctalk <cctalk at>
Sent: Sunday, March 20, 2022 6:53 PM
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Subject: ID UV erasable PROMS used on an IBM PC board?

I cannot find a datasheet by any of the numbers silkscreened on these ICs.

Could these be proprietary IBM P/N numbers?

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Don Resor

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