What is this IC? - Page 1
Forum section: electronics / general

author: PStevenson
author_rank: Regular Contributor
timestamp: February 01, 2012, 03:34:07 pm
content: now before you fire up google, I've tried google, all variations of the code on the IC so my only hope is that someoneknows what these are through experience or you have some method of locating what IC's better than my methods.they came from a clear out, the person knew I was into electronics and said I could take anything, this was a number of years agonow but I just found them again under my lab bed with a load of other weird componentsanyway see picture posted below

author: Lightages
author_rank: Unknown
timestamp: February 01, 2012, 03:48:55 pm
content: Based on the package, they were made in the early 70s. Based on the number on them written in pencil I would guess they are ROM or some kind of memory. Usually when there was a series of memory, ROM or otherwise, that needed to be placed in a certain order it was common practice to number the chips for their position or place in a series. I am sure they have little utility anymore. Remove one of the caps on the die window and have a look with a magnifier or microscope if you have one.

author: Bored@Work
author_rank: Super Contributor
timestamp: February 01, 2012, 05:31:17 pm
content: All I can state is the obvious, made by HP during a time HP was still HP.

author: A-sic Enginerd
author_rank: Regular Contributor
timestamp: February 01, 2012, 06:09:50 pm
content: Yeah, my guess would be possibly an eeprom.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 01, 2012, 06:14:46 pm
content: Quote from: BoredAtWork on February 01, 2012, 05:31:17 pmNot necessarily - HP was notorious for using standard parts which had been marked with their own part numbers.

author: Unknown
author_rank: Unknown
timestamp: February 01, 2012, 06:41:24 pm
content: Quote from: A-sic Enginerd on February 01, 2012, 06:09:50 pmDid they have EEPROM when these packages were popular? If it's from the early seventies, then they probably only had EPROM.Analog ICs that form matched sets may also be labeled, though I'm not sure if they were manufactured in this case style.

author: Rufus
author_rank: Super Contributor
timestamp: February 01, 2012, 10:14:35 pm
content: Quote from: alm on February 01, 2012, 06:41:24 pmEEPROM started around 1978. I probably have some ER1451 EAROMS (Electrically alterable read only memory) but can't find a datasheet with a date for them. 50 x 14 bit words, they need +5 and -30v supplies, 1 bit serial interface, max clock speed 17kHz - lol.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 01, 2012, 10:30:50 pm
content: Quote from: alm on February 01, 2012, 06:41:24 pmPackages like this are often used for test runs & very low volumes, so numbers could simply be device number within a small batch.These are not usually too hard to crack open the lid on, so if you're curious a look at the die may revel something.Actually looking at the pics the caps look like they are only tacked on, so a sharp knife may be all you need to lift the lid

author: PStevenson
author_rank: Regular Contributor
timestamp: February 03, 2012, 11:48:10 am
content: cheers guys, I might have to take a dremmel to them see what's going on or even just make a giant wall picture of the useless IC's I've got lying around haha

author: tinhead
author_rank: Super Contributor
timestamp: February 03, 2012, 12:37:24 pm
content: probably 2708 or 2716 EPROMs.I would first read back the content to check if something insideto recognize what device they belongs too (or post here and i will try to recognize)You might wonder why, well it might be that someoneif looking for a firmware dump from exact that old gear.So if not too late and you have a chance to dump themyou can upload then here ko4bb.com

author: Zero999
author_rank: Super Contributor
timestamp: February 03, 2012, 06:55:03 pm
content: Does anyone know why early ROMs were packaged in this manner? Why a white ceramic case and what does the metal cap do?

author: Simon
author_rank: Unknown
timestamp: February 03, 2012, 07:40:54 pm
content: whats with the flying wire ?

author: Rufus
author_rank: Super Contributor
timestamp: February 03, 2012, 08:17:23 pm
content: Quote from: Hero999 on February 03, 2012, 06:55:03 pmLots of chips came in hermetically sealed ceramic packages and some still do. The package is more reliable in production and service, better thermally, possibly cheaper to produce in small quantities. If you have an expensive chip or require high reliability you don't skimp on the packaging. The lid is just a soldered on cover for the cavity containing the chip (and probably dry nitrogen).It isn't going to be an EPROM without a window like the 8751 attached. The other chips are a TI processor, Analog 12 bit ADC, and I think a 256 byte CMOS RAM.

author: PStevenson
author_rank: Regular Contributor
timestamp: February 03, 2012, 10:51:47 pm
content: Quote from: Hero999 on February 03, 2012, 06:55:03 pmI have some nice Instrumentation amplifiers (AD8229 I think) packaged in this manner too@ Simon - I'm not too sure, that's how they were when I got them, I asked the guy who gave them me and he didn't know what they wereI've never wanted to just throw them away or anything because they were too beautiful haha

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 03, 2012, 11:41:08 pm
content: Quote from: Hero999 on February 03, 2012, 06:55:03 pmOne reason for using this package is that the cap can be put on after the chip is packaged, which can be useful for testing/probing of prototype ICs, laser-trimming etc. The ones pictured appear to only have the lids tacked on, rather then the normal all-round solder fillet.