ID on Old Chips

MrChips

Joined Oct 2, 2009
21,666
I am going to guess that most, if not all of them, are OEM in-house numbers. That is, these are custom chips requisitioned from the chip manufacturer for the OEM. Some of the chips could be mask programmed ROMS.

You can either bin them or make a mosaic mural out of them.

(I have a few thousands of them myself. Want to trade?) :)
 

dl324

Joined Mar 30, 2015
11,282
Welcome to AAC!
Can anyone help me ID the chips in the attached pictures
I'd go with house marked parts. Many manufacturers did this. Some to disguise parts to discourage copying, others liked to use in house numbers (e.g. Hewlett Packard). HP published cross references, but noted that they sometimes cherry picked parts, so a generic part might not be satisfactory for a long term repair.

If you're very patient, you can sometimes determine function by experimentation. I've never attempted doing that, but I had a colleague who said he had done it. He was very detail oriented. One of those who completed his MSEE at Stanford in a year (1.5-2 years is more typical).
 

atferrari

Joined Jan 6, 2004
4,069
Next time you take pictures of anything small like components, do it, if possible, with day light, but not with sun shining directly on your target.
 

dl324

Joined Mar 30, 2015
11,282
I'll just chuck them. I have enough spares anyway lol
I wouldn't be so hasty. You might have some gems; maybe not. Unless they're taking up valuable storage space, I'd keep them until you, or someone else, is inclined to invest the effort to find out what they are.

EDIT: If you decide to keep them and you're not certain if they're static sensitive; treat them as if they were. You might also offer them to an AAC member for the cost of postage to keep them out of landfill.
 
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MrChips

Joined Oct 2, 2009
21,666
I would not bother getting that tester. It can only test what is already in its database. I seriously doubt that you will be able to identify your chips.
 

dl324

Joined Mar 30, 2015
11,282
Don't be discouraged by naysayers. I say it can be done if you're patient. I know someone who has done that type of experimentation.

Just make sure you current limit any voltages you apply to the pins. Power pins are typically in a few configurations. Once you know which pins are power, then you can look for relationships between the pins.

I'm not saying it will be easy. Just that it can be done if you're methodical, patient, and persistent.

The device I mentioned will test hundreds of possible devices. If it finds a match, your done. If it doesn't, you've eliminated a lot of things to try.
 
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Thread Starter

danielantonic

Joined Sep 22, 2019
4
Interesting idea - I haven't seen a tool like that before. However, I'm not tied to these (unless they are analog multipliers or I2C interface or something cool like that - I'm getting into analog stuff after a lifetime of digital lol)

I have about a dozen extra of the "Mullard C" chips that weren't in the photo. Is there a place on this forum (or elsewhere) you can go to trade components?
 

dl324

Joined Mar 30, 2015
11,282
Interesting idea - I haven't seen a tool like that before. However, I'm not tied to these (unless they are analog multipliers or I2C interface or something cool like that - I'm getting into analog stuff after a lifetime of digital lol)
They're likely old, so I2C is out.

Here's a tool that would be useful when trying to determine if they're unknown logic chips: HP548A Logic Clip It will let you view the status of 16 pins at the same time and will automatically connect to power on the chip being tested.
1585233991031.png
1585234083722.png

I have about a dozen extra of the "Mullard C" chips that weren't in the photo. Is there a place on this forum (or elsewhere) you can go to trade components?
There's a Marketplace forum.
 
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