Why would Delco/Delphi/GM use mystery codes for ICs etc.?

[dentaku]

I just opened up an old Factory Delco CASSETTE-AM-FM radio, Model # 09367585 mostly to salvage the potentiometers and buttons from it and I see that most of the components seem to have been custom made for Delco/Delphi. Lots of them start with 014 (even what looks like voltage regulators) which would lead me to believe they're specific to the manufacturer of the radio and not the regular part numbers. The ones with the Delco Electronics logo on them also have their own number that re-appears on different ICs.

Is there anywhere with a repository of Delco/Delphi/Chevy/GM component codes? The only part that has a number that's shows up in search engines is the DM-171 which turns out is an ancient LM1894 Dynamic Noise Reduction IC.

I recently opened up my old Toyota radio and it had regular part numbers for everything that I could easily find datasheets for but these are a mystery.

[David_AVD]

I suspect "house numbering" (also called other names) is often where the manufacturer wants to control the sale of spare parts.  In some cases it could be that the parts have been selected for certain characteristics (such as gain for transistors)?

[notsob]

It also was once (perhaps still is) used to avoid taxes in foreign countries, the listed cost price of 'home' branded components is massively more than the actual commercial component, allowing minimal taxes and maximum profit in the 'overseas' spare parts market.

[dentaku]

Interesting. It's all down to greed in other words 
There's lots of interesting looking stuff on these 90s era boards because it's all through hole and easily un-solderable/breadboardable. Too bad it's almost impossible to find out what they are.

[JackOfVA]

Although not necessarily a direct answer, a bit of electronic history may be of benefit.

In the 1940's - perhaps a bit earlier even - the EIA assigned manufacturer ID codes to component companies. These were 3 and later 4 digit codes that would be marked on components instead of or in addition to the manufacturer's name or logo.

Code 014 is National Semiconductor, so it's entirely possible, if not probable, that the semiconductors are manufactured by National Semiconductor. 

It's also possible that the 014 is a Delco-assigned part number prefix - I would look at non-semiconductor parts and see if they also have the 014 identifier. If it's only found on the semiconductors, the odds increase that it's National Semiconductor's manufacturer code. If it's on mechanical parts or transformers, inductors, etc., then it's a Delco-assigned part number prefix.

There are a few lists around of the codes:
1994 version is at http://www.davelevasseur.com/1994%20EIA%20Source%20and%20Date%20Code%20Book.pdf

This document has both a company -> number and number -> company list.

Older information:
http://www.thevintagesound.com/ffg/eia-codes.html
http://www.triodeel.com/eiacode.htm

[dentaku]

Good stuff.
The recurring numbers are all on ICs and things that look like voltage regulators (I'm truly a beginner as you can see so I'm not sure )
Some of the larger ICs with 466 have the Delco logo on them so they where obvious and the PDF you linked to does say that 466 is General Electric Hughes Electronics formerly Delco Electronics.
Along with 014, there's also some 714 parts and I just noticed that they say TOKO RCL on them and that matches what the .PDF shows.

Thanks for that great resource. It'll probably help out someone else someday too.

[rsjsouza]

This can also be called "customer part number" and is done for several purposes:
- As mentioned above, the part may be derived from a catalog part but has specific characteristics tailored to the application - this is more common to end product manufacturers that also have a semiconductor division in their corporation (in the past, Philips, Motorola, Siemens and so on).
- This also happens with parts that were characterized to operate in harsher conditions (automotive, space, military, etc.) - this was very common in the 70's and 80's but nowadays it is more common to see them marked with a different prefix/suffix;
- Custom part numbers also are marked in micro processors that have a custom ROM programmed in factory - they would only belong to a specific customer and would act as a full custom ASIC;
- A pure ASIC. This would be a completely customized part for a customer and therefore the customer part number is just a consequence of having to name the device.

Regarding controlling the sales of specific part numbers, this is done not because of greed but most importantly to help the end customer avoid counterfeit parts and track the part shipment/distribution. For example, you would need to do some investigation to check if a catalog part number is counterfeit when you see it for sale at an auction site or obscure distributor, but it is almost guaranteed that custom part numbers are counterfeit or have shady origins at best.

[marshallh]

Burroughs have done this too, sometimes the vanilla part number was put on the bottom of the chip by the mfg...