Some kind of intel overdrive processor.

https://theretroweb.com/chips/796

Looks like an Intel DX4ODP75 or Intel DX4ODP100 without heatsink

https://www.cpu-galerie.de/html/intel486-80486overdrive.html

@asdf53: Yes, but on that link i see no extra pin in the corner...mine is 3 dots and fourth corner with extra pin.
Hmmm....

...and what are those gold dots on the top for? Contacts?

Nibitor wrote on 2025-11-29, 22:39:

...and what are those gold dots on the top for? Contacts?

Probably test points, or maybe they used the same base for some CPUs with differing amounts of pins and soldered only the needed ones

Nibitor wrote on 2025-11-29, 22:27:

@asdf53: Yes, but on that link i see no extra pin in the corner...mine is 3 dots and fourth corner with extra pin.
Hmmm....

There are two kinds of overdrive processors: One kind is meant to be installed by removing the original processor and installing the overdrive processor into the same socket. As the original 486 processor did not have the extra pin in the corner, this kind of overdrive processor does not have that pin as well. These processors have "ODPR" (OverDrive Processor for Replacement) in their model number. On the other hand, there were processors that you should insert into a dedicated "overdrive" socket without removing the original processor (which might possibly be soldered to the board). The presenece of the overdrive processor causes the mainboard to disable the original processor (e.g. by keeping it in reset or permanent bus hold state). That specific overdrive socket did have that extra hole for the corner pin, but obviously only in one of the four corners. This makes the field installation by laypeople mostly foolproof, as it forces installation in the correct orientation.

The original socket had 168 pins, the extra corner pin is the 169th pin, thus the package type names "PGA168" and "PGA169", where "PGA" means "Pin Grid Array".

Thank you all so much!
So... this could be either Intel DX4ODP75 DX4 OverDrive, or 100 MHz equivalent.
I assume that the gold dots on the top side then have no role to play because it is a fanless model, unlike some with active cooling where contact had to be made for the processor to work at full frequency (sport od dan fail protection).
I also used AI which told me that, judging by the date code from the voltage regulator, it is probably a 75 MHz model.
Thanks again!

*(sort of fan fail protection)
Damn auto correction:/

The contacts on the top of the CPU for models with fans supplied the power for the fan through the CPU itself (and also reported the fan speed so it could run at full speed)

So you agree that they have no role in my case?

Yes they would just be under the heatsink doing nothing

Everyone is right - it is a 486 DX4 overdrive, missing the passive heatsink.

The "extra" pin on the inside perimeter implies that it is the "Overdrive socket" version, so most likely DX4ODP75 or DX4ODP100, as opposed to the DX4ODPR75 or DX4ODPR100 "replacement" version.

I have a DX4ODP100 (purchased new ~1995) and looks identical to your pics. I never made any sense of the bottom labels, but mine has:
E5132803CC
A4
31

I'm not sure how much the "Overdrive socket" versus "Replacement" versions actually matter for motherboard compatibility. My "Overdrive" went into the family Packard Bell Legend 1920 (not my purchase decision, 🤣) replacing a 486SX @ 33MHz in a standard socket 3. That motherboard was a bit strange - has a socket 3 ZIF socket (no specific Overdrive branding) next to unpopulated pads for non-socketed 80486SX. It does have a physical hole for the extra pin, but I don't know if it actually connects to anything. It is still ambiguous to me which Overdrive model is the "correct" one for this application, because it almost seems like I choose the wrong one, yet it worked great for years. Perhaps it matters more for standard 486 motherboards. My point is, in your shoes, I wouldn't hesitate to try out that CPU in a regular socket 3 motherboard, assuming it can physically be installed without crushing that extra pin.

Fazeshift wrote on 2025-11-30, 17:20:

It is still ambiguous to me which Overdrive model is the "correct" one for this application, because it almost seems like I choose the wrong one, yet it worked great for years.

Both models are correct for your mainboard. You need the ODPR model if you have a socket 1 mainbaord in which the ODP does not physically fit, because the extra pin would hit the plastic. You are recommended to use the standard ODP model if you have a socket that has space for the extra pin (an "overdrive compatible socket"), because this prevents inserting it in the wrong orientation. So basically, your ODP processor actually is the better option for your board, but both will work equally well if installed in the correct orientation.