I don’t know if this has anything to do with your number but some of it matches up

https://datasheets.chipdb.org/Intel/x86/486/Intel486.htm

May be an engineering sample of a DX-50 ?

This chip is an engineering sample of a DX2-50 and has the same pin-1 arrow style: https://www.chipdb.org/img-intel-a80486dx2-50 … sample-2631.htm

The tester/engineer may have written the iComp score underneath after testing it.

Some SL enhanced DX2 66 looks the same from the bottom.
https://www.cpu-world.com/CPUs/80486/Intel-A80486DX2-66.html
The A4 is the identification of the country of manifacture. This designation was still used on pentium MMX CPU's.

Could just plug it in and test

Slower dx chips usually didn’t overclock very well

Slow 20mhz SX chips (full wafer size which is the same as a dx) were very poor overclockers.

A few simple burn in tests should ballpark what the chip really is.

At least you can be certain of the process node this chip is since it’s before the die shrink.

Yeah the "perky" straight up pointer seems to be same as those CPU and some early DX2/66... kinda seems associated with A4 if that's the code for the plant or something. Though that long code seems like an FPO code, but some say it's for the die, whereas the FPO on top is for final assembly.

rmay635703 wrote on 2024-08-27, 03:10:

I don’t know if this has anything to do with your number but some of it matches up

https://datasheets.chipdb.org/Intel/x86/486/Intel486.htm

I can't see what you are meaning really for what matches, though the internal CPUIDs will be useful if I do plug it into something and run it. Figuring where to start with my 486 stuff at the moment though is like starting a sudoku on "nightmare" skill level, you've only got a tiny handful of numbers on the grid and are thinking you've gotta try and play out 20 different starters before you commit something to ink (plug it in) or it all blows up in your face.... I was building my dependency chain down from socket 7 still.

BitWrangler wrote on 2024-08-27, 22:50:

Yeah the "perky" straight up pointer seems to be same as those CPU and some early DX2/66... kinda seems associated with A4 if that's the code for the plant or something. Though that long code seems like an FPO code, but some say it's for the die, whereas the FPO on top is for final assembly.

rmay635703 wrote on 2024-08-27, 03:10:

I don’t know if this has anything to do with your number but some of it matches up

https://datasheets.chipdb.org/Intel/x86/486/Intel486.htm

I can't see what you are meaning really for what matches, though the internal CPUIDs will be useful if I do plug it into something and run it. Figuring where to start with my 486 stuff at the moment though is like starting a sudoku on "nightmare" skill level, you've only got a tiny handful of numbers on the grid and are thinking you've gotta try and play out 20 different starters before you commit something to ink (plug it in) or it all blows up in your face.... I was building my dependency chain down from socket 7 still.

Considering it’s Intel, It has a heatsync which makes it a 90% chance it’s 50mhz or faster. About a 70% chance of being a dx2-66

Some folks put heatsyncs on dx2-40’s and dx33’s but most didn’t care enough.

Personally some 486 boards behaved almost like an auto switching design with very few jumpers while working with almost everything.

If you have a working board like that set voltage to 3.3, dx2, (not od) and try 25mhz FSB do a burn in test if it posts.

If it doesn’t post or is unstable it’s a 5 volt chip.

Once stable test out WT vrs WB, only late dx2’s had the fastest option.

Then lastly test 33mhz FSB to see if it’s a dx2-66, if it’s stable at 50mhz with 3.3 but not 66 it’s still a 5 volt chip.

3.3 volt DX2’s were almost exclusively an AMD thing