Need help with MM3 PS1 Chip

That's strange - the 12F629 is specced to work down to 2V with a 4MHz clock and the ADC not in use. I've used them on 3.3V with a 10MHz clock with no issues at all.

 

Tried the 12C508A with an MM3 hex for that particular chip and changed the CALIB value. Got an error after programming and the software reset itself, but when I read from the chip it showed the modified hex file. However, still nothing when I try to boot up a game.

I think I might just order a couple of chips from Bad_Ad84 for now and try programming later, as I've just got too many console lying around at the moment to spend too much time on them.

 

It could either the programmer or the software (Most likely the software). I very highly doubt its the batch of chips your getting. In your screencap and the first post, it seems to be almost the same software i was using when making the guide back then but your software could possibly be an earlier version, renamed and have bugs in it. I would check out this one, it's almost the exact same as the one you were using but could have those possible bugs fixed. Can't go wrong with hitting up bad_ad but if you want to get another go at it, here is the software.

http://www.mcumall.com/usb_pic_cd.zip

 

Try it one more time.
Make sure you place the chip the correct way in the socket.
Click READ and then scroll down to see the osc value.
Load HEX code, click no if it asks to save before loading.
Click CALIB
Click read then insert, value should match the number at the end when you read the chip.
Click program and that's it.

 

God, after all that it turns out there was something wrong with my original soldering. Swapped my chip for one of Bad_Ad's and still had the same issue, so re-soldered everything meticulously and it works great now. Time for some Vib Ribbon!