Socketed E²Prom chips are pin-compatible with Eprom. So, as an ex-hardware guy, I can tell you you have performed the Frankenstein trick of reversing the polarities. You put the negative lead to +, and vice-versa.
Most of the other leads don't matter. Inherent in each FET is a reverse diode. So all those reverse diodes were forward biased and conducted a high current Your only protection is that they did this together. You'll have to see what survived. Here's a few guesses
- Eproms often survived that. They're tough by standards. E²Proms die 90% of the time.
- The + or - track from the socket could be blown if the tracks are not thick.
- If any other pin passed significant current (possible) your motherboard is a write-off.
- You may have blown your power supply.
Here you see the difference between an expensive & cheap psu. There is a trick called 'Fold-back current limiting.' Let's say you have 20 Amps available on your 5V line. When an over-current is detected, fold-back limiting will not continue to pump out >20A, but 'fold back' to a lower figure of ≅ 8-12A.
If you have or can borrow another Programmed BIOS in a chip of the same size, ideally from a blown m/b, you might insert it and turn on the machine. ASCII on the monitor would be a sign of life in the m/b.
You will probably need to replace the BIOS chip anyhow. Switch on the motherboard with everything on, and monitor heat on parts that shouldn't get hot. If they do, goodbye motherboard. Allow a few minutes. Parts may get lukewarm, but no more. If they keep getting hotter, say goodbye.
