Playstation 2 BIOS Pin significance

@PS_2

Published in 

Playstation 2 tutorials

 · 27 Nov 2021

People installing Messiah/Magic/Apple and the like have been investigating their BIOS connexions and, in ignorance of the BIOS layout, have drawn false conclusions when checking pins for continuity with a multi-meter.

Attached to this post is a picture illustrating (as typical):

1. v5/v6/v7 60 pin BIOS
2. v3 Gap BIOS (note it has 50 pins with the gap pins "missing")
3. v3 No-Gap BIOS (note it has 44 pins)
4. v4 Gap/No-Gap ditto as for v3

The picture lists the broad pin functions and also shows the related Messiah 2 points (applicable in the also to Magic/Apple except point W).

When testing continuity between the pins, the GND points will obviously show zero ohms. The other points will show some continuity because of internal circuitry.

Pins are bridged only if they show zero ohms. Not a few ohms; zero ohms.

Playstation 2 bios pinout