SpritesMind.Net

I got some Mega-CD and Sega CD bios files from a Genesis No-Intro ROM set, all of them are labeled with version numbers such as v1.00, v1.10 and v2.00, this itself should be self explanatory.

Some of them however come with a letter:

[BIOS] Mega-CD Model 1 (Japan) (v1.00P)
[BIOS] Mega-CD Model 1 (Japan) (v1.00S)
[BIOS] Sega CD Model 2 (USA) (v2.00W)

What exactly do the letters P, S and W mean? It's a mystery that's been bothering me for quite a while.

I don't now exactly what they are, they're from SEGA that's why I've leave them in the version number.

I suppose that's the version number of the BIOS. I'm not sure if it says the exact version number or not (never paid attention) but that's what I think that's about. The major version numbers depends on if it's a model 1 or model 2 Sega/Mega CD.