OK, so I've noticed now that a second MK1 arcade prototype is now floating around the internet. Apparently it's fairly recent, as I can find no information on it.

Is there any difference between the 8.0 and 9.0 prototypes, or is it the same thing as the 9.0 proto? Or is there a link to a site somewhere documenting the changes?

(NOTE: I am NOT asking for the ROM.)