PB2K uses a PC mainboard in BAT formfactor with Cyrix Media GX processor on it. This cyrix processor and his cyrix bridge (CX5520) are obligatory for PB2K and not replaceable by any other PC mainboard or processor! Boards with a CX5510 bridge do start the P2K game code, but cannot display the P2K video output when the game has started. Boards with a CX5530 bridge don't work either.