The below post is from the PBR about the Ni-Wumph CPU. Read the very bottom: *Note
NI-WUMPF Gottlieb® System 1 Mark II CPU Board
The NI-WUMPF Gottlieb® System 1 Mark II Replacement CPU Board supports all 16 System 1 Games! This board is a technological pinball breakthrough for System 1 owners!
The NI-WUMPF Replacement board
GTB-A1-A $209.00ea
*Note: The above board is only compatible with original Gottlieb® Boards, Ni-Wumpf Driver Board, and/or GPE Power Supplies. Suggest checking with Ni-Wumpf before using with replacement boards from other vendors.