> I'm hoping for a decap on that Namco C139 because the contents on that chip aren't > known (unless someone can confirm). I think it's an MCU because of how responsive > that controller is (tested it with Cyber Cycles, Time Crisis 2 and Motocross Go). > Would be nice to see a non Sega game with networking emulated.
The Final Lap schematics suggest C139 is a full-fledged ASIC or else some really offbeat DSP (host data is 13 bits wide). The signal names used there suggest that it's implementing something approximating a token ring protocol. The chip has Fujitsu markings, which is not a good sign.