This SNAC adapter is custom built for the PC Engine, which requires faster level shifters than SNAC/SNAX for turbo functionality. While SNAC/SNAX Work fine otherwise, this adapter works with all known original controller hardware. The original design was lovingly created by PC Engine enthusiast David Shadoff. The sleek, MJF printed nylon enclosure was made by Dinierto Designs.
This plugs directly into the User port of the IO board.