The header of this small board has to be connected with the corresponding pin on the circuit board of the Piston Honda.
The expander offers six eight-pin sockets for sound chips. Chips are not supplied with the expander and have to be ordered separately (or programmed by yourself with the Harvestman ROM programmer).
Sound chips are available for instance from Brandon Smith
This item is discontinued or sold out and no longer available, please feel free to look for comparable new stuff in the following categories.