Williams Diagnostic Switch Inputs

Quick plug-in board that gives you push buttons and switches to operate your diagnostic inputs. Works with System 3 through System 11, to act as substitutes for your coin door diagnostic switches.

Very handy little board, particularly for bench testing.

To use this board, it's a simple press-fit onto the header connector on your CPU board where the coin door switches attach into. For any generation of System 3 to 11, this is going to be connector 1J4.

Left side switch is for the memory-protect switch at your coin door.

Center button is the 'Advance' button on your coin door.
Right side switch is the "Auto-Up / Manual Down"

Makes life much easier than using alligator clips or other messy wire jumpers. Stays in place, stays out of the way, and is quick and easy to move through the menus using the advance button.