All switches are connected at one end to a pull-up input, and connect to ground on close. The analog input for the food pedal expects a potentiometer (e.g. 10k). Note that the MIDI output is used.
This repository contains recreations of main board PCBs for Sega's Mega CD/Sega CD add-on for the Mega Drive/Genesis console. These boards are often subject to damage caused by leaking capacitors ...