Here is a schematic of how the LCD was connected to the system.
A schematic of the pin layout for the Sega Genesis gamepad.
Fortunately, Sega was farsighted enough to realise that their
controllers would have other uses beyond just plugging into
a Sega Genesis console. Like plugging into our...ummm... game...
This DAC was used to help create the wonderful, soothing melodies
that people can enjoy while pursuing their goal of getting just one more