GoTo Connector

Sega Genesis Controller

9 PIN DSUB ??

Pin Name (Select=GND) Name (Select=+5V)
1 Up Up
2 Down Down
3 Gnd / Left
4 Gnd / Right
5 +5VDC +5VDC
6 Button A Button B
7 Select Select
8 Ground Ground
9 Start Button C

The chip inside the controller is a 74HC157. This is a high-speed cmos quad 2-line to 1-line multiplexer. The console can with help of the Select-pin choose from two functions on each input.