This project allows you to use an original NES controller with a PC. It uses the Teensy 2.0 USB Joystick functionality to accomplish this. This works great with FCEUX and SuperTux.
The NES controller uses a 4021 8-bit shift register, which is easily interfaced with the Teensy (see the Arduino ShiftIn Tutorial).
____
1 |o \
2 |o o| 5
3 |o o| 6
4 |o o| 7
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1. GND
2. CLK
3. Latch
4. Data
5. VCC
6. NC
7. NC
| NES Controller | Joystick/Gamepad |
|---|---|
| Left | 1 |
| Right | 2 |
| Down | 3 |
| Up | 4 |
| Start | 5 |
| Select | 6 |
| B | 7 |
| A | 8 |