Extrait de la FAQ des ports EJP (Enhanced Joystick Port)
3.6 Joypad -> joystick adaptor circuit diagram
==================================================
15 pin high density 9 pin D
D socket socket
14 O------------------------------O 1
13 O------------------------------O 2
12 O------------------------------O 3
11 O------------------------------O 4
10 O------------------------------O 6
7 O------------------------------O 7
9 O----------------*-------------O 8
|
4 O----------------*
|
3 O----------------*
|
2 O----------------+
This works because the joypad and the joystick both work on "negative
logic" - i.e. a LOW value is considered to be TRUE. By connecting the
control lines of the joypad to 0V, all the buttons are effectively
ORed together. For use as a joystick, this allows you to use UP, DOWN,
LEFT, RIGHT and any of the fire buttons. Several of the other buttons
will also mirror these effects, although that should not cause any
problems.
5.3 Joystick -> EJP adaptor circuit diagram
===============================================
Get five friends, six joysticks, two adaptors, a copy of Dynablasters
and HAVE FUN!!! If you don't have that many joysticks, but do have a
joypad, bear in mind that you can use the "Padaptor" described above -
or even incorporate it into this design.
15 pin high density 9 pin D plug
D plug (joystick 1)
1 O------------------------------O 1 UP
2 O------------------------------O 2 DOWN
3 O------------------------------O 3 LEFT
4 O------------------------------O 4 RIGHT
6 O------------------------------O 6 FIRE
9 O----------------*-------------O 8 GROUND
|
|
| 9 pin D plug
| (joystick 2)
|
+-------------O 8 GROUND
10 O------------------------------O 6 FIRE
11 O------------------------------O 1 UP
12 O------------------------------O 2 DOWN
13 O------------------------------O 3 LEFT
14 O------------------------------O 4 RIGHT
Avec ça tout le monde sera content
Il ne reste plus qu'à développer un DDR sur le fauve alors
Il ne reste plus qu'à développer un DDR sur le fauve alors 
)