MSI MICRO NLX BX4 User Manual page 42

You can connect MIDI keyboard, joystick or game pads to this connector.
PIN SIGNAL
1 +5v
2 Joystick But0
3 Joystick X1
4 GND
5 GND
6 Joystick Y1
7 Joystick But1
8 +5v
9 +5v
10 Joystick But2
11 Joystick X2
12 Midi Out
13 Joystick Y2
14 Joystick But3
15 Midi In
2-37
8
15
9
1
JAUD1