Since this circuit is also used in all the other versions of the interface I will give a detailed description of its operation. This one is intended for use with 4QD NCC or Pro-120 series controllers which use a 9v internal supply, so the circuit is powered from this. However the supply voltage is not critical.
If you have watched an adventure movie featuring aircraft you have probably encountered someone yelling, Pull up Pull up You are gonna crash A huge explosion in which one of the good guys dies in a ball of flames usually occurs a few moments later.
Bernard shows us how to use an use an accelerometer as a mouse. This project uses a MEMS X/Y accelerometer, a PIC microcontroller and a old mouse. He also describes a trick for powering the new mouse with the unused RS232 serial control lines.
The joystick port is a quick and dirty analog to digital converter that can be used for many more things than just joysticks and gamepads.