Amiga mouse

smouse

Commodore Amiga has 2 joystick ports where (most of the time) in port 1, a mouse is connected. Since the pinout of these ports are Atari like, Commodore reused the 4 direction pins to send the mouse quadrature signals for both axis. The firmware interprets these quadrature signals and send them via USB as a standard HID mouse. Windows 8 / MAC OS X with an Amiga mouse!? Why not?

More info on how the firmware reads the two rotary encoders here.

Controller pinout

dsub9f

PinFUNCTION
1V-PULSE
2H-PULSE
3VQ-PULSE
4HQ-PULSE
5BUTTON 3 (M)
6BUTTON 1 (L)
7+5V
8GND
9BUTTON 2 (R)