[Coco] PS-2 Mouse on CoCo

[Torsten Dittel]

Derek schrieb:
> Would I have an easier time if I tried to convert a mouse from an Atari ST or Amiga since they both use the joystick port like the CoCo does for mouse input?

Not really. At least the Atari ST one is a "digital" mouse. It has less 
intelligence then the "serial" ones (e.g. PS/2).

In case of the ST, a special keyboard/mouse processor (MC-10 type) 
inside the ST is reading the 2 times 2-phase digital output of that 
mouse through the ST's "digital" joystick port (the "up/down/left/right" 
ATARI type) and caculating the cursor position like the µC in the serial 
mouse does as well before transmitting it serially.

There was WICO trackball available for the CoCo which contains a 
customized chip reading the digital trackball, converting it to 
(digital) x/y values (8-bit) and then doing an DA converison to proper 
analog voltages which can be read by the CoCo's joystick ports.

Regards,
Torsten