Playstation 2 controller interface with quadrature mode

[Homer79]

Hi,

I've recently taken up hardware and programming again. I've designed and made a NES & SNES controller interface with a PIC16F628A.
I was looking at the PS2 controller and thought it should be possible with the same PIC, maybe clocked a little higher. I was looking at adding
a mouse mode with the analogue sticks. I've tried searching how quadrature signalling works, but none of them seem to explain the update
frequency and how to vary the speed of the mouse movement. The best page I've found so far is this one.

http://www.creative-robotics.com/quadrature-intro

After this one, then I will work on doing a wii nunchuck to joystick/mouse interface

Regards