Atari 2600 Driving Controller Mouse Hack

[Great Hierophant]

As I understand how the Atari 2600 driving controller works, it is a purely mechanical/electrical device. The center terminal is connected to the ground wire and the left and right terminals are each connected to an input on the 6532. When you turn the dial, the shaft connects the center terminal connects to one wire before the other. The switching is purely contact based.

By contrast, a ball mouse has two rotary wheels. Most, if not all, have the wheel in between a LED and a photodiode. When the wheel turns, one side of the photodiode receives the light before the other side, and this information is sent to the mouse controller.

 

What I want to have happen is for the Driving Controller to function like the X-axis of the mouse by connecting the signals directly to the LED and photodiode. The LED has two pins and the photodiode has three. I am a bit hazy about the wiring required with the three connectors to Driving Controller's rotary dial. Can anyone help me out?

[Osgeld]

yes you are correct they are both whats called rotary encoders, one is optical (mouse) one is mechanical (tari)

 

what you would need to do is take a multimeter set to continuity with the mouse unplugged, one of the three pins on the photodiode package should be connected to +5 or ground the other 2 are outputs to the brains of the mouse

 

inside the controller you should see the same arrangement on the mechanical encoder, one common and 2 output (the button shares the same common and has its own output which you would wire to a mouse button)

 

 

 

 

[Great Hierophant]

On further reflection, I think that I should not use an Atari controller because its resolution is very coarse compared to a computer mouse. The Atari controller has roughly four spokes in its "wheel" while the mouse usually has at least 30. I think a dedicated optical spinner would work better.