OK, so I finally got the spinner working with the ME4. I first tried replacing the active low optical board on the spinner with a homemade active high board. This appeared to work great but for some reason the ME4 wouldn't read the signals correctly. Basically the mouse would jump back and forth rapidly instead of moving in one direction. This would lead me to believe the signals weren't actually quadrature, but after looking at them with an o-scope they certainly looked quadrature. So at this point I was somewhat disapointed and so I went back to the pullup resistor idea. This time I used two variable resistors as pullups. Once again at 1Kohm the ME4 was not reading the signals, but I turned up both resistors and at about 1.8K the ME4 started responding. Now on to control panel construction...