Sorry, halkintool, just in a silly mood.
That MPG is used via the PP port ( need to use up two pins), and the settings used are 50 for the count/unit and 400 for the velocity which gives a nice feel for using it and about .008" of movement per rotation of the wheel. So i can just tweak right into something down in very fine increments. Of course the faster you turn the faster the axis will move. In fact it works great for doing some turning on my punny lathe. The mouse is a good idea, but if high resolution is what your after, then for 1/2 a buck you just can't go wrong.
Oh, you need a screw driver to take the printer apart, and if the encoder is bad, you can beat the printer up with the hammer should you feel cheated.
RICH