Thanks for that Ken. My project is involved with turning a screw that moves a mounted camera "in tune" with the earth's rotation, so as to do astrophotography. Right now I'm doing this manually, which is tedious and error-prone, which leads to blurry photos. At any rate, I think I understand you, in that the "controlling" part of the motor would be transmitted to it via the parallel port...now I just have to figure out a way to design a cable that will connect to both the motor and the PC.