A method and apparatus for storing and retrieving program material for subsequent replay is disclosed. A dental or orthopedic input device includes energy source and an energy sensor, both of which can be either external or intraoral to the patient. An apparatus according to another embodiment includes a first module configured to at least read data stored on a magnetic recording tape in a first range of formats, and at least a second module configured to at least read data stored on a magnetic recording tape in at least a second range of formats. The interpolation dynamically adjusts the phase of the interpolated output clock signal to correct for errors in the phase of said output signal.