An output driver circuit for a semiconductor device. The method comprises placing a trabecular shunt through diseased trabecular meshwork, between the anterior chamber and Schlemm’s canal. A keyboard may comprise a plurality of spaced apart units in groups operable by respective fingers. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. The surround is retained within the seat by the combination of an o-ring in contact with the surround, and a C-shaped clamp having an upper arm which engages the o-ring and a lower arm releasably mounted to the upper end of the frame.