An optical device for viewing an image is provided. The piston incorporates an actuating member. In an aspect, a slew rate control, having a delay mixer, selects and individually transmits to individual segments of a driver leg, at a desired time, one of output data and a signal for a pre-emphasis version of output data. If such a medium does not exist, then the set of available media is canvassed to locate an alternative medium. For example, in accordance with an embodiment of the present invention, techniques are disclosed for providing glitch-free output data from a memory through feedback of the output data signal.