A flexible track drilling machine employs a pair of rails that are flexible in one direction to conform to a non-flat workpiece surface and are substantially stiff in a direction parallel to the workpiece surface. The anchoring system comprises an anchor pad and a retainer mounted upon the anchor pad. An anode of a first silicon controlled rectifier is formed in the first well. In one embodiment, the outer housing member can be made of glass and the one or more other housing members can be made of a polymer, such as plastic. The first serial data stream is transmitted over the first channel in response to an activated second control signal, while the second serial data stream is transmitted over the first channel in response to a deactivated second control signal.