A plurality of heavy mass irregularities attached to an inner wall of the drill collar attenuate waves traveling through the collar. The silicon and insulating layers contain either or both of at least one continuous cavity filled with materials such as to constitute a photodetector zone, or at least one continuous cavity filled with materials such as to constitute a light source zone. A system BIOS identifies one of the first and second video adapters 203, 207 as a primary video adapter and the other of the first and second video adapters 203, 207 as a secondary video adapter. The method also comprises the step of searching through the candidate fragments using window sizes which fall within the reference window size range to select a minimum number of consecutive RBs sufficient to empty data stored in the transmission buffer. One steering handle bar is is supported by split couplers or connectors coupled to each top fork portion of the left and right front legs. Three different settings 64, 16 and 2 are enabled as the number of gray scale levels in an electro-optical apparatus, the number of subfields becoming smaller as the number of gray scale levels is reduced.