A bit block transfer circuit includes a read register, a write register, a bit shifting circuit and an overflowing register. It also includes a means that applies the probe beam to the target to be analyzed, combines the probe and reference beams interferometrically, detects concurrent interferometric signals and correlates the detected signals with previously stored electronic data to determine the attribute of the target. Slots are used to store fragments. This feature is shaped to engage and hold the canted clip found on the first end of the surform file. At least two riser elements may be stacked respectively on at least two riser clusters. Through-holes are formed in four corners of a pan receiver, upwardly protruding pieces of a plate spring fixed to a bottom surface of the pan receiver are inserted into the through-holes, and pan receiver legs are attached to the upwardly protruding pieces.