A digital to analog converter converting digital data into a corresponding analog voltage is disclosed. The trailer includes a forward support section including a first tubular frame having a main body portion with a first upper platform and rear interface side, and forward trailer neck; a pair of caster wheels attached proximate said rear interface; and a first planar deck substantially covering the first upper platform. The optical system also includes an optical fiber optically coupled to the first waveguide and bounded to the substrate. Operations in the heap may be pipelined so as to provide for high-speed sorting.