An Evolutionary Process
For many years, the Sony PCM1630 digital processor and Umatic tape were the standard for CD cutting masters. In the late 1980’s, Doug Carson and Associates, who specialize in manufacturing hardware and software, wrote an LBR mastering scheme called Disc Description Protocol (DDP) utilizing 8mm Exabyte tapes as the mastering medium. This was used for many years for the mastering of Yellow Book CD-ROMS. Later, it was adapted for use as a Red Book mastering medium to replace the aging 1630. The audio was converted to data, then transferred the tape as a CD image utilizing the Yellow Book standard error correction CIRC. In the late 1990’s, manufacturing plants began accepting Red Book CD-R’s as cutting masters. Red Book CDs use a different error correction scheme allowing each CD player to evaluate, correct, and even interpolate errors.