A Different Kind of Upgrade The Compact Disc is a spin-off of Laserdisc engineering science. Sony first publicly presented an optical digital audio disc in September 1976. In September 1978, they demonstrated an optical digital sound recording disc with provisions of 16-bit linear result, 44,056 Hz sample delivery rate, cross-interleaved error alteration system also with a 150 minute playing time, that were akin to those of the Compact Disc introduced