A disc apparatus includes a readout unit, an audio signal output unit, a memory, a switch, and a controller. The readout unit reads out data from a disc wherein the data includes at least digital audio data. The audio signal output unit produces an audio signal output in accordance with the digital...http://www.google.com/patents/US5748585?utm_source=gb-gplus-sharePatent US5748585 - Disc apparatus for selectively outputting data from a disc and a memory
