For several years the DJ's of most dicotheques are working with audio CD's and the CD archives, cases and wall closets fill more and more each year. You cannot expect of an allround DJ in this time to have all his CD's with him at all opportunities again and again CD's are being lost or get damaged when used in a professional way. Additionally it is getting harder to overlook the whole music archive. The high speed development of the computer technology and storage media on one hand and of certain compressing algorithms on the other made it possible for the first time to store, play back and archive larger amounts of audio data without an audible loss of quality on a PC. It was an obvious consequence to create a product with these technologies relieving the DJ in a professional environment from audio CD's. Additionally there would be further invaluable advatages in using a PC in a discotheque, such as fast search functions within the whole music archive or the ability to prepare complete music sets and getting back on past music sequences. The main target was to satisfy professional needs with all developments. In cooperation with DJ's the development of the software got put on the way and, at the same time a 19" control unit was designed resembling known double CD players in structure and function. This control unit is a must for the professional use.