A data playback system in which multiple disks are stored in a magazine. A first random number is generated to select one of the disks believed to be present in the magazine, or temporarily, on the turntable. The disk is fetched and it is determined if the disk exists. If not, it is eliminated from a catalog and the disk selection is reflected. Then a table of contents is read, either from the disk or, if used, from a previously stored random access memory. A second random number selects the piece of data on the selected disk for playing. If the table of contents is stored in random access memory, it is completed as the information becomes available. Then process is repeated for other randomly selected disks and pieces.