Abstract: A fully automatic microcomputer-controlled tape cartridge handling system. As illustrated here, it has a high degree of redundancy providing maximum reliability in radio broadcasting service and other applications. It comprises two storage drums, four stacks of playback transducers, two cartridge transfer mechanisms, a loading chute, and an unloading chute. Each drum has a cylindrical configuration with 512 cartridge storage compartments arranged in 16 vertical columns around its circumference and 32 horizontal rows along its axis. Two transducer stacks and one transfer mechanism are on each side of the pair of drums. Each transfer mechanism is positioned adjacent both drums and positioned adjacent two of the transducer stacks, one of the transfer mechanisms also being adjacent the loading and unloading chutes. Each transfer mechanism has a cage which is selectively rotatably swingable to positions aligned with either drum or either adjacent transducer.