Abstract: A data storage unit includes multiple media processors that are each moveable between a transfer position and a corresponding standby position, and are able to receive a storage medium. A shuttle assembly moves a selected one of the media processors between the transfer position and the corresponding standby position. A magazine is provided with a plurality of compartments that are each able to receive a storage medium. A magazine drive assembly moves the magazine so as to move a selected one of the compartments into the transfer position. A transfer assembly transfers a storage medium between the selected media processor and the selected compartment while the selected media processor and the selected compartment are in the transfer position. A controller controls the operations of the shuttle assembly, magazine drive assembly, and transfer assembly.