Abstract: A digital data storage unit having: a multiplicity of media storage slots for receiving a plurality of storage media units, each storage media unit including a storage medium and a memory device (MD) for storing data, the memory device including an interface for transferring data to and from the memory device; one or more media data transfer devices physically distributed within the digital data storage unit in relation to the storage media slots for transferring data to and from the storage medium in each storage media unit; a loader mechanism for selectively moving a storage media unit between a storage media slot and said media data transfer devices for transferring data to or from the storage medium in the storage media unit; at least one memory data transfer device (MDTD) including a memory device interface for transferring data to and from the memory device of one or more storage media units; and a controller within the digital data storage unit, configured for controlling the loader mechanism to move s