Abstract: An interlock system is provided for removable-media drive unit to prevent the drive loader from attempting to pull in and mount a data cartridge before it is released by a mechanical gripper or human hand. The interlock system includes a light source and a photodetector positioned in front of the drive on opposite sides of the path cartridge takes when it is being inserted or removed from the drive loader. The presence of the cartridge, gripper or other object in the path interrupts a light beam from the light source thereby signalling the drive controller to disable the drive loader. When the gripper has released the cartridge and withdrawn, or when the path is otherwise clear, the photodetector again detects the light beam and signals the drive controller that the loader can be safely enabled. In one embodiment, the light source and photodetector are mounted on a card which plugs into the face of the drive.

Abstract: A magazine is provided for storing a plurality of cartridges for processing and provides an operator with a visual indication as to the processing status thereof. The magazine includes a base and a pair of elongated sidewalls which are mounted to the base in a spaced-apart relationship so as to receive the cartridges therebetween. A plurality of shelves are connected between the sidewalls of the magazine at spaced intervals therealong for slidably supporting the cartridges. The magazine sidewalls and shelves form a plurality of receptacles, each receptacle having oppositely located open ends so that each receptacle will accommodate the travel of a cartridge therethrough as the cartridge slides on the shelf. First and second stop devices are mounted within each receptacle for stopping travel of a cartridge through the receptacle at first and second positions therealong.