Abstract: A dual-purpose robotic picker apparatus for picking entire magazines of data storage cartridges as well as individual data storage cartridges in an automated data storage library. The multi-slot picker combines a detachable magazine and a "through-the-magazine" cartridge manipulator to function as a multi-gripper picker. A first magazine gripper acts to hold a multi-cartridge magazine. A second cartridge picker acts to move cartridges in and out of the magazine. An indexing mechanism moves the detachable magazine with respect to the cartridge gripper, permitting random access to the cartridges held within the magazine. The gripper mechanism can transport cartridges automatically within the library, either in magazines or as individual cartridges. The combination of multi-slot picking and bulk cartridge movement functions sharply increases library efficiency and data storage cartridge loading speed.