Abstract: An optical disk cartridge has two opposed cartridge sections held together by four locking assemblies. Each locking assembly includes a first locking jamb attached to one section, a second locking jamb attached to the other section, a locking detent and a spring. The jambs can be locking fingers parallel to and adjacent to one another when the cartridge sections are joined, in which case the detent surrounds the fingers as a sleeve, preventing the fingers from moving apart. The spring biases the detent into locking engagement with the fingers, keeping the cartridge closed. Alternatively, the jambs can be aligned slots in the cartridge top and bottom sections, with each detent having a protrusion that enters its associated slots. The spring and most of the detent are contained inside the cartridge. However, each detent includes a leg extended outside the cartridge through an aperture in the cartridge side wall. Also disclosed is a drive apparatus for use with the cartridge.