Abstract: Random access peripheral data storage apparatus for use with microcomputers comprising a drive unit including a housing containing two separate selectively operated film transport mechanisms for respectively engaging and driving two endless loops of magnetic recording film separately contained in two identical and interchangeable cartridges of unique construction which are adapted to be manually loaded on the drive unit. The drive unit additionally includes a "flying" read/write head which moves back and forth laterally across respective access ports in the cartridges to selectively access either film, with the film being completely contained inside of the respective cartridges and being substantially inaccessible except for a read/write head access port.