Abstract: The coaxial reel tape cartridge uses a lengthy tape path within the tape cartridge to reduce the stresses on the tape medium as it is transported between the two reels. The tape is drawn from each reel around a corresponding rotating guide element which is coplanar with the tape reel. The tape is then transported along one side of the tape cartridge exterior housing to a corresponding hydrostatic bearing which is located at a corner of the tape cartridge adjacent the tape access opening. The hydrostatic bearing is coplanar with the tape guide, but at a slight angle with the vertical to thereby impart a slight twist to the tape as it traverses the length of the tape cartridge. The two hydrostatic bearings are located inside of and at opposite ends of the tape cartridge exterior housing, flanking the tape access opening. The two hydrostatic bearings are attached to a base plate which maintains the hydrostatic bearings coplanar with respect to each other.

Abstract: A data storage system includes a data storage medium, such as a magnetic tape, that has a first control data storing area or drive partition that is addressable only by a peripheral drive mounting the medium and a plurality of other addressable data storing partitions for storing data. A volume table of contents may be stored in one of the addressable partitions. A tachometer measures and indicates physical locations on the storage medium. Each of the partitions have an extent on the storage medium indicated by said physical locations. The control data in the drive partition includes directories of medium control blocks, such as tape marks, defect marks and the like; directory of all addressable partitions including the physical locations at the beginning of each partitions and other medium physical and logical parameter data. A so-called mount-demount medium control block in the drive partition indicates a demount status that shows all data stored in the drive partition is valid.