Abstract: An optical disk drive system with which data may be permanently and correctly stored on removable media. The system includes a drive into which the media, a disk housed in a cartridge, may be removably inserted. The drive interfaces with a host CPU through a storage control unit, which storage control unit may also have other peripheral devices, such as magnetic disk drives, coupled therethrough to the host CPU. A special data format is used for data stored on the disk in order to provide efficient use of and access to the available storage space. The disk is divided into data bands, each data band having a prescribed number of concentric data tracks therein. Each data track is divided into equal length sectors. The data is organized into data blocks, each block being made up of a selected sequence of prescribed data sections. Many of the data sections commence with synchronization bits followed by the data to be stored. The data of each data section is adapted to fit within each data sector on the disk.

Abstract: A generic key, for allowing a data use to efficiently search a set of user data recorded in blocks in an efficient method using a multiplicity of user keys. As user data blocks are built up for recording, the unique identifiers are placed in the header of the data block, recorded on the disk surface with the contents stored on the device and the platter index. The user can then sort and search the index based upon which of the multiplicity of user keys he selects.

Abstract: In extended for a digital information storage device comprised of a host having the capability of placing Key identifiers in the header of user data blocks to be recorded, a recording device having a random access memory said memory having an Index register, a plurality of Pointer Table registers, a Target register, a Key Start register, a Key Length register and a Pointer Table Select register, and a micro-processor able to perform an indirect binary search between a selected Pointer Table the contents of the Pointer Table being the address from the Index (the address being the band location, and the register contents of the Index being the Identifier Keys selected by the host, said Keys being the lowest Key entry on any given band).