Abstract: A method and apparatus for arbitrating requests for access to a single buffer memory embedded within a disk drive in which a disk data channel is assigned a highest priority for buffer access within a queue. An arbitration cycle progressively services access requests pending within the queue, beginning with providing buffer access to the disk data channel and following with accesses to other channels during an arbitration cycle completion interval in accordance with a round-robin circular priority arrangement providing orderly access to all channels contending for memory access. At the end of completion interval, buffer access returns to the disk data channel, and thereafter, the arbitration cycle is repeated.

Abstract: A method for managing data blocks in a cache buffer defining date block segments, and for automatically transferring data into and out of the cache buffer. A cache list comprises a plurality of entries each including information identifying a corresponding cache segment, and a set of consecutive data blocks stored in the cache segment. Providing cache status for a requested set of date blocks includes traversing the cache list to locate entries identifying the starting data block in the requested set, and consecutive data blocks successively following the starting data block without interruption, and identifying as a missing data block the first data block in said succession, including said starting data block, not identified in any entry. The missing data block is used to provide status: a full hit if the missing data block is not in the requested set; a miss if the missing data block is the starting data block in the requested set, or a partial hit otherwise.

Abstract: An insulation displacement connector that includes a plurality of apertures disposed through a mating face and a ribbon-contacting face of the insulation displacement connector. The mating face is configured to mate with a complementary connector complementary in gender to the insulation displacement connector. The ribbon-contacting face is disposed opposite the mating face and configured for coupling with an interspersed ground conductor ribbon cable having a plurality of parallel insulated conductors. The insulation displacement connector includes a plurality of first conductor coupling structures. Each of the first conductor coupling structures is disposed in one of the plurality of apertures and is configured to couple to one of first designated conductors of the plurality of parallel insulated conductors and a contact on the complementary connector when the complementary connector is coupled to the insulation displacement connector at the mating face.

Abstract: A method of coordinating access to a data buffer including a plurality of data blocks, using a buffer list with a plurality of entries corresponding to the data blocks. Each buffer list entry includes: (i) a status code for indicating the status of data in the corresponding data block, and (ii) a partial address common to both the next buffer list entry and a data block corresponding to said next buffer list entry. A status code is selected from a cyclical set of sequential status codes having a period of N, the status codes sequentially, and alternately, representing the most recent history of a data block, including: (i) full status, indicating data in the data block has been retrieved from the storage device or is to be stored to the storage device, or (ii) empty status, indicating data transferred out of the data block to a host or to the storage device. A store flag maintains a status code representing empty status, and a retrieve flag maintains a status code representing full status.

Abstract: An insulation displacement connector that includes a plurality of apertures disposed through a mating face and a ribbon-contacting face of the insulation displacement connector. The mating face is configured to mate with a complementary connector complementary in gender to the insulation displacement connector. The ribbon-contacting face is disposed opposite the mating face and configured for coupling with an interspersed ground conductor ribbon cable having a plurality of parallel insulated conductors. The insulation displacement connector includes a plurality of first conductor coupling structures. Each of the first conductor coupling structures is disposed in one of the plurality of apertures and is configured to couple to one of first designated conductors of the plurality of parallel insulated conductors and a contact on the complementary connector when the complementary connector is coupled to the insulation displacement connector at the mating face.

Abstract: A programmable data sequencer transfers fixed length data blocks between variable length storage segments of a magnetic storage disk and a buffer memory within a data storage device. The data sequencer includes a stack memory for holding user byte count values read from a header field preceding each data sector having variable length split storage segments. Each byte count value indicates respective length of a following variable length storage segment, so that the storage capacity of each segment is dynamically determined by the data sequencer in real time by popping the user byte count value from the stack into a storage segment length counter and by counting down the count value within the segment length counter.

Abstract: A magnetic data storage disk record carries a pattern of magnetic domains defining a plurality of concentric data tracks divided into data sectors by embedded servo sectors recorded at a predetermined constant frequency and containing head positioning information for positioning a data transducer head for reading the disk track. Each data sector is recorded at a data transfer rate selected in relation to displacement of the track from a center of the disk. Each data sector defines a plurality of variable length data segments which are combined to provide a fixed length user data block. In order to avoid a write-to-read transition and Barkhausen noise, each data sector begins with an ID header immediately following a servo sector. The ID header includes a plurality of count byte fields for providing a count of bytes of each one of the user data segments within the data sector, and a flag field for indicating whether the user data block begins at the first data block segment of the particular data sector.

Abstract: A miniature disk drive achieves storage densities of at least approximately 1700 tracks per inch per storage surface of a storage disk defining a series of radially extensive servo sectors embedded within circumferential zones of data tracks. The sectors are recorded at a constant data transfer rate while each zone has a data transfer rate adapted to disk radius. The drive includes a head and head positioner, a read preamplifier for amplifying analog signals read from, and for amplifying signals to be written to, a storage surface.

Abstract: A method is provided for decoding a unique data sequence forming an address mark within a stream of RLL coded data values in order to start a byte clock for synchronizing operations within a data sequencer of a data storage system. The unique data sequence nominally comprises at least two adjacent sequences of zeros of a maximum permitted length occurring between three flux transitions under a predetermined RLL data code.