Quantum Corporation

James H Do

Bruce R Peterson

Clifford M Gold

Michael G Machado

Daniel E Barnard

William G Moon

Thomas A Tacklind

Ronald R Moon

James A Henson

Tim R Glassburn

James P McGrath

Michael L Raab

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.

Miniature disk drive having embedded sector servo with split data fields

An improved disk drive architecture includes a microcontroller interface circuit connected between a drive microcontroller and a buffer controller. The microcontroller interface circuit includes address mapping registers for mapping at least one predetermined portion of directly addressable memory of the microcontroller to address locations of the drive's cache buffer. The buffer controller circuit includes an access arbitration circuit for arbitrating requests for access to the cache buffer by the drive's data sequencer, the drive's host interface controller and the drive's microcontroller. A microcontroller wait state generator responds to the access arbitration circuit by generating and applying a wait state sequence to the microcontroller until a request it makes for access to the cache buffer can be executed.

Shared memory array for data block and control program storage in disk

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. A circuit board carries drive electronics including a read channel, a servo processing circuit for recovering head location information from the servo sectors, a data block sequencer for sequencing data blocks between a buffer and the storage surface, a buffer memory controller for controlling the buffer, a bus level interface circuit for transferring data blocks between the buffer and a host computer, and a programmed digital controller which functions within a head position servo loop and which also controls the sequencer, buffer controller and bus level interface circuit. As one feature, the servo sectors split data blocks into segments. Segment byte counts in each data block header are used by the sequencer automatically to assemble the segments into data blocks during read and to divide the blocks into segments during write. A single VLSI circuit including the sequencer, servo processing circuit, memory controller and an interface to the microcontroller is disclosed.

High capacity submicro-winchester fixed disk drive

Growing community of inventors

Milpitas, CA, United States of America

James H Do