04669004 is referenced by 159 patents and cites 16 patents.

A high performance, low cost rotating disk data storage subsystem includes a head and disk assembly. A plurality of sectors in data tracks include a servo portion containing a prerecorded pattern of a plurality of repeating, time staggered, non-phase-coherent bursts, each burst having a predetermined integral fraction radial offset relative to the other bursts and having a constant frequency preamble field followed by a unique value field related to its burst spatial location. A head is positionable relative to the tracks in response to information derived from a servo portion, a programmed microcontroller supervisor for receives operational data storage and retrieval commands from a host system with which the subsystem is operationally associated and controls the position of the head during track seeking and following operations in response to servo information read by the head from each servo portion and further in response to the commands, an interface under the control of the microcontroller supervisor receives the commands and data blocks from the host system and for sending commands, status words and data blocks to the host system, a data sequencer and memory controller under the control of the microcontroller manages flow of data blocks to and from the disk via the head and stores the information read by the head means from said unique value fields for subsequent processing by the microcontroller. A servo burst pattern providing phase quadrature and absolute position information, a servo writer, a servo qualification area and a timer, a media defect management method, an amplitude measurement circuit, and a time division control program for the microcontroller are aspects of this invention.

Title
High capacity disk file with embedded sector servo
Application Number
6/834009
Publication Number
4669004
Application Date
February 27, 1986
Publication Date
May 26, 1987
Inventor
Hoa V Luong
Milpitas
CA, US
Tuong T Quan
San Jose
CA, US
Steven G Campbell
San Jose
CA, US
Gregg J Uhlendorf
San Jose
CA, US
Mark E Strysko
Sunnyvale
CA, US
Curtis H Bruner
Los Gatos
CA, US
Patrick M Weiher
Los Altos
CA, US
Thomas G Cooper
Palo Alto
CA, US
Michael G Machado
San Jose
CA, US
Ronald R Moon
Santa Clara
CA, US
Agent
David B Harrison
Assignee
Quantum Corporation
CA, US
IPC
G11B 5/56
G11B 5/55
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