1
Robert L Cloke, Richard W Hull, Vafa James Rakshani, David P Turner: Disk drive employing read channel IC with common port for data and servo. Western Digital, Milad G Shara, August 21, 2001: US06278568 (203 worldwide citation)

A disk drive includes a disk having a disk surface. The disk surface has a plurality of tracks arranged in an embedded servo format including servo track segments for storing servo data and data track segments for storing user data. Data from the disk surface is read to produce a time-multiplexed an ...


2
Robert Leslie Cloke, Richard W Hull, Vafa James Rakshani, David Price Turner: Disk drive employing state variable trap registers for providing stored servo and user data state variables to sampled-data channel. Western Digital Corporation, Milad G Shara, January 23, 2001: US06178056 (156 worldwide citation)

A disk drive includes a disk surface having a plurality of tracks arranged in an embedded servo format including servo track segments for storing servo data and data track segments for storing user data. The disk drive includes a read element operative during a user-data read operation for reading d ...


3
Richard W Hull, David B Joan, Charles R Patton III, Vafa James Rakshani, Charles W Simmons: Method and apparatus to compensate for servo wedge rotational offset after a head switch. Western Digital Corporation, Milad G Shara, May 23, 2000: US06067206 (154 worldwide citation)

A disk drive controller having a microprocessor and a sampled signal head positioning system measures and stores the relative rotational offsets between heads arranged in a stacked relationship and respective servo wedges on different disk surfaces. The offsets are stored in a table and subsequently ...


4
Richard W Hull, Hoover K Jung, Sanjay S Mathur: Disk drive with unified channel-disk controller bus for transmitting user data, servo data, and register data. Western Digital Technologies, Milad G Shara, July 2, 2002: US06415349 (153 worldwide citation)

A disk drive has a unified bus forming a signal path for transmitting register data, user data and servo sectors. The unified bus is connected between a channel circuit and a disk controller circuit. The channel circuit has an output stream engine which responds to and provides control signals to mu ...


5
Alireza Atai Azimi, Richard W Hull, Mark F Vallis: Disk drive employing a non-volatile serial semiconductor memory for storing a control program for a microprocessor. Western Digital Technologies, Jason T Evans Esq, Howard H Sheerin Esq, April 11, 2006: US07028174 (144 worldwide citation)

A disk drive is disclosed comprising a microprocessor, a non-volatile serial semiconductor memory for storing code segments of a control program, a first semiconductor memory for storing code segments of a loader program, and a second semiconductor memory for receiving the code segments of the contr ...


6
Robert L Cloke, Vafa James Rakshani, Richard W Hull, David P Turner: Computer system comprising a host connected to a disk drive employing state variable trap registers for providing stored servo and user data state variables to sampled-data channel. Western Digital Technologies, Milad G Shara Esq, November 26, 2002: US06487032 (140 worldwide citation)

A computer system is disclosed comprising a host connected to a disk drive, the disk drive comprising a disk surface having a plurality of tracks arranged in an embedded servo format including servo track segments for storing servo data and data track segments for storing user data. The disk drive i ...


7
Robert L Cloke, David P Turner, Richard W Hull, Vafa James Rakshani: Computer system comprising a host connected to a disk drive employing read channel IC with common port for data and servo. Western Digital Technologies, Milad G Shara Esq, February 11, 2003: US06519104 (136 worldwide citation)

A computer system is disclosed comprising a host connected to a disk drive, the disk drive comprising a disk having a disk surface. The disk drive further includes a controller and a channel integrated circuit chip. The controller includes a controller port. The channel integrated circuit chip inclu ...


8
Richard W Hull, Hoover K Jung, Sanjay S Mathur: DISK DRIVE HAVING A CHANNEL CIRCUIT WHICH RECEIVES A READ SIGNAL REPRESENTING DATA IN A DATA SECTOR AND DATA IN A SERVO SECTOR IN A FIRST ORDER AND DEMODULATES THE READ SIGNAL TO PROVIDE DATA SECTOR DATA AND SERVO-SECTOR DATA IN A SECOND ORDER. Western Digital Technologies, Milad G Shara Esq, Young Law Firm, June 17, 2003: US06580573 (126 worldwide citation)

A disk drive has a channel circuit for demodulating data sectors and servo sectors stored on a rotating medium to provide data-sector data and servo-sector data. The channel circuit transmits the data-sector data and servo-sector data to a disk controller circuit in an order which is different than ...


9
Richard W Hull, Donald E Tolsch, James H P Wang: High order digital phase-locked loop system. Western Digital Corporation, Spensley Horn Jubas & Lubitz, February 28, 1989: US04808884 (46 worldwide citation)

A digital data separator operates to separate data pulses from clock pulses in MFM encoded signals read from a magnetic disk system. The data separator includes a digital phase-locked loop system incorporating a variable length shift register which functions as a variable oscillator and programmed s ...


10
Timothy G O Shaughnessy, David K Chung, Richard W Hull, Kenneth W Ouyang, Victor G Pierotti, Joseph A Souza: Method and apparatus for reducing transient noise in integrated circuits. Western Digital Corporation, Christie Parker & Hale, August 7, 1990: US04947063 (38 worldwide citation)

The transient noise generated at the output drivers of an integrated circuit chip is reduced by maintaining an increasing ramp shaped current through each output driver during the entire transition interval between binary states of a capacitive load. A capacitor fed by a fixed current source is conn ...