Daniel P Curran

US Patent:

D3473945, May 31, 1994

Filed:

Jan 14, 1993

Appl. No.:

D/003777

Inventors:

Daniel J. Schlesinger - Hammond IN
Daniel C. Curran - Pine CO

US Classification:

D10 65

US Patent:

55439756, Aug 6, 1996

Filed:

Sep 23, 1994

Appl. No.:

8/311832

Inventors:

Daniel J. Curran - Fort Collins CO

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G11B 509

US Classification:

360 45

Abstract:

A method for removing precompensation in a Write Data signal from a flexible disk controller. A timer measures the time between consecutive transitions. Numerical values from the timer are delayed in a buffer. Numerical times from the buffer are compared to numerical ranges by an array of parallel numerical comparators. Numerical times corresponding to precompensation ranges are numerically compensated. The compensated values are then used to control the time between transitions in a regenerated Write Data signal.

US Patent:

54125162, May 2, 1995

Filed:

Nov 12, 1993

Appl. No.:

8/151598

Inventors:

Ronald R. Kennedy - Fort Collins CO
Daniel J. Curran - Fort Collins CO

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G11B 1512

US Classification:

360 62

Abstract:

A data storage system such as a tape drive or flexible disk drive having a dual-gap head being controlled by a dual-mode flexible disk controller. The flexible disk controller has a first mode designed to use a head having one section for perpendicular reading and writing and a second section for erasing. The flexible disk controller has a second mode designed to use a conventional flexible disk head having a single gap for reading, writing and erasing. The data storage system has a head which has one relatively long gap optimized for overwrite/erase capability and a separate shorter read-only gap optimized for reading high bit densities. The data storage system uses the flexible disk controller in its first mode for formatting and writing and in its second mode for reading. When the controller is being used in a perpendicular recording mode, the head design with the write section offset from the erase section requires extended formatted sector fields. The data storage system takes advantage of these extended formatted data sector fields to accommodate a dual-gap head with an offset between the read gap and the write gap.