David L Detro

US Patent:

6459540, Oct 1, 2002

Filed:

Sep 4, 2001

Appl. No.:

09/946414

Inventors:

Kelly J. Beavers - Boulder CO
Michael A. Blatchley - Longmont CO
David L. Detro - Longmont CO
Christopher J. Turner - Longmont CO
Thomas E. Zaczek - Louisville CO

Assignee:

Exabyte Corporation - Boulder CO

International Classification:

G11B 1546

US Classification:

360 7308

Abstract:

A method and apparatus for varying track recording speed to maximize host-to-tape data transfer rates is presented. Variable data transfer rates of host systems and networks are accommodated by continually adjusting the tape speed to match the tape drive to the hosts actual transfer rate. The speed of the tape is adjusted according to both the level of data present in the tape drive data buffer and whether the current mode of the drive is write mode or read mode. In the preferred embodiment, when the tape speed is accelerated or decelerated while writing a number of data track pairs to tape, a predetermined number of dummy track pairs are first written to tape at the current speed. On the next write head phase after the speed is increased or decreased as appropriate while the read heads are over the track, a predetermined number of dummy track pairs followed by more data track pairs are written to the tape at the new speed.

US Patent:

7277842, Oct 2, 2007

Filed:

Apr 3, 2001

Appl. No.:

09/825267

Inventors:

Michael A. Blatchley - Longmont CO, US
David L. Detro - Longmont CO, US
Paul Dunn - Longmont CO, US

Assignee:

Tandberg Data Corporation - Boulder CO

International Classification:

G06F 9/14
G11B 15/10
G11B 21/04
G11B 31/00

US Classification:

703 21, 360137, 360271

Abstract:

A helical scan drum design for use in non-tracking tape devices which assures 70% coverage of a track to be read by overscanning with at least two read heads at approximate 1X speed. The present invention further provides a simulation method for evaluating potential drum designs for such overscan applications. The preferred drum design uses pairs of read heads having identical azimuth angles and positioned on the rotating drum such that in combination they overlap the scan of a track by 130% the track width. These dimensions assure at least 70% coverage of each track by at least one of the pair of heads at up to 1X speed while assuring no overlap with another recorded track recorded along an identical azimuth angle. The simulation method allows for evaluation of potential drum designs by accepting parameters describing the intended drum application and then simulating track read operations over a plurality of simulated tracks to determine the efficacy of the design over a range of tape speeds and gap widths. Designs that simulate successful reading of a sufficient threshold number of tracks over a sufficiently broad range of tape speeds may then be selected for further test and evaluation.

US Patent:

20030001036, Jan 2, 2003

Filed:

Aug 15, 2002

Appl. No.:

10/219434

Inventors:

Kelly Beavers - Boulder CO, US
Michael Blatchley - Longmont CO, US
David Detro - Longmont CO, US
Christopher Turner - Longmont CO, US
Thomas Zaczek - Louisville CO, US

International Classification:

B65H059/38
G11B027/36
G11B015/46

US Classification:

242/334500, 360/073060, 360/031000

Abstract:

A method and apparatus for varying track recording speed to maximize host-to-tape data transfer rates is presented. Variable data transfer rates of host systems and networks are accommodated by continually adjusting the tape speed to match the tape drive to the host's actual transfer rate. jThe speed of the tape is adjusted according to both the level of data present in the tape drive data buffer and whether the current mode of the drive is write mode or read mode. In the preferred embodiment, when the tape speed is accelerated or decelerated while writing a number of data track pairs to tape, a predetermined number of dummy track pairs are first written to tape at the current speed. On the next write head phase after the speed is increased or decreased as appropriate while the read heads are over the track, a predetermined number of dummy track pairs followed by more data track pairs are written to the tape at the new speed.

US Patent:

62465511, Jun 12, 2001

Filed:

Oct 20, 1998

Appl. No.:

9/176013

Inventors:

Michael A. Blatchley - Longmont CO
David L. Detro - Longmont CO
Paul Dunn - Longmont CO

Assignee:

Ecrix Corporation - Boulder CO

International Classification:

G11B 552

US Classification:

3602715

Abstract:

A helical scan drum design for use in non-tracking tape devices which assures 70% coverage of a track to be read by overscanning with at least two read heads at approximate 1. times. speed. The present invention further provides a simulation method for evaluating potential drum designs for such overscan applications. The preferred drum design uses pairs of like-azimuth read heads positioned on the rotating drum such that in combination they overlap the scan of a track by 130% the track width. These dimensions assure at least 70% coverage of each track by at least one of the pair of heads at up to 1. times. speed while assuring no overlap with another like-azimuth recorded track. The simulation method allows for evaluation of potential drum designs by accepting parameters describing the intended drum application and then simulating track read operations over a plurality of simulated tracks to determine the efficacy of the design over a range of tape speeds and gap widths. Designs that simulate successful reading of a sufficient threshold number of tracks over a sufficiently broad range of tape speeds may then be selected for further test and evaluation.

US Patent:

63077019, Oct 23, 2001

Filed:

Oct 20, 1998

Appl. No.:

9/176079

Inventors:

Kelly J. Beavers - Boulder CO
Michael A. Blatchley - Longmont CO
David L. Detro - Longmont CO
Christopher J. Turner - Longmont CO
Thomas E. Zaczek - Louisville CO

Assignee:

Ecrix Corporation - Boulder CO

International Classification:

G11B 1546

US Classification:

360 7308

Abstract:

A method and apparatus for varying track recording speed to maximize host-to-tape data transfer rates is presented. Variable data transfer rates of host systems and networks are accommodated by continually adjusting the tape speed to match the tape drive to the host's actual transfer rate. The speed of the tape is adjusted according to both the level of data present in the tape drive data buffer and whether the current mode of the drive is write mode or read mode. In the preferred embodiment, when the tape speed is accelerated or decelerated while writing a number of data track pairs to tape, a predetermined number of dummy track pairs are first written to tape at the current speed. On the next write head phase after the speed is increased or decreased as appropriate while the read heads are over the track, a predetermined number of dummy track pairs followed by more data track pairs are written to the tape at the new speed.