Browse Prior Art Database

Disk Surface Digital Addressing

IP.com Disclosure Number: IPCOM000098997D
Original Publication Date: 1967-Nov-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Wilford, CR: AUTHOR [+3]

Abstract

This method of interspersing servo information with data allows the tracks to be recorded closer together. This is because the addressed data head also provides the servo track-following information.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Disk Surface Digital Addressing

This method of interspersing servo information with data allows the tracks to be recorded closer together. This is because the addressed data head also provides the servo track-following information.

Each data track 10 is divided into a plurality of data fields 11, each preceded by a servo sector 12. The latter contains information for synchronization, track following, and on-track and offset-track addresses. Each sector 12 contains four fields of data. The first field 13 comprises a sector pulse recorded both on and between tracks. The sector pulse is arranged to synchronize a phase-locked oscillator which provides timing information until the next sector 12 is read.

The second field 14 comprises the address of each track to provide coarse position information. The third field 15 comprises another synchronization field, but recorded only between tracks and in which alternate tracks are recorded in opposite phase to thus provide track following information. The fourth field 16 comprises the track addresses offset between tracks to coincide with field 15. Again, alternate tracks are recorded in opposite phase to provide track-following information.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]