Browse Prior Art Database

Disk Storage Apparatus

IP.com Disclosure Number: IPCOM000081237D
Original Publication Date: 1974-Apr-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 21K

Publishing Venue

IBM

Related People

Case, WJ: AUTHOR [+3]

Abstract

The magnetic disk storage apparatus shown schematically consists of a magnetic recording disk 1 mounted for rotation about a spindle 2. A data read/write head 3 is positioned above one surface of the disk 1 and two servo heads 4 and 5 are positioned above the opposite surface. All three heads are ganged together to be moved simultaneously to and fro across the surfaces of the disk by a suitable actuator mechanism. The actuator mechanism is not shown and movement of the heads is simply depicted by the double-headed arrow 6.

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Disk Storage Apparatus

The magnetic disk storage apparatus shown schematically consists of a magnetic recording disk 1 mounted for rotation about a spindle 2. A data read/write head 3 is positioned above one surface of the disk 1 and two servo heads 4 and 5 are positioned above the opposite surface. All three heads are ganged together to be moved simultaneously to and fro across the surfaces of the disk by a suitable actuator mechanism. The actuator mechanism is not shown and movement of the heads is simply depicted by the double-headed arrow 6.

Servo information associated with servo head 4 extends over region 8 of the disk and takes the form of a plurality of concentric servo tracks. Servo information associated with servo head 5 extends over region 9 of the disk and takes the form of a continuous spiral, having as many convolutions as there are servo tracks in region 8.

The information derived from these two servo regions is used in a closed- loop system to control the movement of the data head over a corresponding data region 7, in accordance with instructions received from an external control unit. Accessing of the data head from one track location to another is achieved under control of the information derived from servo head 4. The data head 3 is also held stationary in a "parked" position under control of information derived from these concentric servo tracks.

Whenever data is written, however, and subsequently read, the movement of the data head 3 is und...