Browse Prior Art Database

Data Code Servo

IP.com Disclosure Number: IPCOM000084500D
Original Publication Date: 1975-Nov-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Bleher, JH: AUTHOR

Abstract

Data on adjacent parallel tracks of a moving storage medium 1, such as a magnetic disk or tape, are alternately encoded, so that data on track N use code A data on track N+1 code B, data on track N+2 code A, etc. (code A, for example, may be a 3 out of 7 code and code B a 4 out of 7 code.)

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Data Code Servo

Data on adjacent parallel tracks of a moving storage medium 1, such as a magnetic disk or tape, are alternately encoded, so that data on track N use code A data on track N+1 code B, data on track N+2 code A, etc. (code A, for example, may be a 3 out of 7 code and code B a 4 out of 7 code.)

One data read head 3 and two servo read heads 2 fixed to a slider 4 scan the data, servo heads 2 scanning two adjacent tracks simultaneously. The servo head output signals are fed, via amplifiers 5, to low-pass filters 6. The outputs of filters 6 - one inverted by an analog inverter 7 - are applied to an analog summing network 8, the output of which is the analog servo information used for track following by mechanically centering slider 4.

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