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Rotating Record Disk Initialization for Sector Servoing

IP.com Disclosure Number: IPCOM000089271D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 3 page(s) / 53K

Publishing Venue

IBM

Related People

Dennison, JC: AUTHOR [+4]

Abstract

In a flexible disk storage with a single transducer cooperating with a single disk surface, servo signals for track seeking and following are interleaved between data signals. Initialization comprises recording patterns of positioning information signals along sectors of the track locating lines. In this system auxiliary signals are temporarily recorded in data sectors for accurately locating servo signal patterns, without using additional external positioning devices. The surface quality of the data sectors is verified at the same time.

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Rotating Record Disk Initialization for Sector Servoing

In a flexible disk storage with a single transducer cooperating with a single disk surface, servo signals for track seeking and following are interleaved between data signals. Initialization comprises recording patterns of positioning information signals along sectors of the track locating lines. In this system auxiliary signals are temporarily recorded in data sectors for accurately locating servo signal patterns, without using additional external positioning devices. The surface quality of the data sectors is verified at the same time.

Magnetic disk 1 of Fig. 1 is divided into servo sectors S1 and data sectors S2. Signals are written and sensed by transducer 2 mounted on access arm 3. The radial position of arm 3 is controlled by processor unit PU via access motor
M.

Fig. 2 diagrammatically illustrates the signal patterns. Triburst sets of servo marks F, G, H are overlappingly arranged in sectors S1.

The recording of the servo signals generated by PU is initiated by writing burst F1 into sectors S1 and auxiliary bursts F1' into sectors S2 by means of double track width transducer 2' positioned in outermost track C1. During the following disk revolutions, signals F1, F1' are read back for surface quality verification.

Upon completion of this check, PU radially shifts transducer 2' into the next track position by comparing the amplitude of the full-scale signal with a predetermined fractional value thereof, say, 50 %. Transducer 2' then has moved from centerline C1 to centerline C2.

Bursts G1, followed by auxiliary bursts G1', are written at close spacing T1 from preceding bursts F1, using the end of F1 as a time reference.

Similarly, by repeating this sequence, bursts H1 and auxiliary bursts H1' are written after transducer 2' has been shifted to centerline C3, using the 50 % ...