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Randomizing Head Load Positions in a Diskette Drive

IP.com Disclosure Number: IPCOM000045440D
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Ashbee, WH: AUTHOR [+2]

Abstract

A common problem in diskette drives is frequently accessed data sectors may develop a wear spot on the recording disk. Because the disk is driven at a constant speed and because the average interval between lift-off and landing of the head on the disk is relatively constant, the head tends to land on the disk at the same point in a given track. Such a wear spot is depicted in Fig. 1 as spot 10 on flexible recording disk 12. The program shown as a flowchart in Fig. 2 can be used in a microprocessor-controlled diskette drive to randomize the landing area of the head so that a wear pattern developes substantially uniformly along the track, as depicted by wear spots 14 in Fig. 1.

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Randomizing Head Load Positions in a Diskette Drive

A common problem in diskette drives is frequently accessed data sectors may develop a wear spot on the recording disk. Because the disk is driven at a constant speed and because the average interval between lift-off and landing of the head on the disk is relatively constant, the head tends to land on the disk at the same point in a given track. Such a wear spot is depicted in Fig. 1 as spot 10 on flexible recording disk 12. The program shown as a flowchart in Fig. 2 can be used in a microprocessor-controlled diskette drive to randomize the landing area of the head so that a wear pattern developes substantially uniformly along the track, as depicted by wear spots 14 in Fig. 1.

An example of a microprocessor controlling the disk speed in a diskette drive is described in the article entitled "Zone Recording Flexible Diskette Drive via Microprocessor Control", by R. F. Herald and W. P. Quinlan, published in the IBM Technical Disclosure Bulletin 23, 5068-5069 (April 1981). The random speed program represented by the high level flowchart in Fig. 2 may be used with such a microprocessor-controlled disk speed system. The purpose of the random speed program is to drive disk 12 at randomly selected speeds when the head is not in contact with the disk. By so driving the disk, the point at which the head will be loaded onto the disk when a head load command occurs is randomized.

After the head is lifted off the surface of d...