Browse Prior Art Database

Automatic Head Recalibrate

IP.com Disclosure Number: IPCOM000041607D
Original Publication Date: 1984-Feb-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Ashbee, WH: AUTHOR [+2]

Abstract

The recalibration of the access mechanism against an inner reference stop is supervised by software in a microcomputer that controls the access mechanism. The microcomputer remembers the track position unless power is turned off. Therefore, during a recalibration, if power has not turned off, the access mechanism is only driven the number of steps necessary to move the mechanism to the reference stop. After the mechanism has been recalibrated by striking the reference stop, the microcomputer moves the access mechanism so that the head goes directly from the reference position to the addressed track without accessing track zero. A flowchart for the recalibration process is shown on the preceding page.

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 72% of the total text.

Page 1 of 2

Automatic Head Recalibrate

The recalibration of the access mechanism against an inner reference stop is supervised by software in a microcomputer that controls the access mechanism. The microcomputer remembers the track position unless power is turned off. Therefore, during a recalibration, if power has not turned off, the access mechanism is only driven the number of steps necessary to move the mechanism to the reference stop. After the mechanism has been recalibrated by striking the reference stop, the microcomputer moves the access mechanism so that the head goes directly from the reference position to the addressed track without accessing track zero. A flowchart for the recalibration process is shown on the preceding page. In this process it is assumed that the diskette has 40 tracks; track zero is the outermost track; the reference stop is the equivalent of track 41 position. Of course, the process could be modified to work with more than 40 tracks and with track zero defined as the innermost track. Decision 10 checks whether the diskette has been changed since the last access. If not, the recalibration process is skipped. The mechanism moves NOLD-NNEW track positions to locate the head at the new track. Decision 12 checks whether the present access is the first access after "power on." If the answer is yes, the computer has no memory of prior track position so it assumes the head is as far away from the reference position as possible (45 tracks -- 41 tracks...