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Subsystem Verification of SEEK Addresses

IP.com Disclosure Number: IPCOM000077117D
Original Publication Date: 1972-Jun-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Jones, RA: AUTHOR [+3]

Abstract

Verification of cylinder and track position on a direct-access storage device can be achieved, by recording the cylinder and head number of the track immediately preceding every count field and every home address field on the track. This information can be checked and corrected by the error-correction function of the system. When reading or clocking home address and count fields, this information can be read in, corrected by the error-correction facility, if necessary, and compared with the current cylinder and track number of the direct-access storage device established by the last seek or recalibrate command. If they match, all is in order and the track position is verified. If they do not match, the access arm can be repositioned by the subsystem, using the command retry function, to the proper cylinder and head address.

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Subsystem Verification of SEEK Addresses

Verification of cylinder and track position on a direct-access storage device can be achieved, by recording the cylinder and head number of the track immediately preceding every count field and every home address field on the track. This information can be checked and corrected by the error-correction function of the system. When reading or clocking home address and count fields, this information can be read in, corrected by the error-correction facility, if necessary, and compared with the current cylinder and track number of the direct-access storage device established by the last seek or recalibrate command. If they match, all is in order and the track position is verified. If they do not match, the access arm can be repositioned by the subsystem, using the command retry function, to the proper cylinder and head address.

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