The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2001
Filed:
Nov. 18, 1997
Glen Alan Jaquette, Tucson, AZ (US);
Leonard George Jesionowski, Tucson, AZ (US);
John Edward Kulakowski, Tucson, AZ (US);
Judson Allen McDowell, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A tamper-resistant Hard-WORM data storage system and a magneto-optical storage disk therefor is disclosed. The disk has a plurality of sectors thereon containing one or more uniquely formatted fields to provide an indication that the disk is a Write-Once Read Many (WORM) disk. A motor is provided in the storage system for rotating the disk at an operational rotational speed and a laser read/write (R/W) head unit is provided for reading and writing information in the sectors. A read/write (R/W) control unit within the storage system controls read and write operations on the disk in response to commands from an external data processing device, such as a computer. The R/W control unit is adapted to decode the one or more uniquely formatted fields in order to read and correctly interpret information contained therein. In an additional aspect of the disclosure, the R/W control unit disables erase operations in sectors containing uniquely formatted fields but allows such operations in sectors that do not contain such fields in order to permit calibration testing and the maintenance of media defect lists, first available sector lists and the like.