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:
Sep. 13, 1994
Filed:
Apr. 23, 1991
William T Burke, Tucson, AZ (US);
Larry W Loen, Rochester, MN (US);
Randy K Rolfe, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A removable optical disk of the write once type is managed to minimize size of the control area for user data recorded on the disk. Instead of recording each recorded file indicating token (serial number) as each file is recorded, a maximum value file token having a numerical value greater than a previous maximum value token is recorded in the control area such that any optical recorder receiving the disk may start recording data using such maximum value token. If the file indicating token values reach the maximum value token, then a new maximum value token is created. A pseudo end of volume (EOV) value is maintained which points to a one of the addressable data storing ares of the disk which is allocated and not recorded as EOV. All allocated data storing areas with addresses greater than EOV are recorded in contiguously addressed data storing areas. When any data storing area having an address higher than EOV is left unrecorded, then EOV is updated to point to that unrecorded allocated data storing area. When either the maximum value token or EOV are changed or updated, both the EOV and maximum value token are recorded in the control area. Operations in a closed environment, super or umbrella allocation sizes and reduced EOV values are also disclosed.