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:
Mar. 29, 1994
Filed:
Nov. 19, 1991
David J Van Maren, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
The present invention provides a method and apparatus for compressing user data and for storing the user data on magnetic tape. The user data is accepted and organized into a plurality of records. The user data is then compressed according to a compression algorithm involving converting at least some of the user data to codewords using a dictionary which is derived from the data. The compressed data is flushed from memory before a new dictionary is created. The user data may be written to magnetic tape after being organized into groups, the groups being independent of the record organization. A codeword indicating the start of a new dictionary is inserted at the beginning of a group and preferably at the beginning of the first record within a group. Records may be further organized into entities. A codeword indicating a flush operation is inserted following each entity and a codeword indicating the start of a new dictionary is inserted at the beginning of the first entity within a group.