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. 27, 2005
Filed:
Apr. 29, 2004
Paul Merrill Greco, Tucson, AZ (US);
Glen Alan Jaquette, Tucson, AZ (US);
Hiroshi Itagaki, Yokohama, JP;
Hironobu Nagura, Kawasaki, JP;
Hirokazu Nakayama, Fujisawa, JP;
Satoshi Tohji, Kanagawa, JP;
Terue Watanabe, Yokohama, JP;
Paul Merrill Greco, Tucson, AZ (US);
Glen Alan Jaquette, Tucson, AZ (US);
Hiroshi Itagaki, Yokohama, JP;
Hironobu Nagura, Kawasaki, JP;
Hirokazu Nakayama, Fujisawa, JP;
Satoshi Tohji, Kanagawa, JP;
Terue Watanabe, Yokohama, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Backspacing over data to overwrite the data as recorded on magnetic tape is provided logically, rather than by causing a magnetic tape to drive to backhitch. The data is written to the magnetic tape as it was before it was logically changed in order to insure that the data is preserved on tape. Recovery of the data is from a succeeding data set which logically invalidates the original data by a superseding identifier. Control logic arranges data transactions for writing to magnetic tape as data sets; and, in response to backspace and overwrite commands, or when transactions are accumulated into a succeeding data set, rewrites the original transaction adjusted in accordance with the commands as a superseding data set downstream from the original transaction, logically invalidating the original transaction by setting a superseding identifier in the superseding data set(s).