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. 25, 2008
Filed:
Sep. 25, 2006
Hiroshi Itagaki, Yokohama, JP;
Takashi Katagiri, Yokohama, JP;
Hironobu Nagura, Kawasaki, JP;
Hirokazu Nakayama, Fujisawa, JP;
Yutaka Oishi, Kawasaki, JP;
Toshiyuki Shiratori, Komae, JP;
Terue Watanabe, Yokohama, JP;
Hiroshi Itagaki, Yokohama, JP;
Takashi Katagiri, Yokohama, JP;
Hironobu Nagura, Kawasaki, JP;
Hirokazu Nakayama, Fujisawa, JP;
Yutaka Oishi, Kawasaki, JP;
Toshiyuki Shiratori, Komae, JP;
Terue Watanabe, Yokohama, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A write/read control method for recording at least one datum on a magnetic tape within a predetermined distance is provided. The method includes sequentially accumulating a plurality of blocks of data of variable length in a buffer divided into fixed length segments and writing the contents of each segment to the tape. If the segment contains at least one block of data, the data is written to the tape as a dataset and if the segment does not contain any data, then a null dataset is written to the tape within the predetermined distance. The predetermined distance may vary depending upon the format of a tape drive embodying the method. In response to a request to read a block of data, reading at least one dataset that includes the requested block of data from the tape to segments in the buffer, and reading the requested block of data for invalidating data transfer of a null dataset in the segment. By invalidating the transfer of a null dataset, blocks of data separated by the null dataset can be reconstructed.