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:
Oct. 22, 1996
Filed:
Jun. 05, 1992
Yoshiaki Mori, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
The control unit for the magnetic tape unit compresses data and writes in a physical block unit in the buffer according to the data write instruction from the host computer or without compressing writes in a logical block unit in the buffer. And, according to the data read instruction from the host computer, the data read from the magnetic tape unit is stored in the buffer and transferred to the host computer. When the read data is an extended format due to compression, the data is expanded before being transferred. When an error occurs in writing data in the magnetic tape unit, information such as the maximum block size and total capacity of data within the buffer is informed to the host computer. In the following data recovery process, the unwritten data within the buffer is recovered in the logical block unit or physical block unit. In the recovery in the logical block unit, when it is the standard format data, it is read as it is and transferred to the host computer. When it is the extended format due to compression, it is read after effecting expansion processing. In the recovery in the physical block unit, the data is not expanded and read to be recovered in the compressed data.