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:
May. 11, 1993
Filed:
Aug. 22, 1989
Jeff J Kato, Greeley, CO (US);
David W Ruska, Greeley, CO (US);
David J Van Maren, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A tape packet assembler/disassembler (TPAD) for a tape drive accumulates host-transmitted records, which may or may not be blocked by the host. The accumulated host-transmitted records are combined into packets comprising a data portion made up of data blocks and of a trailer portion made up of table entries describing how to disassemble the packet. Host-transmitted commands to write a tape mark are intercepted by the TPAD and replaced by corresponding information in the trailer. Packets are accumulated in a buffer in the TPAD, and are written to the tape drive when the buffer becomes full, or upon a command from the host to reposition the tape, such as rewind. The interblock gaps that would ordinarily separate the host-transmitted records now separate packets, resulting in a considerable increase in the efficiency of tape utilization. The TPAD maintains in the trailer various pointers to assist in forward and back spacing by file and records. It also can automatically and adaptively compress and decompress the user's data. To assist in this it also maintains in the trailer information identifying data blocks containing a dictionary reset.