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:
Jan. 09, 1990
Filed:
Apr. 25, 1988
John R Cogley, Jr, Covina, CA (US);
Qualstar Corporation, Chatsworth, CA (US);
Abstract
A nine track digital tape system operating in accordance with a feedback shift register redundancy scheme, includes in both the encoding and writing section and in the reading and error correction section, arrangements for shifting successive bytes of information by one digit place, and adding the shifted bytes, to provide a 'low product' and a 'high product', constituting an address or 'pointer' to a modifier table, from which a modifier value is obtained to be added to the 'low product'. In the error correction circuitry, additional tables, using a sample parity error vector and an identification of the columns in which errors occur, as 'pointers', provide data which is used to calculate error correction vectors. Instead of using feedback registers, and complex decoding hardware, the circuitry obtains the same result as would have been obtained by the hardware, in a unique manner, to provide a simple, high speed, error correction system.