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Improved Encoder and Decoder for a Byte-Oriented (0,3) 8/9 Code

IP.com Disclosure Number: IPCOM000065831D
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Patel, AM [+details]

Abstract

An encoder and decoder for a (0,3) 8/9 code is described in [*]. The present design for such encoders and decoders has two properties not found in the earlier embodiment of the code, while retaining all of the properties described in [*]. One new property is word parity. Each code word provides opposite parity relation with the corresponding data byte. Such relation can be used as a diagnostic check of encoder decoder and other related hardware. Also, in magnetic tape application, a 9x9 encoded frame comprises 8 data and one parity byte in a set of 9 tracks. In every 9x9- byte encoded frame, the new code always produces an odd number of ones. The other new property is a unique sync pattern which can be used to identify various format boundaries.