Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Common Usage Of A Special Character In A Data Recording

IP.com Disclosure Number: IPCOM000052079D
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Dunn, EC: AUTHOR [+2]

Abstract

A technique is described providing positive identification to the beginning of a data record, a resynchronization character, and ending sequence that can be read both forward and backward all with one special character.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 88% of the total text.

Page 1 of 1

Common Usage Of A Special Character In A Data Recording

A technique is described providing positive identification to the beginning of a data record, a resynchronization character, and ending sequence that can be read both forward and backward all with one special character.

The character or symbol must be selected to have the same bit configuration when read from left to right and from right to left, follow all of the constraints imposed on the data encoding, and not represent valid data. The beginning configuration must be the same as the ending configuration. Resynchronization characters must be inserted at multiples of the deskew RAM (random-access memory) capacity.

In parallel recording, each track is considered independent yet associated with the other tracks. Each track must detect the beginning of data in a forward and backward direction and provide resynchronization, if required. Note the format configuration below. See Original.

The beginning of data can positively be recognized by decoding the last one bit of the burst and the 'C' symbol followed n bits later by another 'C' symbol. The end of the block can be identified by decoding the two sequential 'C' symbols after processing data. Note that the format appears the same from either direction. A 'C' symbol, inserted in an increment that is a multiple of the deskew RAM capacity (this provides for a known starting position), can be decoded to restart or resynchronize a track.

The use of the 'C' symbol m...