Browse Prior Art Database

Implementation of an Error Detection Method for Decimal Terminals

IP.com Disclosure Number: IPCOM000090244D
Original Publication Date: 1969-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Lum, VY: AUTHOR [+2]

Abstract

An error-detection system uses two check digits per message to check errors of single substitution, switchover, single detection and single insertion, regardless of message length.

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Implementation of an Error Detection Method for Decimal Terminals

An error-detection system uses two check digits per message to check errors of single substitution, switchover, single detection and single insertion, regardless of message length.

The digits V(1), V(2), ... V(k) comprising the message determine the two check digits C(1), C(2)to be added to the end of the message: C(1) is determined by the first check equation it satisfies. original page 1274-1275.

Drawing 2 shows an encoder for performing the calculations of C(1), C(2), b(2) and b(1) according to the above formulas for a message k digits long.

Drawing 3 shows a decoder for the check digits. The decoder includes encoder 10 as in drawing 2 which processes the received message again to provide a check of the last two digits of a message designated as C(1)' and C(2)' against C(1)'' and C(2)'' in module 2 adders. Ex-Or's registers in encoders 10 and 13 and 14 receive the message plus checks C(1)' and C(2)' in serial order.

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