Browse Prior Art Database

Automatic Deletion of Invalid Messages

IP.com Disclosure Number: IPCOM000092002D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Chandik, RW: AUTHOR [+2]

Abstract

In a communications terminal where there is detection of a faulty block of data, there can be a requirement to delete the faulty data. As each character of data in a block of data is recorded by an output device, a clock pulse is applied to forward counter 10 through input 12. Counter 10 includes a plurality of bistable devices 14 which count in binary fashion.

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Automatic Deletion of Invalid Messages

In a communications terminal where there is detection of a faulty block of data, there can be a requirement to delete the faulty data. As each character of data in a block of data is recorded by an output device, a clock pulse is applied to forward counter 10 through input 12. Counter 10 includes a plurality of bistable devices 14 which count in binary fashion.

At the end of transmission of a block of data, a determination by error control circuitry that no errors are transmitted resets counter 10 at input 16. If an error is detected, an input 18 is pulsed to transfer the 1's complement of the number in counter 10 into inverse counter 20. This 1's complement is entered by applying the input to the proper terminal in bistable devices 22.

Clock pulses are applied to the data output device to backup the output device one character at a time. The clock pulses are also sent to reverse count input 24. The pulses step counter 20 until it is standing at its maximum all 1's indication which is detected to stop the backup of the output device. Counter 20 is then advanced by an input at 26 to zero all stages 22. Counter 20 is again set with the 1's complement of the number standing in counter 10. The output device is then advanced and, on each advance, the character is deleted and a pulse supplied to delete count line 28 to again step counter 20 to a maximum.

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