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Printing Modulus 10 Check Digits

IP.com Disclosure Number: IPCOM000076982D
Original Publication Date: 1972-May-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Johnson, RL: AUTHOR

Abstract

As each consecutive number is printed on a form at one station, the modulus 10 check digit appropriate to that number is automatically calculated and is then printed on the form one cycle later.

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Printing Modulus 10 Check Digits

As each consecutive number is printed on a form at one station, the modulus 10 check digit appropriate to that number is automatically calculated and is then printed on the form one cycle later.

Mounted side-by-side on a common shaft in control box 1 (Fig. 1) are a series of wheels 2, one for each digit position of the basic number to be printed. The operator manually rotates wheels 2 to expose through window 3, a number corresponding to the next basic consecutive number to be imprinted by a conventional numbering unit, not shown. With wheels 2 thus positioned, a stationary contact arm, not shown, laterally makes contact with the appropriate one of a number of circumferentially spaced contact plates to generate an electrical signal in a discrete one of ten wires, the signal being generated only in that wire corresponding to the proper check digit for the exposed number, and hence to the basic number being imprinted by the conventional numbering unit. The single signals from each wheel constitute parallel inputs 4 to logic circuitry that preferably is identical with that in the Modulus 10 self-checking numbering unit 5 of an IBM 024/026 keypunch; the only difference is that the mechanical position of the wheels 2 generate the signals, rather than depression of punch keys by the operator.

Unit 5 computes the check digit appropriate to the basic number being imprinted by the aforementioned conventional numbering unit. Then it generat...