Dismiss
The Prior Art Database and Publishing service will be updated on Sunday, February 25th, from 1-3pm ET. You may experience brief service interruptions during that time.
Browse Prior Art Database

# Self Check Numbering Device

IP.com Disclosure Number: IPCOM000093940D
Original Publication Date: 1966-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 4 page(s) / 64K

IBM

## Related People

Burns, WE: AUTHOR

## Abstract

The system is for checking and generating self-check number sets formulated with more than one number base. Two commonly used self-check number systems operate on modulus-10 or modulus-1 1 number bases. This system can be operated with these number bases. It can be modified to employ similar principles to operate on some other number base.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 29% of the total text.

Page 1 of 4

Self Check Numbering Device

The system is for checking and generating self-check number sets formulated with more than one number base. Two commonly used self-check number systems operate on modulus-10 or modulus-1 1 number bases. This system can be operated with these number bases. It can be modified to employ similar principles to operate on some other number base.

In a self-check number system, a check-digit is generated and becomes a part of the self-checked number, usually the low-order digit. The check-digit is obtained by multiplying each digit of the number of a weighting factor and then summing the resultant products. The weighting factors and the applicable rules for generating the check digit vary with the number base used.

The number is placed in a storage device from a data entering device such as a keyboard. Digits are keyed into the storage device in a high-order to low- order sequence. A tag is entered at the storage location containing the high- order data digit. When all the digits are entered into the storage device, the digits are then scanned in reverse order, low-order to high-order digit, appropriately weighted. Arithmetic is performed on the weighted digits in accordance with the rules of the operating modulus. When the high-order digit tag is recognized, the control circuits then check the calculated check-digit against the check-digit which keyed into the storage device.

The system consists of a plurality of counting registers CR. CR10 and CR12 count in the desired radix and contain sufficient binary equivalent storage positions to store the largest required data digit value. A binary equivalent of the decimal value 9, requires 4 bits of storage. CR 14 and CR16 count in a binary mode and contain sufficient binary equivalent storage positions to store the largest required weighting digit value. A binary equivalent of the decimal value 7 requires 3 bits of storage. Gates TG18 transfer a data digit from CR10. Count counter CC24 increments or decrements CR10. AA34 senses when CR10 is zero. Count counter CC26 counts CR12 up one bit at a time each time CR10 counts or adds in a carry to CR12. Carry store CS36 and control of CS36 optionally adds the carry back into CR12. MW20 initializes the weighting digit into CR14. Count counter CC38 alters the value of the weighting digit in CR14. Gates TG22 transfer the contents of CR14 to CR16. Count counter CC28 counts CR16 bit-by-bit to zero. Zero detector ZD32 detects when CR16 is zero complement. Compare CM42 determines if the calculated check-digit equals the predicted check-digit. Gate TG40 transfers the calculated check-digit when operating in the generate mode. Control MC30 governs CC26 and carry gating circuitry to transfer said carry back into CR12.

The arithmetic for producing a self-check number digit module-10 follows. Start with the low-order position of the basic number. Multiply the first, the third, and every odd-numbered order digit by two. Multiply the ot...