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ABA IATA Code Reader

IP.com Disclosure Number: IPCOM000081854D
Original Publication Date: 1974-Aug-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Garofalo, FJ: AUTHOR

Abstract

Machine-readable documents such as magnetic stripe cards are often coded in American Banking Association (ABA) or International Air Transport Association (IATA) code, and it is desirable to have a card reader which can recognize either. The ABA code is a four-bit code which constitutes a subset of the lower four bits of the six-bit IATA code. To distinguish between the two codes, a magnetic stripe card can be encoded with one or another of two start characters which, when analyzed, will determine whether the card being read has been recorded in four-bit ABA or six-bit IATA code. If the recording is an ABA code, circuits can be provided to force two leading bits whereby the code is converted into six-bit IATA code.

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ABA IATA Code Reader

Machine-readable documents such as magnetic stripe cards are often coded in American Banking Association (ABA) or International Air Transport Association (IATA) code, and it is desirable to have a card reader which can recognize either. The ABA code is a four-bit code which constitutes a subset of the lower four bits of the six-bit IATA code. To distinguish between the two codes, a magnetic stripe card can be encoded with one or another of two start characters which, when analyzed, will determine whether the card being read has been recorded in four-bit ABA or six-bit IATA code. If the recording is an ABA code, circuits can be provided to force two leading bits whereby the code is converted into six-bit IATA code. The data can be then stored in the six-bit form and interpreted by decoding apparatus without regard to the original form of the recorded code, since all of the stored code is in the single six-bit format.

The four lower order bits repeat every sixteen values as the higher order bits are stepped from 00 to 01, to 10, and finally to 11. The numerics in the IATA code all occur in the cycle in which the high-order bits are 01. Therefore, it is merely necessary to force an 01 in the high-order bit positions whenever it is known that ABA code is being read. The resulting code will have the same value as the originally recorded ABA code, but will be in IATA format.

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