Browse Prior Art Database

Data Repacking Apparatus

IP.com Disclosure Number: IPCOM000098762D
Original Publication Date: 1959-Dec-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 72K

Publishing Venue

IBM

Related People

Margopoulos, WP: AUTHOR

Abstract

Maximum utilization of data storage facilities and increased speed during transfer operations are realized in equipment which ordinarily handles six bit (A-B-8-4-2-1) alphabetic characters and four bit (8-4-2-1) numeric characters. This is accomplished by repacking three numeric characters (Normal format) into the space usually occupied by two alphabetic characters (Repacked format) if it is expected that numeric characters only are to be encountered in a particular application.

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Data Repacking Apparatus

Maximum utilization of data storage facilities and increased speed during transfer operations are realized in equipment which ordinarily handles six bit (A- B-8-4-2-1) alphabetic characters and four bit (8-4-2-1) numeric characters. This is accomplished by repacking three numeric characters (Normal format) into the space usually occupied by two alphabetic characters (Repacked format) if it is expected that numeric characters only are to be encountered in a particular application.

In the circuitry, an analog to digital converter applies three four bit numeric characters in parallel to a repacking network on three sets of lines each of which is labeled 8-4-2-1, during the time t(0)-t(1) (Timing Chart A). An A pulse at terminal A simultaneously gates all bits of the first character and the 8-4 bits of the third character to storage, such as a magnetic tape unit, or to an Input-Output unit I/O via the repacking network output lines E(8)-E(4)-E(2)-E(1)-E(A)-E(B). At a later time a B pulse at terminal B gates all bits of the second character and the 2-1 bits of the third character to storage via the repacking network output lines E(8)-E(4)-E(2)-E(1)-E(A)-E(B). As evidenced in Timing Chart A actual writing of any repacked character on tape may be delayed until after a check bit has been generated.

In a typical situation the new six bit characters formed by repacking are valid characters and, hence, are compatible with existing error checking or redundancy circuits. In some cases certain four bit characters, such as the zero...