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Punched Card Sensing Method

IP.com Disclosure Number: IPCOM000096614D
Original Publication Date: 1963-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Goldbach, E: AUTHOR [+2]

Abstract

When sensing punched cards serially, the values read in the individual columns or groups of columns are respectively applied by special devices to predetermined storage locations or channels. Therefore, it is necessary to insure an accurate synchronism between the movement of the punched card being sensed and the special devices. Particularly when reading information from punched cards into electronic storage units, it is very necessary to maintain such synchronism.

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Punched Card Sensing Method

When sensing punched cards serially, the values read in the individual columns or groups of columns are respectively applied by special devices to predetermined storage locations or channels. Therefore, it is necessary to insure an accurate synchronism between the movement of the punched card being sensed and the special devices. Particularly when reading information from punched cards into electronic storage units, it is very necessary to maintain such synchronism.

In order to achieve a very substantial reduction in the strict demands to be met by the synchronism between the punched card movement and the devices for distributing the information read out of the individual columns among the individual storage locations, synchronization in this method is essentially effected by the information itself.

The values sensed in the first column to contain punched holes are read into a storage location. Then, the storage unit is advanced one position. The same operations take place with respect to the information contained in the next and in all subsequent columns. When a column containing no punched holes is sensed, a blank character is read into the respective storage location scheduled to receive information and the storage unit is advanced one position. If the next column again is unpunched, nothing happens. The same applies for all additional blank columns. When the next column containing punched information is sensed, the information is read into the available storage location and the storage unit is again advanced one position. In this manner, the entire card is transferred into the storage unit.

When information is sensed in a column, a synchronizing pulse is produced. Its width is slightly larger than 1.5 times the index spacing. Due to this width of the sync pulse, the pulses of two punched holes displaced by a maximum amount in opposite directions, the first one lying at the very beginning and the second one at the extreme end of two successive index areas, are still certain to ov...