Browse Prior Art Database

End of Card Control for a Buffered Key Device

IP.com Disclosure Number: IPCOM000077086D
Original Publication Date: 1972-Jun-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Ferreri, V: AUTHOR [+4]

Abstract

This scheme permits electronic control of removal of a punch card from a card-punch mechanism of a buffered key entry device after the card has passed through the eightieth column of the card.

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End of Card Control for a Buffered Key Device

This scheme permits electronic control of removal of a punch card from a card-punch mechanism of a buffered key entry device after the card has passed through the eightieth column of the card.

During punching the card is stepped along in the mechanism by the stepping motor 10. The stepping motor 10 has four windings 12, 14, 16 and 18 which are activated and deactivated in pairs 12 and 16, 16 and 14, 14 and 18, and 12 and 18 to cause the motor to step, and thereby advance the punch card along the card-punch mechanism in a key entry device. Energization and de-energization of windings 12-18 is under control of drivers 20 which, in turn, are operated by motor control logic 22.

While data for each column is being entered by the operator, a series of eighty binary "1's", called flags, are inserted into one of the serial buffers of the key entry device. As data is being punched, these flags are read out of the buffer in sequence over a period t. Furthermore, as each column of data is removed from the buffer and punched by the key entry device, the first flag or binary occurring in the sequence is removed so that when eighty columns of data have been removed and punched. all of the flags are gone.

The key entry device also contains a pulse generator 28 which produces a pulse called the SCAN pulse. At any one time, the length of the SCAN pulse depends on the number of flags stored in the buffer. As each flag is wiped out, the...