Browse Prior Art Database

Fail Safe Encoding Circuit

IP.com Disclosure Number: IPCOM000097264D
Original Publication Date: 1962-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Allen, EK: AUTHOR

Abstract

Fail safe encoding into odd parity alphanumeric BCD code is afforded by this circuit. No more than four transfer contact switches for each of the six bails and the checking mechanism of a ball head typewriter are required.

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Fail Safe Encoding Circuit

Fail safe encoding into odd parity alphanumeric BCD code is afforded by this circuit. No more than four transfer contact switches for each of the six bails and the checking mechanism of a ball head typewriter are required.

The bails R1, R2, R , R-5, T1 and T2 and the checking mechanism C are operated by key pressure calling for combinations of rotate 1, rotate 2, auxiliary rotate 2, rotate negative 5, tilt 1 and tilt 2 in positioning the ball head. Upper or lower case shift mode contacts SU and S are also closed in the operation.

The character assigned in lower case is automatically encoded where there is no character corresponding in upper case. Odd parity is destroyed in the event of single contact failure. The checking circuit is arranged to prevent entry of the data into the computer from the typewriter if the checking fails (even parity).

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