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Program Technique for Shift Character Insertion

IP.com Disclosure Number: IPCOM000076501D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Eisenbies, JL: AUTHOR [+2]

Abstract

Described is a programming scheme to provide improved transmission controls for case-shifting signals, where special characters such as nonprinting codes or characters common to the upper and lower case printing sets occur between upper case printing characters. Previously, when any control or common character was decoded for transmission, it was always as a lower-case character and the decoder control would, if printing was in upper case, cause transmission of unnecessary down-shift and up-shift signals before and after the character.

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Program Technique for Shift Character Insertion

Described is a programming scheme to provide improved transmission controls for case-shifting signals, where special characters such as nonprinting codes or characters common to the upper and lower case printing sets occur between upper case printing characters. Previously, when any control or common character was decoded for transmission, it was always as a lower-case character and the decoder control would, if printing was in upper case, cause transmission of unnecessary down-shift and up-shift signals before and after the character.

These unnecessary shift signals are eliminated from the transmission stream by a change in the decoder, so that all such control or common characters are decoded with a variation from that for the usual printing characters, e.g., having even rather than an odd parity. Since the character is tested before character transmission is initiated, detection of the variation is utilized to cause a processor branch with entry into a special control character processing program.

In the described system, the first step of the branch program enters the special character into a table to transfer control to the program appropriate to the particular character. This latter program will enter a selected character code into the transmission hardware, at a point after the program which controls the insertion of case shift characters during the processing of the usual printing characteristics. The progra...