Browse Prior Art Database

Printing Communications System

IP.com Disclosure Number: IPCOM000095918D
Original Publication Date: 1964-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Pingry, CO: AUTHOR [+2]

Abstract

This teletypewriter arrangement has a synchronizing system in which the receiver clock is corrected in phase upon each bit transition and in which a special code is transmitted with data to not only define the data position but to assure adequate transitions for the synchronizing system.

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Printing Communications System

This teletypewriter arrangement has a synchronizing system in which the receiver clock is corrected in phase upon each bit transition and in which a special code is transmitted with data to not only define the data position but to assure adequate transitions for the synchronizing system.

Each terminal is constructed with sufficient components so that the terminal can be switched to a transmit mode or to a receive mode. When a terminal is in the transmit mode, its clock oscillator is continually free-running. The clock times the transmission of words serial by bit. Depression of a key at the keyboard closes contacts which ultimately insert a binary code descriptive of the key depressed into the shift register. The special code, a binary 101, is always produced in conjunction with a data code and is inserted beside the data code for serial transmission. The entire word is transmitted serially.

At the receiver, the serial data is entered serially in a shift register where it is positioned in parallel for control of printing by the keyboard. Center sensing of data and other timing is controlled by the receiver clock oscillator. It is free- running, but is recycled to a predetermined phase with each data transition. Since sufficient data transitions are assured by the special code 101, drift in synchronization is frequently corrected and the clock oscillator therefore can be built with wide tolerances.

The special code serves a second fu...