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Console Using a Cathode Ray Tube Display

IP.com Disclosure Number: IPCOM000092863D
Original Publication Date: 1967-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Nussbaumer, H: AUTHOR [+2]

Abstract

The console is attached to a time division exchange equipped with a single trunk. The exchange operates in the pulse amplitude modulation PAM mode with one hundred time slots. Each time slot comprises a pulse duration and a guard time.

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Console Using a Cathode Ray Tube Display

The console is attached to a time division exchange equipped with a single trunk. The exchange operates in the pulse amplitude modulation PAM mode with one hundred time slots. Each time slot comprises a pulse duration and a guard time.

The trunk directly drives the grid of a cathode ray tube CRT. This results in an intensity modulation of the spot by the PAM samples. This modulation is arranged in such a way that the spot is invisible during the guard time or when time slots are idle and that bright dots of variable brightness appear on busy time slots.

Control circuits deliver a synchronization pulse Sx once in every ten time slots and another synchronization pulse Sy once in every hundred time slots. Sx and Sy trigger respectively sawtooth generators G1 and G2 which provide for horizontal and vertical scanning. This results on the screen in an array of 10x10 dots, each corresponding to one time slot. As the bright dots correspond to busy slots, the CRT displays continuously an image of the occupancy of the network.

The operator is equipped with a photocell probe which is connected to switch S1 through amplifier A. When S1 is in position 1, the photocell drives a loudspeaker through the amplifier and a low-pass filter F1. The operation on a given time slot can be checked by applying the probe opposite to the corresponding dot. The light from this dot modulates the photocell in synchronism with time slot information. There...