CATHODE RAY TUBE DISPLAY CONTROL APPARATUS

摘要

A cathode-ray tube control device is for connecting a personal computer with a television receiver to superimpose information from the computer on the picture of a TV broadcast. There is a store for data to be displayed. An oscillator circuit (21) produces clock signals in synchronism with the horizontal and vertical synchronising signals from the TV receiver. An arrangement (22) counts the clock signals and delivers timing signals. These timing signals define horizontal scanning display period, horizontal scanning retrace period, vertical scanning display period and vertical retrace period. An arrangement (23) controls the read-out of data to be displayed in accordance with the timing signals and supplies the data to the TV receiver.