Subscriber equipment for Videotex service

摘要

The equipment consists of: a microprocessor 1, which makes the telephone connection with the Videotex management centre; a non-volatile memory 2; a modulator 3 for frequency shifting at 75 baud; a demodulator 4 for frequency shifting at 1200 baud; a dialler 5; a sensor 6, which detects if the telephone set is busy; a switch 7; an audio amplifier 8; and an interface 9 between the equipment and the television set.