Etablissement Public De Diffusion Dit 'Telediffusion De France'

Other

L'etat Francais

L'etat Francais, Represente Par Le Secretaire D'etat Aux Postes Et

Claude Sechet

Louis C Guillou

Christian Jean Gautier

Gabriel R Degoulet

Roger Motsch

Gerard Babonneau

A teletext receiver incorporating a demodulation circuit, a data demultiplexing circuit, a memory, a microprocessor and a numbering keyboard. The inventive receiver also comprises an early article acquisition decision circuit disposed between the demultiplexing circuit and the memory. This circuit incorporates a shift register with five cells, a storage module having a first group of three storage cells able to store three bytes, a second group of three storage cells able to store three bytes, a two-bit flip-flop, a logic comparison circuit incorporating a first group of three byte comparators, a second group of three byte comparators, an article start code detector, and a comparison synthesis logic circuit connected to the six byte comparators, to the detector and to the flip-flop. This circuit supplies an opening or closing control signal applied to the control input of the memory. The microprocessor loads in an appropriate manner the storage cells with bytes defining a page to be selected and bytes defining a threshold, such that all the articles whose classification bytes exceed this threshold, bring about the appearance of the memory opening signal. The microprocessor checks after each data transmission cycle the state of the memory in order to raise or lower the threshold, or leave it unchanged.

Teletext receiver

The invention relates to a scratch pad memory system having a table of contents for identifying program material recorded on a magnetic tape in a cassette or cartridge with program material being recorded or changed responsive to user command. The scratch pad memory system comprising an address register, a read only storage, and having an interface for read/write storage and a text displaying terminal coupled to a television receiver for display of program material.

Scratch pad memory for cassette of magnetic tape recording

A television system with access control comprises a transmitter and receis. The transmitter comprises a video signal and sound signal formation circuit, means for transmitting these signals and a jamming circuit using a service key. Each receiver comprises means for receiving the transmitted signals, means for the display of the picture and for restoring the sound and an unjamming circuit connected to the reception means and working with the service key. It also comprises a subscription management center and in the transmitter a digital signal generator, a circuit for the formation of digital messages and a data broadcasting system and in the receiver a subscription card, an extraction circuit for the data, and a circuit for restoring the service key. There is also at least one subscription card loading station connected to the subscription management center.

Television system with access control

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Rennes, France

Claude Sechet