Abstract: A method and apparatus for automatically transmitting a message to a telephone terminal. Each message is assigned an identification code which identifies a message stored in a calling telephone. When the calling telephone calls the telephone which generated the identification code, the identified message is caused to be displayed to the calling party.

Abstract: An exchange system includes a plurality of terminal devices, a plurality of interface devices for transmitting signal data and control data among the terminal devices and the interface devices on the basis of a two way bidirectional burst transmission system, and a control circuit which assigns a time slot to a PCM highway according to control data transmitted through a control highway from one of the interface devices, and transmits within the assigned time slot the signal data through the PCM highway to a selected one of the interface devices, through the PCM highway. Each of the terminal circuits generates 2-bit mode data representing the type of the terminal device. The control circuit assigns one or two time slots to the PCM highway according to the mode data.

Abstract: A programmable semiconductor integrated circuit device is disclosed, which includes different kinds of MSI scale function blocks formed on a substrate. First wiring lines extending in a row direction are connected to input terminals of the function blocks, respectively. Second wiring lines are connected to output terminals of the function blocks, respectively. The second wirings are T-shaped and have respective line components extending in a column direction, with the first wiring lines. Floating gate type field effect transistors are provided, in a matrix manner, at mutually electrically insulated crossing points among the first and second lines.

Abstract: There is provided a telephone exchange including a switching network, a plurality of interface circuits whose corresponding transmit/receive paths are connected to the switching network, a data generator connected to the interface circuits to sequentially generate state information indicative of the states of the interface circuits, and a control circuit for controlling the switching network according to an output data from the data generator. The data generator generates state-variation information when the state of the interface circuit is varied and the control circuit is responsive to the state-variation information from the data generator to cause the switching network to be set to a state corresponding to the above-mentioned state information.

Abstract: A telephone exchange comprises a plurality of central office trunk circuits, a plurality of line circuits, a plurality of switching circuits coupled to transmission paths of the trunk and line circuits, a plurality of switching circuits coupled to the reception paths of the trunk and line circuits, a variable attenuator having one end coupled commonly to the switching circuits that are coupled to the transmission path, a conference circuit coupled to the variable attenuator and the switching circuits that are coupled to the reception paths, a control circuit which controls both groups of switching circuits and the variable attenuator in time-sharing fashion thereby to provide speech paths in time-sharing fashion between selected ones of the central office trunk circuits and line circuits and which controls in time-sharing fashion the attenuation factor of the variable attenuator for each speech path established.

Abstract: A switching apparatus comprising a switching circuit provided with a plurality of input terminals and a plurality of output terminals; a plurality of regenerative repeaters connected between the prescribed ones of said plural input and output terminals, the number of the regenerative repeaters being less than that of circuits through which signals of high error rate are expected to pass; and means for conducting signals from the prescribed input terminals to the output terminals directly or through the regenerative repeaters.

Abstract: There are disclosed first and second groups of internal office trunks used for an exchange. Each internal office trunk comprises first and second terminals for connecting two subscribers' telephones through a switching matrix circuit according to a demand signal from a central controller. The internal office trunks of the second group respectively further comprise a third terminal. The third terminal is connected to a switching circuit controlled by the central controller. The switching circuit controls a mutual connection of the internal office trunk circuits. As a result of being connected to the third terminal mutually by the switching circuit, the second group of the internal office trunks operates as a conference trunk.