Fujitsu Corporation

Yasuo Satake

Toru Masuda

Nobuyuki Yasoshima

Kazuhiro Sato

Kenichi Ogawa

Shoji Nojiri

Satoshi Nagata

Takuhito Kojima

Hirohiko Kurosu

Makoto Fujisawa

Hisao Kanzaki

In an external memory system having a program mode for controlling a read/write operation of a memory of the external memory system by a central processing unit and having a direct memory access mode permitting a direct access to a main memory, there are provided first and second location address registers. The memory addressing is performed by the first location address register in the direct memory access mode and by the second location address register in the program mode, whereby it is possible to execute the read/write operation with the memory of the external memory system in the program mode during a burst timing interval during data transfer in the direct memory access mode, thus permitting high-efficiency data processing.

High-speed external memory system

An electronic exchange of the time division system type or the space division system type, employing electronic contacts, in which a U-junctor is connected to the switching network of the electronic exchange. The switching network program for controlling the connection of the switching network regards the U-junctor as a combination of an outgoing and an incoming trunk. The connection between the trunks, between subscribers or between each subscriber and each trunk in a special calling service is controlled by using the U-junctor and the switching network.

Network connection system

A signal sending control system for use in a telephone system includes a ringing signal sending circuit having a signal source for generating a continuous ringing signal, interrupting means for controlling the sending of the ringing signal over each subscriber line, one switch for each subscriber line for selectively and switchably connecting the respective subscriber line to a speech network of the system and to the ringing signal sending circuit, a common controller for providing control information as to the duration of the ringing signal, and a control circuit for individually controlling the switching circuit of each subscriber line in accordance with the control information and for controlling the transmission duration of the ringing signal.

Signal sending control system

Key information from an attendant console is transferred to a telephone exchange in a bit serial manner, and line status information from the telephone exchange is also transferred in a bit serial manner and in a time-shared manner. At the request of the attendant console, the line status information is transferred from the telephone exchange to the attendant console in a bit serial manner, and subjected to serial-parallel conversion to obtain parallel signals for driving lamp indicator portions so as to provide an indication of the line status information. The number of signal lines connected to the attendant console is markedly reduced and, in the case of telephone number modification or the like, proper steps can be taken immediately.

Attendant console control system

Growing community of inventors

Kawasaki, Japan

Yasuo Satake