Abstract: An interface connects a data processing unit to at least one working stat including data transmitting and receiving devices, such as peripheral devices. The interface includes a transmitter/receiver circuit for a station at the unit and a transmitter/receiver circuit associated with each of the devices. Data are transmitted between the circuit at the unit and the circuit at the device by a pair of transmission lines, whereby data are exchanged between the unit and the devices sequentially, character by character. Each of the characters is formed by the sequential transmission of bits along the lines. A dialogueing sequence between the unit and one of the devices is initiated when a first character is derived from the unit transmitter/receiver circuit.

Abstract: An interface connects a data-processing unit to a group of m working stations, each including items of data emitting and receiving apparatus. The unit and each of the items of apparatus transmit and receive binary data in parallel characters in response to control signals generated by the unit. The characters are coupled between the interface and stations as serial bits via a separate channel that extends to each station. Each channel includes separate lines for sending the characters in opposite directions. At the interface, there are provided m transmitter/receiver circuits, one of which is associated with each of the m stations. There is a transmitter/receiver circuit associated with each item of apparatus at each of the stations. Each transmitter/receiver circuit includes a parallel to serial converter for each parallel input character supplied to it and a serial to parallel converter for each series character applied to it.