COMPUTER SYSTEM COMPRISING PERIPHERAL APPARATUS

An as large as possible number of peripheral apparatus should be connectable to a computer, without it being determined in advance which apparatus is to be connected at which location, i.e. the peripheral apparatus should be exchangeable at random. To this end, the peripheral apparatus are connected to the central control unit, besides via a data bus, via at least one control line, a signalling line, a selection line and a request line. A data exchange between a peripheral apparatus and the central control unit is possible only if the selection line is actuated. The control line indicates whether the information represents a control command or an information character. Further control lines for indicating the direction of the data transfer and additional data concerning control commands can be provided. For extension, several peripheral apparatus can be connected to a selection line, possibly via a connection unit including priority control system.