Abstract: A data processing system, comprising a central unit, peripheral units, and input/output processors which are connected parallel to a common bus. The said processors centralize the exchanges between a plurality of peripheral units and the store. The data exchanges can be effected in the mode "programmed bus", in which the central unit is the master of the system, or by way of the "multiplex bus", where the exchange is controlled by the input/output processor in word blocks. The interruption system utilizes a second bus which is independent of the first bus, so that the simultaneous transfer of the interruption vectors and data is possible.