A data processing system has a facility for a rapid access to the data store by simultaneous reading of data channels over a time multiplexing unit. Multiplexed data is transmitted to comparator stages for comparison with keying-in words in order to control the search process. The output channels from the magnet disc store are coupled over a control unit (2) to a multiplexer (3) handling twelve data channels each operating independently. The multiplexed outputs are transmitted to a bank of sixteen comparator stages (5). The comparator compare the output with the stored keying-in values and the result is transmitted to a search control unit (7). If the search criteria is satisfied (10) the process controller (8) generates an access control signal (9) to the memory output control circuits (2).
