Abstract: In a data processing system having on-line storage containing data entities to be sorted and a central processor unit, a sorting machine interconnected with both. The sorting machine functions independently of the central processor unit except for the use of a start and finish signal. The sorting machine contains all logic elements required for sorting and merging thus rendering it independent of the central processor unit. The sorting machine includes two control buffers holding data representing parameters selected for the data processing operation, a job identification control buffer, and a plurality of cells each of which contains two key buffers holding data used for a sort/merge basis, two pointer buffers holding data defining an original sequence order for key data, a control register for indicating the last data to be sorted, and a processor for logically comparing pairs of data entities being sorted and for determining further cell directions.