Patent US 3,949,370

A data processing system includes an external store for storing macroinstructions, a microprogrammed control section, and a processing section. The control section includes a control unit having an instruction register for receiving the operation codes of selected macroinstructions from the external store, and a control store for storing microinstructions. The processing section includes a register unit for storing data information to be processed and an arithmetic and logic unit connected to the register unit for performing operations on the data information contained therein. A programmed means is employed for generating address information in accordance with the operation codes of selected macroinstructions and supplying such address information to the control store. One or both of either the programmed means or the control store are implemented with programmable logic arrays.