Data processing system with separate memory stages for peripherals - avoids need for peripheral instructions to be stored

A number of peripherals are readily coupled without undue demand on the main programme memory capability. The main processor system consists of a read-only-memory providing the main programme control of the central processor. A keyboard input communicates over control circuitry. A read-write memory provides storage for data from the keyboard and a general two way bus communicates information between units. Output peripherals, such as printers card punches are coupled over a control stage with a read-only-memory controlling the cycle and a buffer memory for data. By assigning memory externally to the peripherals the demands made on the main processor memory are minimised.