AQA A Level Computer Science Revision Questions and Answers

ist two components with which the CPU works to execute program instructions. Memory Input and Output Devices Describe the role of the Control Unit in the fetch-decode-execute cycle. The control unit coordinates the actions of the computer. It sends out control signals to other parts of the CPU and to other components of the computer. State the function of the Program Counter. This holds the address of the next instruction to be fetched. State the function of the Memory Data Register (MDR). The MDR is temporary store(buffer) for anything copied from memory. State the function of the Accumulator. The accumulator is a temporary store for the results of calculations carried out by the ALU. State two components of Von Neumann's design in addition to the CPU. Memory to store program data and instructions. Input and output devices.