AQA A Level Computer Science Study Guide Exam And Answers Already Answered 2024.

Arithmetic Logic Unit (ALU) - Answer The part of the central processing unit that performs arithmetic computations and logical operations Control Unit - Answer Coordinates activities in the CPU, memory and peripherals Clock - Answer A continuous sequence of clock pulses to step the control unit through its operations Registers - Answer Very fast memory stored on or near the processor Program Counter (PC) - Answer Holds the address of the next instruction to be executed Current Instruction Register (CIR) - Answer Stores the current instruction (in binary) Memory Address Register (MAR) - Answer Holds the address of a memory location from which data will be read or data will be written to Memory Buffer Register (MBR) - Answer Temporarily stores the data read from or written to memory Status Register (SR) - Answer Contains many bits that are set (1) or cleared (0) depending on the result of an instruction Clock Speed - Answer The frequency at which the system clock ticks Bus Width - Answer The number of parallel signal lines or wires allocated to a bus