GCSE AQA Computer Science 8525 Unit 3.4 Computer Systems (100% Correct Answers)

What is the difference between System and Application software? System software helps run the computer's hardware Application software helps the user perform tasks What is the purpose of an Operating System (OS)? The OS manages the computer's hardware and software resources 4 parts of the CPU/Von Neumann architecture (RCCAB) Arithmetic Logic Unit (ALU) Control Unit (CU) Clock Bus Registers Which factors affect the performance of a CPU? (CCC) Clock speed Number of Cores Cache size Fetch-Decode-Execute cycle F-fetch instruction from main memory D-decode instruction to process what to do E-execute the instruction (carry it out) NOTE: may involve reading/writing to main memory Purpose of Random Access Memory (RAM) volatile memory (temporary memory) used to store running applications until power is lost Purpose of Read Only Memory (ROM) non-volatile memory which stores the BIOS - instructions needed to turn on the computer Purpose of Secondary storage non-volatile memory used to store data permanently Cannot be accessed directly by the CPU 3 types of secondary storage Solid State (Flash) Optical Magnetic Pros vs Cons of Solid State memory Pro: data access is very fast Pro: no moving parts, so more robust and portable