GSCE :Section 1: Components of a Computer System Flashcards
GCSE
What is a computer?
A computer is a machine that processes data
What is the purpose of a computer?
- To take data
- Process it
- Then output it
What does a computer system include?
- Hardware
- Software
What is Hardware?
The physical stuff that makes up the computer e.g. CPU, motherboard
What is Software?
The programs or applications that computer system runs e.g. an operating system
What are embedded systems?
They are computers that are inside a larger system e.g. dishwasher
What is inside a typical desktop computer?
- Motherboard
- Hard disk drive
- Graphics Card
- CPU
These are only a couple of examples
What is the purpose of the CPU?
It processes all the data and instructions to make a system work.
What is the purpose of the GPU?
It handles graphics and images + relieves processing load on CPU
What are some of the factors that affect the CPU?
- Clock speed
- Cache size
- Number of cores
What are the CPU’s main 3 parts?
- The Control Unit (CU)
- The Arithmetic Logic Unit (ALU)
- The Cache
What does the Control Unit (CU) do?
It executes instructions and controls the flow of data in the CPU
What does the Arithmetic Logic Unit do (ALU)?
- Does all the calculations
- Performs logic operations (AND, OR , NOT)
- Performs binary shifts
What does the Cache do?
- Stores regularly used data so the CPU can access it quickly
- It has low capacity + is expensive
- Has very fast memory
What does the Von Neumann architecture describe?
A system where the CPU runs programs stored in memory
What are the two types of registers?
- Memory Address Register (MAR)
- Memory Data Register (MDR)
What does the Program Counter do?
Holds the address of the instruction for each cycle
What does the Accumulator do?
Stores results of calculation in the ALU
What does the MAR do?
Hold the memory address ABOUT to be used by the CPU
What does the MDR do?
Holds the ACTUAL data/ instruction used by the CPU
What is the Fetch –> Decode –> Execute cycle?
Fetch:
- Memory address is copied from the program counter to the MAR
- Cppy the instruction stored in the MAR address to the MDR
- Increments the program counter to point to the address of the next instruction
Decode:
- Instruction from the MDR is decoded by the CU
- The CU prepares the next step by loading the values into the MAR or MDR
Execute:
- The instruction is performed
What is RAM?
Random Access Memory
What is ROM?
Read Only Memory
What is virtual memory?
It’s secondary storage used by the RAM
