CPU - Central Processing Unit

CPU - Central Processing Unit

1. Fetch, Decode, Execute

   • Fetch
   • Decode
   • Execute

2. Power Supply

   • Supplies power to the components

3. RAM

   • Stores data while powered
   • Random Access Memory
   • RAM needs electricity to hold while ROM can hold data even without electricity

4. CPU

   • Processes information

5. Fan

   • Cools the components that may get hot

6. Motherboard

   • Connects all components

7. Floppy Drive

   • Reads and writes information from floppy disks

8. Hard Drive

   • Reads and writes data onto metal platters

9. Optical Drive

   • Reads and writes data stored on compact discs

10. ROM

    • Read Only Memory
    • Is a form of permanent storage while RAM is a form of temporary storage
    • ROM is non-volatile memory while RAM is volatile memory

11. Starting a Computer

    • When you switch on a computer, a small program held in ROM called the bootstrap loader is automaticallly executed
    • The program performs some self-tests, and loads the operating system into memory

12. Fetch, Decode, Execute Cycle

    • The processor checks the program counter to see which instruction to run next. The program counter gives an address value in the memory of where the next instruction is. The processor fetches the instruction value from this memory location. Once the instruction has been fetched, it needs to be decoded and executed. For example, this could involve taking one value, putting it into the ALU, then taking a different value from a register and adding the two together. Once this is complete, the processor goes back to the program counter to find the next instruction. This cycle is repeated until the program ends.

13. Graphic Card

    • Produces 2D and 3D images on the screen, can be a separate card or built into the motherboard.

14. Sound Card

    • A device which can be slotted into a computer to allow the use of audio components for multimedia applications.

15. Heat sink

    • A device or substance for absorbing excessive or unwanted heat.