1. HARDWARE Lesson 2

2. Components of a computer: 1)A Processor (or CPU) The brain of the computer 2)Memory To remember the programs and data that it uses 3) Input devices To enter information into the computer 4) Output devices To show us what it has done to our information 5) Backing storage devices To save our information

3. Input – Process – Output INPUTPROCESSOUTPUT Data is INPUT into the computer (using an Input device) Data is PROCESSED to produce useful information (CPU) Information is then OUTPUT (using an Output device)

4. Input – Process – Output INPUT DEVICES PROCESSOR (CPU) OUTPUT DEVICES BACKING STORAGE DEVICES MAIN MEMORY

5. Processor (CPU) This is the brain of the computer The processor does calculations and makes decisions Processor clock speed is measured in GigaHertz (GHz) 1GHz = 1000 million pulses per second

6. Main Memory This is inside the main computer system unit. The Main Memory is responsible for storing the parts of a program(s) and data which are in current use. Some of the memory is Random Access Memory (RAM) and some is Read Only Memory (ROM).

7. Random Access Memory Chip  Read/Write memory  Stores our programs and data temporarily  Contents are lost when computer is switched off Read Only Memory Chip  Stores programs and data permanently  Holds vital system data and programs  Contents are not lost when computer is switched off Main Memory Chips RAM ROM

8. List of Terms Binary - Having only 2 states, ON or OFF Bit - Binary Digit - Either 1 or 0 Character - Letters, Numbers or Symbols - a * 1 Byte(b) - 8 bits - 01010101 = 1 Character Kilobyte(Kb) - 1024 bytes = 1024 Characters = 1/2 page Megabyte(Mb) - 1024 Kb = 500 pages = 1 book Gigabyte(Gb) - 1024Mb = 1000 books = 1 library Terabyte(Tb) - 1024Gb = 1000 libraries

9. The sound card processes audio, freeing up the processor for other tasks Used to record digital audio Devices can be plugged into the sound card:  Speakers (Output)  Headphones (Output)  Microphones (Input) Sound Card

10. The graphics card contains a dedicated graphics processor and memory This is used to process videos, animations, 3D graphics, etc, freeing up the processor for other tasks Graphics Card