Computing

Logic gates
1. The output is always the opposite of the input. The output is only ever 1 when the input is 0.
2. Both of the inputs have to be 1 for the output to be one.
3. The output is only 1 when either of the inputs are 1. There is only ever a 0 when both of the inputs are 0.
4. AND GATE
5. OR GATE
6. NOT GATE
Why do computers use binary?
1. It is the universal computer language
2. It is a definite yes or no
3. There can be no maybes
4. Has a charge or no charge - so logic gates turn them off or on
Fetch De-execute cycle
1. The CPU fetches the data from the RAM
2. Decode the data so that the ALU can understand the binary code, each CPU has a set of instructions which can understand the binary in different ways.
3. The computer then carries out the process and resets the ALU and CPU for the next cycle
Storage Devices
1. Flash
  1. Non-volatile
  2. No moving parts
  3. Solid state
  4. Universal serial bus - USB
2. Magnetic
  1. Non-Volatile
  2. All data is deleted when the power to the storage device is stopped
  3. Large storage capacity
  4. RAM (Random Access Memory)
3. Optical
  1. Non-volatile
  2. Is read by a laser
  3. DVD
Input and Output devices
1. Input devices allow information to go into the computer
  1. EG/ Keyboard
2. Output devices allow information to be displayed to humans
  1. EG/ Monitor

Resource summary

	Created by Ben Leader about 11 years ago