2.4 COMPUTATIONAL LOGIC

2.4 COMPUTATIONAL LOGIC

1. Transistors: made from semiconductor materials that can act as electrically-controlled switches.

2. a CPU, transistors are arranged and configured into circuits to perform operations such as calculations when electricity is passed Inside d through them.

3. Logic Gates

   • Multiple transistors can be arranged together to form more complex "switches" that only allow electricity to flow through if all or some of the transistors are "on".
     • Such arrangements of transistors are called logic gates - they act like gates that only open if certain logical conditions are met.
       • There are three types of logic gate that you must be familiar with at GCSE - AND, OR and NOT logic gates.
         • And Gates
           • AND gates have two inputs and one output
             • An AND gate will only output current (represented as a 1 on the output) if both inputs are on (also represented as 1s)
         • OR Gates
           • OR gates have two inputs and one output
             • An OR gate will output current (represented as a 1 on the output) if either or both inputs are on (also represented as 1s)
         • NOT Gates
           • NOT gates have one inputs and one output.
             • NOT gates invert the input so their output is the opposite of the input given.