2.4 Computational Logic

2.4 Computational Logic

1. binary form

   • Computer systems store and process data as binary digits (represented as 0s and 1s)
   • This is because, underneath the surface, computers are electrical devices that process information by controlling the flow of electricity through billions of wires and switches (called transistors) inside the CPU, memory chips and between components.

2. Transistors

   • Transistors are electrical components made from semiconductor materials that can act as electrically-controlled switches.
   • A common way to think of transistors is that they are like taps. When a tap is turned on, water coming into the tap is allowed to flow through the tap and to come out.

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.

4. AND gate

   • 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)

5. OR gate

   • 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)