AS Computing
Unit 1.2 Logical Operations
What is meant by a logic gate?
A logic gate is an electronic component that can be used to conduct electricity based on a
rule.
The outputs of the gate is the result of applying the rule to one or more sources.
We use them because without them there would be no computers
There are seven kinds of logic gate but we only need to know of four
Logic gates are the building blocks of electronics. Therefore the building blocks of computer
programming. In short they are incredibly important.
The different types of logic gate are:
1. AND
2. NOT
3. OR
4. NAND
5. NOR
6. XOR
7. XNOR
8. Etc.
We only need to know the ones highlighted in red (FOR AS). Computer CPUs contain billions of tiny
circuits that perform certain logical functions. These are called logic gates.
NOT Gate
This is the simplest logic gate. The output is simply the opposite of the input. This gate is usually
used in programming to signify negation. E.g. if x is != to y .
Truth Table
Input Output
0 1
1 0
Diagram
AND Gate
AND logic gates are used to signify two conditions being met.
Diagram
Truth Table
Input A Input B Output
0 0 0
Page |1 Luca Passariello AS Computing
Unit 1.2 Logical Operations
What is meant by a logic gate?
A logic gate is an electronic component that can be used to conduct electricity based on a
rule.
The outputs of the gate is the result of applying the rule to one or more sources.
We use them because without them there would be no computers
There are seven kinds of logic gate but we only need to know of four
Logic gates are the building blocks of electronics. Therefore the building blocks of computer
programming. In short they are incredibly important.
The different types of logic gate are:
1. AND
2. NOT
3. OR
4. NAND
5. NOR
6. XOR
7. XNOR
8. Etc.
We only need to know the ones highlighted in red (FOR AS). Computer CPUs contain billions of tiny
circuits that perform certain logical functions. These are called logic gates.
NOT Gate
This is the simplest logic gate. The output is simply the opposite of the input. This gate is usually
used in programming to signify negation. E.g. if x is != to y .
Truth Table
Input Output
0 1
1 0
Diagram
AND Gate
AND logic gates are used to signify two conditions being met.
Diagram
Truth Table
Input A Input B Output
0 0 0
Page |1 Luca Passariello AS Computing
