Area 04
Digital logic
Ones, zeros and the decisions inside every computer
Digital logic is the language of computers. Simple gates that answer yes or no can be combined into devices that count, remember and decide.
What you will learn
- What binary signals are: 1 and 0, on and off
- How AND, OR and NOT gates work
- How to read and build a truth table
- How gates combine into circuits that count and remember
Example experiments
-
Use two switches and an AND gate to make a light that needs both buttons.
-
Build a circuit that turns on a lamp when either of two doors opens.
-
Combine gates to add two binary numbers.
Things you can build
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A lock with a secret combination
-
A binary counter
-
A simple traffic-light controller
These examples show the kind of work in this area. The published lessons may differ.
Try a small model
These small models run right here in your browser and keep working offline once the page has loaded. They are simplified teaching models, not the MEKALUMI simulation engine.
Logic gate
Switch the inputs on and off, then choose a gate. The lamp shows the output.
- Output
- Lamp off (0)
AND: the lamp lights only when A and B are both 1.
| A | B | Output |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
Logic gates follow exact rules, so this model behaves like real digital logic.
What the simulation simplifies
- In most lessons signals switch instantly, while real chips need a tiny amount of time.
- Electrical details such as power use and noise are usually left out.
Every simulation simplifies reality. Knowing how it does so is part of learning engineering.
Links to school subjects
Mathematics (binary numbers), computer science, electronics
Connections to other areas
Digital logic connects circuits with automation, programming and robotics.
Good to know
Every computer and phone contains billions of tiny switches that work like logic gates.