Choose an emoji
Use the palette or type LOAD, ADD and PRINT on your keyboard.
Emoji operating systems
These demos are full emoji operating system simulations. They run entirely in your browser, no server needed. Boot them up, spawn processes, and watch OS concepts come alive!
Learn how it works
A free learning lab from 3D3D
See the machine think.
A computer follows small instructions. Here, you can see every one of them.
Build a program with emoji, press Step, and watch its registers and memory change. Nothing to install. No account to make.
Open the lab →Your first three instructions
📥 42 🖨️ ⏹️
Load 42. Print it. Stop.
OUTPUT 42
Small instructions. Big ideas.
R0 is the accumulator: a place to hold the number you are working with. LOAD puts a value there, arithmetic changes it, and PRINT shows it. Seven more registers keep other values safe while you work.
Follow the counter
The program counter points to the next instruction. A jump changes where it goes.
Go back and try again
Step back restores the whole machine. You can inspect memory, stacks and every result.