NAND²

Build a computer from a single NAND gate, alone or with up to three friends on the same board: from clicking relays to a 16-bit CPU with a pipeline, branch prediction and a cache. Then write the programs it runs.

Invite friends through Steam or connect over a local network: up to four players work on one board at once. You see everyone's cursor with their name, parts and wires appear the moment they are placed, and a passed check counts for the whole team.

• Build together: place parts, wire and run checks side by side; the host can switch anyone to watch-only

• Code together: one shared program with everyone's cursors in it, and undo only takes back your own edits

• Shared sandbox: jump from a level into the sandbox as a group, follow a friend's view, hand everyone a Workshop course

• Progress for everyone: friends play on the host's save, their own saves stay untouched, and levels solved together count toward their achievements

You start with one NAND gate. Wire it into NOT, AND and OR, then adders, latches, registers and memory.

Every part you finish goes into your palette and becomes a building block for the next level.

• Relays: logic, selection, binary numbers

• Transistors: memory, clocks, the ALU, RAM, a Turing machine

• Integrated circuits: your first processor, programs, I/O ports

• Microprocessors: your own instructions, a stack, algorithms, robots, a RISC-V-style core

• Speed: pipeline, branch prediction, cache and your own game

• System: booting and multitasking

• Built-in code editor: assembler, HEX view, clear error messages

• Games on I/O ports: a robot in a maze, Guess the Number, Nim

• Tests that explain: truth tables and cycle-by-cycle checks show exactly where your circuit goes wrong

Circuits are simulated gate by gate, fast enough to run a whole processor live.

In era V you add a keyboard and a pixel screen, then run a first-person shooter on the CPU you wired yourself.

The section editor builds your own level chains with reference solutions, tests, briefs and hints. Share them on the Steam Workshop.

• Online co-op for up to 4 players: Steam invites or local network, optional password

• No black boxes: every complex part is built from parts you made earlier

• A reference card for every part

• Sandbox, Steam Workshop, achievements and Steam Cloud saves

• Fully localized