Manufactoria: the state machines and queues behind the puzzles
Manufactoria began in 2010 as a browser game by Nicholas Feinberg of PleasingFungus, and returned as Manufactoria 2022, a paid game on Steam for Windows and macOS (PleasingFungus Games, released August 16, 2022, $19.99 when we checked) from the same creator as Silicon Zeroes. Its store page promises a little more than a hundred puzzles built from just eight types of machine. Each robot carries a tape of colored symbols. A branch machine reads the first symbol and sends the robot one way or another, consuming it, while a writer adds a symbol to the end, so the tape behaves as a queue. You lay out conveyors so that the right robots reach the exit and the rest are rejected, or so that each robot leaves carrying the right new tape. Under the robots, it is computer science: a finite state machine with a queue for memory.
What is really going on in Manufactoria
Without writers, a robot's path through the factory depends only on which machine it is at and the symbols it reads, which is exactly a finite state machine: each position is a state, each branch a transition, the exit is the accepting state. Such a machine can check patterns like "starts with blue" or "has an even number of reds", but not "as many reds as blues", because counting without limit needs memory. Writers supply it: appending to the end while reading from the front turns the tape into a queue, and a state machine with an unbounded queue can compute anything a Turing machine can. That is why the later puzzles feel like programming. (digiwleea is an independent project, not affiliated with PleasingFungus Games.)
The same ideas as circuits
In hardware a finite state machine is a few flip-flops holding the state and gates computing the next state, and a queue is a shift register or a small memory with read and write pointers. digiwleea lets you build those for real in the browser, from CMOS transistors to gates, flip-flops, state machines, registers, RAM and an 8-bit CPU that runs a stored program, plus the assembly language behind it, with every part checked and an AI tutor (Wleea). Manufactoria teaches you to think like the control logic; digiwleea shows you the wires it is made of.
| Manufactoria | digiwleea | |
|---|---|---|
| Made of | Conveyors, branches and writers (eight machine types) | Transistors, then gates, flip-flops and the parts you build |
| State | Where the robot is in the factory | A pattern of bits in flip-flops |
| Memory | The robot's tape, read at the front and written at the end | Registers, shift registers and RAM |
| Goal | Accept or rewrite the right robots, then optimize | Build an 8-bit CPU step by step, through 40+ levels |
| Runs on | Windows and macOS (Manufactoria 2022, on Steam) | Any modern browser, nothing to install |
Manufactoria ideas, as live circuits
- Accept or reject by pattern. A sequence detector is a state machine that recognizes a pattern in a stream of bits; a turnstile is the smallest useful one, and the Mealy machine and vending machine go further.
- Even or odd counts. A single flip-flop that toggles on each red tracks parity, like the parity checker or a T flip-flop.
- The tape as a queue. Bits that go in at one end and come out at the other are a shift register; loading a whole word and reading it out a bit at a time is a PISO shift register.
- Comparing. "Is the number on the tape bigger?" in hardware is a magnitude comparator.
Liked the puzzles? The same creator's Silicon Zeroes is about building CPUs from parts, and our logic gate games comparison lists more.
No sign-up is needed to start: open the lab and place your first transistor, or read the free theory course. The account (and the AI tutor) are optional.
More comparisons: Games about logic and computers
See for yourself: build a logic gate from transistors in the simulator, then follow the path from sand to an 8-bit CPU.
Open the digiwleea lab →Frequently asked
Is Manufactoria Turing complete?
Its tape is read from the front and written at the end, which makes it a queue, and a finite state machine with an unbounded queue can compute anything a Turing machine can. Fans have written it up as a Turing-complete language on esolangs.org.
What is the difference between Manufactoria and Manufactoria 2022?
The original was a browser game from 2010. Manufactoria 2022 is a new paid game by the same creator for Windows and macOS on Steam, with a little more than a hundred puzzles, global leaderboards and a cast of characters.
What does Manufactoria teach?
Finite state machines and how memory adds power to them: which patterns of symbols a fixed layout of machines can recognize, and how writing to a queue lets it compute much more.
How are state machines built in hardware?
With flip-flops that hold the current state and logic gates that compute the next state from the state and the inputs, all updated on a clock edge. digiwleea's state machine examples run live in the browser.