The Wireworld computer #TuringMachine #Computers

Via Wireworld is a cellular automaton on an infinite square grid, invented by Brian Silverman in about 1984. It appeared as part of his ‘Phantom Fish Tank’ program in 1987, but we only found out about it when it was described in Scientific American in January 1990. The automaton has a similar flavour to J. H. Conway’s well-known ‘Game of Life’.

Each cell can be in one of four different states, forming a pattern on the grid. The four states are:

  • blank, shown in the pictures here in black;
  • ‘copper’, shown here as a sort of orange colour;
  • ‘electron head’, or just ‘head’ for short, shown here as white; and
  • ‘electron tail’, or ‘tail’, shown in blue.
black square on black background orange square white square blue square

The rules of Wireworld

Time proceeds in discrete steps called generations. At each generation the state of each cell may change; whether it changes, and what it changes to, depend on its current state and the state of its eight nearest neighbour cells according to a simple set of rules:

  • a blank square always stays blank
  • an electron head always becomes an electron tail
  • an electron tail always becomes copper
  • copper stays as copper unless it has just one or two neighbours that are electron heads, in which case it becomes an electron head


As you can see from the illustration below, an electron head-tail pair (which we’ll call an ‘electron’) moves along a row of copper cells (which we’ll call a ‘wire’) at the rate of one cell per generation.

electron head-tail pair moving on copper wire

Wires give us a way of transporting a sequence of electrons from one point to another. The pattern of electrons is preserved as they move along a wire and so, if we can represent data using these patterns, we can use the wires to carry data from one place to another.

See the article for how such logic is combined to form logic gates, registers, an instruction set, and the full computer which is able to run programs such as calculating prime numbers

block diagram

Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here:

Join Adafruit on Mastodon

Adafruit is on Mastodon, join in!

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Join over 36,000+ makers on Adafruit’s Discord channels and be part of the community!

CircuitPython – The easiest way to program microcontrollers –

Maker Business — “Packaging” chips in the US

Wearables — Enclosures help fight body humidity in costumes

Electronics — Transformers: More than meets the eye!

Python for Microcontrollers — Python on Microcontrollers Newsletter: Silicon Labs introduces CircuitPython support, and more! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi

Adafruit IoT Monthly — Guardian Robot, Weather-wise Umbrella Stand, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — #NewProds 7/19/23 Feat. Adafruit Matrix Portal S3 CircuitPython Powered Internet Display!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at !

No Comments

No comments yet.

Sorry, the comment form is closed at this time.