A digital clock built inside Conway's Game of Life, running in real time behind your Windows desktop icons.
Up close, in the watch view at 1/4 zoom, the segments are bundles of gliders and the colon is two discs of pulsars:
The pattern is dim's digital clock from the Code Golf Stack Exchange challenge "Build a digital clock in Conway's Game of Life" (2017): a real Life machine with a glider-gun timebase, counters, latches and lookup tables, and a 7-segment display drawn by glider streams. Nothing about the rules is changed; the machine computes the time. One displayed minute is 11,520 generations, so real time is 192 generations per second.
This repository runs it as a single small native program: a Hashlife engine in C, precomputed states of the machine so it starts at the current minute, and a window parented behind the desktop icons that draws only when a new generation lands.
- Download
life-clock.exefrom the latest release. - Double-click it. It syncs to the current time in a second or two and
appears behind your desktop icons. Run it with
--setupto install it properly, with shortcuts and an entry in Installed apps. - Right-click the tray icon for Settings (colours, size, position, frame
rate; changes apply live), Pause, Watch full screen
(a window at 1/4 zoom where you can see the gliders), Start with Windows
and Quit. Renamed to
.scrit is a screensaver that tours the machine.
Cost with the desktop visible: about 3 % of one core at the default 6 fps, around 75 MB of memory, no GPU. Nothing while a window covers the desktop.
- Setup and settings: installation, start at login, every ini key, troubleshooting.
- How it works: the engine, wall-clock sync, how the window gets behind the icons on Windows 11, what the display does over a minute, measurements, building and regenerating.
- Research: the survey of hosts, engines and precomputation that led to this design.
MIT for everything in this repository (see LICENSE). The pattern
clock.rle is dim's and is CC BY-SA.
Pattern: dim, answer to "Build a digital clock in Conway's Game of Life" on codegolf.stackexchange.com (2017), CC BY-SA. Everything else was written for this wallpaper.