The EJS Cellular Automata (Rule 90) model displays a lattice with any one of a finite number of states which are updated synchronously in discrete time steps according to a local (nearby neighbor) rule. Rule 90 is a specific nearby neighbor rule following the classification scheme developed by Stephen Wolfram that produces a Pascal triangle mod 2 (Sierpinski gasket) if there is a single initial cell with a value of one. You can modify this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item.

The Cellular Automata (Rule 90) model was created using the Easy Java Simulations (Ejs) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking the ejs_ms_explicit_Automata1DRule90.jar file will run the program if Java is installed.  Ejs is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models.  Additional Ejs models are available.  They can be found by searching ComPADRE for Open Source Physics, OSP, or Ejs.

Please note that this resource requires at least version 1.5 of Java (JRE).