FRISC processor simulator in JavaScript
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FRISCjs is a FRISC processor simulator written in JavaScript.

The FRISCjs simulator has two parts: a FRISC assembler (built using PEGjs) which translates FRISC assembly code to machine code and a FRISC CPU simulator which executes machine code.

Furthermore, there are two user interfaces to the simulator: a Web application graphical interface and a NodeJS command-line interface. The Web application interface is available here and supports many cool features like breakpoints and step-by-step execution.


Using the assembler and simulator libraries

In node, install using npm:

> npm install friscjs

and then access the assembler and simulator:

var friscjs = require("friscjs");
var asm = friscjs.assembler;
var sim = friscjs.simulator;

In a browser, link to the browser script that contains both the assembler and simulator:

<script src="lib/friscjs-browser.js"></script>

and then access the assembler and simulator:

var asm = friscjs.assembler;
var sim = friscjs.simulator;

After installing the libraries, check out the FRISCjs API docs for instructions on using them.

Using the simulator console and Web applications

To use the Web-based simulator, launch the webapp/index.html page in a browser or access the on-line version at

To use the console-based simulator application, clone the FRISCjs repo:

> git clone

and then run the app with node to see the instructions:

> node ./consoleapp/frisc-console.js


  1. Fork and/or clone repo: git clone
  2. Change dir to noam: cd FRISCjs
  3. Install dependencies: npm install
  4. Make changes to noam sources (./src), tests (./tests) or apps (./webapp/* and ./consoleapp/*)
  5. Build using grunt: grunt (on linux), grunt.cmd (on windows)
  6. Run tests: npm test
  7. Fix issues reported by grunt and tests, and then repeat 5)
  8. Commit, push and make a pull request, or send a git patch by e-mail
  9. E-mail me if you have questions (e-mail address is below)

Similar projects

This project was inspired by the GameBoy emulator in JavaScript and jsLinux projects. There are many other processor simulators in JavaScript, such as the GameBoy Color emulator, visual transistor-level simulation of the 6502 CPU, 6502 compatible assembler and emulator and this other 6502 CPU simulator.


FRISCjs was developed by Ivan Zuzak. Contributors: Ivan Budiselic, Stanko Krtalic.

FRISCjs is built with many open-source projects:

  • PegJS - used for generating the FRISC assembly code parser.
  • NodeJS - used for the command-line version of the simulator.
  • jQuery - used for the Web application version of the simulator.
  • Bootstrap - used for the Web application version of the simulator.
  • Ace - used as the editor for the Web application version of the simulator.
  • Mustache - used for client-side templates.
  • Keymaster - used for reconfiguring/disabling keyboard shortcuts.


Licensed under the Apache 2.0 License.

gaugestracking alpha