chip8js

CHIP-8 Emulator designed to work in your web browser

Running the demo

Clone the repository, open index.html with your browser. That's it!

Select a ROM file on your disk and enjoy.

You can adjust the cyclerate of the emulation with the controls in the demo.

Embedding the emulator

This whole project consists of three parts.

• EmulationEngine, the emulator class itself.
• Renderer, canvas-based graphics output.
• IOController, keyboard event handler which binds to document.body.

You can replace Renderer and IOController with your own implementations if needed.

EmulationEngine API

import EmulationEngine from './EmulationEngine'

// initialize the engine
// alias for EmulationEngine.wipeState(), the difference is semantics
EmulationEngine.initialize()

// load the ROM
// the ROM should be either Uint8Array or a normal array of ROM data bytes
// (this sample ROM adds 1 to V1 until 5 is accumulated)
EmulationEngine.loadRom([0x71, 0x01, 0x31, 0x05, 0x12, 0x00])

// emulate one cycle
// returns false if a NOOP (0x0000) was hit, otherwise true
EmulationEngine.emulateCycle()

// graphics memory buffer, useful if you want to 
// override the existing Renderer implementation
EmulationEngine._graphicsMemory

// key states buffer, useful if you want to override
// the existing IOController implementation
EmulationEngine._keyState