This is a CHIP-8 emulator written in JavaScript. Try it here: http://mir3z.github.io/chip8-emu/
The emulator has a decent implementation of all 35 CHIP-8 op-codes, all of which are well-tested.
Two known "quirks" have also been implemented (see: chip8.CPU#quirks):
- Load/store quirks - Instructions
LD [I], VxandLD Vx, [I]increments value of I register but some CHIP-8 programs assumes that they don't. - Shift quirks - Shift instructions originally shift register VY and store results in register VX. Some CHIP-8 programs incorrectly assumes that the VX register is shifted by this instruction, and VY remains unmodified.
Project repository contains 90 CHIP-8 roms and their descriptions which can be found at http://chip8.com (CHIP-8 Program Pack). All of them were checked and should work fine on the emulator. It is a common issue among emulators I have tested, that some of ROMS were not working correctly - this is mostly because of quirks I have mentioned above and errors in op-codes implementation.
Original CHIP-8 keyboard layout is mapped to PC keyboard as follows by default:
|1|2|3|C| => |1|2|3|4|
|4|5|6|D| => |Q|W|E|R|
|7|8|9|E| => |A|S|D|F|
|A|0|B|F| => |Z|X|C|V|
The simplest way to set up the emulator is the following code:
// Initialize chip8 with default options
chip8.initialize({
ctx: document.querySelector('canvas').getContext('2d')
});
// Load ROM file asynchronously...
chip8.loadROM('roms/Puzzle.ch8', function () {
// ... and run emulator when ROM loading is done
chip8.run();
});
Take a look at API documentation the learn more advanced usage.
This emulator should work in any decent web browser supporting typed arrays and canvas element.
The MIT License (MIT). Copyright (c) 2014 mirz (mirz.hq@gmail.com)