Chip-8 Emulator

Play online at http://ajor.co.uk/chip8

Native Build

This code has only been tested on Linux, although it may work on other platforms provided the required dependencies are available.

Requirements

• A C++11 compiler
• GLFW3
• GLEW (OpenGL Extension Wrangler)

Compilation

Then compile using CMake:

mkdir build
cd build
cmake ../
make

or just run:

g++ main.cpp chip8.cpp font_loader.cpp -std=c++11 -lglfw -lGLEW -lGL -lGLU -pthread -O3 -Wall -pedantic

Emscripten/asm.js Build

Requirements

• Emscripten SDK
• Node.js

Compilation

Compile using CMake, substituting the path to the Emscripten.cmake toolchain file on your system:

mkdir build
cd build
cmake ../ -DCMAKE_TOOLCHAIN_FILE=/usr/lib/emscripten/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_BUILD_TYPE=Release
make

Usage

Native

./chip8 [options] rom
Options:
  -i  Instructions per step (default: 10)
  -s  Screen scale factor (default: 20)

Emscripten/asm.js

Place chip8.html and the generated chip8.js and chip8.js.mem files in the same directory and open in a web browser.

General

You can adjust the speed of the emulator by changing instructions_per_step (defaults to 10). This parameter represents the number of Chip-8 instructions executed per frame.

Assuming a frame rate of 60fps, an instructions_per_step value of 10 (or a little higher) works well for most Chip-8 games tested, but Connect4 needs instructions_per_step=1 to be playable. Super-Chip games generally need to be run a bit faster - somewhere in the 20-60 range seems to work well.

Keyboard map

Chip-8:    QWERTY keyboard:
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

Pressing Enter resets the emulator.

Compatibility

• All Chip-8 and Super-Chip games tested appear to work correctly

TODO

• Stop using abort() everywhere
• Fix threading