GBRuby is another Game Boy emulator, written in ruby. No ambitions to become the better emulator ever, it's just a side project made for fun. Despite all it aims to run more games as possible at a decent fps and pass all the common tests.

Ruby is slow and not a good choice for an emulator. The challenge is to write something good enough to play games and check if it is possible to run it at 60 fps (spoiler: yes)

• Cycle accurate CPU
• Scanline accurate PPU
• Resizable window with full screen support

There are no automated tests yet, but GBRuby pass some common tests ROM. I will add more and more.

DMG Acid2	Blargg‘s CPU Tests

• Boot sequence
• Add automated testing using Github Actions.
• Support to cartridge type other than MBC1.
• Optimizations to reach constant 60 FPS with every game.
• Command line interface.
• Configuration file.
• Sound support.
• Game Boy Color support.

• Ruby 3
• SDL 2

$ brew install sdl2
$ brew install sdl2_image
$ brew install sdl2_mixer
$ brew install sdl2_ttf

Initialize the Game Boy, choose a cartridge, load it, and play!

$ game_boy = GameBoy.new
$ cartridge = Cartridge.new('roms/tetris.gb')
$ game_boy.load_cartridge(cartridge)
$ game_boy.play(boot: false)

• Pan Docs
• Game Boy development WIKI
• codeslinger.co.uk
• The Ultimate Game Boy Talk (33c3)

• Optcarrot, a NES emulator in ruby
• Waterfoul, a Game Boy emulator in ruby