Game Boy and Game Boy Color emulator written in C
C Objective-C Assembly GLSL C++ Makefile Other
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LIJI32 Merge pull request #99 from max-m/daa-patch
Rewrite the DAA instruction
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SameBoy is an open source Game Boy (DMG) and Game Boy Color (CGB) emulator, written in portable C. It has a native Cocoa frontend for macOS, an SDL frontend for other operating systems, and a libretro core. It also includes a text-based debugger with an expression evaluator. Visit the website.


Features common to both Cocoa and SDL versions:

  • Supports Game Boy (DMG) and Game Boy Color (CGB) emulation
  • Lets you choose the model you want to emulate regardless of ROM
  • High quality 96KHz audio
  • Battery save support
  • Save states
  • Includes open source DMG and CGB boot ROMs:
    • Complete support for (and documentation of) all game-specific palettes in the CGB boot ROM, for accurate emulation of Game Boy games on a Game Boy Color
    • Supports manual palette selection with key combinations, with 4 additional new palettes (A + B + direction)
    • Supports palette selection in a CGB game, forcing it to run in 'paletted' DMG mode, if ROM allows doing so.
    • Support for games with a non-Nintendo logo in the header
    • No long animation in the DMG boot
  • Advanced text-based debugger with an expression evaluator, disassembler, conditional breakpoints, conditional watchpoints, backtracing and other features
  • Extremely high accuracy
  • Emulates PCM_12 and PCM_34 registers
  • T-cycle accurate emulation of LCD timing effects, supporting the Demotronic trick, Prehistorik Man, GBVideoPlayer and other tech demos
  • Real time clock emulation
  • Retina/High DPI display support, allowing a wider range of scaling factors without artifacts
  • Optional frame blending (Requires OpenGL 3.2 or later)
  • Several scaling algorithms (Including exclusive algorithms like OmniScale and Anti-aliased Scale2x; Requires OpenGL 3.2 or later or Metal)

Features currently supported only with the Cocoa version:

  • Native Cocoa interface, with support for all system-wide features, such as drag-and-drop and smart titlebars
  • Game Boy Camera support

Read more.


SameBoy passes all of blargg's test ROMs, all of mooneye-gb's tests (Some tests require the original boot ROMs), and all of Wilbert Pol's tests. SameBoy should work with most games and demos, please report any broken ROM. The latest results for SameBoy's automatic tester are available here.


SameBoy requires the following tools and libraries to build:

  • clang
  • make
  • Cocoa port: OS X SDK and Xcode command line tools
  • SDL port: SDL2.framework (OS X) or libsdl2 (Other platforms)
  • rgbds, for boot ROM compilation

On Windows, SameBoy also requires:

  • Visual Studio (For headers, etc.)
  • GnuWin
  • Running vcvars32 before running make. Make sure all required tools and libraries are in %PATH% and %lib%, respectively.

To compile, simply run make. The targets are cocoa (Default for macOS), sdl (Default for everything else), libretro, bootroms and tester. You may also specify CONF=debug (default), CONF=release or CONF=native_release to control optimization and symbols. native_release is faster than release, but is optimized to the host's CPU and therefore is not portable. You may set BOOTROMS_DIR=... to a directory containing precompiled dmg_boot.bin and cgb_boot.bin files, otherwise the build system will compile and use SameBoy's own boot ROMs.

SameBoy was compiled and tested on macOS, Ubuntu and 32-bit Windows 7.