Nintendo - Game Boy / Color (Gearboy)¶

Background¶

Gearboy is an open source, multi-platform, Nintendo Game Boy (DMG) / Game Boy Color (CGB) emulator written in C++.

Highly accurate CPU emulation, passes cpu_instrs.gb from blargg's tests.
Accurate instruction and memory timing, passes instr_timing.gb and mem_timing.gb from blargg's tests.
Memory Bank Controllers (MBC1, MBC2, MBC3 with RTC, MBC5), ROM + RAM and multicart cartridges.
Accurate LCD controller emulation. Background, window and sprites, with correct timings and priorities including mid-scanline timing.
Mix frames: Mimics the LCD ghosting effect seen in the original Game Boy.
Sound emulation using SDL Audio and Gb_Snd_Emu library.
Battery powered RAM save support.
Save states.
Game Genie and GameShark cheat support.
Runs on Windows, Linux, Mac OS X, Raspberry Pi, iOS and as a libretro core (RetroArch).

The Gearboy core has been authored by

The Gearboy core is licensed under

A summary of the licenses behind RetroArch and its cores have found here.

Not required.

Content that can be loaded by the Gearboy core have the following file extensions:

RetroArch database(s) that are associated with the Gearboy core:

Frontend-level settings or features that the Gearboy core respects.

The Gearboy core's library name is 'Gearboy'

The Gearboy core saves/loads to/from these directories.

Frontend's Save directory

File	Description
*.srm	Cartridge battery save
*.rtc	Real time clock save

Frontend's State directory

File	Description
*.state#	State

The Gearboy core has the following option(s) that can be tweaked from the core options menu. The default setting is bolded.

Settings with (Restart) means that core has to be closed for the new setting to be applied on next launch.

Emulated Model (restart) [gearboy_model] (Auto|Game Boy DMG)

Select which hardware/model is emulated.
- Auto selects the best hardware based in the rom.
- Game Boy DMG forces original Game Boy hardware.
Palette [gearboy_palette] (Original|Sharp|B/W|Autumn|Soft|Slime)

Select a color palette for Game Boy DMG games.
Allow Up+Down / Left+Right [gearboy_up_down_allowed] (Disabled|Enabled)

Enabling this will allow pressing / quickly alternating / holding both left and right (or up and down in some games) directions at the same time.

This may cause movement based glitches to occur in certain games.

It's best to keep this core option disabled.