f8ith / Hermes

Hermes is a gameboy DMG emulator

Hermes

Hermes is a gameboy emulator written in C++. It was made as a passion project and originally started as an attempt to emulate Pokemon Red/Blue. As such, it was never meant to have perfect timings (though it does make a fair effort), so some games that heavily rely on such timings may or may not work.

Features

• All opcodes supported
• Joypad, LCD Stat, VBlank, and Timer interrupts
• Passes all of blargg's CPU tests
• MBC1, MBC2, MBC3, and MBC5 support
• Background, window, and sprite rendering
• Save files

Screenshots

Input Controls

Action Key UP ↑ DOWN ↓ LEFT ← RIGHT → B K A L START Enter/Return SELECT Right Shift SAVE Escape

Dependencies

Hermes uses SDL2 for the display. Note that on Windows SDL and cmake can be a bit of a hassle, so make sure that CMake can find the sdl2-config.cmake files for everything to build properly.

Usage

Building

Building the emulator is easily done using cmake

mkdir build
cd build
cmake ..
make

Running

Hermes <ROM file> <optional: save file name>

Resources

Just a list of some helpful resources I've come across while working on Hermes

• https://cturt.github.io/cinoop.html
• https://imrannazar.com/Gameboy-Z80-Opcode-Map
• https://www.pastraiser.com/cpu/gameboy/gameboy_opcodes.html
• https://gbdev.gg8.se/wiki/articles/Gameboy_Bootstrap_ROM
• https://www.youtube.com/watch?v=HyzD8pNlpwI&t=3028s&ab_channel=media.ccc.de
• https://blog.tigris.fr/2019/09/15/writing-an-emulator-the-first-pixel/
• http://www.codeslinger.co.uk/pages/projects/gameboy/graphics.html
• https://github.com/Jonazan2/PatBoy