crater ====== **crater** is an emulator for the [Sega Game Gear][game gear], written in C. [game gear]: https://en.wikipedia.org/wiki/Sega_Game_Gear Why? ---- While the internet is full of emulators for retro game systems, writing one is nevertheless a fun learning project. crater is named after [31 Crateris][crateris], a star that was – for a short time in 1974 – misidentified as [a moon of Mercury][moon]. Mercury was Sega's codename for the Game Gear during development. [crateris]: http://www.astrostudio.org/xhip.php?hip=58587 [moon]: https://en.wikipedia.org/wiki/Mercury%27s_moon Installing ---------- Only OS X and Linux are tested. You'll need a decent compiler that supports C11 (clang preferred) and SDL 2. Using Homebrew, you can `brew install sdl2`; using apt, you can `apt-get install libsdl2-dev`. Run `make` to create `./crater`. To build the development version with debug symbols (they can exist simultaneously), run `make DEBUG=1`, which creates `./crater-dev`. Usage ----- Running `./crater` without arguments will display a list of ROM images located in the `roms/` directory, and then ask the user to pick one, or enter their own ROM path. You can provide a path directly with `./crater path/to/rom`. Add or symlink ROMs to `roms/` at your leisure. Note that they should end in `.gg` or `.bin`. Add `--fullscreen` (`-f`) to enable fullscreen mode, or `--scale ` (`-s `) to scale the game screen by an integer factor. `./crater -h` gives (fairly basic) command-line usage, and `./crater -v` gives the current version. ### Advanced options crater supports several advanced features. Add `--debug` (`-g`) to display detailed information about emulation state while running, including register values and memory contents. You can also pause emulation to set breakpoints and change state. `--assemble []` (`-a`) converts z80 assembly source code into a `.gg` binary that can be run by crater. `--disassemble []` (`-d`) executes the opposite operation. If no output file is given, crater will use the name of the input file, with the extension replaced with `.gg` for `-a` and `.s` for `-d`. By default, this will never overwrite the original filename; pass `--overwrite` (`-r`) to let crater do so.