IronBoy

A Gameboy emulator written in Rust as both a learning exercise and a love letter to the console that got me into gaming. If you just want to test it out, try the web version at https://chiplis.com/ironboy

I decided to focus only on the original Game Boy (DMG) to achieve the highest degree of accuracy that I possibly can. The repository also contains more than 100 different test ROMs to verify correctness and detect any regressions.

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Building

cargo build --release

trunk build --release --filehash=false

Download trunk from https://trunkrs.dev/ and run a local webserver in the generated /dist folder if you want to run the WASM version. The emulator has been built and executed without issues on Windows, Linux and macOS.

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Testing

cargo test --release

Install This should execute all available test ROMs and save the rendered output for each of them in the test_output folder.

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Running

Usage:
  cargo run --release -- [OPTIONS] <ROM_FILE>

Arguments:
  <ROM_FILE>  GameBoy ROM file to input

Options:
      --headless               Runs the emulator without a backing window, used during test execution
      --cold-boot              Boot title screen even when opening save file
      --fast                   Start emulator with unlocked framerate
      --save-on-exit           Automatically save state before exiting emulator
      --boot-rom <BOOT_ROM>    Use specified boot ROM
      --format <FORMAT>        Use specified file format for saves [default: bin] [possible values: json, bin]
  -h, --help                   Print help information
  -V, --version                Print version information

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Controls

Z -> A
C -> B
Enter (PC) / Return (Mac) -> Start
Backspace (PC) / Delete (Mac) -> Select

S -> Save
P -> Pause
F -> Toggle frame limiter
M -> Toggle sound
R -> Reset
Esc -> Close

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Missing features

• Sound - Credits to @maxwalley

• MBC 0/1/2/3/5 support - If you find any games that don't seem to start, please open an issue!

• GameBoy Color support