CoreBoy

GAME BOY COLOR EMULATOR

CoreBoy

CoreBoy is an open-source Game Boy / Game Boy Color emulator written in C# targeting .NET Core. It provides a Windows WinForms frontend, an Avalonia frontend (cross‑platform), and a headless CLI/library surface for embedding or automation.

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CoreBoy emulator screenshot.

game boy colorPRIMARY SYSTEM

2020PROJECT BEGAN

Open sourcePROJECT MODEL

WHY IT MATTERS

Why use CoreBoy?

CoreBoy is a compact, C#/.NET Core implementation of Game Boy hardware useful for developers, hobbyists, or anyone who wants a .NET-friendly emulator library or a simple cross‑platform GUI/CLI player for GB/GBC ROMs. It started as a port of Coffee-GB and is MIT licensed for modification and reuse.

BEST FOR

Best for

Developers who want a .NET-based emulator core they can embed or extend, users who prefer a simple WinForms or Avalonia frontend, and people who want a headless CLI runner for automation or testing.

The people behind CoreBoy

History and status

CoreBoy was published by David Whitney and documented as a quarantine project on his blog in May 2020. The repository identifies itself as a .NET Core port of Coffee-GB and contains multiple frontends (Windows WinForms and an Avalonia frontend for non-Windows platforms). The README states .NET Core 3.1 as the prerequisite and notes that audio was not working at the time of the README. The project is active on GitHub (issue and pull request activity visible) and distributed under an MIT license. The official source and project artifacts are hosted on GitHub; releases may provide packaged binaries but building from source with dotnet is the recommended route when binaries are not provided.

What CoreBoy supports

Game Boy (DMG)
Game Boy Color (CGB)
Windows (WinForms frontend)
macOS (Avalonia frontend / CLI)
Linux (Avalonia frontend / CLI)

Download and availability

OFFICIAL DOWNLOADS

Get CoreBoy

Official code and any binary releases are hosted on the project's GitHub repository/releases. If no prebuilt binaries are available for your platform, build from source using the .NET SDK.

Get CoreBoy ↗

DOCUMENTATION

Official documentation

Read the official configuration, compatibility, and troubleshooting material before changing advanced options.

Read official documentation ↗

Broken or missing download? Emulator projects move and official links sometimes change. Please contact Retro Replay so the source can be verified and updated.

CoreBoy setup guide

Setup note: Concrete setup steps — follow these exactly for a working CoreBoy build. This guide assumes you have administrative or developer rights on the machine and can install the .NET SDK.

1) Official repository: Repository and project home: davidwhitney/CoreBoy on GitHub. Check the repository README for the latest notes and any release assets.
2) Install prerequisites: Install the .NET Core / .NET SDK required by the project. The repository README lists .NET Core 3.1 as the prerequisite. Install the matching SDK/runtime from Microsoft's official downloads for your OS. Also install Git to clone the repo if you need to build from source.
3) Get the code or release binaries: If the GitHub Releases page contains platform packages, download the appropriate release. If not, clone the repository: git clone https://github.com/davidwhitney/CoreBoy.git
4) Build from source (recommended when no binaries provided): Open a terminal/PowerShell in the repository root. Use dotnet build to compile the solution: dotnet build CoreBoy.sln -c Release. This builds the core library plus the Frontend projects (CoreBoy.Windows, CoreBoy.Avalonia, CoreBoy.Cli). On Windows you can run the WinForms frontend; on macOS and Linux use the Avalonia frontend or the CLI.
5) Run the Windows frontend: If you built on Windows, run the CoreBoy.Windows executable produced under the project's bin/Release folder. Use the File menu to open a .gb or .gbc ROM file. The README notes audio may not be working and window resizing may be buggy.
6) Run on macOS / Linux (Avalonia) or headless CLI: Run the CoreBoy.Avalonia project binary (or use dotnet run –project CoreBoy.Avalonia for development). For headless operation or scripting, run CoreBoy.Cli from the command line; the README mentions a headless CLI mode. Use the frontend's file/open commands or CLI parameters to point to your ROM file.
7) Controls and usage: Default keyboard mapping documented in the README: arrow keys for D‑pad, Z = A, X = B, Enter = Start, Backspace = Select. Consult the repo README for further command-line options or UI controls.
8) Troubleshooting: If audio or resizing is buggy (as noted in the README), check the repository issues for workarounds or open a new issue with logs and exact platform details. If a required .NET runtime error appears, confirm that the installed SDK/runtime version matches the project target (README lists .NET Core 3.1).

Software reminder: CoreBoy does not include commercial games, BIOS files, or copyrighted firmware. Provide your own legally obtained ROMs and firmware; follow local laws and platform policies.