Level 3 screenshot of the Game Boy video game Bubble Ghost. Game Boy version released in 1990, author: Christophe Andréani. Image by Christjeudi10, via Wikimedia Commons (CC BY-SA 3.0).

peanutgb

GAME BOY EMULATOR

peanutgb

Peanut-GB is a Game Boy (DMG) emulator port that runs as an app on NumWorks graphing calculators. It is a port of the Peanut-GB engine to the NumWorks platform and is distributed from the nwagyu GitHub repository.

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Level 3 screenshot of the Game Boy video game Bubble Ghost. Game Boy version released in 1990, author: Christophe Andréani. Image by Christjeudi10, via Wikimedia Commons (CC BY-SA 3.0).

Game BoyPRIMARY SYSTEM

History documentedPROJECT BEGAN

Open sourcePROJECT MODEL

WHY IT MATTERS

Why this project exists

Peanut-GB for NumWorks brings a compact, lightweight Game Boy (original DMG-01) emulator to NumWorks calculators so users can run original Game Boy ROM dumps on the calculator hardware or in the NumWorks simulator. It leverages the Peanut-GB emulator core and is packaged as a NumWorks app (.nwa) for easy installation via my.numworks.com.

BEST FOR

What it does best

Runs many original (DMG) Game Boy ROMs on NumWorks calculators with simple key mappings and palette options, provided the ROMs fit within the target device's available memory. The project focuses on portability and simplicity rather than cycle-perfect accuracy or Game Boy Color compatibility.

Gameplay from Tetris on Game Boy.

The people behind peanutgb

History and lineage

The repository identifies this app as a NumWorks port based on the Peanut-GB emulator core. The GitHub README describes the app as a Game Boy emulator for the NumWorks calculator and credits Peanut-GB as the basis. Community posts and forks of Peanut-GB indicate the underlying core has been used in other small-device ports (Playdate, microcontroller projects). The nwagyu repository contains the NumWorks-specific wrapper, a sample ROM (src/flappyboy.gb) and build instructions for the NumWorks toolchain. Issues and community discussion show the NumWorks port is intended as a straightforward emulator application rather than a full-accuracy Game Boy implementation.

What peanutgb supports

Original Game Boy (DMG) ROMs
NumWorks calculators (NumWorks app format .nwa)
NumWorks emulator/simulator via the NumWorks simulator or deployed firmware
Build environments that support the embedded ARM toolchain (arm-none-eabi-gcc) and nwlink

Download and availability

OFFICIAL DOWNLOADS

Get peanutgb

Official app bundles and packaged releases are published on the project's GitHub Releases page as .nwa assets. The repository also contains source and a build target to produce the .nwa using the NumWorks toolchain and nwlink.

Get peanutgb ↗

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.

peanutgb setup guide

Setup note: This setup guide explains how to obtain a release or build Peanut-GB for NumWorks from source, prepare a Game Boy ROM, and install the app onto a NumWorks calculator or run it in the NumWorks simulator. It assumes you have a legal ROM dump that you own (the project does not include commercial ROMs or firmware).

1) Get the app bundle or source: Visit the project's GitHub Releases page and download the latest .nwa release asset if available. If you prefer to build from source, clone the repository and follow the build instructions in the README.
2) Prepare a Game Boy ROM: You must supply a ROM file (cartridge dump) in .gb format. The README mentions a sample ROM at src/flappyboy.gb for testing. Commercial ROMs and BIOS files are not included; obtain ROMs only if you legally own the original cartridge.
3) Installing via my.numworks.com: Use my.numworks.com/apps to upload the .nwa file and the .gb ROM to your calculator. The README explicitly instructs to send the .nwa and the .gb file via the NumWorks web app. Follow NumWorks' normal app installation process (the calculator or simulator will receive the app and data files).
4) Running on the calculator or simulator: After installing, launch Peanut-GB from the calculator's apps list. Controls map to NumWorks keys (arrows to D-pad; Back/OK/Shift/Backspace used for A/B/Select/Start). The README lists palette and scaling keys (1/2/3 for palettes; + and – to change rendering scale).
5) Building from source (developer steps): To build the app yourself, install an embedded ARM toolchain (arm-none-eabi-gcc) and the nwlink tool (npm package). The README gives example commands (brew install arm-none-eabi-gcc node; npm install -g nwlink). Run make clean && make build in the repository to produce the .nwa. Deploy the built .nwa and .gb to the calculator the same way as a release asset.
6) Practical limitations and tips: Peanut-GB on NumWorks targets the DMG feature set (original Game Boy). It does not claim Game Boy Color emulation. Expect memory and performance constraints inherent to the calculator hardware. If a ROM fails to load, try a smaller ROM, confirm the .gb is a raw ROM dump, and check available free memory on the device. Consult repository issues for reports of specific game incompatibilities.

Software reminder: The project does not include commercial games, BIOS files, or proprietary firmware; you must provide any ROM dumps or BIOS you legally own. Use NumWorks official tools and follow NumWorks installation instructions when deploying apps.