EmuDevz

🕹️ A game about building emulators! Check it out!

Created by [r]labs.

Key features

• Full 🕹️ NEEES emulation guide from scratch

• Interactive 🔨 6502 Assembly tutorial

• Implement 🧠 CPU, 🖥️ PPU, and 🔊 APU in any order

• Play 👾 homebrew games to unlock ROMs

• 🧪 Unit tests, video tests, and audio tests are provided

• 💻 Unix-style shell and code editor

• 🎶 Original retro-synthwave soundtrack

• 📃 Included documentation and in-game dictionary

• 🗣️ Fully localized into English and Spanish

• 🐞 Powerful debugger with:

• 🐏 Memory viewer

• 🔢 Instruction log

• 🏞️ Name tables, CHR, Sprites, Palettes

• ♒ Individual APU channel views

• 🎮 Controllers

• 🗃️ Emulator logging

• 🔭 Free mode to use the IDE to develop emulators for other systems!

Where’s the save file?

• Portable: .devz files (import/export from Settings menu)
• Web: IndexedDB and LocalStorage
• Steam/Windows: %USERPROFILE%/AppData/Roaming/EmuDevz
• Steam/Linux: $XDG_CONFIG_HOME/EmuDevz
• Steam/macOS: ~/Library/Application Support/EmuDevz

Development

Install and run

# install nvm & node
npm install
npm start

Scripts

• Package levels: npm run package
• Sort locales: node scripts/sort-locales.js
• Sort dictionary entries: node scripts/sort-dictionary.js
• Build: npm run build
• Deploy to GitHub Pages: npm run deploy <GH_USERNAME> <GH_TOKEN>

Generate licenses

cp pre-licenses.txt public/licenses.txt
yarn licenses generate-disclaimer --prod >> public/licenses.txt

Known issues

These are notes from the January 2026 release on Steam. I hope these issues can be resolved in the future.

Windows

• On Windows 11, when using a full-screen Electron app with the Steam overlay, ghost Alt-Tab windows are created. As a workaround, fullscreen mode is disabled on Windows.

macOS

• The Steam overlay doesn’t seem to work.

Linux

• The app doesn’t boot in sandbox mode when launched via Steam. As a workaround, Steam launches the app with --no-sandbox.
• The app doesn’t boot on Arch Linux with the latest Electron when using the Steam Linux Runtime 3.0. As a workaround, Electron 36.9.5 was used and forced to launch using X11 with --enable-features=UseOzonePlatform --ozone-platform=x11.