Digimon World 2003 decompilation

A decompilation of Digimon World 2003 (PlayStation, Europe, SLES-03936), the PAL release of Digimon World 3, and a native PC port built from it.

The decompiled C rebuilds a byte-identical copy of the game's executable and overlays, and the same C, compiled for your PC, runs the game natively, with a launcher and a few optional mods.

[!IMPORTANT] This repository contains no game data. You need your own copy of the game: the port reads everything from your disc image. This project is not affiliated with or endorsed by Bandai, Bandai Namco or Sony.

Contents

• Playing the PC port
  • Supported platforms
  • Download
  • Provide your disc image
  • Settings, controls and saves
• Reporting an issue
• Documentation
• Contributing
• License

Playing the PC port

Supported platforms

Platform	State
Linux x86_64 (glibc 2.39 or newer: Ubuntu 24.04, Fedora 40, or later)	Supported
Windows	On the way
macOS	Not planned yet

Download

1. Open the Releases page and download the latest dw2003-<version>-x86_64.AppImage (and SHA256SUMS, to check it with sha256sum -c SHA256SUMS).
2. Make it executable and run it:

   chmod +x dw2003-*-x86_64.AppImage
   ./dw2003-*-x86_64.AppImage
   

   The AppImage opens the launcher, which holds the game and its mods. Nothing needs installing or compiling. If your system has no FUSE, run it with --appimage-extract-and-run.

Updates: when it starts, the launcher asks GitHub for this repository's latest release (one request to api.github.com's releases endpoint through your system's curl, with the launcher's name and version as the User-Agent: no identifiers, nothing about you or your machine). When a newer one is out it says so and can download and install it for you (Update now, checked against GitHub's SHA-256 of the file), or open its page. Drafts and prereleases are never offered. To turn the check off: untick "Check for updates when the launcher starts" on the Settings screen (launcher.updates.check in settings.json), or start the launcher with --no-update-check; the Settings screen's Check now still works. Details: docs/RELEASE.md "The launcher's update check".

Provide your disc image

The game is read from your own disc image of Digimon World 2003 (Europe) (En,Fr,De,Es,It):

• It must be the raw .bin + .cue dump (MODE2/2352, one track, 692,146,560 bytes), SHA-1 457cb233349ba841e03b33d8060f8fbcadd45cb3. Dumping tools such as Redump-style rippers produce this format.
• A 2048-byte .iso conversion will not work: it loses the movies' audio sectors.
• Other releases (the US Digimon World 3, the Japanese release) are not supported.

In the launcher's Disc screen choose the .cue (or .bin), drag it onto the window, or type its path. The launcher checks the SHA-1 once and remembers the disc; then press Play.

Settings, controls and saves

• Settings (window scale, fullscreen, scaling (fit, integer or stretch), 50 or 60 Hz, mute, memory cards), controls (keyboard and gamepad rebinding, hotkeys, a second gamepad as player 2) and mods (fast-forward, faster loading, skip dialogues, disable battle animations) are all in the launcher.
• The in-game menu: Escape, or Back (Select) held with Start on a gamepad, pauses the game and opens the same Settings, Controls and Mods inside its window (the Steam Deck's way: no switching windows). Changes apply at once, except the few marked (restart); Resume or the key again goes on, Quit returns to the launcher. It fits itself to the screen; Menu size in Settings makes it smaller or larger.
• Steam: Settings > Steam > Add to Steam puts the game in your Steam library as a non-Steam game (for the Steam Deck's Game Mode, Steam's controller settings and overlay); quit Steam first. Remove from Steam takes it out again, and Update shortcut follows the AppImage when you move it.
• Quick save and load: F5 saves the whole game to a quick slot, F9 goes on from it (one slot, quick.state beside the settings; a slot is valid for the build that wrote it). Both keys are rebindable in the launcher's hotkeys.
• Settings and memory cards (card1.mcd, card2.mcd, the same format as PCSX-Redux's) are kept in ~/.local/share/dw2003/. A portable.txt file beside the launcher keeps them beside it instead.

Details: docs/LAUNCHER.md and psxstack's launcher/README.md.

Reporting an issue

Found a bug, a crash, or something that plays differently from the original? Please open an issue and pick the matching template; what a useful report has is in docs/REPORTING.md. Never attach the game's files or a disc image.

Documentation

Document	Contents
docs/REPORTING.md	Reporting a bug or a crash: what a useful report has
docs/BUILDING.md	Building and testing: requirements, setup, the byte-identical build, the tests, the port and the launcher
docs/PROGRESS.md	How much of the game's code is matched, per part and per overlay
docs/CONTRIBUTING.md	How to contribute
docs/DEVELOPMENT.md	The working guide: repository layout, workflow, conventions, commands
docs/STATUS.md	Where the project stands
docs/DECISIONS.md	The key decisions and why
docs/MATCHING.md	How to match a function: workflow, tools, C patterns
docs/TOOLCHAIN.md	What built the original game
docs/DISC_LAYOUT.md	Disc files, memory map, overlays
docs/FORMATS.md	The game's file formats
docs/MECHANICS.md	Game mechanics mapped to functions and tests
docs/PORT.md	How the PC port works
docs/LAUNCHER.md	The launcher/game contract, settings and mods
docs/SOUND.md	Sound: LIBSND, the SPU, CD audio
docs/RELEASE.md	Making a release
docs/THIRD_PARTY.md	Everything borrowed from other projects
tests/README.md	The reference tests

Planned work lives in the project board, problems in issues.

Contributing

Contributions are welcome: matching a function, naming symbols, documenting a format, fixing the port, or testing it on your machine. Read docs/CONTRIBUTING.md before opening a pull request.

License

Our own work (source, tools, tests, documentation) is under the MIT licence. The decompiled source was written by reading the game's machine code; every borrowing from other projects is recorded in docs/THIRD_PARTY.md. The game itself remains the property of its publisher.