DuckTales: The Quest for Gold (DOS) – native port

A native port of the 1990 PC/DOS game DuckTales: The Quest for Gold for Windows, Linux and macOS. The original program is statically recompiled from x86-16 machine code to portable C. It runs on a small SDL2 runtime that provides the PC hardware the game expects: EGA/CGA/Tandy video, the PC speaker and Tandy sound chips, the keyboard, the joystick and DOS.

As an option, the port can also use the Amiga version's graphics, music, sound effects and speech, taken from your own copy of the Amiga game.

This repository contains no part of the game. You need your own copy of the original DOS game. The game is converted and compiled on your own computer from that copy. Do not share the game files or anything built from them (see Legal).

Features

• Runs the original game logic unchanged. It is recompiled code, not an emulator and not a remake.
• Graphics: EGA, CGA, Tandy (as the original supports) or Amiga 32 colours. The Amiga mode shows the Amiga version's pictures and palettes, including its colour cycling and per-minigame status bars.
• Sound: Tandy 3-voice, PC speaker, Amiga or off.
  • The Amiga option runs the Amiga version's own sound engine with its own instruments: music, effects and speech, read from your Amiga game. No sound files are converted.
  • The Amiga version's speech can be switched on or off, and it can also be heard with the Tandy and PC speaker sound.
• Game speed, frame rate limit and music tempo can be set separately, also during play.
• Game controllers (XInput etc.) act as the PC joystick. A keyboard-as-joystick mode is also available.
• The code wheel check (copy protection) can be switched off.
• The jungle minigame can take the nephews in the Amiga order (green, blue, red) instead of the DOS order (red, blue, green).
• Photography flash: the Amiga mode flashes the picture white as the Amiga game does; in EGA the original lights the screen border, shown as a frame, a whole-screen flash or off (setting "Photo flash (EGA)").
• Rival plane: Glomgold's plane in the flying game is hit by the same obstacles as yours (spinning and losing time) and dodges most of them; "original" keeps it untouched as in the PC game.
• Music at Launchpad (Amiga sound): stops before his screen as in the Amiga game, or plays on as in the DOS game.
• PC speaker sound: "original" imitates a PC's small built-in speaker with a filter (thin, almost no bass); "clean" plays the sounds as the game makes them, unfiltered.
• Log file: one file per run in logs/ (date and time in its name), for crash reports.
• Random numbers: "Fixed" (default) avoids the original generator's short repeating sequences; "Original" works as the PC game. Both differ from game to game.
• Settings program: game folder selection, import of the Amiga disk images (.adf/.ipf), a one-click build, and adding the Amiga sound later.
• Windows (x64; ARM64 through emulation), Linux (x86_64, aarch64) and macOS (Intel, Apple Silicon).

What you need

• The DOS game: DUCKTALE.EXE, IT.DRV and the *.ARC files.
• Optional, for the Amiga graphics and sound options: the Amiga version, as its two disk images (.adf, or .ipf), which the settings program imports, or as a folder holding the DT1 and DT2 disk contents.
• Linux/macOS: SDL2 and Python 3.8 or newer. On Windows everything is downloaded by the installer.

Getting started (release package)

The release package (dist/DuckTalesDOS) contains the settings program, the installer and the sources, but no game material. Make it from the repository with python make_dist.py (Windows, Linux or macOS; no game files needed), or use a published release.

Windows

1. Run settings.exe and drop your game folder onto its window, or copy the game files into the files folder. "Game folder" turns green when DUCKTALE.EXE and IT.DRV are found.
2. Optional: set "Amiga game folder" to your Amiga copy, or import its two disk images: drop the .adf files (or .ipf) on the settings window, or choose Import Amiga disk image. They are extracted into the Amiga game folder. The Amiga graphics only need the folder. The Amiga sound is built into the game: set the folder before step 3, or later choose Add Amiga sound.
3. Choose Build game from game files. A console window runs the installer.
4. Choose Save and start game.

Linux / macOS

# Debian/Ubuntu: sudo apt install libsdl2-2.0-0
# Fedora:        sudo dnf install SDL2
# macOS:         brew install sdl2
./install.sh            # or: ./install.sh /path/to/game
./settings              # then "Save and start game"

The first run downloads the build tools into toolchain/ and verifies their SHA-256 checksums: Zig 0.16.0 (C compiler), Capstone 5.0.7 and, on Windows only, an embeddable Python 3.12. It then recompiles your copy of the game and compiles it. This takes a few minutes. Run it again if you change the game folders.

Controls

Key / button	Action
Arrow keys, Space	as in the game's manual (office: hold a direction and press Space)
PgUp / PgDn (keypad + / −)	game speed
Ctrl + PgUp / PgDn	music speed
Alt + PgUp / PgDn	frame rate limit (steps of 5, 1 with Shift)
F11 / F12	fullscreen / screenshot (screenshot_001.bmp, _002, …)
Controller stick or d-pad, A/X, B/Y	joystick, fire buttons 1 and 2 (in menus one press per button press)
Controller LB / RB, Back + LB / RB	game speed, music speed

Changes made during play are not saved. Use the settings program (ducktales_dos.ini) for that. A held key repeats after 0.5 s, about 11 times a second, whatever the frame rate.

How it works

• Unpacking. DUCKTALE.EXE is EXEPACK-compressed (tools/unexepack.py). It carries 10 Microsoft LINK overlays that are called through INT 3Fh. IT.DRV holds the compressed video and sound driver modules.
• Recompilation. tools/analyze.py finds the code: functions, jump tables, overlay entries and self-modifying driver code. tools/recomp.py turns every instruction into C on a global CPU state and a 1 MB memory. Hooks at chosen addresses connect the game to the runtime, for example for settings, the copy protection, the joystick and the Amiga options.
• Runtime (runtime/). Implements:
  • DOS and BIOS services and the overlay loader;
  • video (EGA planes, CGA, Tandy, Hercules);
  • the PIT timer, the PC speaker and the Tandy SN76489;
  • keyboard, joystick and pacing.
• Amiga graphics (runtime/amiga86.c). Every call to the EGA driver is repeated on 8-bit surfaces. The Amiga version's picture is decoded for each picture the game loads. EGA colours drawn by the game are mapped to the scene's Amiga palette.
• Amiga sound (runtime/amigasnd.c, tools/amiga/sndgen.py). The Amiga program's root code, which holds the sound engine and the instrument loaders, is recompiled from your Amiga copy with the companion Amiga recompiler. It runs in its own small Amiga memory with a Paula emulation and a few exec/dos calls. The DOS game's sound requests are passed to it; the sound numbers are the same in both versions. The voices, which the DOS game never asks for, are started from what the DOS game shows (its texts, pictures and a few events), and the game waits for each as the Amiga version does.

NOTES.md has the detailed findings: file formats, driver entry points, palettes, sound engine, timing, and the reasons behind each fix.

Building from source (development)

Both scripts are Python and run on Windows (also from cmd), Linux and macOS. They need Python 3 with the capstone and ziglang packages (pip install capstone ziglang).

python make_dist.py     # -> dist/DuckTalesDOS (no game files needed; checks that no game material is included)
python build.py         # game in files/ -> build/ducktales_dos, build/settings

• SDL2 on Windows: the SDL2 MinGW development files. They are downloaded into toolchain/ on first use (official release, checksum pinned), or taken from SDL_DIR. make_dist.py uses them on every platform, because it cross-compiles the Windows settings program.
• SDL2 on Linux/macOS: build.py uses the system SDL2 (pkg-config sdl2).
• Amiga sound option: build.py uses the Amiga game folder in AMIGA (default ../ducktales/files).
• .ipf disk image import: make_dist.py adds CAPSImg.dll (the SPS decoder) from toolchain/CAPSImg.dll (or the file named in CAPS_DLL) if present; .adf images work without it. It is not in the repository (its licence allows passing it on unchanged, not as part of this project's source). To get it:
  1. Download the Windows zip of Greaseweazle v1.23 from https://github.com/keirf/greaseweazle/releases (the file used here came from it), or the IPF decoder library from https://www.softpres.org.
  2. Take CAPSImg.dll out of it. It must be the 64-bit (x64) version, like the settings program.
  3. Put it in toolchain/ and run python make_dist.py; the package then has CAPSImg.dll and licenses/CAPSImg-LICENCE.txt.

build.sh and make_dist.sh are wrappers for the same scripts.

Testing aids (environment variables): DT_HEADLESS=1, DT_MAX_FRAMES=n, DT_KEYS="frame:key,…" (scripted input, shot / f12 save a screenshot), DT_WAV=file (raw audio capture).

Repository layout

Path	Contents
tools/	unpacker, analyser, recompiler (x86-16 → C)
tools/amiga/	Amiga 68000 recompiler and sndgen.py (Amiga sound code)
runtime/	SDL2 runtime: CPU helpers, DOS/BIOS, video, sound, Amiga modes, settings
launcher/	settings program, Amiga disk image import (diskimage.c)
dist_src/	installer (install.py, install.bat, install.sh) and the package README
NOTES.md	technical notes

Not in the repository (made from the game, keep them local): files/, unpacked/, gen/, build/, dist/, build_tmp/, toolchain/.

Legal

DuckTales and its characters are trademarks of Disney. The game was developed by Incredible Technologies. This project is not affiliated with or endorsed by them. It contains no game code or data. It only provides tools that convert a copy you own. The game files, and everything generated from them (unpacked program, generated C, the compiled game), must not be distributed.

The source code of this project is released under the MIT licence. Included components keep their own licences: SDL2 (zlib licence), the SPS decoder library CAPSImg used for .ipf images (free for non-commercial use), and the public-domain font8x8 fonts. The release package lists them in licenses/.