Witchspace — a free reimplementation of Elite Plus (1991)

Elite Plus is the PC version of Elite by David Braben and Ian Bell, written in assembly for DOS by Chris Sawyer (Realtime Software). Witchspace rebuilds that game, routine by routine, as portable C, and runs it on today's computers and in the browser. Everything is there: trading, combat, missions, docking, hyperspace, the AdLib music.

Witchspace contains none of the original game. It reads the game's data from your copy of Elite Plus when it starts. (The name is the game's own word for the space between the stars.)

See it

The title, with the AdLib music	Launching from Lave	The station's screens
The docking computer	A hyperspace jump to Zaonce	A pirate (the start staged)

Click a picture for the video with sound. They are made with make clips from scripted scenes played through Witchspace (and kept with the release, not in this repository).

Play in your browser

rembish.github.io/witchspace

The page asks where the game's three files should come from: your own copy, or the copy preserved by the Internet Archive (a mirror of the one on Ian Bell's Elite pages, Elite's co-author's), which it downloads for you once you agree. The files stay in your browser for the next visit, and so do your commanders: import saved games (.CDR files, or a zip of them, such as George Hooper's saves for each mission) and export yours on the page, or drop files on the game while you play.

Play on your computer

1. Get the game's files. You need three files from Elite Plus for DOS (V3.1, 1991):

   File	What for
   ELITE.EXE	the game's data: tables, texts, ships
   ELITE.GRF	the pictures (without it the game shows placeholders)
   ADBLUE.MID	the AdLib's title music

   Upper or lower case both work; the other files of the original are not needed. To check your copy (sha256sum), three copies of ELITE.EXE are known to work: the game as sold, and two with the copy protection patched out (they differ only there). Ian Bell's Elite archive keeps the first two (b1022000.zip, b1022001.zip):

   237b1be342c5dba6565fbd17c851595f605005d69873436daeefaf4d221fee43  ELITE.EXE  (as sold)
   9c257f53909c8335cfd240c8be6d94128361fe8906ef781de774d3434a959668  ELITE.EXE  (patched; the Internet Archive's)
   6d7e748345f31e41cd8c90fc739a2c23fed32a277fc9b3e530f5d6c6bae86ef5  ELITE.EXE  (patched)
   900fb787f5e7ed905e6931f1b522085a88a538b4e61396aed4ba329e05593b22  ELITE.GRF
   ee0d9a9d4b388f3af3ed6ec6aadd38a27823c1eee614af4bf378227e98364081  ADBLUE.MID
   

2. Get Witchspace. Download it for Linux, Windows or macOS from the releases, or build it. To build you need a C compiler, CMake and SDL2:

   sudo apt install build-essential cmake libsdl2-dev     # Debian, Ubuntu
   brew install cmake sdl2                                  # macOS
   cmake -S . -B build && cmake --build build -j
   

   It is developed on Linux; the release's macOS and Windows builds are made by CI and not yet tried by hand.

3. Run it. Put witchspace (from the download, or build/witchspace) into the folder with the game's files and start it there. Or keep it anywhere and point it at them:

   ./witchspace --data /path/to/elite-plus
   

Keys

As in the original's manual:

Key
keypad 8 2, or ↑ ↓	dive, climb
keypad 4 6, or ← →	roll anticlockwise, clockwise
> < (the . and , keys)	faster, slower
Space	fire the laser
F1…F12, or 1…9 0 - =	the icon with that number on the bar at the bottom: launch and docking, views, market, charts, equipment, missiles, ECM, jumps…
Esc	the menu: controls, sound, save and load, quit
Alt+Enter	full screen

The keypad's keys steer while Num Lock is off; with it on they select icons, as the number keys do. On the title screen the icons choose keyboard, joystick or mouse control (and let you redefine the keys) before Space starts the game. A game controller works as the joystick.

Everything else behaves as it did in 1991: the original's manual, preserved by the Internet Archive (PDF), explains trading, combat, the ship's equipment and the missions.

Options

Option
--data DIR	where the game's files are (default: this program's folder, then the current one, then original/)
--saves DIR	where commanders are saved (default: beside the game's files, as the original did)
--speaker	the PC speaker instead of the AdLib
--protection	ask the original's copy-protection question (off by default): a word from the novella Imprint that came with the game. Ian Bell's Elite archive keeps the novella (b1022010.zip) and the release's list of the answers (PRTCODES.TXT in b1022000.zip; a few of its entries have slips, see re/NOTES.md)
--original	the original's gameplay bugs as they were in 1991 (see below)
--theme FILE	an MP3 the title plays instead of its own music (see below)
--no-theme	the title's own music even when a theme is there
--version	print the version

Two bugs of 1991, mended. Players reported them in the 1990s and the reconstruction explains them (re/NOTES.md, re/FLIGHT.md): the hold lost a tonne of room for good with every Alien Item scooped and sold, and the docking computer flew through the station when it started from behind it. Witchspace mends both (a loaded commander's hold is counted again); --original plays them as they were. The comparisons with the original always run the original's behaviour.

The Elite theme at the title. Ian Bell's Elite archive keeps recordings of the Elite theme (Aidan Bell's, in two arrangements by C. Abbott): b8060000.mp3 and b8060010.mp3. Put one beside the game's files (or name it THEME.MP3) and the title plays it instead of the AdLib's Blue Danube; everything else sounds as the original. With --speaker the title plays the speaker's own music, unless a theme is given with --theme. In the browser, add it on the page.

Status

The game is complete. Not planned: the Roland LAPC-1's music and effects and the 16-colour EGA/VGA screen modes; the AdLib and the 256-colour MCGA mode cover them. Two places where the original misbehaves are described in re/FLIGHT.md: a bug in the docking computer, which Witchspace handles without the original's stray picture, and a case shown never to happen in play.

How it works

• The core (core/) is the game itself, rebuilt from the original's machine code: the galaxy, markets, ships and their AI, combat, the station screens, saving and loading, the speaker's sound and the AdLib's music driver. It is plain C99, deterministic, with no input or output of its own, and it keeps the original's quirks.
• It is checked against the original. The original runs in an x86 emulator; each reconstructed routine gets the same game state (taken from the running original, and randomly varied) and must leave the same memory that the core models, draw the same primitives and make the same sounds (the writes to the speaker and the sound chip), byte for byte. Larger tests boot the whole original and compare its start-up, play from the title into space and compare where both arrive, and compare the title screen frame by frame. These compare what the core says, not the final pixels; the frontend's renderer has checks of its own where its colours matter.
• The core says what to draw, not how. It emits polygons, lines, circles, pictures by number and text in the original's 320 × 200 coordinates; the frontend (src/, SDL2) draws them as the original did. Another renderer could draw the same stream its own way (docs/core-interface.md).

For developers

Path	Contents
core/	The game: plain C99, deterministic, no I/O
src/	The SDL2 frontend: screen, timer, keyboard, mouse, controller, speaker and AdLib, files
web/	The browser page around the Emscripten build
tests/	Small programs the differential tests drive; ep_flow; ep_datadump
re/	Reverse engineering: notes, tools (re/tools), the emulator harness (re/emu)
docs/	How a frontend uses the core; testing the Windows version
third_party/	Nuked OPL3, the AdLib's chip

Everyday commands are in the Makefile (make help):

make build        # the game and the test tools, warnings as errors
make web          # the browser version (needs Emscripten)
make check        # formatting, Python lint and types, the tests, the data check
make difftest     # every reconstructed routine against the original (about an hour)
make wintest      # from WSL: the Windows build's tests, run on Windows (docs/windows-testing.md)
make clips        # the videos and previews above, from your copy (needs ffmpeg)

The tools in re/ are Python 3.12, typed and checked with ruff and mypy; uv sync --extra dev makes their environment. They need your copy of the game in original/ (git-ignored, never distributed). CI checks everything that does not need the game: the build with gcc and clang, the Windows build as released, the web build, formatting, and the Python tooling. Testing the Windows version from WSL: docs/windows-testing.md.

The notes on the original:

• re/NOTES.md: the executable, start-up, galaxy, descriptions, pictures, copy protection, sound and the AdLib driver, the object update.
• re/FLIGHT.md: the flight loop, travel, docking, the original's bugs.
• re/AI.md, re/SHIPS.md: the ship AI and the ships.

Tool	Used for
Python 3.12, uv, Unicorn, capstone	unpacking, control-flow recovery, the emulator harness, differential tests
Ghidra (headless)	decompiling ELITE.EXE (16-bit real mode); names in re/ghidra/names.txt
DOSBox-X, Xvfb, xdotool, ffmpeg	running the original for reference, screenshots
Emscripten	the web build

Thanks

To Ian Bell's Elite pages, Elite's co-author's, which keep Elite Plus (as sold, and the copy the Internet Archive mirrors), the Elite theme, and the history around them; and to the Internet Archive, which keeps the original's manual.

License

Witchspace is free software under the BSD 3-Clause License. It includes Nuked OPL3 by Nuke.YKT (third_party/nuked-opl3, LGPL-2.1 or later), in the release binaries SDL2 (zlib), and in the web version Emscripten's runtime and musl (MIT); see THIRD_PARTY.md, which also says how to relink with your own Nuked OPL3. The icon (assets/icon.png, its sizes made by tools/make_icon.py) was made for Witchspace and is under the same license.

Elite © 1984 David Braben and Ian Bell. Elite Plus © 1991 Chris Sawyer, Realtime Software, and Bell & Braben. Elite is a trademark of Frontier Developments. Witchspace is an unofficial reimplementation for preservation, not affiliated with any of them. The program and its source contain no part of the original game; the clips above show it being played (they are kept with the release, not in this repository).