Microsoft Space Simulator, recompiled

A static recompilation of Microsoft Space Simulator (1994, Bruce Artwick Organization / Microsoft Home) from its DOS executable to a native Windows program. The game's 16-bit real-mode code, most of it hand-written 386 assembly, is translated to C by pcrecomp and runs on a small DOS machine in src/. No DOSBox, no emulator. You supply the three floppy images; nothing from the game is in this repository.

Part of the pcrecomp family, built in its shared house style (the same pipeline, flags, headless recording and harness as the other recomp repos).

Status

v0.1.0-dev, pre-alpha. It boots to the simulator and the simulation runs.

Install from the floppies	the 21 data generators the 1994 installer ran (MAKEDATA, MAKEHMO, S01–S19DATA) are recompiled too, and build the 543 star, planet and sky files
Microsoft Home logo, title screen	✅
Simulator: view window, star field, instrument panel, mission clock	✅ renders and runs (seen headless)
Expanded memory (EMS 4.0)	✅ the game's 40 pages, bank switching
Menus, dialogs, keyboard	✅ menus, the Location dialogs (deep sky, stars, planets, comets, surface), Open Situation, Arrange Windows; scripted keys in headless runs
3D models, planets, surfaces	✅ stations, spacecraft, Mars terrain, the Milky Way (every shipped situation runs headless)
Keyboard, joystick	✅ arrows for attitude, keypad +/- for thrust; the game's own analog joystick (port 201h), driven by an Xbox controller's left stick
Mouse in play	not yet verified
Music and sound effects	✅ the game runs under SS1.EXE as it did on DOS, and SS1's own AdLib player (lifted too) plays the music, or the engine sounds
Super VGA 640×400 and 800×600	✅ 800×600 by default: the driver files are lifted as variants of the driver region, over a VESA 1.2 model
Lift	1,157 functions, 58,299 instructions, 3 code segments

On top of the original, as in the Gunman, SimCity 2000 and Theme Park recomps:

Direct3D 11 presenter	sharp-bilinear (crisp at any size), smooth, CRT, nearest and integer scaling; vivid colour; resizable; borderless fullscreen
Settings menu (F11)	save states, window size, scaling, speed, mute, screenshot; kept in settings.ini beside the exe
Save states	9 slots, the whole machine; a state loads where it was saved (in flight, from flight)
Speed control	the game's clock at 0.5x, 1x, 2x or 4x real time (on top of its own time rate)
Xbox controller	the left stick is the game's analog joystick, centred automatically; triggers, bumpers and buttons are mapped to keys
Mods	--mod NAME lays mods\NAME\ over the game: replace any file, add situations (mods/README.md)
Headless recording	--headless --record out.mp4: video and audio, deterministic, no window

It has been played headless and in a window on a virtual monitor; treat it as pre-alpha.

Screenshots

All made headless (--headless --shot-at, --record) at 800x600; see tools/screens.py.

Getting Started

You need your own copy: the three 1.44 MB floppy images (Microsoft Space Simulator 1.IMA … 3.IMA), loose or in the zip they often come in.

Quick start

1. Download this repository (Code → Download ZIP) and unpack it anywhere.
2. Put the floppy images (or their zip) in its original folder.
3. Double-click Setup.cmd.

Setup checks for Python 3, CMake, Git and the Visual Studio 2022 C++ build tools and offers to install whatever is missing (it says what, why and how big first). It finds the images in original\, the repository folder or your Downloads, or asks. Then it runs the steps below and leaves Microsoft Space Simulator.lnk in the folder. Building takes a few minutes. If anything fails it stops with one sentence saying what to do, and the details are in setup.log; running it again carries on from there.

Step by step

Prerequisites: Windows 10/11; Visual Studio 2022 with "Desktop development with C++" (or the Build Tools); CMake 3.20+; Git; Python 3.10+ with pip install capstone. Use py -3 -- a bare python can be the Microsoft Store alias, which only opens the Store. Open a new terminal after installing anything, so PATH is current.

1. The toolkit, at the commit this needs (its changes are open pull requests):

   git clone https://github.com/sp00nznet/pcrecomp work\pcrecomp
   git -C work\pcrecomp checkout 357136a
   

2. Unpack the floppy images (or their zip) into game\:

   py -3 tools\unpack_floppies.py original game
   

   375 files unpacked to game -- each archive member's CRC is checked.
3. Lift the game and the 21 install tools to C (work\*\gen, never committed):

   py -3 tools\lift.py all
   

   The first line should read SPACESIM.EXE: ... 3 code segments, 1157 functions or close to it. SS1.EXE, the launcher with the music player, is lifted too and linked into spacesim.exe.
4. Build:

   cmake -B build -G "Visual Studio 17 2022" -A x64
   cmake --build build --config Release -- -m
   

5. Generate the star systems, as the installer did:

   py -3 tools\generate.py
   

   It runs the recompiled MAKEDATA, MAKEHMO and S01–S19DATA and ends with star systems generated. S10DATA is skipped, exactly as the original FINISH.BAT's typo (s10ata) skipped it; --s10data adds that system.
6. Write the settings the 1994 SETUP program wrote:

   py -3 tools\make_ini.py
   

   and a two-line game\SETUP.INI (your name, then a product ID). Defaults: 800x600, music on, starting in the FLIGHT situation; --sound effects, --sound off, --situation NAME and --driver vga.drv change them.
7. Play the scripted inputs in tools\exercise\ headless, lifting and rebuilding until no new code turns up:

   py -3 tools\converge.py
   

   Some user-interface code is only named by pointers in data, so the lifter finds it when a run reaches it (work\spacesim\misses.txt, never committed). The runs include every shipped situation. Each pass prints how many new routines it found; it stops at 0.
8. Run build\Release\spacesim.exe.

Usage

Key
F11	settings menu: save / load state, window size, scaling, speed, vivid colour, fullscreen, mute, screenshot
F12	next scaling mode (sharp, smooth, CRT, nearest, integer)
Shift+F12	screenshot to screenshots\
Alt+Enter	fullscreen
click in the picture	the mouse is the game's; Alt+Tab or F11 frees it

The game uses F1–F10 and the rest of the keyboard as it always did (arrows for yaw and pitch, keypad + and – for thrust, F1/F2 for the time rate, Alt for the menus).

Xbox controller: left stick = the joystick (analog yaw and pitch, or whatever the Control mode steers), d-pad = arrows, RT / LT = thrust up / down, RB / LB = F1 / F2, A = Enter, B or Start = Esc, X = Space, Back = Tab.

spacesim [options]
  --headless          no window, no audio device; deterministic time
  --record out.mp4    video + audio through ffmpeg
  --shot-at MS:FILE   frames at emulated times, e.g. 20000:title.bmp
  --seconds N         stop after N seconds of emulated time
  --keys MS:KEY,...   scripted input (SAVEn / LOADn for save states, JX / JY
                      -100..100 for the joystick)
  --mod NAME          lay mods\NAME (or a folder) over the game's files
  --display MODE      scaling: sharp, smooth, crt, nearest, integer
  --fullscreen        start fullscreen
  --no-ss1            run SPACESIM.EXE without its launcher (no music)
  --trace             DOS calls to stderr

The full list is at the top of src/main.c.

Building from source

Steps 3 and 4 above, or on a recomp-netlab farm: netlab check msspacesim (recipe projects/msspacesim.env) builds with clang-cl into build-farm/ and runs selftest.exe on a test VM. The lifter and its decisions are described in docs/lifting.md; the parts and how they fit in docs/architecture.md.

Contributing

See CONTRIBUTING.md: no game files or anything lifted from them, no code from GPL emulators, and claims come with the run that shows them. Security reports: SECURITY.md.

License

MIT, see LICENSE; third-party code is listed in NOTICE. That covers this repository's own code only. Microsoft Space Simulator is Microsoft's; the lifted C is generated on your machine from your copy and is never distributed.