author Sam Lantinga <>
Sun, 19 Feb 2006 23:46:34 +0000
changeset 1379 c0a74f199ecf
parent 1190 173c063d4f55
child 1442 e3242177fe4a
permissions -rw-r--r--
Use only safe string functions

SDL on OS/2

Last updated on Oct 02, 2005.

1. How to compile?

To compile this, you'll need the followings installed:
- The OS/2 Developer's Toolkit
- The OpenWatcom compiler 
- The FSLib library

Please edit the second, fourth and fifth lines of setvars.cmd file
to set the folders where the toolkit, the OW compiler and the FSLib are. 
You won't need NASM yet (The Netwide Assembler), you can leave that line.
Run setvars.cmd, and you should get a shell in which you can
compile SDL.

Check the "Watcom.mif" file. This is the file which is included by all the
Watcom makefiles, so changes here will affect the whole build process.
There is a line in there which determines if the resulting SDL.DLL will be
a 'debug' or a 'release' build. The 'debug' version is full of printf()'s,
so if something goes wrong, its output can help a lot for debugging.

Then go to the 'src' folder, and run "wmake -f makefile.wat".
This should create the SDL.DLL and the corresponding SDL.LIB file there.

To test applications, it's a good idea to use the 'debug' build of SDL, and
redirect the standard output and standard error output to files, to see what
happens internally in SDL.
(like: testsprite >stdout.txt 2>stderr.txt)

To rebuild SDL, use the following commands in 'src' folder:
wmake -f makefile.wat clean
wmake -f makefile.wat

2. How to compile the testapps?

Once you have SDL.DLL compiled, navigate into the 'test' folder, copy in there
the newly built SDL.DLL, and copy in there FSLib.DLL.

Then run "wmake -f makefile.wat" in there to compile some of the testapps.

3. What is missing?

The following things are missing from this SDL implementation:
- MMX, SSE and 3DNOW! optimized video blitters?
- HW Video surfaces
- OpenGL support

4. Special Keys / Full-Screen support

There are two special hot-keys implemented:
- Alt+Home switches between fullscreen and windowed mode
- Alt+End simulates closing the window (can be used as a Panic key)
Only the LEFT Alt key will work.

5. Joysticks on SDL/2

The Joystick detection only works for standard joysticks (2 buttons, 2 axes
and the like). Therefore, if you use a non-standard joystick, you should
specify its features in the SDL_OS2_JOYSTICK environment variable in a batch
file or CONFIG.SYS, so SDL applications can provide full capability to your
device. The syntax is:


So, it you have a Gravis GamePad with 4 axes, 2 buttons, 2 hats and 0 balls,
the line should be:

SET SDL_OS2_JOYSTICK=Gravis_GamePad 4 2 2 0

If you want to add spaces in your joystick name, just surround it with
quotes or double-quotes:

SET SDL_OS2_JOYSTICK='Gravis GamePad' 4 2 2 0


SET SDL_OS2_JOYSTICK="Gravis GamePad" 4 2 2 0

   Notive However that Balls and Hats are not supported under OS/2, and the
value will be ignored... but it is wise to define these correctly because 
in the future those can be supported.
   Also the number of buttons is limited to 2 when using two joysticks,
4 when using one joystick with 4 axes, 6 when using a joystick with 3 axes
and 8 when using a joystick with 2 axes. Notice however these are limitations 
of the Joystick Port hardware, not OS/2.

6. Next steps...

Things to do:
- Implement missing stuffs (look for 'TODO' string in source code!)
- Finish video driver (the 'wincommon' can be a good example for missing
  things like application icon and so on...)
- Enable MMX/SSE/SSE2 acceleration functions
- Rewrite CDROM support using DOS Ioctl for better support.

7. Contacts

   You can contact the developers for bugs:

   Area					Developer		email
   General (Audio/Video/System)		Doodle
   CDROM and Joystick			Caetano

   Notice however that SDL/2 is 'in development' stage so ... if you want to help,
please, be our guest and contact us!