An attempt of porting chocolate-doom 2.3.0 to AIX 4.3.3.
Releases are compiled using xlC 6.0 for small footprint and maximum optimization.
Requires SDL-1.2 to run. You can get it here: https://github.com/holzachr/SDL-1.2.16-aix43
Extract to /opt/doom or whereever you feel is right. Place your preferred WAD file there. If you want MIDI sound, you have to download the "Gravis Ultrasound patches" and create a subfolder "dgguspat" containing the patches.
In setup, select Gravis Ultrasound and point to the dgguspat directory.
To enable the MIT-SHM X11 extension for fast shared memory, you have to
export DISPLAY=:0.0
export EXTSHM=on
before launching the executable.
Using the SDL driver for the Ultimedia Services (UMS) instead of direct audio seems to make use of the sound card's DMA capability:
export SDL_AUDIODRIVER="UMS"
run_ums ./chocolate-doom
Check the contained COPYING file for the authors' rights.