Here is the whole source code of 'rebirth' demo. It is implemented as:

• a low level reusable layer available in demOS folder
  
• specialized high level implementations
  

So feel free to re-use, improve... demOS

rebirth is implemented as a mix of C and ASM68k code. It can be build with pure C without linking any standard library (have a look at configuration is BASETYPES.H)

3 project .PRJ files are provided:

• debug target with .C metafile (for optimized build times) DEMOSBLD.PRJ
  
• final target with .C metafile (for optimized build times) DEMOSOPT.PRJ
  
• 'normal' target DEMOS.PRJ (useful to identify link errors)
  

Trace system keymap:

[TAB] shift trace plane display
[BACKSPACE] toggle video mode (2 planes / 4 planes)
[S] toggle refresh rate (50hz / 60hz)
[V] toggle verbose mode
[F1] display nb frames used by current effect
[F2] display various hardware states (keyboard...)
[F3] display allocators state
[F4] display loading system state
[F5] display soundtrack system state
[F6] display finite states machines
[F8] display build version number
[F9] global raster (background color change)
[F10] set colors 1 to 15 in green