Implement partial VGA emulation.
Add missing headers.
Attempt to approximate effect of CRTC VGA registers.
Improve palette handling and enable most simple drawing functions.
Correct various errors and implement basic SDL video output.
Improve VGA emulation.
Move some header related #ifdefs to more appropriate places.
Synchronize video output.
Allow multiple timer threads.
Slightly improve timing.
Correct video viewport.
Hopefully make synchronization more robust.
Cosmetics; Rename timer.
VGA related cosmetics.
Improve VGA timing and fix palette handling.
Enable more drawing functions.
Implement screen clearing routine.
Fix VGA plane handling for various drawing functions.
Implement assembler substitutions relevant to the main intro.
Improve CPU usage.
Several busy waiting routines are now synchronized to the tic timer.