Similar to SuperVidel's but requires an additional C2P pass.
Also, a few optimizations added like cursor is being assumed to be in
a persistent memory so we don't copy it over. And it's using a mask
instead of key.
This graphics mode is not perfect though and works reliably only with
source surfaces allocated via Surface::init() otherwise wrong memory
location is being read.
Still, can gain quite a few CPU cycles, especially on 640x480 screens.
- Atari TT support
- all video and audio is now handled via XBIOS
- reworked IKBD handling using Kbdvbase vectors, esp. Kbdvec()
- video uses proper triple buffer
- arbitrary game screen size support
- many fixes and optimizations
Miro Kropacek