======= Sega MasterSystem Compatibility Issues =======

* CodeMasters games don't work:
   + CodeMasters games use a custom mapper (implemented now).
   + CodeMasters games use alternate video mode, not implemented.
   + Games are: Cosmic Spacehead, Fantastic Dizzy, Micro Machines

* F16 Fighting Falcon uses old SG-1000 video mode, and doesn't work on a GG/Genesis either.

That said.. I will fix CodeMasters games and F16 Fighting Falcon eventually, and add full
SG-1000 support, it's just not the high priority currently.

* Raster effects are sometimes on the wrong line... but it's correct 99% of the time... :|
  Update: I think this is a timing issue resulting in latching/rendering at the wrong part 
  of a scanline. I should play with this timing.

======= Game Gear compatibility issues =======

* Axe Battler is broken.
* "SEGA" logo audio sample plays at low rate in Sonic & Tails.