Sega Mega Drive/Priority

The Sega Mega Drive VDP draws planes and sprites on the screen in a specific order. In addition, each tile within a plane and each sprite has a priority bit which can be set to draw it in front of those without. The drawing order is as follows:

1. Background colour (set by VDP register 07)
2. Background (Plane B) with priority bit clear
3. Foreground (Plane A) with priority bit clear (also shadowed in shadow/highlight mode)
4. Sprites with priority bit clear
5. Window Plane with priority bit clear
6. Background (Plane B) with priority bit set
7. Foreground (Plane A) with priority bit set (also normal in shadow/highlight mode)
8. Sprites with priority bit set
9. Window Plane with priority bit set