Playfields share the display with sprites. Chapter 7, "System Control
Hardware," shows how playfields can be given different video
 display priorities  relative to the sprites and how playfields can
 collide  with (overlap) the sprites or each other.

   ECS Sprites.
   -----------
   For information relating to sprites in the Enhanced Chip Set (ECS),
   such as  SuperHires sprites  and  SuperHires sprite positioning ,
   see Appendix C.