This chapter covers the control hardware of the Amiga system, including
the following topics:

   *  How playfield priorities may be specified relative to the sprites
   *  How collisions between objects are sensed
   *  How system direct memory access (DMA) is controlled
   *  How interrupts are controlled and sensed
   *  How reset and early powerup are controlled

 video priorities             interrupts 
 collision detection          dma control 
 beam position detection      reset and early startup operation