Bit-Plane Assignment in Dual-playfield Mode .............62 COLOR REGISTERS IN DUAL-PLAYFIELD MODE ...............65 DUAL-PLAYFIELD PRIORITY AND CONTROL ..................66 ACTIVATING DUAL-PLAYFIELD MODE .......................67 DUAL PLAYFIELD SUMMARY ...............................67 Bit-planes and Display Windows of All Sizes .............68 WHEN THE BIG PICTURE IS LRGR THAN THE DISPLAY WINDOW .68 MAXIMUM DISPLAY WINDOW SIZE...........................74 Moving (Scrolling) Playfields ...........................75 VERTICAL SCROLLING....................................75 HORIZONTAL SCROLLING .................................77 SCROLLED PLAYFIELD SUMMARY ...........................80 Advanced Topics..........................................81 INTERACTIONS AMONG PLAYFIELDS AND OTHER OBJECTS ......81 HOLD-AND-MODIFY MODE .................................81 FORMING A DISPLAY WITH SEVERAL DIFFERENT PLAYFELD ....84 USING AN EXTERNAL VIDEO SOURCE .......................84 SUMMARY OF PLAYFIELD REGISTERS .......................84 Summary of Color Selection ..............................87 COLOR REGISTER CONTENTS ..............................87 SOME SAMPLE COLOR REGISTER CONTENTS ..................88 COLOR SELECTION IN LOW-RESOLUTION MODE ...............88 COLOR SELECTION IN HOLD-AND-MODIFY MODE ..............90 COLOR SELECTION IN HIGH-RESOLUTION MODE ..............90 Chapter 4 SPRITE HARDWARE .................................93 Introduction.............................................93 ABOUT THIS CHAPTER....................................94 Forming a Sprite ........................................94 SCREEN POSITION ......................................94 SIZE OF SPRITES ......................................97 SHAPE OF SPRITES .....................................97 SPRITE COLOR..........................................98 DESIGNING A SPRITE...................................101 BUILDING THE DATA STRUCTURE..........................101 Displaying a Sprite.....................................106 SELECTING A DMA CHANNEL AND SETTING THE POINTERS.....107 RESETTING THE ADDRESS POINTERS ......................107 SPRITE DISPLAY EXAMPLE...............................108 Moving a Sprite.........................................110 Creating Additional Sprites.............................111 SPRITE PRIORITY......................................112 Reusing Sprite DMA Channels ............................113 Overlapped Sprites......................................115 Attached Sprites .......................................117 Manual Mode ............................................120 Sprite Hardware Details ................................121 Summary of Sprite Registers.............................124 POINTERS.............................................124 CONTROL REGISTERS....................................124 DATA REGISTERS ......................................126 Summary of Sprite Color Registers.......................126 INTERACTIONS AMONG SPRITES AND OTHER OBJECTS ........128 Chapter 5 AUDIO HARDWARE..................................129 Introduction............................................129 INTRODUCING SOUND GENERATION.........................130 THE AMIGA SOUND HARDWARE.............................133 Forming and Playing a Sound ............................134