LSD Docs/LSD Docs.iso/FILEZ/lsd17.dms/lsd17.adf/2/2

Text File | 1990-09-06 | 25KB | 468 lines

                          TABLE OF CONTENTS


Chapter 1 INTRODUCTION
  Components of the Amiga ..................................2
     THE MC68000 AND THE AMIGA CUSTOM CHIPS.................2
     VCR AND DIRECT CAMERA INTERFACE........................5
     PERIPHERALS............................................5
     SYSTEM EXPANDABILITY AND ADAPTABILITY..................6
  About the Examples........................................7
  Some Caveats to Hardware Level Programmers ...............9


Chapter 2 COPROCESSOR HARDWARE ............................13
  Introduction.............................................13
     ABOUT THIS CHAPTER....................................14
  What is a Copper Instruction? ...........................14
  The MOVE Instruction ....................................15
  The WAIT Instruction.....................................17
     HORIZONTAL BEAM POSITION..............................18
     VERTICAL BEAM POSITION ...............................18
     THE COMPARISON ENABLE BITS............................19
  Using the Copper Registers...............................20
     LOCATION REGISTERS ...................................20
     JUMP STROBE ADDRESS...................................21
     CONTROL REGISTER......................................21
  Putting Together a Copper Instruction List ..............22
     COMPLETE SAMPLE COPPER LIST...........................24
     LOOPS AND BRANCHES ...................................25
  Starting and Stopping the Copper ........................25
     STARTING THE COPPER AFTER RESET.......................25
     STOPPING THE COPPER...................................26
   Advanced Topics.........................................27
     THE SKIP INSTRUCTION..................................27
     COPPER LOOPS AND BRANCHES AND COMPARISON ENABLE.......28
     USING THE COPPER IN INTERLACED MODE ..................30
     USING THE COPPER WITH THE BLITTER.....................31
     THE COPPER AND THE 68000..............................31

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     Summary of Copper Instructions .......................32


Chapter 3 PLAYIELD HARDWARE................................33
  Introduction.............................................33
     ABOUT THIS CHAPTER....................................34
     PLAYFIELD FEATURES ...................................34
  Forming a Basic Playfield ...............................38
     HEIGHT AND WIDTH OF THE PLAYFIELD.....................39
     BIT-PLANES AND COLOR .................................39
     SELECTING HORIZONTAL AND VERTICAL RESOLUTION .........43
     ALLOCATING MEMORY FOR BIT-PLANES .....................46
     CODING THE BIT-PLANES FOR CORRECT COLORING ...........49
     DEFINING THE SIZE OF THE DISPLAY WINDOW ..............50
     TELLING THE SYSTEM HOW TO FETCH AND DISPLAY DATA .....53
     DISPLAYING AND REDISPLAYING THE PLAYFIELD ............56
     ENABLING THE COLOR DISPLAY ...........................56
     BASIC PLAYFIELD SUMMARY ..............................57
     EXAMPLES OF FORMING BASIC PLAYFIELDS .................59
  Forming a Dual-playfield Display ........................62
  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 LARGER 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
  Surnmary 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
  Intrduction..............................................93
     ABOUT THIS CHAPTER....................................94
  Forming a Sprite ........................................94

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     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
     DECIDING WHICH CHANNEL TO USE........................134
     CREATING THE WAVEFORM DATA...........................134
     TELLING THE SYSTEM ABOUT THE DATA ...................136
     SELECTING THE VOLUME ................................136
     SELECTING THE DATA OUTPUT RATE.......................137
     PLAYING THE WAVEFORM ................................140
     STOPPING THE AUDIO DMA...............................141
     SUMMARY..............................................142
     EXAMPLE..............................................142
  Producing Complex Sounds................................143
     JOINING TONES .......................................143
     PLAYING MULTIPLE TONES AT THE SAME TIME..............145
     MODULATING SOUND ....................................145
  Producing High-quality Sound............................148
     MAKING WAVEFORM TRANSITIONS .........................148
     SAMPLING RATE .......................................148
     EFFICIENCY...........................................149
     NOISE REDUCTION......................................150

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     ALIASING DISTORTION .................................150
     LOW-PASS FILTER .....................................152
  Using Direct (Non-DMA) Audio Output ....................153
  The Equal-tempered Musical Scale........................154
  Decibel Values for Volume Ranges .......................159
  The Audio State Machine.................................160


Chapter 6 BLITTER HARDWARE................................163
  Introduction............................................163
  Memory Layout ..........................................164
  DMA Channels............................................164
  Function Generator......................................168
     DESIGNING THE LF CONTROL BYTE WITH MINTERMS..........169
     DESIGNING THE LF CONTROL BYTE WITH VENN DIAGRAMS.....172
  Shifts and Masks........................................173
  Descending Mode ........................................176
  Copying Arbitrary Regions...............................177
  Area Fill Mode..........................................178
  Blitter Done Flag.......................................180
     MULTITASKING AND THE BLITTER ........................181
  Interrupt Flag .........................................181
  Zero Flag...............................................182
  Pipeline Register.......................................182
  Line Mode...............................................184
     REGISTER SUMMARY FOR LINE MODE.......................186
  Blitter Speed ..........................................188
  Blitter Operations and System DMA ......................189
  Blitter Block Diagram...................................193
  Blitter Key Points......................................195
     EXAMPLE: ClearMem....................................195
     EXAMPLE: SimpleLine..................................197
     EXAMPLE: RotateBits..................................199


Chapter 7 SYSTEM CONTROL HARDWARE ........................201
  Introduction............................................201
  Video Priorities .......................................202
     FIXED SPRITE PRIORITES ..............................202
     HOW SPRITES ARE GROUPED..............................203
     UNDERSTANDING VIDEO PRIORITIES ......................203
     SETTING THE PRIORITY CONTROL REGISTER................204
  Collision Detection ....................................207
     HOW COLLISIONS ARE DETERMINED........................207
     HOW TO INTERPRET THE COLLISION DATA .................208
     HOW COLLISION DETECTION IS CONTROLLED ...............209
  Beam Position Detection.................................210
     USING THE BEAM POSITION COUNTER......................210
  Interrupts .............................................211
     NONMASKABLE INTERRUPT ...............................212

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     MASKABLE INTERRUPTS..................................212
     USER INTERFACE TO THE INTERRUPT SYSTEM ..............212
     INTERRUPT CONTROL REGISTERS .........................212
     SETTING AND CLEARING BITS............................213
  DMA Control ............................................217
  Processor Access to Chip Memory.........................217
  Reset and Early Startup Operation.......................219


Chapter 8 INTERFACE HARDWARE..............................221
  Introduction............................................221
  Controller Port Interface...............................222
     REGISTERS USED WITH THE CONTROLLER PORT..............223
Floppy Disk Controller .....,.............................235
     REGISTERS USED BY THE DISK SUBSYSTEM ................236
     DISK INTERRUPTS .....................................244
  The Keyboard............................................245
     HOW THE KEYBOARD DATA IS RECEIVED....................245
     TYPE OF DATA RECEIVED................................245
     LIMITATIONS OF THE KEYBOARD .........................247
  Parallel Input/Output Interface.........................250
  Serial Interface .......................................250
     INTRODUCTION TO SERIAL CIRCUITRY ....................250
     SETTING THE BAUD RATE................................250
     SETTING THE RECEIVE MODE ............................251
     CONTENTS OF THE RECEIVE DATA REGISTER................251
     HOW OUTPUT DATA IS TRANSMITTED.......................253
     SPECIFYING THE REGISTER CONTENTS ....................254
  Display Output Connections .............................255


Appendix A Register Summary-Alphabetical Order............257

Appendix B Register Summary-Address Order.................281

Appendix C Custom Chip Pin Allocation List................289

Appendix D System Memory Map..............................293

Appendix E Interfaces ....................................295

Appendix F Complex Interface Adapters.....................317
  8520 Complex Interface Adaptor (CIA) Chips..............317
  Chip Register Map.......................................319
  Register Functional Description.........................320
     I/O PORTS (PRA, PRB, DDRA, DDRB).....................320
     HANDSHAKING..........................................320
     INTERVAL TIMERS (TIMER A, TIMER B)...................320
     INPUT MODES..........................................322
     BIT NAMES on READ-Register...........................322

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     BIT NAMES on WRITE-Register .........................322
  Time of Day Clock.......................................323
     BIT NAMES for WRITE TIME/ALARM or READ TIME..........323
  Senal Shift Register (SDR)..............................324
     INPUT MODE ..........................................324
     OUTPUT MODE .........................................324
     BIDIRECTIONAL FEATURE ...............................325
  Interrupt Control Register (ICR) .......................325
     READ INTERRUPT CONTROL REGISTER .....................326
     WRITE INTERRUPT CONTROL MASK ........................326
  Control Registers ......................................327
     CONTROL REGISTER A ..................................327
     BIT MAP OF REGISTER CRA .............................328
     BIT MAP OF REGISTER CRB .............................329
  Port Signal Assignments.................................329
  Hardware Connection Details.............................332
     INTERFACE SIGNALS ...................................332


Appendix G AUTOCONFIG ....................................335
  Debugging AUTOCONFIG Boards.............................336
  Address Specification Table.............................337


Appendix H Keyboard.......................................343
  Keyboard Communications.................................344
  Keycodes................................................345
  "CAPS LOCK" Key.........................................345
  "Out-of-Sync" Condition.................................346
  Power-Up Sequence ......................................346
  Reset Warning...........................................348
  Hard Reset..............................................348
  Special Codes...........................................349
  Matrix Table............................................350


Appendix I External Disk Connector Interface Spec. .......353
  General.................................................353
  Summary Table...........................................354
  Signals When Driving a Disk.............................355
  Device I.D..............................................357


Appendix J Hardware Example Include File..................359


Glossary .................................................365

Index ....................................................373

                           - xii -


                     LIST OF FIGURES

Figure 1-1 Block Diagram for the Amiga Computer Family.....11
Figure 2-1 Interlaced Bit-Plane in RAM.....................30
Figure 3-1 How the Video Display Picture Is Produced.......34
Figure 3-2 What Is a Pixel?................................35
Figure 3-3 How Bit-planes Select a Color...................37
Figure 3-4 Significance of Bit-Plane Data in Selecting Colors.38
Figure 3-5 Interlacing.....................................44
Figure 3-6 Effect of Interlaced Mode on Edges of Objects...44
Figure 3-7 Memory Organization for a Basic Bit-Plane.......48
Figure 3-8 Combining Bit-planes............................50
Figure 3-9 Positioning the On-screen Display...............51
Figure 3-10 Data Fetched for the First Line When Modulo=0 .54
Figure 3-11 Data Fetched for the Second Line When Modulo=0.55
Figure 3-12 A Dual-playfield Display.......................63
Figure 3-13 How Bit-Planes Are Assigned to Dual Playfields.64
Figure 3-14 Memory Picture Largerthan the Display..........69
Figure 3-15 Data Fetch for the First Line When Modulo=40...69
Figure 3-16 Data Fetch for the Second Line When Modulo=40..70
Figure 3-17 Data Layout for First Line-Right Half of Big Picture.70
Figure 3-18 Data Layout for Second Line-Right Half of Big Picture.70
Figure 3-19 Display Window Horizontal Starting Position ...72
Figure 3-20 Display Window Vertical Starting Positition ...72
Figure 3-21 Display Window Horizontal Stopping Position  ..73
Figure 3-22 Display Window Vertical Stopping Position .....74
Figure 3-23 Vertical Scrolling.............................76
Figure 3-24 Horizontal Scrolling ..........................78
Figure 3-25 Memory Picture Larger than the Display Window .79
Figure 3-26 Data for Line 1 - Horizontal Scrolling ........79
Figure 3-27 Data for Line 2 - Horizontal Scrolling ........79
Figure 4-1 Defining Sprite On-screen Position..............95
Figure 4-2 Position of Sprites ............................96
Figure 4-3 Shape of Spaceship..............................97
Figure 4-4 Sprite with Spaceship Shape Defined ............98
Figure 4-5 Sprite Color Definition ........................99
Figure 4-6 Color Register Assignments ....................100

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Figure 4-7 Data Structure Layout .........................103
Figure 4-8 Sprite Priority ...............................112
Figure 4-9 Typical Example of Sprite Reuse ...............113
Figure 4-10 Typical Data Structure for Sprite Re-use .....114
Figure 4-11 Overlapping Sprites (Not Attached) ...........116
Figure 4-12 Placing Sprites Next to Each Other ...........117
Figure 4-13 Sprite Control Circuitry .....................122
Figure 5-1 Sine Waveform .................................131
Figure 5-2 Digitized Amplitude Values ....................133
Figure 5-3 Example Sine Wave .............................139
Figure 5-4 Waveform with Multiple Cycles .................149
Figure 5-5 Fuency Domain Plot of Low-Pass Filter .........151
Figure 5-6 Noise-free Output (No Aliasing Distortion) ....151
Figure 5-7 Some Aliasing Distortion ......................152
Figure 5-8 Audio State Diagram ...........................162
Figure 6-1 How Images are Stored in Memory ...............165
Figure 6-2 BLTxP and BLTxMOD calculations ................167
Figure 6-3 Blitter Minterm Venn Diagram ..................172
Figure 6-4 Extracting a Range of Columns .................175
Figure 6-5 Use of the FCI Bit - Bit Is a 0 ...............179
Figure 6-6 Use of the FCI Bit - Bit Is a 1 ...............179
Figure 6-7 Single-Point Vertex Example ...................180
Figure 6-8 Octants for Line Drawing ......................184
Figure 6-9 DMA Time Slot A ocation .......................190
Figure 6-10 Norma 68000 Cycle ............................191
Figure 6-11 Time Slots Used by a Six Bit Plane Display ...192
Figure 6-12 Time Slots Used by a High Resolution Display .192
Figure 6-13 Blitter Block Diagram ........................194
Figure 7-1 Inter-Sprite Fixed Priorities .................202
Figure 7-2 Analogy for Video Priority ....................203
Figure 7-3 Sprite playfield Priority .....................206
Figure 7 4 Interrupt Priorities ..........................216
Figure 8-1 Controler Plug and Computer Connector .........222
Figure 8-2 Mouse Quadrature ..............................224
Figure 8-3 Joystick to Counter Connections ...............227
Figure 8-4 Typical Paddle Wiring Diagram .................229
Figure 8-5 Effects of Resistance on Charging Rate ........230
Figure 8-6 Potentiometer Charging Circuit ................231
Figure 8-7 Chinon Timing Diagram .........................236
Figure 8-8 Chinon Timing Diagram (cont.) .................237
Figure 8-9 The A1000 Keyboard, Showing Keycodes in Hex ...249
Figure 8-10 The A500/2000 Keyboard, Keycodes in Hex ......249
Figure 8-11 Starting Appearance of SERDAT and Shift Reg ..254
Figure 8-12 Ending Appearance of Shift Register...........254
Figure G-1 How to read the Address Specification Table ...338

                              - xiv -


                             LIST OF TABLES

Table 2-1 Interrupting the 68000...........................31
Table 2-2 Copper Instruction Summary ......................32
Table 3-1 Colors in a Single Playfield.....................39
Table 3-2 Porion of the Color Table .......................40
Table 3-3 Contents of the Color Registers .................41
Table 3-4 Sample Color Register Contents ..................41
Table 3-5 Setting the Number of Bit-Planes.................42
Table 3-6 Lines in a Normal Playfield......................43
Table 3-7 Playfield Memory Requirements, NTSC..............46
Table 3-8 Playfield Memory Requirements, PAL ..............47
Table 3-9 DIWSTRT AND DIWSTOP Summary......................53
Table 3-10 Playfield 1 Color Registers-Low-resolution Mode 65
Table 3-11 Playfield 2 Color Registers-Low-resolution Mode 65
Table 3-12 Playfields 1 & 2 Color Registers High-res Mode .66
Table 3-13 Maximum Allowable Vertical Screen Video.........74
Table 3-14 Maximum Allowable Horizontal Screen Video ......75
Table 3-15 Color Register Contents.........................87
Table 3-16 Some Register Values and Resulting Colors.......88
Table 3-17 Low-resolution Color Selection .................89
Table 3-18 Color Selection in Hold-and-modify Mode.........90
Table 3-19 High-resolution Color Selection.................91
Table 4-1 Sprite Data Structure...........................102
Table 4-2 Sprite Color Registers .........................105
Table 4-3 Color Registers for Sprite Pairs................112
Table 4-4 Data Words for First Line of Spaceship Sprite...118
Table 4-5 Color Registers in Attached Sprites ............119
Table 4-6 Color Registers for Single Sprites..............127
Table 4-7 Color Registers for Attached Sprites............128
Table 5-1 Sample Audio Data Set for Channel 0 ............135
Table 5-2 Volume Values ..................................137
Table 5-3 DMA and Audio Channel Enable Bits...............141
Table 5-4 Data Interpretation in Attach Mode..............146
Table 5-5 Channel Attachment for Modulation...............147
Table 5-6 Sampling Rate and Frequency Relationship........153
Table 5-7 Equal-tempered Octave for a 16 Byte Sample......154

                              - xv -


Table 5-8 Five Octave Even-tempered Scale..................15
Table 5-9 Decibel Values and Volume Ranges.................15
Table 6-1 Table of Common Minterm Values...................17
Table 6-2 Typical Blitter Cycle Sequence...................18
Table 6-3 BLTCON1 Code Bits for Octant Line Drawing........18
Table 7-1 Bits in BPLCON2..................................20
Table 7-2 Priority of Playfields Based on Values of Bits PF1P2-PF1P0.20
Table 7-3 CLXDAT Bits......................................20
Table 7-4 CLXCON Bits .....................................20
Table 7-5 Contents of the Beam Position Counter............21
Table 7-6 Contents of DMA Register.........................21
Table 8-1 Typical Controller Connections ..................22
Table 8-2 Determining the Direction of the Mouse...........22
Table 8-3 Interpreting Data from JOY0DAT and JOY1DAT.......22
Table 8-4 POTGO ($DFF034) and POTINP ($DFF016) Registers...23
Table 8-5 Disk Subsystem ..................................23
Table 8-6 DSKLEN Register ($DFF024)........................24
Table 8-7 DSKBYTR Register.................................24
Table 8-8 ADKCON and ADKCONR Regster.......................24
Table 8-9 SERDATR / ADKCON Regsters........................25
Table G-1 Address Specification Table......................33

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End.