Commodore Amiga - Page 10

PLAYING MULTIPLE TONES AT THE SAME TIME ................................. 149
MODULATING SOUND
.............................................................................................. 149
Producing High-quality Sound ............................................................................ :.... 152
MAKING WAVEFORM TRANSITIONS
.............................................................. 152
SAMPLING RATE
.......................................................................................................... 152
EFFICIENCY
.................................................................................................................... 153
NOISE REDUCTION
..................................................................................................... 154
ALIASING DISTORTION
........................................................................................... 154
LOW-PASS FIL
TER ................................................................ ,...................................... 156
Using Direct (Non-DMA) Audio Output .......................................................... 157
The Equal-tempered Musical Scale ....................................................................... 158
Decibel Values for Volume Ranges ....................................................................... 160
The Audio State Machine ............................................................................................ 161
Chapter 6 BLITTER HARDWARE ............................................................................ 165
Introduction ............................................................................................................................. 165
Data Copying ......................................................................................................................... 167
Pointers and Modulos ...................................................................................................... 168
Ascending and Descending Addressing .............................................................. 170
Rectangular or Linear Address Scanning ......................................................... 171
Blitter Logic Operations ................................................................................................ 171
DESIGNING THE LF CONTROL BYTE WITH LOGIC
EQUATIONS
................................................... ................................................................. 172
DESIGNING THE LF CONTROL BYTE WITH VENN
DIAGRAMS
........................................................................................................................ 175
Shifting ........................................................................................................................................ 177
Masking ...................................................................................................................................... 178
Zero Detection ....................................................................................................................... 179
Area Filling .............................................................................................................................. 180
INCLUSIVE (NORMAL) AREA FILLING
........................................................... 180
EXCLUSIVE AREA FILLING
.................................................................................... 182
Line Drawing .......................................................................................................................... 1$3
OCTANTS IN LINE DRAWING
.............................................................................. 184
Blitter Operations and System DMA .................................................................. 186
BLITTER DMA PRIORITY
........................................................................................ 186
DMA TIME SLOT ALLOCATION
.......................................................................... 186
BIT-PLANE/PROCESSOR BUS SHARING
........................................................ 189
EFFECTS
OF DIFFERENT DISPLAY SIZES ................................................... 191
EFFECTS OF BLITTER OPERATION
................................................................ 191
Complete Blitter Example ........................................................................................... 193
Blitter Block Diagram ..................................................................................................... 195
-xii-