Audio, 4 , 9 , 20 
  aliasing distortion, 154 
  amplitude modulation, 4 
  channels - attaching, 149 , 164 , choosing, 137 
  data, 137 
  data length registers, 139 
  data location registers, 138 , 139 
  data output rate, 140 
  decibel values, 140 
  DMA, 138 , 144 , 147 , 164 
  equal-tempered scale, 158 
  frequency modulation, 4 
  in ECS, 310 
  interrupts, 147 , 220 
  joining tones, 147 
  low-pass filter, 154 
  modulation, 164 
    amplitude, 149 
    frequency, 149 
  noise reduction, 154 
  non-DMA output, 157 
  period, 140 
  period register, 143 
  playing multiple tones, 149 
  producing a steady tone, 145 
  sampling period, 141 
  sampling rate, 141 , 152 , 156 , 164 
  state machine, 164 
  stopping, 145 
  system overhead, 153 
  volume, 139 , 163 
  volume registers, 139 
  waveform transitions, 152