Audio Device, 13 AbortIO(), 18 additional information, 34 BeginIO(), 18 changing the volume, 26 channel, 14 CloseDevice(), 18 closing, 18 CMD_FLUSH, 27 CMD_READ, 27 CMD_RESET, 27 CMD_START, 27 CMD_STOP, 27 CMD_WRITE, 25 commands and functions, 15 definitions, 14 device interface, 16 double-buffering, 26 free, 17 hardware control commands, 25 IORequest block, 16 IORequest structures, 16 lock, 17 opening, 16 playing a sound, 25 precedence of users, 22 precedence, 17 reserve, 17 sample, 14 scope of commands, 17 simple audio example, 18 starting a sound, 27 steal channel, 22 stopping a sound, 26, 27 Wait(), 18 WaitPort(), 18