BF_SNDVOL .EQU BF_SND + 1 ; REQUEST SOUND VOL - D IS CHANNEL, E CONTAINS VOLUME (255 MAX, 0 SILENT) - SCALED AS REQUIRED BY DRIVER (EG: MAPS TO JUST 4 BIT RESOLUTION FOR SN76489)
BF_SNDPRD .EQU BF_SND + 2 ; REQUEST SOUND PERIOD - D IS CHANNEL, HL CONTAINS PERIOD (0 LOWEST NOTE) - SCALED BY DRIVER (EG: MAPS TO JUST 10 BITS FOR SN76489 )
BF_SNDVOL .EQU BF_SND + 1 ; REQUEST SOUND VOL - L CONTAINS VOLUME (255 MAX, 0 SILENT) - SCALED AS REQUIRED BY DRIVER (EG: MAPS TO JUST 4 BIT RESOLUTION FOR SN76489)
BF_SNDPRD .EQU BF_SND + 2 ; REQUEST SOUND PERIOD - HL CONTAINS DRIVER SPECIFIC VALUE
BF_SNDNOTE .EQU BF_SND + 3 ; REQUEST NOTE - L CONTAINS NOTE - EACH VALUE IS QUARTER NOTE