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;****************************************************************************
; PlayPCM*
; Plays a PCM sample
;****************************************************************************
PlayPCMSFX:
call PlayPCM ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
PlayPCMBGM:
PollPCM
ld a, (RAM_Locked+6) ; Check if channel is free
or a
jp nz, ProcessBGMSkip1 ; Don't play sample if locked
call PlayPCM ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
PlayPCM:
call GetParam ; Get sample ID
ld a, b
exx ; We'll modify PCM data now
ld b, $01 ; Play PCM!
ld h, RAM_PointerList>>8 ; Get offset in pointer list
ld l, a
ld d, (hl) ; Get PCM address
inc h
ld e, (hl)
inc h
ld c, (hl)
ld hl, $6000 ; Restore $6000 back to HL
exx ; Back to standard variables
ld (ix+0), $2B ; Turn on DAC
ld (ix+1), $80
ld (ix+0), $2A
ld (ix+1), $80
ret ; End of subroutine
;****************************************************************************
; UpdatePCM
; Updates PCM output upon a timer event
;****************************************************************************
UpdatePCM:
;ld (ix+0), $24 ; Reset timer
;ld (ix+1), $FE
;ld (ix+0), $25
;ld (ix+1), $03
ld (ix+0), $27
ld (ix+1), $1F
exx ; Switch to PCM registers
ld a, b ; Do any playback?
or a
jr z, .nopcm
ld a, (RAM_LastBank) ; Bank switch?
cp c
jp z, .noswitchu
ld a, c
ld (RAM_LastBank), a
BankSwitch
.noswitchu:
ld a, (de) ; Get sample
inc a ; Is it end of waveform?
jr z, .stop ; If so, stop
ld (ix+0), $2A ; Nope, send sample to YM2612
ld (ix+1), a
inc e ; Get address for next sample
jr nz, .nopcm
inc d
jr nz, .nopcm
ld d, $80
inc c
.nopcm:
exx ; Go back to normal registers
ret ; End of subroutine
.stop:
ld b, $00 ; Stop playback
ld (ix+0), $2A ; Turn off DAC
ld (ix+1), $80
ld (ix+0), $2B
ld (ix+1), $00
exx ; Go back to normal registers
ret ; End of subroutine
;****************************************************************************
; StopPCM*
; Stops a PCM sample
;****************************************************************************
StopPCMSFX:
call StopPCM ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
StopPCMBGM:
PollPCM
ld a, (RAM_Locked+6) ; Check if channel is free
or a
jp nz, ProcessBGMRun ; Don't stop sample if locked
call StopPCM ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
StopPCM:
exx ; Stop PCM playback
ld b, $00
exx
ld (ix+0), $2B ; Disable DAC
ld (ix+1), $00
ret ; End of subroutine
;****************************************************************************
; LockChannelPCM [event $EC]
; Locks the PCM channel
;****************************************************************************
LockChannelPCM:
ld a, $01 ; Lock PCM channel
ld (RAM_Locked+6), a
call StopPCM ; Stop PCM playback
jp ProcessSFXRun ; End of subroutine
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