SECTION SND

	INCLUDE '/INC/QDOS_inc'
	INCLUDE '/INC/AMIGA_inc'
	INCLUDE '/INC/AMIGQDOS_inc'

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
; SND1_asm - sound routines
;	  - last modified 27/07/94

; These are all the necessary sound related sources, required
; to implement a QDOS BEEP on the Amiga computer.

;  ...latest changes by Mark J Swift

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  ROM header

BASE:
	dc.l	$4AFB0001	; ROM recognition code
	dc.w	0		; add BASIC procs here
	dc.w	ROM_START-BASE
	dc.b	0,32,'Amiga-QDOS SOUND routines v1.06',$A

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  start of ROM code

ROM_START:
	movem.l d0-d3/a0-a3,-(a7)

; --------------------------------------------------------------
;  allocate memory for sound variables

	move.l	#BV_LEN,d1
	moveq	#MT.ALCHP,d0
	moveq	#0,d2
	trap	#1

; --------------------------------------------------------------
;  address of sound variables

	move.l	a0,AV.SNDV
	move.l	a0,a3

; --------------------------------------------------------------
;  enter supervisor mode and disable interrupts

	trap	#0

	ori.w	#$0700,sr	; disable interrupts

; --------------------------------------------------------------
;  link a custom routine into level 7 interrupt server

	lea	AV.LVL7link,a1
	lea	BV.LVL7link(a3),a2

	move.l	(a1),(a2)
	move.l	a2,(a1)

	lea	MY_LVL7(pc),a1
	move.l	a1,$04(a2)

; --------------------------------------------------------------
;  link a custom routine into Trap #1 exception

	lea	AV.TRP1link,a1
	lea	BV.TRP1link(a3),a2

	move.l	(a1),(a2)
	move.l	a2,(a1)

	lea	MY_TRP1(pc),a1
	move.l	a1,$04(a2)

; --------------------------------------------------------------
;  initialise relevant hardware

	bsr	INIT_HW

; -------------------------------------------------------------
; link in external interrupt to act on sound cycle complete

	lea	XINT_SERver(pc),a1 ; address of routine
	lea	BV.XINTLink(a3),a0
	move.l	a1,4(a0)
	moveq	#MT.LXINT,d0
	trap	#1

; --------------------------------------------------------------
;  enable interrupts and re-enter user mode

	andi.w	#$D8FF,sr

; --------------------------------------------------------------
;  initiate a sound process

	movem.l	d5/d7,-(a7)

	lea	BLIP(pc),a3
	moveq	#$11,d0
	trap	#1

	movem.l	(a7)+,d5/d7

; --------------------------------------------------------------
ROM_EXIT:
	movem.l (a7)+,d0-d3/a0-a3
	rts

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  initialise sound for use.

INIT_HW:
	movem.l d0-d2/a0/a3,-(a7)

; --------------------------------------------------------------
;  initialise hardware

	move.w	#%0000000010000000,INTENA ; disable AUD0 ints
	move.w	#$000F,DMACONW	        ; kill sound
	move.w	#%0000000010000000,INTREQ ; clear AUD0 ints

	move.l	a7,d0
	andi.l	#$FFFF8000,d0
	move.l	d0,a0		; Calc address of sys vars

	move.b	#0,SV_SOUND(a0)	; signal as not beeping

	movem.l (a7)+,d0-d2/a0/a3
	rts

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  external interrupt server

XINT_SERver:
	movem.l	d7/a0,-(a7)

	move.w	INTENAR,d7	; read interrupt enable reg
	btst	#7,d7		; branch if AUD0 ints not on
	beq	XINT_OTHer

	move.w	INTREQR,d7	; read interrupt request reg
	btst	#7,d7		; branch if from AUD0
	bne	AUD0_SERV

; --------------------------------------------------------------
;  otherwise let another external interrupt server handle it

XINT_OTHer:
	movem.l	(a7)+,d7/a0
	rts

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  Interrupt from AUD0

AUD0_SERV:
	move.l	a7,d7
	andi.l	#$FFFF8000,d7
	move.l	d7,a0		; Calc address of sys vars

	tst.b	SV_SOUND(a0)	; are we beeping?
	beq.s	XINT_OTHer	; no.

	move.w	#%0000000010000000,INTREQ ; clear interrupts

	movem.l	d1-d4/a0/a1,-(a7)

	move.l	AV.SNDV,a1

	moveq	#0,d0
	move.w	BV.BEEP(a1),d0	; previous pitch
	move.l	d0,d2
	add.w	#11,d2		; calc. length of sample
	lsl.l	#4,d2		; scale it
	add.l	d0,d2

	move.l	BV.DURVAL(a1),d1
	beq.s	AUD0_L1		; infinite dur.

	add.l	d2,BV.DURCNT(a1)	; increment dur count
	move.l	BV.DURCNT(a1),d3
	cmp.l	d3,d1
	ble	AUD0_DONe	; finished?

AUD0_L1:
	move.w	BV.NOTE(a1),d0	; calculated pitch

	move.l	BV.GRDVAL(a1),d1
	beq	AUD0_G3		; no sequence duration

	add.l	d2,BV.GRDCNT(a1)	; increment pitch count
	move.l	BV.GRDCNT(a1),d2
	cmp.l	d2,d1
	bgt	AUD0_G3		; still counting...

	move.w	BV.PITCH(a1),d0	; ideal pitch

AUD0_LUP:
	tst.w	BV.PITINC(a1)
	beq	AUD0_G1		; no pitch increment

	add.w	BV.PITINC(a1),d0

	tst.w	BV.PITINC(a1)
	bmi.s	AUD0_P2

AUD0_P1:
	move.w	BV.PITCH2(a1),d3
	cmp.w	d0,d3		; reached limit?
	bgt.s	AUD0_G1		; no

	move.w	BV.REPCNT(a1),d4
	dbra	d4,AUD0_R1

	move.w	BV.REPVAL(a1),d4
	move.w	d4,BV.REPCNT(a1)
	lsl.w	#1,d3
	sub.w	d0,d3
	move.w	d3,d0
	neg.w	BV.PITINC(a1)	; bounce

	bra.s	AUD0_P2

AUD0_R1:
	move.w	d4,BV.REPCNT(a1)
	sub.w	d3,d0
	add.w	BV.PITCH1(a1),d0	; repeat

	bra.s	AUD0_P1

AUD0_P2:
	move.w	BV.PITCH1(a1),d3
	cmp.w	d0,d3		; reached limit?
	blt.s	AUD0_G1		; no

	move.w	BV.REPCNT(a1),d4
	dbra	d4,AUD0_R2

	move.w	BV.REPVAL(a1),d4
	move.w	d4,BV.REPCNT(a1)
	lsl.w	#1,d3
	sub.w	d0,d3
	move.w	d3,d0
	neg.w	BV.PITINC(a1)	; bounce

	bra.s	AUD0_P1

AUD0_R2:
	move.w	d4,BV.REPCNT(a1)
	sub.w	d3,d0
	add.w	BV.PITCH2(a1),d0	; repeat

	bra.s	AUD0_P2

AUD0_G1:
	sub.l	d1,d2
	cmp.l	d2,d1
	blt.s	AUD0_LUP

	move.l	d2,BV.GRDCNT(a1)
	move.w	d0,BV.PITCH(a1)

	move.w	BV.RAND(a1),d1
	beq.s	AUD0_G3

	move.w	BV.SEED(a1),d2
	addq.w	#1,d2
	mulu.w	#33,d2
	divu	#257,d2
	clr.w	d2
	swap	d2
	subq.w	#1,d2
	andi.w	#$FF,d2
	move.w	d2,BV.SEED(a1)	; make a random number

	addq.w	#1,d1
	divu	d1,d2
	swap	d2
	lsr.w	#1,d1
	sub.w	d2,d1
	add.w	d1,d0		; RANDomise note
	andi.w	#$00FF,d0

AUD0_G3:
	bsr	SETBEEP		; new sound params

	bra.s	AUD0_EXIt

AUD0_DONe:
	bsr	INIT_HW

AUD0_EXIt:
	movem.l	(a7)+,d1-d4/a0/a1

XINT_EXIt:
	bra	XINT_OTHer

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SETBEEP:
	move.w	d0,BV.NOTE(a1)

	move.w	BV.FUZZ(a1),d1
	beq.s	SETBEEP1

	move.w	BV.SEED(a1),d2
	addq.w	#1,d2
	mulu.w	#33,d2
	divu	#257,d2
	clr.w	d2
	swap	d2
	subq.w	#1,d2
	andi.w	#$FF,d2
	move.w	d2,BV.SEED(a1)	; make a random number

	addq.w	#1,d1
	divu	d1,d2
	swap	d2
	lsl.w	#2,d2
	add.w	d2,d0
	andi.w	#$00FF,d0

SETBEEP1:
	move.w	d0,BV.BEEP(a1)

	move.w	d0,d1
	addi.w	#11,d1		; calc. length of sample

	move.w	d1,d0
	lsr.w	#1,d0		; calc. AUDXLEN
	move.w	d0,AUD0LEN

	lea	SAMPLE,a0
	lea	140(a0),a0	; half way thro' sample
	move.l	a0,d2
	ext.l	d0
	sub.l	d0,d2
	bclr	#0,d2		; calc. AUDXLC
	move.l	d2,AUD0LC

	move.w	#313,d0		; AUDXPER

	bclr	#0,d1		; need to adjust AUDXPER?
	beq.s	SETBEEP2 	; no.

	move.w	d0,d2
	ext.l	d2
	divu	d1,d2
	add.w	d2,d0		; calc. new AUDXPER

SETBEEP2:
	move.w	d0,AUD0PER

	rts

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  Custom LVL7 routine to initialise hardware

MY_LVL7:
	bsr	INIT_HW

	subq.l	#4,a7
	movem.l	a3,-(a7)
	move.l	AV.SNDV,a3
	move.l	BV.LVL7link(a3),a3
	move.l	4(a3),4(a7)	; address of next routine
	movem.l	(a7)+,a3

	rts

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  A patch to replace TRAP#1 calls to: MT_IPCOM (d0=$10 and $11)

MY_TRP1:
	bsr	INI_A5A6

	cmp.b	#$11,d0
	beq	MT_IPCOM

MY_TRP1X:
	movem.l (a7)+,d7/a5/a6	; restore registers

	subq.l	#4,a7
	movem.l	a3,-(a7)
	move.l	AV.SNDV,a3
	move.l	BV.TRP1link(a3),a3
	move.l	4(a3),4(a7)	; address of next routine
	movem.l	(a7)+,a3

	rts

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
; initialise A5 and A6 prior to performing a TRAP routine

INI_A5A6
	SUBQ.L	#8,A7
	MOVE.L	8(A7),-(A7)
	MOVEM.L D7/A5/A6,4(A7)

	move.l	a7,d7
	andi.l	#$FFFF8000,d7
	move.l	d7,a6		; Calc address of sys vars

	LEA	4(A7),A5 ; A5 points to saved
				; Registers D7,A5,A6
	MOVEQ	#$7F,D7
	AND.L	D7,D0
	RTS

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  TRAP #1 with D0=$11

MT_IPCOM:
	cmp.b	#10,(a3) ; is IPC command initiate sound ?
	beq.s	MT_IPC10

	cmp.b	#11,(a3) 	; is it kill sound ?
	bne	MY_TRP1X 	; no

MT_IPC11:
	bsr	INIT_HW

	moveq	#0,d0
	bra	TRAP1_X		; exit

MT_IPC10:
	movem.l	d1-d2/a0-a2,-(a7)

	move.l	AV.SNDV,a1

	move.l	a3,a2

	cmp.b	#8,1(a3)
	beq.s	IPC_SKP0

; --------------------------------------------------------------
; change 16 parameter sound into an 8 parameter one

	lea	SAMPLE,a2

	move.b	$6(a3),$6(a2)
	move.b	$8(a3),$7(a2)
	move.w	$A(a3),$8(a2)
	move.w	$C(a3),$A(a2)
	move.b	$E(a3),d0
	lsl.b	#4,d0
	move.b	$10(a3),d1
	andi.b	#$F,d1
	or.b	d1,d0
	move.b	d0,$C(a2)
	move.b	$12(a3),d0
	lsl.b	#4,d0
	move.b	$14(a3),d1
	andi.b	#$F,d1
	or.b	d1,d0
	move.b	d0,$D(a2)

; --------------------------------------------------------------
IPC_SKP0:
	moveq	#0,d1
	move.b	$6(a2),d1
	sub.b	#1,d1		; get PITCH1

	moveq	#0,d2
	move.b	$7(a2),d2
	sub.b	#1,d2		; get PITCH2

	cmp.w	d1,d2
	bge.s	IPC_SKP1

	exg	d1,d2

IPC_SKP1:
	move.w	d1,BV.PITCH1(a1)
	move.w	d2,BV.PITCH2(a1)

; --------------------------------------------------------------
	move.b	$9(a2),d0	; gradient hi
	lsl.w	#8,d0
	move.b	$8(a2),d0	; gradient lo
	mulu	#14,d0
	move.l	d0,BV.GRDVAL(a1)

; --------------------------------------------------------------
	move.b	$B(a2),d0	; duration hi
	lsl.w	#8,d0
	move.b	$A(a2),d0	; duration lo
	mulu	#14,d0
	move.l	d0,BV.DURVAL(a1)

; --------------------------------------------------------------
	moveq	#0,d0
	move.b	$C(a2),d0	; repeats
	andi.b	#$0F,d0
	move.w	d0,BV.REPVAL(a1)

	move.w	d0,BV.REPCNT(a1)

; --------------------------------------------------------------
	move.b	$C(a2),d0	; get pitch increment
	lsr.b	#4,d0
	cmpi.b	#8,d0
	bne.s	IPC_SKP5

	move.w	d1,d0
	sub.w	d2,d0		; maximise pitch inc
	bra.s	IPC_SKP2

IPC_SKP5:
	lsl.b	#4,d0
	ext.w	d0
	asr.w	#4,d0		; sign extend

	tst.w	d0
	bgt.s	IPC_SWP3

IPC_SKP2:
	move.w	d2,BV.PITCH(a1)	; current ideal value
	bra.s	IPC_SWP4

IPC_SWP3:
	move.w	d1,BV.PITCH(a1)	; current ideal value

; --------------------------------------------------------------
IPC_SWP4:
	cmp.w	d1,d2
	bne.s	IPC_SWP5

	moveq	#0,d0

IPC_SWP5:
	move.w	d0,BV.PITINC(a1)

; --------------------------------------------------------------
	moveq	#0,d0
	move.b	$D(a2),d0	; fuzz
	andi.b	#$F,d0
	subq.w	#$7,d0		; make 0-8
	bge.s	IPC_SKP3

	clr.w	d0

IPC_SKP3:
	move.w	d0,BV.FUZZ(a1)

; --------------------------------------------------------------
	moveq	#0,d0
	move.b	$D(a2),d0	; randomness
	lsr.b	#4,d0
	subq.w	#$7,d0		; make 0-8
	bge.s	IPC_SKP4

	clr.w	d0

IPC_SKP4:
	move.w	d0,BV.RAND(a1)

	clr.l	BV.DURCNT(a1)
	clr.l	BV.GRDCNT(a1)
	clr.w	BV.SEED(a1)

; --------------------------------------------------------------
	lea	SAMPLE,a0
	lea	BEEPBEG(pc),a2
	move.w	#((BEEPEND-BEEPBEG)/2-1),d0

MOVSNDLUP:
	move.w	(a2)+,(a0)+
	dbra	d0,MOVSNDLUP

; --------------------------------------------------------------
	move.l	a7,d0
	andi.l	#$FFFF8000,d0
	move.l	d0,a0		; Calc address of sys vars

	move.b	#$FF,SV_SOUND(a0) ; signal as beeping

; --------------------------------------------------------------
	move.w	#64,AUD0VOL	; set volume
	move.w	#$FF,ADKCON	; no modulation

	move.w	BV.PITCH(a1),d0
	bsr	SETBEEP

; --------------------------------------------------------------
	move.w	#%0000000010000000,INTREQ ; clear interrupts
	move.w	#$8001,DMACONW	        ; start sound
	move.w	#%1000000010000000,INTENA ; enable interrupts

	movem.l	(a7)+,d1-d2/a0-a2
	moveq	#0,d0
	bra	TRAP1_X	; exit

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  exit from TRAP call

TRAP1_X	movem.l (a7)+,d7/a5/a6	 ; exit from exception
	rte

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  BEEP sound sample, a square wave with rippled edges.

BEEPBEG:
	DC.B $8D,$8B,$88,$86,$84,$83,$82,$81,$82,$83,$84,$86,$88,$8B,$8D,$8F
	DC.B $90,$91,$91,$91,$90,$8F,$8D,$8B,$88,$86,$84,$83,$82,$81,$82,$83
	DC.B $84,$86,$88,$8B,$8D,$8F,$90,$91,$91,$91,$90,$8F,$8D,$8B,$88,$86
	DC.B $84,$83,$82,$81,$82,$83,$84,$86,$88,$8B,$8D,$8F,$90,$91,$91,$91
	DC.B $90,$8F,$8D,$8B,$88,$86,$84,$83,$82,$81,$82,$83,$84,$86,$88,$8B
	DC.B $8D,$8F,$90,$91,$91,$91,$90,$8F,$8D,$8B,$88,$86,$84,$83,$82,$81
	DC.B $82,$83,$84,$86,$88,$8B,$8D,$8F,$90,$91,$91,$91,$90,$8F,$8D,$8B
	DC.B $88,$86,$84,$83,$82,$81,$82,$83,$84,$86,$88,$8B,$8D,$8F,$90,$91
	DC.B $91,$91,$90,$8F,$8D,$8B,$88,$86,$84,$83,$82,$81,$7F,$7E,$7D,$7C
	DC.B $7A,$78,$75,$73,$71,$70,$6F,$6F,$6F,$70,$71,$73,$75,$78,$7A,$7C
	DC.B $7D,$7E,$7F,$7E,$7D,$7C,$7A,$78,$75,$73,$71,$70,$6F,$6F,$6F,$70
	DC.B $71,$73,$75,$78,$7A,$7C,$7D,$7E,$7F,$7E,$7D,$7C,$7A,$78,$75,$73
	DC.B $71,$70,$6F,$6F,$6F,$70,$71,$73,$75,$78,$7A,$7C,$7D,$7E,$7F,$7E
	DC.B $7D,$7C,$7A,$78,$75,$73,$71,$70,$6F,$6F,$6F,$70,$71,$73,$75,$78
	DC.B $7A,$7C,$7D,$7E,$7F,$7E,$7D,$7C,$7A,$78,$75,$73,$71,$70,$6F,$6F
	DC.B $6F,$70,$71,$73,$75,$78,$7A,$7C,$7D,$7E,$7F,$7E,$7D,$7C,$7A,$78
	DC.B $75,$73,$71,$70,$6F,$6F,$6F,$70,$71,$73,$75,$78,$7A,$7C,$7D,$7E
	DC.B $7F,$7E,$7D,$7C,$7A,$78,$75,$73

BEEPEND:

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;  IPC10 BEEP sound process... a short blip

BLIP:
	DC.B $0A,$08,$AA,$AA,$55,$55
	DC.B $01,$01,$00,$00,$00,$04,$00,$00

; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	END