;ญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญ
;ญ   NoisetrackerV1.0 replayroutine   ญ
;ญ Mahoney & Kaktus - HALLONSOFT 1989 ญ
;ญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญญ

;SPEEDED UP WITH ABOUT 3 RASTERLINES BY CHUCKY OF SARGON

mt_data=$58000

mt_init:lea	mt_data,a0
	move.l	a0,a1
	add.l	#$3b8,a1
	moveq	#$7f,d0
	moveq	#0,d1
mt_loop:move.l	d1,d2
	subq.w	#1,d0
mt_lop2:move.b	(a1)+,d1
	cmp.b	d2,d1
	bgt.s	mt_loop
	dbf	d0,mt_lop2
	addq.b	#1,d2

	lea	mt_samplestarts(pc),a1
	asl.l	#8,d2
	asl.l	#2,d2
	add.l	#$43c,d2
	add.l	a0,d2
	move.l	d2,a2
	moveq	#$1e,d0
mt_lop3:clr.l	(a2)
	move.l	a2,(a1)+
	moveq	#0,d1
	move.w	42(a0),d1
	asl.l	#1,d1
	add.l	d1,a2
	add.l	#$1e,a0
	dbf	d0,mt_lop3

	or.b	#$2,$bfe001
	move.b	#$6,mt_speed
	clr.w	$dff0a8
	clr.w	$dff0b8
	clr.w	$dff0c8
	clr.w	$dff0d8
	clr.b	mt_songpos
	clr.b	mt_counter
	clr.w	mt_pattpos
	rts

mt_end:	clr.w	$dff0a8
	clr.w	$dff0b8
	clr.w	$dff0c8
	clr.w	$dff0d8
	move.w	#$f,$dff096
	rts

mt_music:
	movem.l	d0-d4/a0-a3/a5-a6,-(a7)
	lea	mt_data,a0
	addq.b	#$1,mt_counter
	move.b	mt_counter,D0
	cmp.b	mt_speed,D0
	blt.s	mt_nonew
	clr.b	mt_counter
	bra	mt_getnew

mt_nonew:
	lea	mt_voice1(pc),a6
	lea	$dff0a0,a5
	bsr	mt_checkcom
	lea	mt_voice2(pc),a6
	lea	$dff0b0,a5
	bsr	mt_checkcom
	lea	mt_voice3(pc),a6
	lea	$dff0c0,a5
	bsr	mt_checkcom
	lea	mt_voice4(pc),a6
	lea	$dff0d0,a5
	bsr	mt_checkcom
	bra	mt_endr

mt_arpeggio:
	moveq	#0,d0
	move.b	mt_counter,d0
	divs	#$3,d0
	swap	d0
	cmp.w	#$0,d0
	beq.s	mt_arp2
	cmp.w	#$2,d0
	beq.s	mt_arp1

	moveq	#0,d0
	move.b	$3(a6),d0
	lsr.b	#4,d0
	bra.s	mt_arp3
mt_arp1:moveq	#0,d0
	move.b	$3(a6),d0
	and.b	#$f,d0
	bra.s	mt_arp3
mt_arp2:move.w	$10(a6),d2
	bra.s	mt_arp4
mt_arp3:asl.w	#1,d0
	moveq	#0,d1
	move.w	$10(a6),d1
	lea	mt_periods(pc),a0
	moveq	#$24,d7
mt_arploop:
	move.w	(a0,d0.w),d2
	cmp.w	(a0),d1
	bge.s	mt_arp4
	addq.l	#2,a0
	dbf	d7,mt_arploop
	rts
mt_arp4:move.w	d2,$6(a5)
	rts

mt_getnew:
	lea	mt_data,a0
	move.l	a0,a3
	move.l	a0,a2
	add.l	#$c,a3
	add.l	#$3b8,a2
	add.l	#$43c,a0

	moveq	#0,d0
	move.l	d0,d1
	move.b	mt_songpos,d0
	move.b	(a2,d0.w),d1
	asl.l	#8,d1
	asl.l	#2,d1
	add.w	mt_pattpos,d1
	clr.w	mt_dmacon

	lea	$dff0a0,a5
	lea	mt_voice1(pc),a6
	bsr.s	mt_playvoice
	lea	$dff0b0,a5
	lea	mt_voice2(pc),a6
	bsr.s	mt_playvoice
	lea	$dff0c0,a5
	lea	mt_voice3(pc),a6
	bsr.s	mt_playvoice
	lea	$dff0d0,a5
	lea	mt_voice4(pc),a6
	bsr.s	mt_playvoice
	bra	mt_setdma

mt_playvoice:
	move.l	(a0,d1.l),(a6)
	addq.l	#4,d1
	moveq	#0,d2
	move.b	$2(a6),d2
	and.b	#$f0,d2
	lsr.b	#4,d2
	move.b	(a6),d0
	and.b	#$f0,d0
	or.b	d0,d2
	tst.b	d2
	beq.s	mt_setregs
	moveq	#0,d3
	lea	mt_samplestarts(pc),a1
	move.l	d2,d4
	subq.l	#$1,d2
	asl.l	#2,d2
	mulu	#$1e,d4
	move.l	(a1,d2.l),$4(a6)
	move.w	(a3,d4.l),$8(a6)
	move.w	$2(a3,d4.l),$12(a6)
	move.w	$4(a3,d4.l),d3
	tst.w	d3
	beq.s	mt_noloop
	move.l	$4(a6),d2
	asl.w	#1,d3
	add.l	d3,d2
	move.l	d2,$a(a6)
	move.w	$4(a3,d4.l),d0
	add.w	$6(a3,d4.l),d0
	move.w	d0,8(a6)
	move.w	$6(a3,d4.l),$e(a6)
	move.w	$12(a6),$8(a5)
	bra.s	mt_setregs
mt_noloop:
	move.l	$4(a6),d2
	add.l	d3,d2
	move.l	d2,$a(a6)
	move.w	$6(a3,d4.l),$e(a6)
	move.w	$12(a6),$8(a5)
mt_setregs:
	move.w	(a6),d0
	and.w	#$fff,d0
	beq	mt_checkcom2
	move.b	$2(a6),d0
	and.b	#$F,d0
	cmp.b	#$3,d0
	bne.s	mt_setperiod
	bsr	mt_setmyport
	bra	mt_checkcom2
mt_setperiod:
	move.w	(a6),$10(a6)
	and.w	#$fff,$10(a6)
	move.w	$14(a6),d0
	move.w	d0,$dff096
	clr.b	$1b(a6)

	move.l	$4(a6),(a5)
	move.w	$8(a6),$4(a5)
	move.w	$10(a6),d0
	and.w	#$fff,d0
	move.w	d0,$6(a5)
	move.w	$14(a6),d0
	or.w	d0,mt_dmacon
	bra	mt_checkcom2

mt_setdma:
	move.b	$dff006,d0
	add.b	#3,d0
mt_wait:
	cmp.b	$dff006,d0
	bne	mt_wait
	move.w	mt_dmacon,d0
	or.w	#$8000,d0
	move.w	d0,$dff096
	move.w	#$12c,d0
mt_wai2:dbf	d0,mt_wai2
	lea	$dff000,a5
	lea	mt_voice4(pc),a6
	move.l	$a(a6),$d0(a5)
	move.w	$e(a6),$d4(a5)
	lea	mt_voice3(pc),a6
	move.l	$a(a6),$c0(a5)
	move.w	$e(a6),$c4(a5)
	lea	mt_voice2(pc),a6
	move.l	$a(a6),$b0(a5)
	move.w	$e(a6),$b4(a5)
	lea	mt_voice1(pc),a6
	move.l	$a(a6),$a0(a5)
	move.w	$e(a6),$a4(a5)

	add.w	#$10,mt_pattpos
	cmp.w	#$400,mt_pattpos
	bne.s	mt_endr
mt_nex:	clr.w	mt_pattpos
	clr.b	mt_break
	addq.b	#1,mt_songpos
	and.b	#$7f,mt_songpos
	move.b	mt_songpos,d1
	cmp.b	mt_data+$3b6,d1
	bne.s	mt_endr
	clr.b	mt_songpos
mt_endr:tst.b	mt_break
	bne.s	mt_nex
	movem.l	(a7)+,d0-d4/a0-a3/a5-a6
	rts

mt_setmyport:
	move.w	(a6),d2
	and.w	#$fff,d2
	move.w	d2,$18(a6)
	move.w	$10(a6),d0
	clr.b	$16(a6)
	cmp.w	d0,d2
	beq.s	mt_clrport
	bge.s	mt_rt
	move.b	#$1,$16(a6)
	rts
mt_clrport:
	clr.w	$18(a6)
mt_rt:	rts

mt_myport:
	move.b	$3(a6),d0
	beq.s	mt_myslide
	move.b	d0,$17(a6)
	clr.b	$3(a6)
mt_myslide:
	tst.w	$18(a6)
	beq.s	mt_rt
	moveq	#0,d0
	move.b	$17(a6),d0
	tst.b	$16(a6)
	bne.s	mt_mysub
	add.w	d0,$10(a6)
	move.w	$18(a6),d0
	cmp.w	$10(a6),d0
	bgt.s	mt_myok
	move.w	$18(a6),$10(a6)
	clr.w	$18(a6)
mt_myok:move.w	$10(a6),$6(a5)
	rts
mt_mysub:
	sub.w	d0,$10(a6)
	move.w	$18(a6),d0
	cmp.w	$10(a6),d0
	blt.s	mt_myok
	move.w	$18(a6),$10(a6)
	clr.w	$18(a6)
	move.w	$10(a6),$6(a5)
	rts

mt_vib:	move.b	$3(a6),d0
	beq.s	mt_vi
	move.b	d0,$1a(a6)

mt_vi:	move.b	$1b(a6),d0
	lea	mt_sin(pc),a4
	lsr.w	#$2,d0
	and.w	#$1f,d0
	moveq	#0,d2
	move.b	(a4,d0.w),d2
	move.b	$1a(a6),d0
	and.w	#$f,d0
	mulu	d0,d2
	lsr.w	#$6,d2
	move.w	$10(a6),d0
	tst.b	$1b(a6)
	bmi.s	mt_vibmin
	add.w	d2,d0
	bra.s	mt_vib2
mt_vibmin:
	sub.w	d2,d0
mt_vib2:move.w	d0,$6(a5)
	move.b	$1a(a6),d0
	lsr.w	#$2,d0
	and.w	#$3c,d0
	add.b	d0,$1b(a6)
	rts

mt_nop:	move.w	$10(a6),$6(a5)
	rts

mt_checkcom:
	move.w	$2(a6),d0
	and.w	#$fff,d0
	beq.s	mt_nop
	move.b	$2(a6),d0
	and.b	#$f,d0
	tst.b	d0
	beq	mt_arpeggio
	cmp.b	#$1,d0
	beq.s	mt_portup
	cmp.b	#$2,d0
	beq	mt_portdown
	cmp.b	#$3,d0
	beq	mt_myport
	cmp.b	#$4,d0
	beq	mt_vib
	move.w	$10(a6),$6(a5)
	cmp.b	#$a,d0
	beq.s	mt_volslide
	rts

mt_volslide:
	moveq	#0,d0
	move.b	$3(a6),d0
	lsr.b	#4,d0
	tst.b	d0
	beq.s	mt_voldown
	add.w	d0,$12(a6)
	cmp.w	#$40,$12(a6)
	bmi.s	mt_vol2
	move.w	#$40,$12(a6)
mt_vol2:move.w	$12(a6),$8(a5)
	rts

mt_voldown:
	moveq	#0,d0
	move.b	$3(a6),d0
	and.b	#$f,d0
	sub.w	d0,$12(a6)
	bpl.s	mt_vol3
	clr.w	$12(a6)
mt_vol3:move.w	$12(a6),$8(a5)
	rts

mt_portup:
	moveq	#0,d0
	move.b	$3(a6),d0
	sub.w	d0,$10(a6)
	move.w	$10(a6),d0
	and.w	#$fff,d0
	cmp.w	#$71,d0
	bpl.s	mt_por2
	and.w	#$f000,$10(a6)
	or.w	#$71,$10(a6)
mt_por2:move.w	$10(a6),d0
	and.w	#$fff,d0
	move.w	d0,$6(a5)
	rts

mt_portdown:
	clr.w	d0
	move.b	$3(a6),d0
	add.w	d0,$10(a6)
	move.w	$10(a6),d0
	and.w	#$fff,d0
	cmp.w	#$358,d0
	bmi.s	mt_por3
	and.w	#$f000,$10(a6)
	or.w	#$358,$10(a6)
mt_por3:move.w	$10(a6),d0
	and.w	#$fff,d0
	move.w	d0,$6(a5)
	rts

mt_checkcom2:
	move.b	$2(a6),d0
	and.b	#$f,d0
	cmp.b	#$e,d0
	beq.s	mt_setfilt
	cmp.b	#$d,d0
	beq.s	mt_pattbreak
	cmp.b	#$b,d0
	beq.s	mt_posjmp
	cmp.b	#$c,d0
	beq.s	mt_setvol
	cmp.b	#$f,d0
	beq.s	mt_setspeed
	rts

mt_setfilt:
	move.b	$3(a6),d0
	and.b	#$1,d0
	asl.b	#$1,d0
	and.b	#$fd,$bfe001
	or.b	d0,$bfe001
	rts
mt_pattbreak:
	not.b	mt_break
	rts
mt_posjmp:
	move.b	$3(a6),d0
	subq.b	#$1,d0
	move.b	d0,mt_songpos
	not.b	mt_break
	rts
mt_setvol:
	cmp.b	#$40,$3(a6)
	ble.s	mt_vol4
	move.b	#$40,$3(a6)
mt_vol4:move.b	$3(a6),$8(a5)
	rts
mt_setspeed:
	move.b	$3(a6),d0
	and.w	#$1f,d0
	beq.s	mt_rts2
	clr.b	mt_counter
	move.b	d0,mt_speed
mt_rts2:rts

mt_sin:
dc.b $00,$18,$31,$4a,$61,$78,$8d,$a1,$b4,$c5,$d4,$e0,$eb,$f4,$fa,$fd
dc.b $ff,$fd,$fa,$f4,$eb,$e0,$d4,$c5,$b4,$a1,$8d,$78,$61,$4a,$31,$18

mt_periods:
dc.w $0358,$0328,$02fa,$02d0,$02a6,$0280,$025c,$023a,$021a,$01fc,$01e0
dc.w $01c5,$01ac,$0194,$017d,$0168,$0153,$0140,$012e,$011d,$010d,$00fe
dc.w $00f0,$00e2,$00d6,$00ca,$00be,$00b4,$00aa,$00a0,$0097,$008f,$0087
dc.w $007f,$0078,$0071,$0000,$0000

mt_speed:	dc.b	$6
mt_songpos:	dc.b	$0
mt_pattpos:	dc.w	$0
mt_counter:	dc.b	$0

mt_break:	dc.b	$0
mt_dmacon:	dc.w	$0
mt_samplestarts:blk.l	$1f,0
mt_voice1:	blk.w	10,0
		dc.w	$1
		blk.w	3,0
mt_voice2:	blk.w	10,0
		dc.w	$2
		blk.w	3,0
mt_voice3:	blk.w	10,0
		dc.w	$4
		blk.w	3,0
mt_voice4:	blk.w	10,0
		dc.w	$8
		blk.w	3,0