--- a/ptplayer.asm
+++ b/ptplayer.asm
@@ -2495,6 +2495,10 @@
 mt_arpeggio:
 ; cmd 0 x y (x = first arpeggio offset, y = second arpeggio offset)
 ; d4 = xy
+; As Protracker 2.3: the period, wherever a slide has left it, is looked
+; up in the channel's finetune row, and the note x or y above taken from
+; there -- past B-3, from the next finetune's row, which the table runs on
+; into. (Counting from n_noteoff instead kept the note from before a slide.)
 
 	moveq	#0,d0
 	move.b	mt_Counter(a4),d0
@@ -2509,16 +2513,26 @@
 	; step 2, arpeggio by right nibble
 .1:	and.w	#$000f,d4
 
-	; offset current note
+	; find the period in the tuned table: 37 entries, as Protracker reads
 .2:	add.w	d4,d4
-	add.w	n_noteoff(a2),d4
-	cmp.w	#2*36,d4
+	lea	mt_PeriodTableEnd(pc),a1
+	move.l	n_pertab(a2),a0
+	move.w	n_period(a2),d1
+	moveq	#37-1,d0
+.3:	cmp.l	a1,a0
+	bhs	.5
+	cmp.w	(a0),d1
 	bhs	.4
+	addq.l	#2,a0
+	dbf	d0,.3
+	rts
 
-	; set period with arpeggio offset from note table
-	move.l	n_pertab(a2),a0
-	move.w	(a0,d4.w),AUDPER(a5)
-.4:	rts
+	; set period with arpeggio offset, unless it runs off the table
+.4:	add.w	d4,a0
+	cmp.l	a1,a0
+	bhs	.5
+	move.w	(a0),AUDPER(a5)
+.5:	rts
 
 arptab:
 	dc.b	0,1,-1,0,1,-1,0,1,-1,0,1,-1,0,1,-1,0
@@ -2689,7 +2703,7 @@
 ; cmd 5 x y (x = volume-up, y = volume-down)
 ; d4 = xy
 
-	pea	mt_volumeslide(pc)
+	pea	mt_volslide_noper(pc)
 	bra	mt_toneporta_nc
 
 
@@ -2698,12 +2712,13 @@
 ; d4 = xy
 
 	move.w	d4,d3
+	moveq	#0,d2			; the depth indexes a table: no stale high byte
 	move.b	n_vibratoamp(a2),d2
 	move.b	n_vibratospd(a2),d4
 	bsr	mt_vibrato_nc
 
 	move.w	d3,d4
-	bra	mt_volumeslide
+	bra	mt_volslide_noper
 
 
 mt_tremolo:
@@ -2723,47 +2738,53 @@
 	bra	.4
 .3:	move.b	n_tremolospd(a2),d4
 
-	; calculate tremolo table offset: 64 * amplitude + (pos & 63)
-.4:	lsl.w	#6,d2
-	moveq	#63,d0
-	and.b	n_tremolopos(a2),d0
-	add.w	d0,d2
-
-	ifne	ENABLE_SAWRECT
-	; select tremolo waveform
+	; As Protracker 2.3: twice a vibrato's depth (the wave times y, over
+	; 64), and the saw ramping as the channel's VIBRATO position says.
+.4:	moveq	#31,d0
+	and.b	n_tremolopos(a2),d0	; d0 = position in the wave's half
 	moveq	#3,d1
 	and.b	n_tremoloctrl(a2),d1
 	beq	.6
+
+	lsl.b	#3,d0			; saw and square: the ramp's step
 	subq.b	#1,d1
-	beq	.5
+	bne	.5
 
-	; ctrl 2 & 3 select a rectangle tremolo
-	lea	mt_VibratoRectTable(pc),a0
+	; ctrl 1 selects a saw, falling in the vibrato's negative half
+	btst	#5,n_vibratopos(a2)
+	beq	.9
+	not.b	d0			; 255 - ramp
 	bra	.9
 
-	; ctrl 1 selects a sawtooth tremolo
-.5:	lea	mt_VibratoSawTable(pc),a0
+	; ctrl 2 & 3 select a square
+.5:	st	d0
 	bra	.9
-	endc	; ENABLE_SAWRECT
 
-	; ctrl 0 selects a sine tremolo
-.6:	lea	mt_VibratoSineTable(pc),a0
+	; ctrl 0 selects a sine
+.6:	move.b	mt_ProTrackerSine(pc,d0.w),d0
 
-	; add tremolo-offset to volume
-.9:	move.w	n_volume(a2),d0
-	add.b	(a0,d2.w),d0
-	bpl	.10
-	moveq	#0,d0
-.10:	cmp.w	#64,d0
+	; scale by the depth, then add or subtract by the position's half
+.9:	and.w	#$00ff,d0
+	mulu	d2,d0
+	lsr.w	#6,d0
+	move.w	n_volume(a2),d1
+	btst	#5,n_tremolopos(a2)
+	beq	.10
+	sub.w	d0,d1
+	bpl	.11
+	moveq	#0,d1
+	bra	.11
+.10:	add.w	d0,d1
+	cmp.w	#64,d1
 	bls	.11
-	moveq	#64,d0
+	moveq	#64,d1
 .11:	move.w	n_period(a2),AUDPER(a5)
 	ifeq	MINIMAL
 	move.l	mt_MasterVolTab(a4),a0
-	move.b	(a0,d0.w),d0
-	and.b	n_enable(a2),d0
+	move.b	(a0,d1.w),d1
+	and.b	n_enable(a2),d1
 	endc
-	move.w	d0,AUDVOL(a5)
+	move.w	d1,AUDVOL(a5)
 	ifd	VOL0_UNLOOPS
 	bne	.12
 	move.b	d7,n_looped(a2)
@@ -2773,6 +2794,12 @@
 .12:	add.b	d4,n_tremolopos(a2)
 	rts
 
+mt_ProTrackerSine:
+	; Protracker's mt_VibratoTable: the first half of the sine
+	dc.b	0,24,49,74,97,120,141,161,180,197,212,224,235,244,250,253
+	dc.b	255,253,250,244,235,224,212,197,180,161,141,120,97,74,49,24
+	even
+
 
 mt_volumeslide:
 ; cmd A x y (x = volume-up, y = volume-down)
@@ -2815,6 +2842,34 @@
 .1:	rts
 
 
+mt_volslide_noper:
+; The volume slide of 5xy and 6xy, and EAx/EBx's: as mt_volumeslide but
+; leaving Paula's period alone, as Protracker 2.3 does -- setting it back to
+; n_period undid 6xy's vibrato, 5xy's glissando, and a tick of either.
+; d4 = xy
+
+	move.w	n_volume(a2),d0
+	moveq	#$0f,d1
+	and.b	d4,d1
+	lsr.b	#4,d4
+	beq	vol_slide_down_np
+
+	; slide up, until 64
+	add.b	d4,d0
+vol_slide_up_np:
+	cmp.b	#64,d0
+	bls	set_vol
+	moveq	#64,d0
+	bra	set_vol
+
+	; slide down, until 0
+vol_slide_down_np:
+	sub.b	d1,d0
+	bpl	set_vol
+	moveq	#0,d0
+	bra	set_vol
+
+
 mt_posjump:
 ; cmd B x y (xy = new song position)
 ; d4 = xy
@@ -3079,7 +3134,7 @@
 	rts
 
 .1:	add.w	n_volume(a2),d0
-	bra	vol_slide_up
+	bra	vol_slide_up_np
 
 
 mt_volfinedn:
@@ -3092,7 +3147,7 @@
 
 .1:	move.b	d0,d1
 	move.w	n_volume(a2),d0
-	bra	vol_slide_down
+	bra	vol_slide_down_np
 
 
 mt_notecut:
@@ -3448,6 +3503,7 @@
 	dc.w	862,814,768,725,684,646,610,575,543,513,484,457
 	dc.w	431,407,384,363,342,323,305,288,272,256,242,228
 	dc.w	216,203,192,181,171,161,152,144,136,128,121,114
+mt_PeriodTableEnd:
 
 	ifeq	MINIMAL
 MasterVolTab0: