diff --git a/engine/menus/savemenu_copytilemapatonce.asm b/engine/menus/savemenu_copytilemapatonce.asm
index 51b7ea8fe..2f30b7c7e 100644
--- a/engine/menus/savemenu_copytilemapatonce.asm
+++ b/engine/menus/savemenu_copytilemapatonce.asm
@@ -3,33 +3,37 @@ SaveMenu_CopyTilemapAtOnce:
 	and a
 	jp z, WaitBGMap
 
-; The following is a modified version of CopyTilemapAtOnce.
+; The following is a modified version of _CopyTilemapAtOnce
+; that waits for [rLY] to be $60 instead of $80 - 1.
 	ldh a, [hBGMapMode]
 	push af
 	xor a
 	ldh [hBGMapMode], a
+
 	ldh a, [hMapAnims]
 	push af
 	xor a
 	ldh [hMapAnims], a
-.WaitLY:
+
+.wait
 	ldh a, [rLY]
 	cp $60
-	jr c, .WaitLY
+	jr c, .wait
 
 	di
 	ld a, BANK(vBGMap2)
 	ldh [rVBK], a
 	hlcoord 0, 0, wAttrmap
-	call .CopyTilemapAtOnce
+	call .CopyBGMapViaStack
 	ld a, BANK(vBGMap0)
 	ldh [rVBK], a
 	hlcoord 0, 0
-	call .CopyTilemapAtOnce
-.WaitLY2:
+	call .CopyBGMapViaStack
+
+.wait2
 	ldh a, [rLY]
 	cp $60
-	jr c, .WaitLY2
+	jr c, .wait2
 	ei
 
 	pop af
@@ -38,7 +42,8 @@ SaveMenu_CopyTilemapAtOnce:
 	ldh [hBGMapMode], a
 	ret
 
-.CopyTilemapAtOnce:
+.CopyBGMapViaStack:
+; Copy all tiles to vBGMap
 	ld [hSPBuffer], sp
 	ld sp, hl
 	ldh a, [hBGMapAddress + 1]
@@ -46,16 +51,18 @@ SaveMenu_CopyTilemapAtOnce:
 	ld l, 0
 	ld a, SCREEN_HEIGHT
 	ldh [hTilesPerCycle], a
-	ld b, 1 << 1
+	ld b, 1 << 1 ; not in v/hblank
 	ld c, LOW(rSTAT)
 
 .loop
 rept SCREEN_WIDTH / 2
 	pop de
+; if in v/hblank, wait until not in v/hblank
 .loop\@
 	ldh a, [c]
 	and b
 	jr nz, .loop\@
+; load vBGMap
 	ld [hl], e
 	inc l
 	ld [hl], d
diff --git a/engine/phone/phonering_copytilemapatonce.asm b/engine/phone/phonering_copytilemapatonce.asm
index 0ddb3c852..029c2958c 100644
--- a/engine/phone/phonering_copytilemapatonce.asm
+++ b/engine/phone/phonering_copytilemapatonce.asm
@@ -6,15 +6,18 @@ PhoneRing_CopyTilemapAtOnce:
 	cp $0
 	jp z, WaitBGMap
 
-; What follows is a modified version of CopyTilemapAtOnce.
+; The following is a modified version of _CopyTilemapAtOnce
+; that waits for [rLY] to be LY_VBLANK - 1 instead of $80 - 1.
 	ldh a, [hBGMapMode]
 	push af
 	xor a
 	ldh [hBGMapMode], a
+
 	ldh a, [hMapAnims]
 	push af
 	xor a
 	ldh [hMapAnims], a
+
 .wait
 	ldh a, [rLY]
 	cp LY_VBLANK - 1
@@ -24,11 +27,12 @@ PhoneRing_CopyTilemapAtOnce:
 	ld a, BANK(vBGMap2)
 	ldh [rVBK], a
 	hlcoord 0, 0, wAttrmap
-	call .CopyTilemapAtOnce
+	call .CopyBGMapViaStack
 	ld a, BANK(vBGMap0)
 	ldh [rVBK], a
 	hlcoord 0, 0
-	call .CopyTilemapAtOnce
+	call .CopyBGMapViaStack
+
 .wait2
 	ldh a, [rLY]
 	cp LY_VBLANK - 1
@@ -41,7 +45,8 @@ PhoneRing_CopyTilemapAtOnce:
 	ldh [hBGMapMode], a
 	ret
 
-.CopyTilemapAtOnce:
+.CopyBGMapViaStack:
+; Copy all tiles to vBGMap
 	ld [hSPBuffer], sp
 	ld sp, hl
 	ldh a, [hBGMapAddress + 1]
@@ -55,10 +60,12 @@ PhoneRing_CopyTilemapAtOnce:
 .loop
 rept SCREEN_WIDTH / 2
 	pop de
+; if in v/hblank, wait until not in v/hblank
 .loop\@
 	ldh a, [c]
 	and b
 	jr nz, .loop\@
+; load vBGMap
 	ld [hl], e
 	inc l
 	ld [hl], d
diff --git a/home/tilemap.asm b/home/tilemap.asm
index 379b1464a..56e6182ef 100644
--- a/home/tilemap.asm
+++ b/home/tilemap.asm
@@ -58,13 +58,13 @@ CGBOnly_CopyTilemapAtOnce::
 	jr z, WaitBGMap
 
 CopyTilemapAtOnce::
-	jr .CopyTilemapAtOnce
+	jr _CopyTilemapAtOnce
 
 ; unused
 	farcall HDMATransferAttrmapAndTilemapToWRAMBank3
 	ret
 
-.CopyTilemapAtOnce:
+_CopyTilemapAtOnce:
 	ldh a, [hBGMapMode]
 	push af
 	xor a
@@ -77,22 +77,22 @@ CopyTilemapAtOnce::
 
 .wait
 	ldh a, [rLY]
-	cp $7f
+	cp $80 - 1
 	jr c, .wait
 
 	di
-	ld a, BANK(vTiles3)
+	ld a, BANK(vBGMap2)
 	ldh [rVBK], a
 	hlcoord 0, 0, wAttrmap
-	call .StackPointerMagic
-	ld a, BANK(vTiles0)
+	call .CopyBGMapViaStack
+	ld a, BANK(vBGMap0)
 	ldh [rVBK], a
 	hlcoord 0, 0
-	call .StackPointerMagic
+	call .CopyBGMapViaStack
 
 .wait2
 	ldh a, [rLY]
-	cp $7f
+	cp $80 - 1
 	jr c, .wait2
 	ei
 
@@ -102,7 +102,7 @@ CopyTilemapAtOnce::
 	ldh [hBGMapMode], a
 	ret
 
-.StackPointerMagic:
+.CopyBGMapViaStack:
 ; Copy all tiles to vBGMap
 	ld [hSPBuffer], sp
 	ld sp, hl
@@ -122,7 +122,7 @@ rept SCREEN_WIDTH / 2
 	ldh a, [c]
 	and b
 	jr nz, .loop\@
-; load BGMap0
+; load vBGMap
 	ld [hl], e
 	inc l
 	ld [hl], d