From 1317273aa0324b4ef31079017b6957466e3518af Mon Sep 17 00:00:00 2001
From: wintiger0222 <0xodbs02@naver.com>
Date: Mon, 25 Nov 2019 11:09:11 +0000
Subject: [PATCH] [Reduction] [th03/th04/th05] Music Room code identical to
 TH02

---
 th02/music/{polygons.asm => music.asm}        |  93 +++++++++
 .../{polygons[bss].asm => music[bss].asm}     |   5 +
 th03_op.asm                                   | 166 ++++-----------
 th04_op.asm                                   | 172 ++++------------
 th05_op.asm                                   | 193 +++++-------------
 5 files changed, 219 insertions(+), 410 deletions(-)
 rename th02/music/{polygons.asm => music.asm} (75%)
 rename th02/music/{polygons[bss].asm => music[bss].asm} (56%)

diff --git a/th02/music/polygons.asm b/th02/music/music.asm
similarity index 75%
rename from th02/music/polygons.asm
rename to th02/music/music.asm
index 0f08e43d..329ec16f 100644
--- a/th02/music/polygons.asm
+++ b/th02/music/music.asm
@@ -10,6 +10,68 @@ else
 POLYGONS_RENDERED = 16
 endif
 
+public SCREEN_BACK_B_SNAP
+screen_back_B_snap	proc near
+	push	bp
+	mov	bp, sp
+	push	si
+	call	hmem_allocbyte pascal, (ROW_SIZE * RES_Y)
+	mov	_screen_back_B, ax
+	xor	si, si
+	jmp	short loc_A5DF
+; ---------------------------------------------------------------------------
+
+loc_A5CA:
+	les	bx, _VRAM_PLANE_B
+	add	bx, si
+	mov	eax, es:[bx]
+	mov	es, _screen_back_B
+	mov	es:[si], eax
+	add	si, 4
+
+loc_A5DF:
+	cmp	si, (ROW_SIZE * RES_Y)
+	jl	short loc_A5CA
+	pop	si
+	pop	bp
+	retn
+screen_back_B_snap	endp
+
+
+public SCREEN_BACK_B_FREE
+screen_back_B_free	proc near
+	push	bp
+	mov	bp, sp
+	call	hmem_free pascal, _screen_back_B
+	pop	bp
+	retn
+screen_back_B_free	endp
+
+
+public SCREEN_BACK_B_PUT
+screen_back_B_put	proc near
+	push	bp
+	mov	bp, sp
+	push	si
+	push	di
+	push	ds
+	mov	ax, 0A800h
+	mov	es, ax
+	assume es:nothing
+	mov	ax, _screen_back_B
+	mov	ds, ax
+	xor	di, di
+	xor	si, si
+	mov	cx, (ROW_SIZE * RES_Y) / 2
+	rep movsw
+	pop	ds
+	pop	di
+	pop	si
+	pop	bp
+	retn
+screen_back_B_put	endp
+
+
 polygon_build	proc near
 
 var_3	= byte ptr -3
@@ -295,3 +357,34 @@ loc_A88F:
 	pop	bp
 	retn
 polygons_update_and_render	endp
+
+
+public MUSIC_FLIP
+music_flip	proc near
+	push	bp
+	mov	bp, sp
+	call	screen_back_B_put
+if GAME eq 5
+	call	_piano_render
+endif
+	call	grcg_setcolor pascal, ((GC_RMW or GC_B) shl 16) + 15
+	call	polygons_update_and_render
+if GAME ge 4
+	GRCG_OFF_CLOBBERING dx
+	if GAME eq 5
+		call	frame_delay pascal, 1
+	endif
+else
+	call	grcg_off
+endif
+	graph_showpage _music_page
+	mov	al, 1
+	sub	al, _music_page
+	mov	_music_page, al
+	graph_accesspage al
+if GAME le 4
+	call	frame_delay_2 pascal, 1
+endif
+	pop	bp
+	retn
+music_flip	endp
diff --git a/th02/music/polygons[bss].asm b/th02/music/music[bss].asm
similarity index 56%
rename from th02/music/polygons[bss].asm
rename to th02/music/music[bss].asm
index 12e483ab..56cfe50f 100644
--- a/th02/music/polygons[bss].asm
+++ b/th02/music/music[bss].asm
@@ -1,5 +1,10 @@
+; (only covering TH03 and above, until their decompilation)
 polygon_points	Point 0Ah dup(<?>)
 polygon_pos	Point 10h dup(<?>)
 polygon_move_speed	Point 10h dup(<?>)
 polygon_angle	db 10h dup(?)
 polygon_rot_speed	db 10h dup(?)
+
+public _music_sel, _music_page
+_music_sel	db ?
+_music_page	db ?
diff --git a/th03_op.asm b/th03_op.asm
index ceda5aac..a1d6a77c 100644
--- a/th03_op.asm
+++ b/th03_op.asm
@@ -1619,7 +1619,7 @@ arg_2		= byte ptr  6
 
 		enter	2, 0
 		mov	al, 1
-		sub	al, byte ptr word_F828+1
+		sub	al, _music_page
 		mov	[bp+var_1], al
 		graph_accesspage al
 		push	10h
@@ -1638,7 +1638,7 @@ arg_2		= byte ptr  6
 		mov	bx, ax
 		pushd	_MUSIC_TITLES[bx]
 		call	graph_putsa_fx
-		graph_accesspage byte ptr word_F828+1
+		graph_accesspage _music_page
 		push	10h
 		mov	al, [bp+arg_2]
 		mov	ah, 0
@@ -1701,103 +1701,7 @@ loc_A5AD:
 		retn	2
 sub_A590	endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_A5B7	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	7D00h
-		call	hmem_allocbyte
-		mov	word_F82A, ax
-		xor	si, si
-		jmp	short loc_A5DF
-; ---------------------------------------------------------------------------
-
-loc_A5CA:
-		les	bx, _VRAM_PLANE_B
-		add	bx, si
-		mov	eax, es:[bx]
-		mov	es, word_F82A
-		mov	es:[si], eax
-		add	si, 4
-
-loc_A5DF:
-		cmp	si, 7D00h
-		jl	short loc_A5CA
-		pop	si
-		pop	bp
-		retn
-sub_A5B7	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_A5E8	proc near
-		push	bp
-		mov	bp, sp
-		push	word_F82A
-		call	hmem_free
-		pop	bp
-		retn
-sub_A5E8	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_A5F6	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	di
-		push	ds
-		mov	ax, 0A800h
-		mov	es, ax
-		assume es:nothing
-		mov	ax, word_F82A
-		mov	ds, ax
-		xor	di, di
-		xor	si, si
-		mov	cx, 3E80h
-		rep movsw
-		pop	ds
-		pop	di
-		pop	si
-		pop	bp
-		retn
-sub_A5F6	endp
-
-include th02/music/polygons.asm
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_A899	proc near
-		push	bp
-		mov	bp, sp
-		call	sub_A5F6
-		call	grcg_setcolor pascal, ((GC_RMW or GC_B) shl 16) + 15
-		call	polygons_update_and_render
-		call	grcg_off
-		graph_showpage byte ptr word_F828+1
-		mov	al, 1
-		sub	al, byte ptr word_F828+1
-		mov	byte ptr word_F828+1, al
-		graph_accesspage al
-		push	1
-		call	frame_delay_2
-		pop	bp
-		retn
-sub_A899	endp
-
+include th02/music/music.asm
 
 ; =============== S U B	R O U T	I N E =======================================
 
@@ -2098,7 +2002,7 @@ sub_AB99	proc near
 		push	si
 		push	di
 		call	music_cmt_load pascal, [bp+@@track]
-		call	sub_A5F6
+		call	screen_back_B_put
 		call	sub_AA7C
 		push	1300040h
 		push	1Fh
@@ -2134,7 +2038,7 @@ loc_ABE5:
 		les	bx, _VRAM_PLANE_B
 		add	bx, si
 		mov	eax, es:[bx]
-		mov	es, word_F82A
+		mov	es, _screen_back_B
 		mov	es:[si], eax
 		add	si, 4
 
@@ -2169,7 +2073,7 @@ loc_AC15:
 		jl	short loc_AC0E
 		call	super_free
 		call	text_clear
-		mov	byte ptr word_F828+1, 1
+		mov	_music_page, 1
 		mov	PaletteTone, 0
 		call	far ptr	palette_show
 		graph_showpage 0
@@ -2181,14 +2085,14 @@ loc_AC15:
 		call	pi_slot_put pascal, large 0, 0
 		freePISlotLarge	0
 		mov	al, music_track_playing
-		mov	byte ptr word_F828, al
-		push	word_F828
+		mov	_music_sel, al
+		push	word ptr _music_sel
 		call	sub_A590
 		push	0
 		call	graph_copy_page
 		graph_accesspage 1
 		graph_showpage 0
-		call	sub_A5B7
+		call	screen_back_B_snap
 		call	sub_A8CF
 		graph_accesspage 1
 		mov	al, music_track_playing
@@ -2205,7 +2109,7 @@ loc_ACC2:
 		call	input_mode_interface
 		cmp	_input_sp, INPUT_NONE
 		jz	short loc_ACD3
-		call	sub_A899
+		call	music_flip
 		jmp	short loc_ACC2
 ; ---------------------------------------------------------------------------
 
@@ -2213,50 +2117,50 @@ loc_ACD3:
 		call	input_mode_interface
 		test	_input_sp.lo, low INPUT_UP
 		jz	short loc_AD0E
-		push	word_F828
+		push	word ptr _music_sel
 		push	3
 		call	sub_A51E
-		cmp	byte ptr word_F828, 0
+		cmp	_music_sel, 0
 		jbe	short loc_ACF5
-		dec	byte ptr word_F828
+		dec	_music_sel
 		jmp	short loc_ACFA
 ; ---------------------------------------------------------------------------
 
 loc_ACF5:
-		mov	byte ptr word_F828, 14h
+		mov	_music_sel, 14h
 
 loc_ACFA:
-		cmp	byte ptr word_F828, 13h
+		cmp	_music_sel, 13h
 		jnz	short loc_AD05
-		dec	byte ptr word_F828
+		dec	_music_sel
 
 loc_AD05:
-		push	word_F828
+		push	word ptr _music_sel
 		push	0Fh
 		call	sub_A51E
 
 loc_AD0E:
 		test	_input_sp.lo, low INPUT_DOWN
 		jz	short loc_AD44
-		push	word_F828
+		push	word ptr _music_sel
 		push	3
 		call	sub_A51E
-		cmp	byte ptr word_F828, 14h
+		cmp	_music_sel, 14h
 		jnb	short loc_AD2B
-		inc	byte ptr word_F828
+		inc	_music_sel
 		jmp	short loc_AD30
 ; ---------------------------------------------------------------------------
 
 loc_AD2B:
-		mov	byte ptr word_F828, 0
+		mov	_music_sel, 0
 
 loc_AD30:
-		cmp	byte ptr word_F828, 13h
+		cmp	_music_sel, 13h
 		jnz	short loc_AD3B
-		inc	byte ptr word_F828
+		inc	_music_sel
 
 loc_AD3B:
-		push	word_F828
+		push	word ptr _music_sel
 		push	0Fh
 		call	sub_A51E
 
@@ -2267,11 +2171,11 @@ loc_AD44:
 		jz	short loc_AD9A
 
 loc_AD52:
-		cmp	byte ptr word_F828, 14h
+		cmp	_music_sel, 14h
 		jz	short loc_ADB0
 		kajacall	KAJA_SONG_STOP
 		push	SND_LOAD_SONG
-		mov	al, byte ptr word_F828
+		mov	al, _music_sel
 		mov	ah, 0
 		shl	ax, 2
 		mov	bx, ax
@@ -2279,12 +2183,12 @@ loc_AD52:
 		call	snd_load
 		add	sp, 6
 		kajacall	KAJA_SONG_PLAY
-		mov	al, byte ptr word_F828
+		mov	al, _music_sel
 		mov	music_track_playing, al
 		mov	ah, 0
 		call	sub_AB99 pascal, ax
-		call	sub_A899
-		mov	al, byte ptr word_F828
+		call	music_flip
+		mov	al, _music_sel
 		mov	ah, 0
 		call	sub_AB99 pascal, ax
 
@@ -2293,7 +2197,7 @@ loc_AD9A:
 		jnz	short loc_ADB0
 		cmp	_input_sp, INPUT_NONE
 		jnz	loc_ACC2
-		call	sub_A899
+		call	music_flip
 		jmp	loc_ACD3
 ; ---------------------------------------------------------------------------
 
@@ -2301,12 +2205,12 @@ loc_ADB0:
 		call	input_mode_interface
 		cmp	_input_sp, INPUT_NONE
 		jz	short loc_ADC1
-		call	sub_A899
+		call	music_flip
 		jmp	short loc_ADB0
 ; ---------------------------------------------------------------------------
 
 loc_ADC1:
-		call	sub_A5E8
+		call	screen_back_B_free
 		call	sub_AA53
 		graph_showpage 0
 		graph_accesspage al
@@ -4943,9 +4847,9 @@ include th03/hardware/input[bss].asm
 include th03/formats/cdg[bss].asm
 include th02/formats/pi_slots[bss].asm
 include th03/formats/hfliplut[bss].asm
-include th02/music/polygons[bss].asm
-word_F828	dw ?
-word_F82A	dw ?
+include th02/music/music[bss].asm
+public _screen_back_B
+_screen_back_B	dw ?
 unk_F82C	db    ?	;
 		db    ?	;
 word_F82E	dw ?
diff --git a/th04_op.asm b/th04_op.asm
index 47452989..707b3106 100644
--- a/th04_op.asm
+++ b/th04_op.asm
@@ -2608,7 +2608,7 @@ arg_2		= byte ptr  6
 
 		enter	2, 0
 		mov	al, 1
-		sub	al, byte ptr word_12DBC+1
+		sub	al, _music_page
 		mov	[bp+var_1], al
 		graph_accesspage al
 		push	10h
@@ -2626,7 +2626,7 @@ arg_2		= byte ptr  6
 		mov	bx, ax
 		pushd	_MUSIC_TITLES[bx]
 		call	graph_putsa_fx
-		graph_accesspage byte ptr word_12DBC+1
+		graph_accesspage _music_page
 		push	10h
 		mov	al, [bp+arg_2]
 		mov	ah, 0
@@ -2688,103 +2688,7 @@ loc_BF5E:
 		retn	2
 sub_BF41	endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_BF68	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	7D00h
-		call	hmem_allocbyte
-		mov	word_12DC0, ax
-		xor	si, si
-		jmp	short loc_BF90
-; ---------------------------------------------------------------------------
-
-loc_BF7B:
-		les	bx, _VRAM_PLANE_B
-		add	bx, si
-		mov	eax, es:[bx]
-		mov	es, word_12DC0
-		mov	es:[si], eax
-		add	si, 4
-
-loc_BF90:
-		cmp	si, 7D00h
-		jl	short loc_BF7B
-		pop	si
-		pop	bp
-		retn
-sub_BF68	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_BF99	proc near
-		push	bp
-		mov	bp, sp
-		push	word_12DC0
-		call	hmem_free
-		pop	bp
-		retn
-sub_BF99	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_BFA7	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	di
-		push	ds
-		mov	ax, GRAM_400
-		mov	es, ax
-		assume es:nothing
-		mov	ax, word_12DC0
-		mov	ds, ax
-		xor	di, di
-		xor	si, si
-		mov	cx, (ROW_SIZE * RES_Y) / 2
-		rep movsw
-		pop	ds
-		pop	di
-		pop	si
-		pop	bp
-		retn
-sub_BFA7	endp
-
-include th02/music/polygons.asm
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_C244	proc near
-		push	bp
-		mov	bp, sp
-		call	sub_BFA7
-		call	grcg_setcolor pascal, ((GC_RMW or GC_B) shl 16) + 15
-		call	polygons_update_and_render
-		GRCG_OFF_CLOBBERING dx
-		graph_showpage byte ptr word_12DBC+1
-		mov	al, 1
-		sub	al, byte ptr word_12DBC+1
-		mov	byte ptr word_12DBC+1, al
-		graph_accesspage al
-		push	1
-		call	frame_delay_2
-		pop	bp
-		retn
-sub_C244	endp
-
+include th02/music/music.asm
 include th02/music/music_cmt_load.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -2848,9 +2752,9 @@ sub_C30E	proc near
 loc_C317:
 		mov	_graph_putsa_fx_func, si
 		call	sub_C2C4
-		call	sub_C244
+		call	music_flip
 		call	sub_C2C4
-		call	sub_C244
+		call	music_flip
 		inc	si
 
 loc_C328:
@@ -2858,7 +2762,7 @@ loc_C328:
 		jl	short loc_C317
 		mov	_graph_putsa_fx_func, 2
 		call	sub_C2C4
-		call	sub_C244
+		call	music_flip
 		call	sub_C2C4
 		pop	si
 		pop	bp
@@ -2877,7 +2781,7 @@ sub_C33F	proc near
 		push	1400040h
 		push	1400140h
 		call	sub_E4F8
-		call	sub_C244
+		call	music_flip
 		push	1400040h
 		push	1400140h
 		call	sub_E4F8
@@ -2902,7 +2806,7 @@ sub_C36F	proc near
 
 loc_C37C:
 		call	music_cmt_load pascal, [bp+@@track]
-		call	sub_BFA7
+		call	screen_back_B_put
 		push	1400040h
 		push	1400140h
 		call	sub_E4F8
@@ -2915,11 +2819,11 @@ loc_C37C:
 loc_C3A2:
 		mov	byte_12DBE, 1
 		call	sub_C2C4
-		call	sub_C244
+		call	music_flip
 		call	sub_C2C4
 
 loc_C3B0:
-		call	sub_BFA7
+		call	screen_back_B_put
 		pop	bp
 		retn	2
 sub_C36F	endp
@@ -2935,7 +2839,7 @@ sub_C3B7	proc near
 		mov	byte_12DBE, 0
 		call	cdg_freeall
 		call	text_clear
-		mov	byte ptr word_12DBC+1, 1
+		mov	_music_page, 1
 		mov	PaletteTone, 0
 		call	far ptr	palette_show
 		graph_showpage 0
@@ -2947,15 +2851,15 @@ sub_C3B7	proc near
 		call	pi_slot_put pascal, large 0, 0
 		freePISlotLarge	0
 		mov	al, music_track_playing
-		mov	byte ptr word_12DBC, al
-		push	word_12DBC
+		mov	_music_sel, al
+		push	word ptr _music_sel
 		call	sub_BF41
 		push	0
 		call	graph_copy_page
 		call	sub_E428
 		graph_accesspage 1
 		graph_showpage 0
-		call	sub_BF68
+		call	screen_back_B_snap
 		mov	al, music_track_playing
 		mov	ah, 0
 		call	sub_C36F pascal, ax
@@ -2966,7 +2870,7 @@ loc_C454:
 		call	far ptr	_input_reset_sense
 		cmp	_key_det, INPUT_NONE
 		jz	short loc_C465
-		call	sub_C244
+		call	music_flip
 		jmp	short loc_C454
 ; ---------------------------------------------------------------------------
 
@@ -2974,50 +2878,50 @@ loc_C465:
 		call	far ptr	_input_reset_sense
 		test	_key_det.lo, low INPUT_UP
 		jz	short loc_C4A0
-		push	word_12DBC
+		push	word ptr _music_sel
 		push	5
 		call	sub_BED5
-		cmp	byte ptr word_12DBC, 0
+		cmp	_music_sel, 0
 		jbe	short loc_C487
-		dec	byte ptr word_12DBC
+		dec	_music_sel
 		jmp	short loc_C48C
 ; ---------------------------------------------------------------------------
 
 loc_C487:
-		mov	byte ptr word_12DBC, 17h
+		mov	_music_sel, 17h
 
 loc_C48C:
-		cmp	byte ptr word_12DBC, 16h
+		cmp	_music_sel, 16h
 		jnz	short loc_C497
-		dec	byte ptr word_12DBC
+		dec	_music_sel
 
 loc_C497:
-		push	word_12DBC
+		push	word ptr _music_sel
 		push	3
 		call	sub_BED5
 
 loc_C4A0:
 		test	_key_det.lo, low INPUT_DOWN
 		jz	short loc_C4D6
-		push	word_12DBC
+		push	word ptr _music_sel
 		push	5
 		call	sub_BED5
-		cmp	byte ptr word_12DBC, 17h
+		cmp	_music_sel, 17h
 		jnb	short loc_C4BD
-		inc	byte ptr word_12DBC
+		inc	_music_sel
 		jmp	short loc_C4C2
 ; ---------------------------------------------------------------------------
 
 loc_C4BD:
-		mov	byte ptr word_12DBC, 0
+		mov	_music_sel, 0
 
 loc_C4C2:
-		cmp	byte ptr word_12DBC, 16h
+		cmp	_music_sel, 16h
 		jnz	short loc_C4CD
-		inc	byte ptr word_12DBC
+		inc	_music_sel
 
 loc_C4CD:
-		push	word_12DBC
+		push	word ptr _music_sel
 		push	3
 		call	sub_BED5
 
@@ -3028,14 +2932,14 @@ loc_C4D6:
 		jz	short loc_C51D
 
 loc_C4E4:
-		cmp	byte ptr word_12DBC, 17h
+		cmp	_music_sel, 17h
 		jz	short loc_C533
 		kajacall	KAJA_SONG_FADE, 32
-		mov	al, byte ptr word_12DBC
+		mov	al, _music_sel
 		mov	music_track_playing, al
 		mov	ah, 0
 		call	sub_C36F pascal, ax
-		mov	al, byte ptr word_12DBC
+		mov	al, _music_sel
 		mov	ah, 0
 		shl	ax, 2
 		mov	bx, ax
@@ -3047,7 +2951,7 @@ loc_C51D:
 		jnz	short loc_C533
 		cmp	_key_det, INPUT_NONE
 		jnz	loc_C454
-		call	sub_C244
+		call	music_flip
 		jmp	loc_C465
 ; ---------------------------------------------------------------------------
 
@@ -3055,13 +2959,13 @@ loc_C533:
 		call	far ptr	_input_reset_sense
 		cmp	_key_det, INPUT_NONE
 		jz	short loc_C544
-		call	sub_C244
+		call	music_flip
 		jmp	short loc_C533
 ; ---------------------------------------------------------------------------
 
 loc_C544:
 		kajacall	KAJA_SONG_FADE, 16
-		call	sub_BF99
+		call	screen_back_B_free
 		graph_showpage 0
 		graph_accesspage al
 		push	1
@@ -6056,11 +5960,11 @@ include th04/zunsoft[bss].asm
 		dd    ?	;
 		dd    ?	;
 		dd    ?	;
-include th02/music/polygons[bss].asm
-word_12DBC	dw ?
+include th02/music/music[bss].asm
 byte_12DBE	db ?
 		db    ?	;
-word_12DC0	dw ?
+public _screen_back_B
+_screen_back_B	dw ?
 		dd    ?	;
 		dd    ?	;
 		dd    ?	;
diff --git a/th05_op.asm b/th05_op.asm
index 35701f55..0beaeb0c 100644
--- a/th05_op.asm
+++ b/th05_op.asm
@@ -3043,104 +3043,7 @@ loc_BF6B:
 		retn	2
 sub_BF4D	endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_BFB7	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	7D00h
-		call	hmem_allocbyte
-		mov	word_13E98, ax
-		xor	si, si
-		jmp	short loc_BFDF
-; ---------------------------------------------------------------------------
-
-loc_BFCA:
-		les	bx, _VRAM_PLANE_B
-		add	bx, si
-		mov	eax, es:[bx]
-		mov	es, word_13E98
-		mov	es:[si], eax
-		add	si, 4
-
-loc_BFDF:
-		cmp	si, 7D00h
-		jl	short loc_BFCA
-		pop	si
-		pop	bp
-		retn
-sub_BFB7	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_BFE8	proc near
-		push	bp
-		mov	bp, sp
-		push	word_13E98
-		call	hmem_free
-		pop	bp
-		retn
-sub_BFE8	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_BFF6	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	di
-		push	ds
-		mov	ax, GRAM_400
-		mov	es, ax
-		assume es:nothing
-		mov	ax, word_13E98
-		mov	ds, ax
-		xor	di, di
-		xor	si, si
-		mov	cx, (ROW_SIZE * RES_Y) / 2
-		rep movsw
-		pop	ds
-		pop	di
-		pop	si
-		pop	bp
-		retn
-sub_BFF6	endp
-
-include th02/music/polygons.asm
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_C293	proc near
-		push	bp
-		mov	bp, sp
-		call	sub_BFF6
-		call	_piano_render
-		call	grcg_setcolor pascal, ((GC_RMW or GC_B) shl 16) + 15
-		call	polygons_update_and_render
-		GRCG_OFF_CLOBBERING dx
-		push	1
-		call	frame_delay
-		graph_showpage byte ptr word_13E94+1
-		mov	al, 1
-		sub	al, byte ptr word_13E94+1
-		mov	byte ptr word_13E94+1, al
-		graph_accesspage al
-		pop	bp
-		retn
-sub_C293	endp
-
+include th02/music/music.asm
 include th05/music/music_cmt_load.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -3202,9 +3105,9 @@ sub_C376	proc near
 loc_C37F:
 		mov	_graph_putsa_fx_func, si
 		call	sub_C32D
-		call	sub_C293
+		call	music_flip
 		call	sub_C32D
-		call	sub_C293
+		call	music_flip
 		inc	si
 
 loc_C390:
@@ -3212,7 +3115,7 @@ loc_C390:
 		jl	short loc_C37F
 		mov	_graph_putsa_fx_func, 2
 		call	sub_C32D
-		call	sub_C293
+		call	music_flip
 		call	sub_C32D
 		pop	si
 		pop	bp
@@ -3234,7 +3137,7 @@ sub_C3A7	proc near
 		push	14000B4h
 		push	1400090h
 		call	sub_DB3C
-		call	sub_C293
+		call	music_flip
 		push	1400020h
 		push	1400010h
 		call	sub_DB3C
@@ -3262,7 +3165,7 @@ sub_C3F9	proc near
 
 loc_C406:
 		call	music_cmt_load pascal, [bp+@@track]
-		call	sub_BFF6
+		call	screen_back_B_put
 		push	1400040h
 		push	1400100h
 		call	sub_DB3C
@@ -3275,11 +3178,11 @@ loc_C406:
 loc_C42C:
 		mov	byte_13E96, 1
 		call	sub_C32D
-		call	sub_C293
+		call	music_flip
 		call	sub_C32D
 
 loc_C43A:
-		call	sub_BFF6
+		call	screen_back_B_put
 		pop	bp
 		retn	2
 sub_C3F9	endp
@@ -3305,7 +3208,7 @@ arg_0		= word ptr  4
 		call	sub_DB3C
 		push	si
 		call	sub_BF4D
-		call	sub_C293
+		call	music_flip
 		pushd	20h ; ' '
 		push	1400010h
 		call	sub_DB3C
@@ -3333,7 +3236,7 @@ var_1		= byte ptr -1
 		xor	si, si
 		mov	word_1403A, 0
 		mov	word_1403C, 0
-		mov	byte ptr word_13E94, 0
+		mov	_music_sel, 0
 		mov	bx, music_game
 		add	bx, bx
 		mov	ax, MUSICROOM_TRACKCOUNTS[bx]
@@ -3341,7 +3244,7 @@ var_1		= byte ptr -1
 		mov	byte_13E96, 0
 		call	cdg_freeall
 		call	text_clear
-		mov	byte ptr word_13E94+1, 1
+		mov	_music_page, 1
 		mov	PaletteTone, 0
 		call	far ptr	palette_show
 		graph_showpage 0
@@ -3353,9 +3256,9 @@ var_1		= byte ptr -1
 		call	pi_slot_put pascal, large 0, 0
 		call	pi_slot_free pascal, 0
 		call	_piano_setup
-		call	sub_BFB7
+		call	screen_back_B_snap
 		call	sub_D688
-		push	word_13E94
+		push	word ptr _music_sel
 		call	sub_BF4D
 		push	0
 		call	graph_copy_page
@@ -3365,7 +3268,7 @@ var_1		= byte ptr -1
 		push	ds
 		push	offset aMusic_dat ; "music.dat"
 		call	pfstart
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		call	sub_C3F9 pascal, ax
 		mov	PaletteTone, 64h ; 'd'
@@ -3389,7 +3292,7 @@ loc_C574:
 
 loc_C579:
 		inc	si
-		call	sub_C293
+		call	music_flip
 		jmp	short loc_C555
 ; ---------------------------------------------------------------------------
 
@@ -3397,16 +3300,16 @@ loc_C57F:
 		call	_input_reset_sense_held
 		test	_key_det.lo, low INPUT_UP
 		jz	short loc_C5EB
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	[bp+var_1], al
-		cmp	byte ptr word_13E94, 0
+		cmp	_music_sel, 0
 		jbe	short loc_C5D5
-		dec	byte ptr word_13E94
-		mov	al, byte ptr word_13E94
+		dec	_music_sel
+		mov	al, _music_sel
 		mov	ah, 0
 		cmp	ax, word_1403A
 		jge	short loc_C5AE
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		jmp	short loc_C61C
 ; ---------------------------------------------------------------------------
@@ -3415,14 +3318,14 @@ loc_C5AE:
 		push	word ptr [bp+var_1]
 		push	0
 		call	sub_BE79
-		push	word_13E94
+		push	word ptr _music_sel
 		push	1
 		call	sub_BE79
-		call	sub_C293
+		call	music_flip
 		push	word ptr [bp+var_1]
 		push	0
 		call	sub_BE79
-		push	word_13E94
+		push	word ptr _music_sel
 		push	1
 		call	sub_BE79
 		jmp	short loc_C5EB
@@ -3430,7 +3333,7 @@ loc_C5AE:
 
 loc_C5D5:
 		mov	al, byte ptr musicroom_trackcount
-		mov	byte ptr word_13E94, al
+		mov	_music_sel, al
 		mov	ax, musicroom_trackcount
 		add	ax, 0FFF5h
 		mov	word_1403A, ax
@@ -3440,25 +3343,25 @@ loc_C5D5:
 loc_C5EB:
 		test	_key_det.lo, low INPUT_DOWN
 		jz	short loc_C666
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	[bp+var_1], al
 		mov	ah, 0
 		cmp	ax, musicroom_trackcount
 		jge	short loc_C652
-		inc	byte ptr word_13E94
-		mov	al, byte ptr word_13E94
+		inc	_music_sel
+		mov	al, _music_sel
 		mov	ah, 0
 		mov	dx, word_1403A
 		add	dx, 0Ch
 		cmp	ax, dx
 		jl	short loc_C62B
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		add	ax, 0FFF5h
 
 loc_C61C:
 		mov	word_1403A, ax
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		push	ax
 		call	sub_C441
@@ -3469,23 +3372,23 @@ loc_C62B:
 		push	word ptr [bp+var_1]
 		push	0
 		call	sub_BE79
-		push	word_13E94
+		push	word ptr _music_sel
 		push	1
 		call	sub_BE79
-		call	sub_C293
+		call	music_flip
 		push	word ptr [bp+var_1]
 		push	0
 		call	sub_BE79
-		push	word_13E94
+		push	word ptr _music_sel
 		push	1
 		call	sub_BE79
 		jmp	short loc_C666
 ; ---------------------------------------------------------------------------
 
 loc_C652:
-		mov	byte ptr word_13E94, 0
+		mov	_music_sel, 0
 		mov	word_1403A, 0
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		push	ax
 		call	sub_C441
@@ -3509,7 +3412,7 @@ loc_C680:
 		mov	music_game, 0
 
 loc_C698:
-		mov	byte ptr word_13E94, 0
+		mov	_music_sel, 0
 		mov	word_1403C, 0
 		mov	word_1403A, 0
 		mov	bx, music_game
@@ -3532,35 +3435,35 @@ loc_C6E3:
 		jz	short loc_C767
 
 loc_C6F1:
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		cmp	ax, musicroom_trackcount
 		jz	loc_C77F
 		kajacall	KAJA_SONG_FADE, 32
 		mov	al, byte ptr word_1403C
 		mov	[bp+var_1], al
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		mov	word_1403C, ax
 		push	word ptr [bp+var_1]
 		push	0
 		call	sub_BE79
-		push	word_13E94
+		push	word ptr _music_sel
 		push	1
 		call	sub_BE79
-		call	sub_C293
+		call	music_flip
 		push	word ptr [bp+var_1]
 		push	0
 		call	sub_BE79
-		push	word_13E94
+		push	word ptr _music_sel
 		push	1
 		call	sub_BE79
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		call	sub_C3F9 pascal, ax
 		mov	bx, music_game
 		imul	bx, 78h
-		mov	al, byte ptr word_13E94
+		mov	al, _music_sel
 		mov	ah, 0
 		shl	ax, 2
 		add	bx, ax
@@ -3573,7 +3476,7 @@ loc_C767:
 		cmp	_key_det, INPUT_NONE
 		jnz	loc_C555
 		xor	si, si
-		call	sub_C293
+		call	music_flip
 		jmp	loc_C57F
 ; ---------------------------------------------------------------------------
 
@@ -3581,7 +3484,7 @@ loc_C77F:
 		call	_input_reset_sense_held
 		cmp	_key_det, INPUT_NONE
 		jz	short loc_C790
-		call	sub_C293
+		call	music_flip
 		jmp	short loc_C77F
 ; ---------------------------------------------------------------------------
 
@@ -3591,7 +3494,7 @@ loc_C790:
 		push	offset aKaikidan1_dat1
 		call	pfstart
 		kajacall	KAJA_SONG_FADE, 16
-		call	sub_BFE8
+		call	screen_back_B_free
 		graph_showpage 0
 		graph_accesspage al
 		push	1
@@ -6336,11 +6239,11 @@ include th04/zunsoft[bss].asm
 		dd    ?	;
 		dd    ?	;
 		dd    ?	;
-include th02/music/polygons[bss].asm
-word_13E94	dw ?
+include th02/music/music[bss].asm
 byte_13E96	db ?
 		db ?
-word_13E98	dw ?
+public _screen_back_B
+_screen_back_B	dw ?
 		dd    ?	;
 		dd    ?	;
 		dd    ?	;