diff --git a/th04/main/tile/bb.hpp b/th04/main/tile/bb.hpp
new file mode 100644
index 00000000..e5ef7ae5
--- /dev/null
+++ b/th04/main/tile/bb.hpp
@@ -0,0 +1,3 @@
+// Fills the playfield tile starting at (⌊left/8⌋*8, top) with the current
+// GRCG tile. Assumes that the GRCG is set to TDW mode.
+void fastcall near grcg_tile_bb_put_8(screen_x_t left, vram_y_t top);
diff --git a/th04/main/tile/bb_put.asm b/th04/main/tile/bb_put.asm
new file mode 100644
index 00000000..52e2cee7
--- /dev/null
+++ b/th04/main/tile/bb_put.asm
@@ -0,0 +1,46 @@
+public @grcg_tile_bb_put_8
+@grcg_tile_bb_put_8 proc near
+	@@left	equ <ax>
+	@@top 	equ <dx>
+
+	@@rows_after_roll	equ <bx>
+
+	push	di
+	mov	@@rows_after_roll, @@top
+	sar	@@left, 3
+	shl	@@top, 6
+	add	@@left, @@top
+	shr	@@top, 2
+	add	@@left, @@top
+	mov	di, @@left
+	mov	ax, GRAM_400
+	mov	es, ax
+	assume es:nothing
+	cmp	bx, PLAYFIELD_BOTTOM
+	ja	short @@roll_needed
+	mov	cx, TILE_H
+	xor	@@rows_after_roll, @@rows_after_roll
+	jmp	short @@row_loop
+; ---------------------------------------------------------------------------
+
+@@roll_needed:
+	mov	cx, RES_Y
+	sub	cx, @@rows_after_roll
+	mov	@@rows_after_roll, TILE_H
+	sub	@@rows_after_roll, cx
+
+@@row_loop:
+	stosw
+	add	di, (ROW_SIZE - TILE_VRAM_W)
+	loop	@@row_loop
+	or	@@rows_after_roll, @@rows_after_roll
+	jz	short @@ret
+	sub	di, PLANE_SIZE
+	xchg	cx, @@rows_after_roll
+	jmp	short @@row_loop
+; ---------------------------------------------------------------------------
+
+@@ret:
+	pop	di
+	retn
+@grcg_tile_bb_put_8 endp
diff --git a/th04_main.asm b/th04_main.asm
index 69a3aa7b..68d1c495 100644
--- a/th04_main.asm
+++ b/th04_main.asm
@@ -1740,7 +1740,7 @@ loc_BF48:
 		sub	dx, RES_Y
 
 loc_BF62:
-		call	main_01:sub_11FC8
+		call	@grcg_tile_bb_put_8
 
 loc_BF65:
 		shl	[bp+var_1], 1
@@ -10879,51 +10879,7 @@ sub_11ECB	endp
 
 include th03/formats/cfg_lres.asm
 		db    0
-
-; =============== S U B	R O U T	I N E =======================================
-
-
-sub_11FC8	proc near
-		push	di
-		mov	bx, dx
-		sar	ax, 3
-		shl	dx, 6
-		add	ax, dx
-		shr	dx, 2
-		add	ax, dx
-		mov	di, ax
-		mov	ax, GRAM_400
-		mov	es, ax
-		assume es:nothing
-		cmp	bx, PLAYFIELD_BOTTOM
-		ja	short loc_11FEC
-		mov	cx, TILE_H
-		xor	bx, bx
-		jmp	short loc_11FF6
-; ---------------------------------------------------------------------------
-
-loc_11FEC:
-		mov	cx, RES_Y
-		sub	cx, bx
-		mov	bx, TILE_H
-		sub	bx, cx
-
-loc_11FF6:
-		stosw
-		add	di, (ROW_SIZE - word)
-		loop	loc_11FF6
-		or	bx, bx
-		jz	short loc_12008
-		sub	di, PLANE_SIZE
-		xchg	cx, bx
-		jmp	short loc_11FF6
-; ---------------------------------------------------------------------------
-
-loc_12008:
-		pop	di
-		retn
-sub_11FC8	endp
-
+include th04/main/tile/bb_put.asm
 
 ; =============== S U B	R O U T	I N E =======================================
 
diff --git a/th05_main.asm b/th05_main.asm
index ba51c22a..a898f499 100644
--- a/th05_main.asm
+++ b/th05_main.asm
@@ -2867,51 +2867,7 @@ bomb_yuuka	endp
 		db    0
 
 include th05/formats/bb_playchar.asm
-
-; =============== S U B	R O U T	I N E =======================================
-
-
-sub_CE80	proc near
-		push	di
-		mov	bx, dx
-		sar	ax, 3
-		shl	dx, 6
-		add	ax, dx
-		shr	dx, 2
-		add	ax, dx
-		mov	di, ax
-		mov	ax, GRAM_400
-		mov	es, ax
-		assume es:nothing
-		cmp	bx, PLAYFIELD_BOTTOM
-		ja	short loc_CEA4
-		mov	cx, TILE_H
-		xor	bx, bx
-		jmp	short loc_CEAE
-; ---------------------------------------------------------------------------
-
-loc_CEA4:
-		mov	cx, RES_Y
-		sub	cx, bx
-		mov	bx, TILE_H
-		sub	bx, cx
-
-loc_CEAE:
-		stosw
-		add	di, (ROW_SIZE - word)
-		loop	loc_CEAE
-		or	bx, bx
-		jz	short loc_CEC0
-		sub	di, PLANE_SIZE
-		xchg	cx, bx
-		jmp	short loc_CEAE
-; ---------------------------------------------------------------------------
-
-loc_CEC0:
-		pop	di
-		retn
-sub_CE80	endp
-
+include th04/main/tile/bb_put.asm
 
 ; =============== S U B	R O U T	I N E =======================================
 
@@ -3962,7 +3918,7 @@ loc_DF7F:
 		sub	dx, RES_Y
 
 loc_DF89:
-		call	sub_CE80
+		call	@grcg_tile_bb_put_8
 
 loc_DF8C:
 		shl	[bp+var_1], 1