diff --git a/Makefile.mak b/Makefile.mak
index e343f03a..1477bf23 100644
--- a/Makefile.mak
+++ b/Makefile.mak
@@ -38,6 +38,9 @@ bin\th01\zunsoft.com: th01\zunsoft.c
 # ---------------------------------
 bin\frmdely2.obj: th02\frmdely2.c
 	$(CC) $(CFLAGS) -ml -n$(@D) -c $**
+
+bin\hfliplut.obj: th03\hfliplut.c
+	$(CC) $(CFLAGS) -ml -n$(@D) -c $**
 # ---------------------------------
 
 bin\th01\op.exe: bin\piloadc.obj bin\th01\op.obj th01\op_01.cpp th01\op_02.c th01\op_03.c th01\op_04.c th01\op_05.c th01\op_06.cpp th01\op_07.cpp th01\op_08.c th01\op_09.cpp th01\op_10.c th01\op_11.c th01\op_12.cpp
@@ -80,7 +83,7 @@ bin\th03\res_yume.com: th03\res_yume.cpp
 $**
 | masters.lib
 
-bin\th03\op.exe: bin\th03\op.obj bin\frmdely2.obj
+bin\th03\op.exe: bin\th03\op.obj bin\hfliplut.obj bin\frmdely2.obj
 	$(CC) $(CFLAGS) -ml -DGAME=3 -nbin\th03\ -eOP.EXE @&&|
 $**
 |
@@ -90,6 +93,11 @@ bin\th03\main.exe: bin\th03\main.obj th03\main_01.cpp th03\sprite16.cpp
 $**
 |
 
+bin\th03\mainl.exe: bin\th03\mainl.obj bin\hfliplut.obj
+	$(CC) $(CFLAGS) -ml -DGAME=3 -nbin\th03\ -eMAINL.EXE @&&|
+$**
+|
+
 bin\th04\res_huma.com: th04\res_huma.cpp
 	$(CC) $(CFLAGS) -mt -lt -Z -DGAME=4 -nbin\th04\ -eRES_HUMA.COM @&&|
 $**
@@ -100,26 +108,36 @@ bin\th04\op.exe: bin\th04\op.obj th04\op_01.cpp bin\frmdely2.obj
 $**
 |
 
-bin\th04\main.exe: bin\th04\main.obj bin\th04\scoreupd.obj th04\main011.cpp th04\main032.cpp
+bin\th04\main.exe: bin\th04\main.obj bin\th04\scoreupd.obj th04\main011.cpp bin\hfliplut.obj th04\main032.cpp
 	$(CC) $(CFLAGS) -ml -DGAME=4 -DBINARY='M' -3 -Z -nbin\th04\ -eMAIN.EXE @&&|
 $**
 |
 
+bin\th04\maine.exe: bin\th04\maine.obj bin\hfliplut.obj
+	$(CC) $(CFLAGS) -ml -DGAME=4 -DBINARY='E' -nbin\th04\ -eMAINE.EXE @&&|
+$**
+|
+
 bin\th05\res_kso.com: th05\res_kso.cpp
 	$(CC) $(CFLAGS) -mt -lt -Z -DGAME=5 -nbin\th05\ -eRES_KSO.COM @&&|
 $**
 | masters.lib
 
-bin\th05\op.exe: bin\th05\op.obj th05\op_01.cpp
+bin\th05\op.exe: bin\th05\op.obj th05\op_01.cpp bin\hfliplut.obj
 	$(CC) $(CFLAGS) -ml -DGAME=5 -DBINARY='O' -nbin\th05\ -eOP.EXE @&&|
 $**
 |
 
-bin\th05\main.exe: bin\th05\main.obj th05\main010.cpp th05\main011.cpp th05\p_common.cpp th05\p_reimu.cpp th05\p_marisa.cpp th05\p_mima.cpp th05\p_yuuka.cpp bin\th05\player.obj bin\th05\hud_bar.obj bin\th05\scoreupd.obj th05\main012.cpp th05\main013.cpp  bin\th05\bullet.obj th05\main031.cpp th05\main032.cpp th05\main033.cpp th05\main034.cpp
+bin\th05\main.exe: bin\th05\main.obj th05\main010.cpp th05\main011.cpp th05\p_common.cpp th05\p_reimu.cpp th05\p_marisa.cpp th05\p_mima.cpp th05\p_yuuka.cpp bin\th05\player.obj bin\th05\hud_bar.obj bin\th05\scoreupd.obj th05\main012.cpp th05\main013.cpp bin\hfliplut.obj bin\th05\bullet.obj th05\main031.cpp th05\main032.cpp th05\main033.cpp th05\main034.cpp
 	$(CC) $(CFLAGS) -ml -3 -Z -DGAME=5 -DBINARY='M' -nbin\th05\ -eMAIN.EXE @&&|
 $**
 |
 
+bin\th05\maine.exe: bin\th05\maine.obj bin\hfliplut.obj
+	$(CC) $(CFLAGS) -ml -DGAME=5 -DBINARY='E' -nbin\th05\ -eMAINE.EXE @&&|
+$**
+|
+
 # ZUN.COM packing
 
 {bin\zuncom}.obj{bin\zuncom}.bin:
diff --git a/decomp.h b/decomp.h
index 4305199b..ce8729e5 100644
--- a/decomp.h
+++ b/decomp.h
@@ -7,6 +7,7 @@
 // ----------------
 // When used inside a conditional expression like
 //	if(FLAGS_*) { goto some_label; | return; }
-// these assemble into the single given instruction.
+// these assemble into the single given instruction. Apply the ! operator to
+// get the N versions.
 #define FLAGS_ZERO (_FLAGS & 0x40) /* JZ */
 // ----------------
diff --git a/th03/formats/cdg_put_hflip.asm b/th03/formats/cdg_put_hflip.asm
index 71a40709..81bbe684 100644
--- a/th03/formats/cdg_put_hflip.asm
+++ b/th03/formats/cdg_put_hflip.asm
@@ -40,7 +40,7 @@ proc_defconv cdg_put_hflip
 	add	ax, 0A800h
 	mov	es, ax
 	assume es:nothing
-	mov	bx, offset hflip_lut
+	mov	bx, offset _hflip_lut
 	mov	fs, [si+cdg_t.seg_alpha]
 	xor	si, si
 
diff --git a/th03/formats/hfliplut.asm b/th03/formats/hfliplut.asm
index 2fd8d383..786d34cf 100644
--- a/th03/formats/hfliplut.asm
+++ b/th03/formats/hfliplut.asm
@@ -1,11 +1,8 @@
-; Generates a lookup table for flipping one byte, interpreted as a horizontal
-; line of 8 pixels in a single bitplane.
-
-; int DEFCONV hflip_lut_generate()
-proc_defconv hflip_lut_generate
+public _hflip_lut_generate
+_hflip_lut_generate proc
 	push	di
 	xor	ax, ax
-	mov	di, offset hflip_lut
+	mov	di, offset _hflip_lut
 	xor	dl, dl
 	jmp	short @@check
 
@@ -25,4 +22,4 @@ proc_defconv hflip_lut_generate
 	jnz	short @@outer
 	pop	di
 	ret
-endp_defconv
+_hflip_lut_generate endp
diff --git a/th03/formats/hfliplut.h b/th03/formats/hfliplut.h
new file mode 100644
index 00000000..c315e709
--- /dev/null
+++ b/th03/formats/hfliplut.h
@@ -0,0 +1,5 @@
+// Lookup table for horizontally flipping a dots8_t.
+extern dots8_t hflip_lut[256];
+
+// Fills [hflip_lut].
+void hflip_lut_generate(void);
diff --git a/th03/formats/hfliplut[bss].asm b/th03/formats/hfliplut[bss].asm
index ba4e5c99..8bf0ce57 100644
--- a/th03/formats/hfliplut[bss].asm
+++ b/th03/formats/hfliplut[bss].asm
@@ -1 +1,2 @@
-hflip_lut	db 100h dup(?)
+public _hflip_lut
+_hflip_lut	db 100h dup(?)
diff --git a/th03/hfliplut.c b/th03/hfliplut.c
new file mode 100644
index 00000000..94f52f50
--- /dev/null
+++ b/th03/hfliplut.c
@@ -0,0 +1,34 @@
+#include "platform.h"
+#include "pc98.h"
+#include "planar.h"
+#include "decomp.h"
+#include "th03/formats/hfliplut.h"
+
+#pragma codeseg seg2
+#pragma option -k-
+
+void hflip_lut_generate(void)
+{
+	#define p (dots8_t near *)(_DI)
+	_AX = 0;
+	p = hflip_lut;
+	_DL ^= _DL;
+	goto set_and_loop;
+
+permutation_loop:
+	_DL ^= _DL;
+	_CX = BYTE_DOTS;
+	generation_loop: __asm {
+		rol 	al, 1
+		rcr 	dl, 1
+		loop	generation_loop
+	}
+
+set_and_loop:
+	*(p++) = _DL;
+	_AL++;
+	if(!FLAGS_ZERO) {
+		goto permutation_loop;
+	}
+	#undef p
+}
diff --git a/th03_main.asm b/th03_main.asm
index 33652e3e..54c7d449 100644
--- a/th03_main.asm
+++ b/th03_main.asm
@@ -615,7 +615,7 @@ var_2		= word ptr -2
 		call	sub_13CDD
 		mov	byte_207E3, 0
 		call	sub_9EBF
-		call	hflip_lut_generate
+		call	_hflip_lut_generate
 		nopcall	sub_D5A2
 		mov	byte_23AFA, 0
 		les	bx, _resident
@@ -9228,7 +9228,7 @@ loc_F0A9:
 		mov	bx, [bp+arg_0]
 		shl	bx, 2
 		les	di, [bx+1D64h]
-		mov	bx, offset hflip_lut
+		mov	bx, offset _hflip_lut
 
 loc_F0BB:
 		mov	al, es:[di]
diff --git a/th03_mainl.asm b/th03_mainl.asm
index 0cb8e290..3d4cc53f 100644
--- a/th03_mainl.asm
+++ b/th03_mainl.asm
@@ -906,7 +906,7 @@ loc_9DAD:
 		call	gaiji_entry_bfnt
 		call	snd_load c, offset aYume_efc, ds, SND_LOAD_SE
 		call	snd_se_reset
-		call	hflip_lut_generate
+		call	_hflip_lut_generate
 		les	bx, _resident
 		cmp	es:[bx+resident_t.show_score_menu], 0
 		jz	short loc_9E04
@@ -5588,7 +5588,7 @@ include th03/hardware/input_modes.asm
 include th03/hardware/input_wait.asm
 		db 0
 include th03/formats/cdg_put_noalpha.asm
-include th03/formats/hfliplut.asm
+	extern _hflip_lut_generate:proc
 seg2	ends
 
 	.data
diff --git a/th03_op.asm b/th03_op.asm
index fc23d0e4..5b81b91c 100644
--- a/th03_op.asm
+++ b/th03_op.asm
@@ -2328,7 +2328,7 @@ sub_B38D	proc near
 		push	bp
 		mov	bp, sp
 		push	si
-		call	hflip_lut_generate
+		call	_hflip_lut_generate
 		xor	si, si
 		jmp	short loc_B3B0
 ; ---------------------------------------------------------------------------
@@ -3642,7 +3642,7 @@ include th03/hardware/input_modes.asm
 include th03/hardware/input_wait.asm
 		db 0
 include th03/formats/cdg_put_noalpha.asm
-include th03/formats/hfliplut.asm
+	extern _hflip_lut_generate:proc
 	extern FRAME_DELAY_2:proc
 seg2	ends
 
diff --git a/th04_main.asm b/th04_main.asm
index 99b75a02..acd637f0 100644
--- a/th04_main.asm
+++ b/th04_main.asm
@@ -47,6 +47,7 @@ include th04/main/enemy/enemy.inc
 
 	.seq
 main_01 group main_0_TEXT, main_01_TEXT, main_012_TEXT
+g_seg2 group seg2, seg2_
 main_03 group main_032_TEXT, main_033_TEXT
 
 ; ===========================================================================
@@ -13167,7 +13168,7 @@ main_012_TEXT	ends
 
 ; Segment type:	Pure code
 seg2	segment	word public 'CODE' use16
-		assume cs:seg2
+		assume cs:g_seg2
 		;org 0Dh
 		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
 
@@ -13176,7 +13177,9 @@ include th03/math/vector2.asm
 		nop
 include th03/math/vector2_between_plus.asm
 include th02/hardware/frame_delay.asm
-include th03/formats/hfliplut.asm
+seg2	ends
+
+seg2_	segment	word public 'CODE' use16
 
 ; =============== S U B	R O U T	I N E =======================================
 
@@ -13323,7 +13326,7 @@ include th04/formats/cdg_put_plane_roll.asm
 include th04/hardware/input_sense.asm
 include th04/snd/se.asm
 include th04/formats/cdg_load.asm
-seg2	ends
+seg2_	ends
 
 ; ===========================================================================
 
diff --git a/th04_maine.asm b/th04_maine.asm
index fe99f744..6519a4c5 100644
--- a/th04_maine.asm
+++ b/th04_maine.asm
@@ -28,6 +28,8 @@ include th04/th04.inc
 	extern _tolower:proc
 	extern __ctype:byte
 
+g_seg2 group seg2, seg2_
+
 ; ===========================================================================
 
 ; Segment type:	Pure code
@@ -4694,7 +4696,7 @@ maine_01_TEXT	ends
 
 ; Segment type:	Pure code
 seg2	segment	word public 'CODE' use16
-		assume cs:seg2
+		assume cs:g_seg2
 		;org 0Ah
 		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
 
@@ -4704,7 +4706,9 @@ include th02/formats/pi_slot_palette_apply.asm
 include th02/formats/pi_slot_put.asm
 include th02/formats/pi_slot_load.asm
 include th03/formats/pi_slot_put_quarter.asm
-include th03/formats/hfliplut.asm
+seg2	ends
+
+seg2_	segment	word public 'CODE' use16
 include th04/hardware/input_wait.asm
 include th04/math/vector1_at.asm
 include th04/math/vector2_at.asm
@@ -4726,7 +4730,7 @@ include th04/snd/se.asm
 include th04/bgimage.asm
 include th04/bgimage_put_rect.asm
 include th04/formats/cdg_load.asm
-seg2	ends
+seg2_	ends
 
 	.data
 
diff --git a/th05_main.asm b/th05_main.asm
index 2fea2f08..11d0f9e3 100644
--- a/th05_main.asm
+++ b/th05_main.asm
@@ -39,6 +39,7 @@ include th05/main/enemy/enemy.inc
 
 	.seq
 main_01 group main_TEXT, main__TEXT, main_0_TEXT, main_01_TEXT
+g_seg2 group seg2, seg2_
 main_03 group main_031_TEXT, main_032_TEXT, main_033_TEXT, main_034_TEXT, main_035_TEXT
 
 ; ===========================================================================
@@ -10746,14 +10747,16 @@ main_01_TEXT	ends
 
 ; Segment type:	Pure code
 seg2	segment	word public 'CODE' use16
-		assume cs:seg2
+		assume cs:g_seg2
 		;org 3
 		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
 
 include th03/math/vector2.asm
 		nop
 include th03/math/vector2_between_plus.asm
-include th03/formats/hfliplut.asm
+seg2	ends
+
+seg2_	segment	word public 'CODE' use16
 include th04/snd/pmd_res.asm
 include th02/snd/mmd_res.asm
 include th04/snd/detmodes.asm
@@ -10772,7 +10775,7 @@ include th05/hardware/input_wait.asm
 include th05/hardware/frame_delay.asm
 		db 0
 include th04/formats/cdg_load.asm
-seg2	ends
+seg2_	ends
 
 ; ===========================================================================
 
diff --git a/th05_maine.asm b/th05_maine.asm
index a6cef1ce..59df6b2e 100644
--- a/th05_maine.asm
+++ b/th05_maine.asm
@@ -27,6 +27,8 @@ include th05/th05.inc
 	extern _tolower:proc
 	extern __ctype:byte
 
+g_seg2 group seg2, seg2_
+
 ; ===========================================================================
 
 ; Segment type:	Pure code
@@ -7771,11 +7773,13 @@ maine_01_TEXT	ends
 
 ; Segment type:	Pure code
 seg2	segment	word public 'CODE' use16
-		assume cs:seg2
+seg2	ends
+
+seg2_	segment	word public 'CODE' use16
+		assume cs:g_seg2
 		;org 0Ch
 		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
 
-include th03/formats/hfliplut.asm
 include th04/snd/pmd_res.asm
 include th02/snd/mmd_res.asm
 include th04/snd/detmodes.asm
@@ -7804,7 +7808,7 @@ include th05/hardware/frame_delay.asm
 		db 0
 include th04/formats/cdg_load.asm
 include th04/hardware/egccopyr.asm
-seg2	ends
+seg2_	ends
 
 	.data
 
diff --git a/th05_op.asm b/th05_op.asm
index 1c8c1729..3d47d674 100644
--- a/th05_op.asm
+++ b/th05_op.asm
@@ -30,6 +30,8 @@ include th05/music/piano.inc
 	extern _getch:proc
 	extern _strlen:proc
 
+g_seg2 group seg2, seg2_
+
 ; ===========================================================================
 
 ; Segment type:	Pure code
@@ -3486,11 +3488,13 @@ op_01_TEXT	ends
 
 ; Segment type:	Pure code
 seg2	segment	word public 'CODE' use16
-		assume cs:seg2
+seg2	ends
+
+seg2_	segment	word public 'CODE' use16
+		assume cs:g_seg2
 		; org 4
 		assume es:nothing, ss:nothing, ds:_DATA, fs:nothing, gs:nothing
 
-include th03/formats/hfliplut.asm
 include th04/snd/pmd_res.asm
 include th02/snd/mmd_res.asm
 include th04/snd/detmodes.asm
@@ -3527,7 +3531,7 @@ include th05/hardware/frame_delay.asm
 include th04/formats/cdg_load.asm
 include th04/hardware/egccopyr.asm
 		even
-seg2	ends
+seg2_	ends
 
 	.data