diff --git a/th01/core/initexit.c b/th01/core/initexit.cpp
similarity index 78%
rename from th01/core/initexit.c
rename to th01/core/initexit.cpp
index b3b8a654..517581ef 100644
--- a/th01/core/initexit.c
+++ b/th01/core/initexit.cpp
@@ -6,19 +6,22 @@
 #include "pc98.h"
 #include "planar.h"
 #include "master.hpp"
+extern "C" {
 #include "th01/hardware/graph.h"
 #include "th01/hardware/palette.h"
 #include "th01/hardware/vplanset.h"
-#include "th01/hardware/vsync.h"
-#include "th01/hardware/ztext.h"
+}
+#include "th01/hardware/vsync.hpp"
+#include "th01/hardware/ztext.hpp"
+#include "th01/core/initexit.hpp"
 
 extern bool game_initialized;
-extern void interrupt(* int06_old)();
+extern void interrupt (* int06_old)(...);
 
-void interrupt int06_game_exit();
+void interrupt int06_game_exit(...);
 void game_exit_inner(void);
 
-void interrupt int06_nop()
+void interrupt int06_nop(...)
 {
 }
 
@@ -44,7 +47,7 @@ void game_exit(void)
 	if(game_initialized != true) {
 		return;
 	}
-	game_initialized = 0;
+	game_initialized = false;
 	game_exit_inner();
 	respal_free();
 }
@@ -59,12 +62,12 @@ void game_switch_binary(void)
 	z_text_setcursor(CURSOR_HIDE);
 	z_text_clear();
 	z_text_show();
-	game_initialized = 0;
+	game_initialized = false;
 }
 
 void game_exit_inner(void)
 {
-	game_initialized = 0;
+	game_initialized = false;
 	setvect(6, int06_nop);
 	vsync_exit();
 	z_text_clear();
@@ -74,7 +77,7 @@ void game_exit_inner(void)
 	setvect(6, int06_old);
 }
 
-void interrupt int06_game_exit()
+void interrupt int06_game_exit(...)
 {
 	game_exit();
 	exit(0);
diff --git a/th01/core/initexit.h b/th01/core/initexit.hpp
similarity index 100%
rename from th01/core/initexit.h
rename to th01/core/initexit.hpp
diff --git a/th01/frmdelay.c b/th01/frmdelay.c
deleted file mode 100644
index 2d471485..00000000
--- a/th01/frmdelay.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "th01/hardware/frmdelay.c"
diff --git a/th01/frmdelay.cpp b/th01/frmdelay.cpp
new file mode 100644
index 00000000..49dc40ac
--- /dev/null
+++ b/th01/frmdelay.cpp
@@ -0,0 +1 @@
+#include "th01/hardware/frmdelay.cpp"
diff --git a/th01/fuuin_04.cpp b/th01/fuuin_04.cpp
index 332f67bc..3109dbb1 100644
--- a/th01/fuuin_04.cpp
+++ b/th01/fuuin_04.cpp
@@ -12,8 +12,8 @@
 extern "C" {
 #include "th01/hardware/graph.h"
 #include "th01/hardware/palette.h"
-#include "th01/hardware/vsync.h"
 }
+#include "th01/hardware/vsync.hpp"
 #include "th01/formats/grp.h"
 #include "th01/end/type.hpp"
 
diff --git a/th01/grppffx.c b/th01/grppffx.c
deleted file mode 100644
index c9753f1b..00000000
--- a/th01/grppffx.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "th01/hardware/grppffx.c"
diff --git a/th01/grppffx.cpp b/th01/grppffx.cpp
new file mode 100644
index 00000000..08f68df9
--- /dev/null
+++ b/th01/grppffx.cpp
@@ -0,0 +1 @@
+#include "th01/hardware/grppffx.cpp"
diff --git a/th01/hardware/frmdelay.c b/th01/hardware/frmdelay.cpp
similarity index 81%
rename from th01/hardware/frmdelay.c
rename to th01/hardware/frmdelay.cpp
index 3c76440d..4fada9cc 100644
--- a/th01/hardware/frmdelay.c
+++ b/th01/hardware/frmdelay.cpp
@@ -1,5 +1,7 @@
-#include "th01/hardware/vsync.h"
+#include "th01/hardware/vsync.hpp"
+extern "C" {
 #include "th01/hardware/frmdelay.h"
+}
 
 #define z_vsync_reset1() (vsync_frame = 0)
 // #define z_vsync_reset2() (vsync_unused = 0)
diff --git a/th01/hardware/graph.cpp b/th01/hardware/graph.cpp
index 1ae51d78..ac6c2e61 100644
--- a/th01/hardware/graph.cpp
+++ b/th01/hardware/graph.cpp
@@ -9,8 +9,8 @@
 #include "th01/v_colors.hpp"
 #include "th01/math/clamp.hpp"
 #include "th01/hardware/egc.h"
+#include "th01/hardware/vsync.hpp"
 extern "C" {
-#include "th01/hardware/vsync.h"
 #include "th01/hardware/graph.h"
 #include "th01/hardware/palette.h"
 
diff --git a/th01/hardware/grppffx.c b/th01/hardware/grppffx.cpp
similarity index 86%
rename from th01/hardware/grppffx.c
rename to th01/hardware/grppffx.cpp
index d852519f..6fd5e161 100644
--- a/th01/hardware/grppffx.c
+++ b/th01/hardware/grppffx.cpp
@@ -3,7 +3,9 @@
 #include "platform.h"
 #include "pc98.h"
 #include "planar.h"
-#include "th01/hardware/graph.h"
+extern "C" {
+#include "th01/hardware/grppsafx.h"
+}
 
 void graph_printf_fx(
 	screen_x_t left, vram_y_t top, int16_t col_and_fx, const char *fmt, ...
diff --git a/th01/hardware/vplanset.c b/th01/hardware/vplanset.c
deleted file mode 100644
index 4be2d7f9..00000000
--- a/th01/hardware/vplanset.c
+++ /dev/null
@@ -1,14 +0,0 @@
-#pragma option -zCSHARED
-
-#include "platform.h"
-#include "pc98.h"
-#include "planar.h"
-#include "th01/hardware/vplanset.h"
-
-void vram_planes_set(void)
-{
-	VRAM_PLANE_B = (dots8_t __seg *)(SEG_PLANE_B);
-	VRAM_PLANE_R = (dots8_t __seg *)(SEG_PLANE_R);
-	VRAM_PLANE_G = (dots8_t __seg *)(SEG_PLANE_G);
-	VRAM_PLANE_E = (dots8_t __seg *)(SEG_PLANE_E);
-}
diff --git a/th01/hardware/vplanset.cpp b/th01/hardware/vplanset.cpp
new file mode 100644
index 00000000..2c93d2c3
--- /dev/null
+++ b/th01/hardware/vplanset.cpp
@@ -0,0 +1,16 @@
+#pragma option -zCSHARED
+
+#include "platform.h"
+#include "pc98.h"
+#include "planar.h"
+extern "C" {
+#include "th01/hardware/vplanset.h"
+}
+
+void vram_planes_set(void)
+{
+	VRAM_PLANE_B = reinterpret_cast<dots8_t __seg *>(SEG_PLANE_B);
+	VRAM_PLANE_R = reinterpret_cast<dots8_t __seg *>(SEG_PLANE_R);
+	VRAM_PLANE_G = reinterpret_cast<dots8_t __seg *>(SEG_PLANE_G);
+	VRAM_PLANE_E = reinterpret_cast<dots8_t __seg *>(SEG_PLANE_E);
+}
diff --git a/th01/hardware/vsync.c b/th01/hardware/vsync.cpp
similarity index 78%
rename from th01/hardware/vsync.c
rename to th01/hardware/vsync.cpp
index 1be73b53..3ea89f00 100644
--- a/th01/hardware/vsync.c
+++ b/th01/hardware/vsync.cpp
@@ -9,19 +9,19 @@
 #include "platform.h"
 #include "x86real.h"
 #include "pc98.h"
-#include "th01/hardware/vsync.h"
+#include "th01/hardware/vsync.hpp"
 
-extern char vsync_initialized;
+extern bool vsync_initialized;
 extern int vsync_callback_is_set;
 
 extern pixel_t RES_X_HALF;
 extern pixel_t RES_Y_HALF;
 
 extern int vsync_unused;
-extern void interrupt (*vsync_callback_old)(void);
+extern void interrupt (*vsync_callback_old)(...);
 extern void (*vsync_callback)(void);
 
-static void interrupt vsync_intfunc(void)
+static void interrupt vsync_intfunc(...)
 {
 	pixel_t res_x_half = RES_X_HALF;
 	pixel_t res_y_half = RES_Y_HALF;
@@ -36,14 +36,14 @@ static void interrupt vsync_intfunc(void)
 
 void vsync_init(void)
 {
-	if(vsync_initialized == 0) {
-		vsync_initialized = 1;
+	if(vsync_initialized == false) {
+		vsync_initialized = true;
 		disable();
 		vsync_callback_old = getvect(0x0A);
 		setvect(0x0A, vsync_intfunc);
 
 		// Disable all interrupts from 0x08 to 0x0F except for 0x0A
-		outportb(0x02, inportb(0x02) & 0xFB);
+		outportb(0x02, (inportb(0x02) & 0xFB));
 
 		outportb(0x64, 0); // VSync interrupt trigger
 		enable();
@@ -52,12 +52,12 @@ void vsync_init(void)
 
 void vsync_exit(void)
 {
-	if(vsync_initialized == 1) {
-		vsync_initialized = 0;
+	if(vsync_initialized == true) {
+		vsync_initialized = false;
 		disable();
 
 		// Reenable all interrupts from 0x08 to 0x0F except for 0x0A
-		outportb(0x02, inportb(0x02) | 0x04);
+		outportb(0x02, (inportb(0x02) | 0x04));
 
 		setvect(0x0a, vsync_callback_old);
 		enable();
diff --git a/th01/hardware/vsync.h b/th01/hardware/vsync.hpp
similarity index 100%
rename from th01/hardware/vsync.h
rename to th01/hardware/vsync.hpp
diff --git a/th01/hardware/ztext.c b/th01/hardware/ztext.cpp
similarity index 71%
rename from th01/hardware/ztext.c
rename to th01/hardware/ztext.cpp
index 61b26a24..7fc5ccf7 100644
--- a/th01/hardware/ztext.c
+++ b/th01/hardware/ztext.cpp
@@ -14,7 +14,7 @@
 #include "x86real.h"
 #include "pc98.h"
 #include "master.hpp"
-#include "th01/hardware/ztext.h"
+#include "th01/hardware/ztext.hpp"
 
 extern char txesc_25line[];
 extern char txesc_20line[];
@@ -87,7 +87,7 @@ void z_text_setcursor(z_text_cursor_t type)
 {
 	_BX = peekb2(0, 0x53B); // Text mode line height
 	outportb(0x62, 0x4B); // CSRFORM
-	outportb(0x60, _BL | 0x80);
+	outportb(0x60, (_BL | 0x80));
 	switch(type) {
 		case CURSOR_HIDE:
 			outportb(0x60, 0x9F);
@@ -96,10 +96,10 @@ void z_text_setcursor(z_text_cursor_t type)
 			outportb(0x60, 0x80);
 			break;
 		case CURSOR_UNDERLINE:
-			outportb(0x60, _BL + 0x7D);
+			outportb(0x60, (_BL + 0x7D));
 			break;
 	}
-	outportb(0x60, (_BL << 3) + 2);
+	outportb(0x60, ((_BL << 3) + 2));
 }
 
 void z_text_locate(char x, char y)
@@ -112,15 +112,20 @@ void z_text_locate(char x, char y)
 	int86(0xDC, &regs, &regs);
 }
 
+inline uint8_t* tram_jis(uint16_t offset) {
+	return reinterpret_cast<uint8_t *>(MK_FP(SEG_TRAM_JIS, offset));
+}
+
+inline uint16_t* tram_atrb(uint16_t offset) {
+	return reinterpret_cast<uint16_t *>(MK_FP(SEG_TRAM_ATRB, offset));
+}
+
 void z_text_putsa(tram_x_t x, tram_y_t y, int z_atrb, const char *str)
 {
 	uint16_t codepoint;
-	int p = ((y * text_width()) + x) * 2;
+	int p = (((y * text_width()) + x) * 2);
 	int hw_atrb = 1;
 
-	#define tx_chars(byte) ((char*)MK_FP(0xA000, p + byte))
-	#define tx_atrbs(byte) ((int16_t*)MK_FP(0xA200, p + byte))
-
 	if(z_atrb & Z_ATRB_BLUE) {
 		hw_atrb += 0x20;
 	}
@@ -142,34 +147,36 @@ void z_text_putsa(tram_x_t x, tram_y_t y, int z_atrb, const char *str)
 	if(z_atrb & Z_ATRB_BLINK) {
 		hw_atrb += TX_BLINK;
 	}
-	hw_atrb += hw_atrb << 8;
+	hw_atrb += (hw_atrb << 8);
 	while(str[0]) {
 		if(_ismbblead(str[0])) {
 			codepoint = _mbcjmstojis(
-				(str[0] << 8) + (unsigned char)str[1]
+				(str[0] << 8) + static_cast<uint8_t>(str[1])
 			);
 			str += 2;
-			if(codepoint >= 0x2921 && codepoint <= 0x2B7E) {
-				*tx_chars(0) = ((codepoint >> 8) + 0xE0) | 0x80;
-				*tx_chars(1) = codepoint;
-				*tx_atrbs(0) = hw_atrb;
-			} else if(x == text_width() - 1) {
-				*(int16_t*)tx_chars(0) = ' ';
-				*tx_atrbs(0) = hw_atrb;
+			if((codepoint >= 0x2921) && (codepoint <= 0x2B7E)) {
+				tram_jis(p)[0] = (((codepoint >> 8) + 0xE0) | 0x80);
+				tram_jis(p)[1] = codepoint;
+				tram_atrb(p)[0] = hw_atrb;
+			} else if(x == (text_width() - 1)) {
+				reinterpret_cast<int16_t *>(tram_jis(p))[0] = ' ';
+				tram_atrb(p)[0] = hw_atrb;
 			} else {
-				*tx_chars(0) = (codepoint >> 8) + 0xE0;
-				*tx_chars(1) = codepoint;
-				*tx_chars(2) = ((codepoint >> 8) + 0xE0) | 0x80;
-				*tx_chars(3) = codepoint;
+				tram_jis(p)[0] = ((codepoint >> 8) + 0xE0);
+				tram_jis(p)[1] = codepoint;
+				tram_jis(p)[2] = (((codepoint >> 8) + 0xE0) | 0x80);
+				tram_jis(p)[3] = codepoint;
 
-				*tx_atrbs(0) = hw_atrb;
-				*tx_atrbs(2) = hw_atrb;
+				tram_atrb(p)[0] = hw_atrb;
+				tram_atrb(p)[1] = hw_atrb;
 				p += 2;
 				x++;
 			}
 		} else {
-			*(int16_t*)tx_chars(0) = *(unsigned char*)(str++);
-			*tx_atrbs(0) = hw_atrb;
+			reinterpret_cast<int16_t *>(tram_jis(p))[0] = *reinterpret_cast<
+				const uint8_t *
+			>(str++);
+			tram_atrb(p)[0] = hw_atrb;
 		}
 		p += 2;
 		if(++x >= text_width()) {
diff --git a/th01/hardware/ztext.h b/th01/hardware/ztext.hpp
similarity index 100%
rename from th01/hardware/ztext.h
rename to th01/hardware/ztext.hpp
diff --git a/th01/initexit.c b/th01/initexit.c
deleted file mode 100644
index 0cd3cdf5..00000000
--- a/th01/initexit.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "th01/core/initexit.c"
diff --git a/th01/initexit.cpp b/th01/initexit.cpp
new file mode 100644
index 00000000..5404f3b2
--- /dev/null
+++ b/th01/initexit.cpp
@@ -0,0 +1 @@
+#include "th01/core/initexit.cpp"
diff --git a/th01/vplanset.c b/th01/vplanset.c
deleted file mode 100644
index 5416832d..00000000
--- a/th01/vplanset.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "th01/hardware/vplanset.c"
diff --git a/th01/vplanset.cpp b/th01/vplanset.cpp
new file mode 100644
index 00000000..c7208ca0
--- /dev/null
+++ b/th01/vplanset.cpp
@@ -0,0 +1 @@
+#include "th01/hardware/vplanset.cpp"
diff --git a/th01/vsync.c b/th01/vsync.c
deleted file mode 100644
index d0693f25..00000000
--- a/th01/vsync.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "th01/hardware/vsync.c"
diff --git a/th01/vsync.cpp b/th01/vsync.cpp
new file mode 100644
index 00000000..d2c6fed6
--- /dev/null
+++ b/th01/vsync.cpp
@@ -0,0 +1 @@
+#include "th01/hardware/vsync.cpp"
diff --git a/th01/ztext.c b/th01/ztext.c
deleted file mode 100644
index 1e5c96ca..00000000
--- a/th01/ztext.c
+++ /dev/null
@@ -1 +0,0 @@
-#include "th01/hardware/ztext.c"
diff --git a/th01/ztext.cpp b/th01/ztext.cpp
new file mode 100644
index 00000000..6fe8401c
--- /dev/null
+++ b/th01/ztext.cpp
@@ -0,0 +1 @@
+#include "th01/hardware/ztext.cpp"
diff --git a/th01_fuuin.asm b/th01_fuuin.asm
index 215b04d5..ad9e0e37 100644
--- a/th01_fuuin.asm
+++ b/th01_fuuin.asm
@@ -123,9 +123,9 @@ loc_A139:
 
 loc_A13E:
 		call	_mdrv2_check_board
-		call	_game_init
+		call	@game_init$qv
 		call	@end_and_verdict_and_regist_anima$qv
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		push	0
 		push	0
 		push	ds
@@ -173,8 +173,8 @@ ztext_TEXT	ends
 
 ; Segment type:	Pure code
 initexit_TEXT	segment	byte public 'CODE' use16
-	extern _game_init:proc
-	extern _game_switch_binary:proc
+	extern @game_init$qv:proc
+	extern @game_switch_binary$qv:proc
 initexit_TEXT	ends
 
 ; ===========================================================================
diff --git a/th01_op.asm b/th01_op.asm
index 18306dda..0741c8e2 100644
--- a/th01_op.asm
+++ b/th01_op.asm
@@ -165,7 +165,7 @@ sub_A7B5	proc far
 		call	_resident_stuff_set c, word ptr _opts.O_rank, word ptr _opts.O_bgm_mode, word ptr _opts.O_bombs, word ptr _opts.O_lives_extra, large [_rand]
 		call	sub_A79D
 		call	_mdrv2_bgm_fade_out_nonblock
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		mov	al, _mode
 		cbw
 		cmp	ax, 2
@@ -258,7 +258,7 @@ sub_A8AD	proc far
 loc_A8E1:
 		call	sub_A79D
 		call	_mdrv2_bgm_fade_out_nonblock
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		les	bx, _resident
 		assume es:nothing
 		mov	es:[bx+reiidenconfig_t.debug_mode], DM_OFF
@@ -1163,7 +1163,7 @@ loc_B06F:
 
 loc_B0D6:
 		call	_mdrv2_check_board
-		call	_game_init
+		call	@game_init$qv
 		call	_cfg_load
 		mov	al, _opts.O_bgm_mode
 		cbw
@@ -1320,7 +1320,7 @@ loc_B21A:
 		call	_graph_accesspage_func
 		pop	cx
 		call	_z_graph_clear
-		call	_game_exit
+		call	@game_exit$qv
 		call	_mdrv2_bgm_stop
 		push	ds
 		push	offset format	; "おつかれさまでした！！\n"
@@ -1357,9 +1357,9 @@ ztext_TEXT	ends
 
 ; Segment type:	Pure code
 initexit_TEXT	segment	byte public 'CODE' use16
-	extern _game_init:proc
-	extern _game_exit:proc
-	extern _game_switch_binary:proc
+	extern @game_init$qv:proc
+	extern @game_exit$qv:proc
+	extern @game_switch_binary$qv:proc
 initexit_TEXT	ends
 
 ; ---------------------------------------------------------------------------
diff --git a/th01_reiiden.asm b/th01_reiiden.asm
index 8d1c2062..9c6d7be0 100644
--- a/th01_reiiden.asm
+++ b/th01_reiiden.asm
@@ -547,7 +547,7 @@ loc_CD70:
 		jnz	short loc_CDA2
 		les	bx, _resident
 		mov	es:[bx+reiidenconfig_t.snd_need_init], 0
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		les	bx, _resident
 		mov	es:[bx+reiidenconfig_t.p_value], 0
 		pushd	0
@@ -1530,7 +1530,7 @@ loc_D583:
 		mov	word_34A8A, ax
 		mov	eax, _frame_rand
 		mov	random_seed, eax
-		call	_game_init
+		call	@game_init$qv
 		call	key_start
 		push	3F003Fh
 		call	__control87
@@ -2324,7 +2324,7 @@ loc_DE47:
 		push	78h ; 'x'
 		call	_frame_delay
 		pop	cx
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		pushd	0
 		push	ds
 		push	offset aFuuin	; "fuuin"
@@ -2425,7 +2425,7 @@ loc_DF52:
 		les	bx, _resident
 		mov	al, _bombs
 		mov	es:[bx+reiidenconfig_t.bombs], al
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		pushd	0
 		push	ds
 		push	offset aReiiden	; "reiiden"
@@ -2644,7 +2644,7 @@ loc_E2A8:
 loc_E2CB:
 		call	sub_D487
 		call	sub_D4DD
-		call	_game_switch_binary
+		call	@game_switch_binary$qv
 		call	key_end
 		call	arc_free
 		pushd	0
@@ -2724,8 +2724,8 @@ ztext_TEXT	ends
 
 ; Segment type:	Pure code
 initexit_TEXT	segment	byte public 'CODE' use16
-	extern _game_init:proc
-	extern _game_switch_binary:proc
+	extern @game_init$qv:proc
+	extern @game_switch_binary$qv:proc
 initexit_TEXT	ends
 
 ; ===========================================================================