diff --git a/src/emu/cpu/sm510/sm510.c b/src/emu/cpu/sm510/sm510.c
index b5dcf501265..2968335b68a 100644
--- a/src/emu/cpu/sm510/sm510.c
+++ b/src/emu/cpu/sm510/sm510.c
@@ -25,7 +25,8 @@
 
 enum
 {
-	SM510_PC=1, SM510_ACC, SM510_BL, SM510_BM
+	SM510_PC=1, SM510_ACC, SM510_BL, SM510_BM,
+	SM510_C, SM510_W
 };
 
 void sm510_base_device::device_start()
@@ -52,6 +53,9 @@ void sm510_base_device::device_start()
 	m_c = 0;
 	m_skip = false;
 	m_w = 0;
+	m_div = 0;
+	m_bdc = false;
+	m_cend = false;
 
 	// register for savestates
 	save_item(NAME(m_stack));
@@ -66,12 +70,17 @@ void sm510_base_device::device_start()
 	save_item(NAME(m_c));
 	save_item(NAME(m_skip));
 	save_item(NAME(m_w));
+	save_item(NAME(m_div));
+	save_item(NAME(m_bdc));
+	save_item(NAME(m_cend));
 
 	// register state for debugger
 	state_add(SM510_PC,  "PC",  m_pc).formatstr("%04X");
 	state_add(SM510_ACC, "ACC", m_acc).formatstr("%01X");
 	state_add(SM510_BL,  "BL",  m_bl).formatstr("%01X");
 	state_add(SM510_BM,  "BM",  m_bm).formatstr("%01X");
+	state_add(SM510_C,   "C",   m_c).formatstr("%01X");
+	state_add(SM510_W,   "W",   m_w).formatstr("%02X");
 
 	state_add(STATE_GENPC, "curpc", m_pc).formatstr("%04X").noshow();
 	state_add(STATE_GENFLAGS, "GENFLAGS", m_c).formatstr("%1s").noshow();
@@ -88,6 +97,8 @@ void sm510_base_device::device_start()
 void sm510_base_device::device_reset()
 {
 	m_skip = false;
+	m_bdc = false;
+	m_cend = false;
 	m_op = m_prev_op = 0;
 	do_branch(3, 7, 0);
 	m_prev_pc = m_pc;
diff --git a/src/emu/cpu/sm510/sm510.h b/src/emu/cpu/sm510/sm510.h
index c2674ecb9b0..7af7f1a7542 100644
--- a/src/emu/cpu/sm510/sm510.h
+++ b/src/emu/cpu/sm510/sm510.h
@@ -38,6 +38,7 @@ public:
 		: cpu_device(mconfig, type, name, tag, owner, clock, shortname, source)
 		, m_program_config("program", ENDIANNESS_LITTLE, 8, prgwidth, 0, program)
 		, m_data_config("data", ENDIANNESS_LITTLE, 8, datawidth, 0, data)
+		, m_lcd_ram(*this, "lcd_ram")
 		, m_prgwidth(prgwidth)
 		, m_datawidth(datawidth)
 		, m_stack_levels(stack_levels)
@@ -75,16 +76,15 @@ protected:
 	address_space_config m_data_config;
 	address_space *m_program;
 	address_space *m_data;
+	required_shared_ptr<UINT8> m_lcd_ram;
 
 	int m_prgwidth;
 	int m_datawidth;
 	int m_prgmask;
 	int m_datamask;
 
-	UINT16 m_pc;
-	UINT16 m_prev_pc;
-	UINT8 m_op;
-	UINT8 m_prev_op;
+	UINT16 m_pc, m_prev_pc;
+	UINT8 m_op, m_prev_op;
 	UINT8 m_param;
 	int m_stack_levels;
 	UINT16 m_stack[2];
@@ -96,6 +96,9 @@ protected:
 	UINT8 m_c;
 	bool m_skip;
 	UINT8 m_w;
+	UINT16 m_div;
+	bool m_bdc;
+	bool m_cend;
 
 	// i/o handlers
 	devcb_read16 m_read_k;
diff --git a/src/emu/cpu/sm510/sm510core.c b/src/emu/cpu/sm510/sm510core.c
index 791c44f4a24..58d6035252e 100644
--- a/src/emu/cpu/sm510/sm510core.c
+++ b/src/emu/cpu/sm510/sm510core.c
@@ -24,7 +24,7 @@ ADDRESS_MAP_END
 
 static ADDRESS_MAP_START(data_96_32x4, AS_DATA, 8, sm510_base_device)
 	AM_RANGE(0x00, 0x5f) AM_RAM
-	AM_RANGE(0x60, 0x7f) AM_RAM
+	AM_RANGE(0x60, 0x7f) AM_RAM AM_SHARE("lcd_ram")
 ADDRESS_MAP_END
 
 
diff --git a/src/emu/cpu/sm510/sm510d.c b/src/emu/cpu/sm510/sm510d.c
index 1bacab9c91f..81c1abff33c 100644
--- a/src/emu/cpu/sm510/sm510d.c
+++ b/src/emu/cpu/sm510/sm510d.c
@@ -11,7 +11,7 @@
 #include "sm510.h"
 
 
-// common
+// common lookup tables
 
 enum e_mnemonics
 {
@@ -76,37 +76,13 @@ static const INT8 s_next_pc[0x40] =
 
 
 
-// SM510 disasm
+// common disasm
 
-static const UINT8 sm510_mnemonic[0x100] =
-{
-/*  0      1      2      3      4      5      6      7      8      9      A      B      C      D      E      F  */
-	mSKIP, mATBP, mSBM,  mATPL, mRM,   mRM,   mRM,   mRM,   mADD,  mADD11,mCOMA, mEXBLA,mSM,   mSM,   mSM,   mSM,   // 0
-	mEXC,  mEXC,  mEXC,  mEXC,  mEXCI, mEXCI, mEXCI, mEXCI, mLDA,  mLDA,  mLDA,  mLDA,  mEXCD, mEXCD, mEXCD, mEXCD, // 1
-	mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  // 2
-	mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  // 3 - note: $3A has synonym DC(decimal correct)
-
-	mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   // 4
-	0,     mTB,   mTC,   mTAM,  mTMI,  mTMI,  mTMI,  mTMI,  mTIS,  mATL,  mTA0,  mTABL, 0,     mCEND, mTAL,  mLBL,  // 5
-	mATFC, mATR,  mWR,   mWS,   mINCB, mIDIV, mRC,   mSC,   mTF1,  mTF4,  mKTA,  mROT,  mDECB, mBDC,  mRTN0, mRTN1, // 6
-	mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTML,  mTML,  mTML,  mTML,  // 7
-
-	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // 8
-	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // 9
-	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // A
-	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // B
-
-	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   // C
-	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   // D
-	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   // E
-	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM    // F
-};
-
-CPU_DISASSEMBLE(sm510)
+static offs_t sm510_common_disasm(const UINT8 *lut_mnemonic, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram)
 {
 	// get raw opcode
 	UINT8 op = oprom[0];
-	UINT8 instr = sm510_mnemonic[op];
+	UINT8 instr = lut_mnemonic[op];
 	int len = 1;
 
 	int bits = s_bits[instr];
@@ -151,10 +127,41 @@ CPU_DISASSEMBLE(sm510)
 }
 
 
+// SM510 disasm
+
+static const UINT8 sm510_mnemonic[0x100] =
+{
+/*  0      1      2      3      4      5      6      7      8      9      A      B      C      D      E      F  */
+	mSKIP, mATBP, mSBM,  mATPL, mRM,   mRM,   mRM,   mRM,   mADD,  mADD11,mCOMA, mEXBLA,mSM,   mSM,   mSM,   mSM,   // 0
+	mEXC,  mEXC,  mEXC,  mEXC,  mEXCI, mEXCI, mEXCI, mEXCI, mLDA,  mLDA,  mLDA,  mLDA,  mEXCD, mEXCD, mEXCD, mEXCD, // 1
+	mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  mLAX,  // 2
+	mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  mADX,  // 3 - note: $3A has synonym DC(decimal correct)
+
+	mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   mLB,   // 4
+	0,     mTB,   mTC,   mTAM,  mTMI,  mTMI,  mTMI,  mTMI,  mTIS,  mATL,  mTA0,  mTABL, 0,     mCEND, mTAL,  mLBL,  // 5
+	mATFC, mATR,  mWR,   mWS,   mINCB, mIDIV, mRC,   mSC,   mTF1,  mTF4,  mKTA,  mROT,  mDECB, mBDC,  mRTN0, mRTN1, // 6
+	mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTL,   mTML,  mTML,  mTML,  mTML,  // 7
+
+	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // 8
+	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // 9
+	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // A
+	mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    mT,    // B
+
+	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   // C
+	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   // D
+	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   // E
+	mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM,   mTM    // F
+};
+
+CPU_DISASSEMBLE(sm510)
+{
+	return sm510_common_disasm(sm510_mnemonic, buffer, pc, oprom, opram);
+}
+
 
 // SM511 disasm
 
 CPU_DISASSEMBLE(sm511)
 {
-	return 1;
+	return sm510_common_disasm(sm510_mnemonic, buffer, pc, oprom, opram);
 }
diff --git a/src/emu/cpu/sm510/sm510op.c b/src/emu/cpu/sm510/sm510op.c
index 835289e7ce3..0e3238e1739 100644
--- a/src/emu/cpu/sm510/sm510op.c
+++ b/src/emu/cpu/sm510/sm510op.c
@@ -160,8 +160,8 @@ void sm510_base_device::op_exc()
 
 void sm510_base_device::op_bdc()
 {
-	// BDC: x
-	op_illegal();
+	// BDC: enable LCD bleeder current with C
+	m_bdc = (m_c != 0);
 }
 
 void sm510_base_device::op_exci()
@@ -380,13 +380,13 @@ void sm510_base_device::op_skip()
 void sm510_base_device::op_cend()
 {
 	// CEND: stop clock
-	op_illegal();
+	m_cend = true;
 }
 
 void sm510_base_device::op_idiv()
 {
 	// IDIV: reset divider
-	op_illegal();
+	m_div = 0;
 }
 
 void sm510_base_device::op_illegal()
diff --git a/src/emu/cpu/sm510/sm511core.c b/src/emu/cpu/sm510/sm511core.c
index 237e5b72d7b..8905b4c3239 100644
--- a/src/emu/cpu/sm510/sm511core.c
+++ b/src/emu/cpu/sm510/sm511core.c
@@ -22,12 +22,12 @@ ADDRESS_MAP_END
 
 static ADDRESS_MAP_START(data_96_32x4, AS_DATA, 8, sm510_base_device)
 	AM_RANGE(0x00, 0x5f) AM_RAM
-	AM_RANGE(0x60, 0x7f) AM_RAM
+	AM_RANGE(0x60, 0x7f) AM_RAM AM_SHARE("lcd_ram")
 ADDRESS_MAP_END
 
 static ADDRESS_MAP_START(data_80_48x4, AS_DATA, 8, sm510_base_device)
 	AM_RANGE(0x00, 0x4f) AM_RAM
-	AM_RANGE(0x50, 0x7f) AM_RAM
+	AM_RANGE(0x50, 0x7f) AM_RAM AM_SHARE("lcd_ram")
 ADDRESS_MAP_END
 
 
diff --git a/src/mame/mess.lst b/src/mame/mess.lst
index 63f873c22c8..aa19be4bf23 100644
--- a/src/mame/mess.lst
+++ b/src/mame/mess.lst
@@ -2195,6 +2195,7 @@ maniac      // Ideal
 
 // hh_sm510
 ktopgun     // Konami
+gnwmndon    // Nintendo
 
 // hh_tms1k
 mathmagi    // APF
diff --git a/src/mess/drivers/hh_sm510.c b/src/mess/drivers/hh_sm510.c
index e0ffa12a969..ab51dfeba1e 100644
--- a/src/mess/drivers/hh_sm510.c
+++ b/src/mess/drivers/hh_sm510.c
@@ -92,7 +92,8 @@ UINT8 hh_sm510_state::read_inputs(int columns)
 /***************************************************************************
 
   Konami Top Gun
-  * x
+  * PCB label BH003
+  * Sharp SM510 under epoxy (die label K/CM54C 598)
 
 ***************************************************************************/
 
@@ -109,7 +110,6 @@ public:
 
 // handlers
 
-
 WRITE8_MEMBER(ktopgun_state::input_w)
 {
 	// S1-S3: input mux
@@ -123,7 +123,6 @@ READ8_MEMBER(ktopgun_state::input_r)
 }
 
 
-
 // config
 
 static INPUT_PORTS_START( ktopgun )
@@ -165,6 +164,71 @@ MACHINE_CONFIG_END
 
 
 
+/***************************************************************************
+
+  Nintendo Game & Watch: Mickey & Donald (model DM-53)
+  * PCB label DM-53
+  * Sharp SM510 label DM-53 (die label CM54C 565)
+
+***************************************************************************/
+
+class gnwmndon_state : public hh_sm510_state
+{
+public:
+	gnwmndon_state(const machine_config &mconfig, device_type type, const char *tag)
+		: hh_sm510_state(mconfig, type, tag)
+	{ }
+
+	DECLARE_WRITE8_MEMBER(input_w);
+	DECLARE_READ8_MEMBER(input_r);
+};
+
+// handlers
+
+WRITE8_MEMBER(gnwmndon_state::input_w)
+{
+	// S1,S2: input mux
+	m_inp_mux = data;
+}
+
+READ8_MEMBER(gnwmndon_state::input_r)
+{
+	return read_inputs(2);
+}
+
+
+// config
+
+static INPUT_PORTS_START( gnwmndon )
+	PORT_START("IN.0")
+	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_4WAY
+	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_4WAY
+	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_4WAY
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_4WAY
+
+	PORT_START("IN.1")
+	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_BUTTON1 ) // time
+	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_BUTTON2 ) // b
+	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_BUTTON3 ) // a
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_BUTTON4 ) // alarm
+INPUT_PORTS_END
+
+static MACHINE_CONFIG_START( gnwmndon, gnwmndon_state )
+
+	/* basic machine hardware */
+	MCFG_CPU_ADD("maincpu", SM510, XTAL_32_768kHz)
+	MCFG_SM510_READ_K_CB(READ8(gnwmndon_state, input_r))
+	MCFG_SM510_WRITE_S_CB(WRITE8(gnwmndon_state, input_w))
+
+	/* no video! */
+
+	/* sound hardware */
+	MCFG_SPEAKER_STANDARD_MONO("mono")
+	MCFG_SOUND_ADD("speaker", SPEAKER_SOUND, 0)
+	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
+MACHINE_CONFIG_END
+
+
 
 
 
@@ -176,13 +240,18 @@ MACHINE_CONFIG_END
 
 ROM_START( ktopgun )
 	ROM_REGION( 0x1000, "maincpu", 0 )
-	ROM_LOAD( "topgun_die.bin", 0x0000, 0x1000, CRC(50870b35) SHA1(cda1260c2e1c180995eced04b7d7ff51616dcef5) )
+	ROM_LOAD( "bh003_598", 0x0000, 0x1000, CRC(50870b35) SHA1(cda1260c2e1c180995eced04b7d7ff51616dcef5) )
 ROM_END
 
 
-
+ROM_START( gnwmndon )
+	ROM_REGION( 0x1000, "maincpu", 0 )
+	ROM_LOAD( "dm53_565", 0x0000, 0x1000, CRC(e21fc0f5) SHA1(3b65ccf9f98813319410414e11a3231b787cdee6) )
+ROM_END
 
 
 
 /*    YEAR  NAME       PARENT COMPAT MACHINE   INPUT      INIT              COMPANY, FULLNAME, FLAGS */
 CONS( 1989, ktopgun,   0,        0, ktopgun,   ktopgun,   driver_device, 0, "Konami", "Top Gun (Konami)", GAME_SUPPORTS_SAVE | GAME_NOT_WORKING )
+
+CONS( 1982, gnwmndon,  0,        0, gnwmndon,  gnwmndon,  driver_device, 0, "Nintendo", "Game & Watch: Mickey & Donald", GAME_SUPPORTS_SAVE | GAME_NOT_WORKING )