diff --git a/src/mame/audio/taito_zm.c b/src/mame/audio/taito_zm.c
index 8314dc42490..7a2f0316c06 100644
--- a/src/mame/audio/taito_zm.c
+++ b/src/mame/audio/taito_zm.c
@@ -25,6 +25,7 @@ and a Zoom Corp. ZFX-2 DSP instead of the TMS57002.
 
 TODO:
 - add TMS57002
+- global volume regs
 - a lot more
 
 ***************************************************************************/
@@ -43,7 +44,7 @@ const device_type TAITO_ZOOM = &device_creator<taito_zoom_device>;
 taito_zoom_device::taito_zoom_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
 	: device_t(mconfig, TAITO_ZOOM, "Taito Zoom Sound System", tag, owner, clock, "taito_zoom", __FILE__),
 	m_soundcpu(*this, ":mn10200"),
-	m_control(0),
+	m_reg_address(0),
 	m_tms_ctrl(0)
 {
 }
@@ -57,7 +58,7 @@ void taito_zoom_device::device_start()
 	m_snd_shared_ram = auto_alloc_array_clear(machine(), UINT8, 0x100);
 	
 	// register for savestates
-	save_item(NAME(m_control));
+	save_item(NAME(m_reg_address));
 	save_item(NAME(m_tms_ctrl));
 	save_pointer(NAME(m_snd_shared_ram), 0x100);
 }
@@ -68,6 +69,7 @@ void taito_zoom_device::device_start()
 
 void taito_zoom_device::device_reset()
 {
+	m_reg_address = 0;
 }
 
 
@@ -136,18 +138,26 @@ READ16_MEMBER(taito_zoom_device::sound_irq_r)
 	return 0;
 }
 
-WRITE16_MEMBER(taito_zoom_device::global_volume_w)
+WRITE16_MEMBER(taito_zoom_device::reg_data_w)
 {
-	// TODO
-	// m_control d0 selects left/right speaker volume (zsg2+dsp)
+	switch (m_reg_address)
+	{
+		case 0x04:
+			// zsg2+dsp global volume ch0
+			break;
+		
+		case 0x05:
+			// zsg2+dsp global volume ch1
+			break;
+
+		default:
+			break;
+	}
 }
 
-WRITE16_MEMBER(taito_zoom_device::reset_control_w)
+WRITE16_MEMBER(taito_zoom_device::reg_address_w)
 {
-	// d2: reset sound cpu?
-	m_soundcpu->set_input_line(INPUT_LINE_RESET, (data & 4) ? CLEAR_LINE : ASSERT_LINE);
-
-	m_control = data;
+	m_reg_address = data & 0xff;
 }
 
 
diff --git a/src/mame/audio/taito_zm.h b/src/mame/audio/taito_zm.h
index bae3aeda5e8..5e1ced97615 100644
--- a/src/mame/audio/taito_zm.h
+++ b/src/mame/audio/taito_zm.h
@@ -13,8 +13,8 @@ public:
 
 	DECLARE_WRITE16_MEMBER(sound_irq_w);
 	DECLARE_READ16_MEMBER(sound_irq_r);
-	DECLARE_WRITE16_MEMBER(global_volume_w);
-	DECLARE_WRITE16_MEMBER(reset_control_w);
+	DECLARE_WRITE16_MEMBER(reg_data_w);
+	DECLARE_WRITE16_MEMBER(reg_address_w);
 
 	DECLARE_READ8_MEMBER(shared_ram_r);
 	DECLARE_WRITE8_MEMBER(shared_ram_w);
@@ -32,7 +32,7 @@ private:
 	required_device<mn10200_device> m_soundcpu;
 	
 	// internal state
-	UINT16 m_control;
+	UINT16 m_reg_address;
 	UINT8 m_tms_ctrl;
 	UINT8* m_snd_shared_ram;
 };
diff --git a/src/mame/drivers/taitogn.c b/src/mame/drivers/taitogn.c
index 7c7068e5dca..ade17fd966c 100644
--- a/src/mame/drivers/taitogn.c
+++ b/src/mame/drivers/taitogn.c
@@ -410,6 +410,17 @@ WRITE8_MEMBER(taitogn_state::control_w)
 {
 	// 20 = watchdog
 	m_mb3773->write_line_ck((data & 0x20) >> 5);
+	
+	// 10 = soundcpu reset
+	m_mn10200->set_input_line(INPUT_LINE_RESET, (data & 0x10) ? ASSERT_LINE : CLEAR_LINE);
+	if (~data & m_control & 0x10)
+	{
+		// assume that this also readys the sound flash chips
+		m_pgmflash->write(0, 0xff);
+		m_sndflash0->write(0, 0xff);
+		m_sndflash1->write(0, 0xff);
+		m_sndflash2->write(0, 0xff);
+	}
 
 	// 04 = select bank
 	// According to the rom code, bits 1-0 may be part of the bank
@@ -488,25 +499,7 @@ WRITE8_MEMBER(taitogn_state::znsecsel_w)
 
 READ8_MEMBER(taitogn_state::boardconfig_r)
 {
-	/*
-	------00 mem=4M
-	------01 mem=4M
-	------10 mem=8M
-	------11 mem=16M
-	-----0-- smem=hM
-	-----1-- smem=2M
-	----0--- vmem=1M
-	----1--- vmem=2M
-	000----- rev=-2
-	001----- rev=-1
-	010----- rev=0
-	011----- rev=1
-	100----- rev=2
-	101----- rev=3
-	110----- rev=4
-	111----- rev=5
-	*/
-
+	// see zn.c
 	return 64|32|8;
 }
 
@@ -564,7 +557,7 @@ void taitogn_state::driver_start()
 
 void taitogn_state::machine_reset()
 {
-	m_control = 0;
+	m_control = 0xf8;
 
 	// halt sound CPU since it has no valid program at start
 	m_mn10200->set_input_line(INPUT_LINE_RESET, ASSERT_LINE);
@@ -589,8 +582,8 @@ static ADDRESS_MAP_START( taitogn_map, AS_PROGRAM, 32, taitogn_state )
 	AM_RANGE(0x1fb40000, 0x1fb40003) AM_READWRITE8(control_r, control_w, 0x000000ff)
 	AM_RANGE(0x1fb60000, 0x1fb60003) AM_WRITE16(control2_w, 0x0000ffff)
 	AM_RANGE(0x1fb70000, 0x1fb70003) AM_READWRITE16(gn_1fb70000_r, gn_1fb70000_w, 0x0000ffff)
-	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, global_volume_w, 0x0000ffff)
-	//AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, reset_control_w, 0xffff0000)
+	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, reg_data_w, 0x0000ffff)
+	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, reg_address_w, 0xffff0000)
 	AM_RANGE(0x1fba0000, 0x1fba0003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, sound_irq_w, 0x0000ffff)
 	AM_RANGE(0x1fbc0000, 0x1fbc0003) AM_DEVREAD16("taito_zoom", taito_zoom_device, sound_irq_r, 0x0000ffff)
 	AM_RANGE(0x1fbe0000, 0x1fbe01ff) AM_DEVREADWRITE8("taito_zoom", taito_zoom_device, shared_ram_r, shared_ram_w, 0x00ff00ff) // M66220FP for comms with the MN10200
diff --git a/src/mame/drivers/zn.c b/src/mame/drivers/zn.c
index ddd56f505ce..077faf205bb 100644
--- a/src/mame/drivers/zn.c
+++ b/src/mame/drivers/zn.c
@@ -1186,8 +1186,8 @@ static ADDRESS_MAP_START(coh1000tb_map, AS_PROGRAM, 32, zn_state)
 	AM_RANGE(0x1f000000, 0x1f7fffff) AM_ROMBANK("bankedroms")
 	AM_RANGE(0x1fb00000, 0x1fb003ff) AM_READWRITE8(fx1b_fram_r, fx1b_fram_w, 0x00ff00ff)
 	AM_RANGE(0x1fb40000, 0x1fb40003) AM_WRITE8(bank_coh1000t_w, 0x000000ff)
-	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, global_volume_w, 0x0000ffff)
-	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, reset_control_w, 0xffff0000)
+	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, reg_data_w, 0x0000ffff)
+	AM_RANGE(0x1fb80000, 0x1fb80003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, reg_address_w, 0xffff0000)
 	AM_RANGE(0x1fba0000, 0x1fba0003) AM_DEVWRITE16("taito_zoom", taito_zoom_device, sound_irq_w, 0x0000ffff)
 	AM_RANGE(0x1fbc0000, 0x1fbc0003) AM_DEVREAD16("taito_zoom", taito_zoom_device, sound_irq_r, 0x0000ffff)
 	AM_RANGE(0x1fbe0000, 0x1fbe01ff) AM_DEVREADWRITE8("taito_zoom", taito_zoom_device, shared_ram_r, shared_ram_w, 0x00ff00ff) // M66220FP for comm with the MN10200