diff --git a/src/mess/machine/isa_gus.c b/src/mess/machine/isa_gus.c
index 410e14c546a..5083eeb3be4 100644
--- a/src/mess/machine/isa_gus.c
+++ b/src/mess/machine/isa_gus.c
@@ -489,7 +489,7 @@ READ8_MEMBER(gf1_device::global_reg_data_r)
  * bit 6 - 1 if addresses are decreasing, can change when looping is enabled
  * bit 7 - 1 if Wavetable IRQ is pending */
 		if(offset == 1)
-			return m_voice[m_current_voice].voice_ctrl;
+			return m_voice[m_current_voice].voice_ctrl & 0xff;
 	case 0x81:  // Frequency Control
 		ret = m_voice[m_current_voice].freq_ctrl;
 		if(offset == 0)
@@ -591,12 +591,10 @@ WRITE8_MEMBER(gf1_device::global_reg_data_w)
  * bit 5 - set to 1 to enable wavetable IRQ when end address is reached */
 		if(offset == 1)
 		{
-			m_voice[m_current_voice].voice_ctrl = data & 0x7f;
+			m_voice[m_current_voice].voice_ctrl = data & 0xff;
 			m_voice[m_current_voice].rollover = false;
 			if(data & 0x02)
-			{
 				m_voice[m_current_voice].voice_ctrl |= 0x01;
-			}
 		}
 		logerror("GUS: Ch%i Voice control write %02x\n", m_current_voice,data);
 		break;
@@ -1129,6 +1127,7 @@ void gf1_device::set_irq(UINT8 source, UINT8 voice)
 		m_wave_irq_func(1);
 		m_voice_irq_fifo[m_voice_irq_ptr % 32] = m_irq_source;
 		m_voice_irq_ptr++;
+		m_voice[voice].voice_ctrl |= 0x80;
 	}
 	if(source & IRQ_VOLUME_RAMP)
 	{
@@ -1199,8 +1198,8 @@ void gf1_device::eop_w(int state)
 
 static const acia6850_interface gus_midi_interface =
 {
-	GF1_CLOCK,
-	GF1_CLOCK,  // a guess for now
+	31250 * 16,
+	31250 * 16,
 
 	DEVCB_NULL,
 	DEVCB_NULL,
@@ -1209,8 +1208,7 @@ static const acia6850_interface gus_midi_interface =
 	DEVCB_NULL,
 	DEVCB_NULL,
 
-	DEVCB_NULL
-	//DEVCB_LINE_MEMBER(isa16_gus_device,midi_irq)
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER,isa16_gus_device,midi_irq)
 };
 
 static const gf1_interface gus_gf1_config =
@@ -1232,7 +1230,7 @@ static MACHINE_CONFIG_FRAGMENT( gus_config )
 	MCFG_SOUND_CONFIG(gus_gf1_config)
 	MCFG_SOUND_ROUTE(0,"lspeaker",0.50)
 	MCFG_SOUND_ROUTE(1,"rspeaker",0.50)
-//  MCFG_ACIA6850_ADD("midi",gus_midi_interface)
+	MCFG_ACIA6850_ADD("midi",gus_midi_interface)
 MACHINE_CONFIG_END
 
 static INPUT_PORTS_START( gus_joy )
@@ -1275,7 +1273,7 @@ isa16_gus_device::isa16_gus_device(const machine_config &mconfig, const char *ta
 void isa16_gus_device::device_start()
 {
 	m_gf1 = subdevice<gf1_device>("gf1");
-	//m_midi = subdevice<acia6850_device>("midi");
+	m_midi = subdevice<acia6850_device>("midi");
 	set_isa_device();
 	m_isa->install_device(0x0200, 0x0201, 0, 0, read8_delegate(FUNC(isa16_gus_device::joy_r),this), write8_delegate(FUNC(isa16_gus_device::joy_w),this) );
 	m_isa->install_device(0x0220, 0x022f, 0, 0, read8_delegate(FUNC(isa16_gus_device::board_r),this), write8_delegate(FUNC(isa16_gus_device::board_w),this) );
@@ -1355,6 +1353,7 @@ WRITE8_MEMBER(isa16_gus_device::board_w)
 		break;
 	case 0x0f:
 		m_gf1->stat_w(space,offset-15,data);
+		break;
 	default:
 		logerror("GUS: Invalid or unimplemented register write %02x of port 0x2X%01x\n",data,offset);
 	}
@@ -1364,10 +1363,10 @@ READ8_MEMBER(isa16_gus_device::synth_r)
 {
 	switch(offset)
 	{
-//  case 0x00:
-//      return m_midi->status_read(space,0);
-//  case 0x01:
-//      return m_midi->data_read(space,0);
+	case 0x00:
+		return m_midi->status_read(space,0);
+	case 0x01:
+		return m_midi->data_read(space,0);
 	case 0x02:
 	case 0x03:
 		return m_gf1->global_reg_select_r(space,offset-2);
@@ -1389,10 +1388,10 @@ WRITE8_MEMBER(isa16_gus_device::synth_w)
 	switch(offset)
 	{
 	case 0x00:
-//      m_midi->control_write(space,0,data);
+		m_midi->control_write(space,0,data);
 		break;
 	case 0x01:
-//      m_midi->data_write(space,0,data);
+		m_midi->data_write(space,0,data);
 		break;
 	case 0x02:
 	case 0x03:
@@ -1674,9 +1673,9 @@ void isa16_gus_device::reset_midi_irq(UINT8 source)
 WRITE_LINE_MEMBER( isa16_gus_device::midi_irq )
 {
 	if(state)
-		set_irq(IRQ_MIDI_TRANSMIT);
+		set_midi_irq(IRQ_MIDI_TRANSMIT);
 	else
-		reset_irq(IRQ_MIDI_TRANSMIT);
+		reset_midi_irq(IRQ_MIDI_TRANSMIT);
 }
 
 WRITE_LINE_MEMBER( isa16_gus_device::nmi_w)