diff --git a/src/devices/cpu/z80/z80.cpp b/src/devices/cpu/z80/z80.cpp
index 4f38a4e1866..e798a1153b2 100644
--- a/src/devices/cpu/z80/z80.cpp
+++ b/src/devices/cpu/z80/z80.cpp
@@ -3510,15 +3510,15 @@ void nsc800_device::device_reset()
  ****************************************************************************/
 void z80_device::execute_run()
 {
-	if (m_wait_state)
-	{
-		// stalled
-		m_icount = 0;
-		return;
-	}
-	
 	do
 	{
+		if (m_wait_state)
+		{
+			// stalled
+			m_icount = 0;
+			return;
+		}
+
 		// check for interrupts before each instruction
 		if (m_nmi_pending)
 			take_nmi();
@@ -3532,24 +3532,20 @@ void z80_device::execute_run()
 		debugger_instruction_hook(this, PCD);
 		m_r++;
 		EXEC(op,rop());
-
-		if (m_wait_state)
-			m_icount = 0;
-
 	} while (m_icount > 0);
 }
 
 void nsc800_device::execute_run()
 {
-	if (m_wait_state)
-	{
-		// stalled
-		m_icount = 0;
-		return;
-	}
-
 	do
 	{
+		if (m_wait_state)
+		{
+			// stalled
+			m_icount = 0;
+			return;
+		}
+
 		// check for interrupts before each instruction
 		if (m_nmi_pending)
 			take_nmi();
@@ -3565,10 +3561,6 @@ void nsc800_device::execute_run()
 		debugger_instruction_hook(this, PCD);
 		m_r++;
 		EXEC(op,rop());
-		
-		if (m_wait_state)
-			m_icount = 0;
-
 	} while (m_icount > 0);
 }
 
@@ -3745,10 +3737,3 @@ nsc800_device::nsc800_device(const machine_config &mconfig, const char *tag, dev
 }
 
 const device_type NSC800 = &device_creator<nsc800_device>;
-
-
-
-WRITE_LINE_MEMBER( z80_device::irq_line )
-{
-	set_input_line( INPUT_LINE_IRQ0, state );
-}
diff --git a/src/devices/cpu/z80/z80.h b/src/devices/cpu/z80/z80.h
index 70c8b8f68ac..38cc207347e 100644
--- a/src/devices/cpu/z80/z80.h
+++ b/src/devices/cpu/z80/z80.h
@@ -42,8 +42,6 @@ class z80_device : public cpu_device
 public:
 	z80_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
 
-	DECLARE_WRITE_LINE_MEMBER( irq_line );
-
 	void z80_set_cycle_tables(const UINT8 *op, const UINT8 *cb, const UINT8 *ed, const UINT8 *xy, const UINT8 *xycb, const UINT8 *ex);
 	template<class _Object> static devcb_base &set_irqack_cb(device_t &device, _Object object) { return downcast<z80_device &>(device).m_irqack_cb.set_callback(object); }
 	template<class _Object> static devcb_base &set_refresh_cb(device_t &device, _Object object) { return downcast<z80_device &>(device).m_refresh_cb.set_callback(object); }
diff --git a/src/mame/drivers/bw12.cpp b/src/mame/drivers/bw12.cpp
index fb9e1ce66c2..e0b9a4584de 100644
--- a/src/mame/drivers/bw12.cpp
+++ b/src/mame/drivers/bw12.cpp
@@ -574,8 +574,8 @@ static MACHINE_CONFIG_START( common, bw12_state )
 	MCFG_PIA_WRITEPB_HANDLER(DEVWRITE8("cent_data_out", output_latch_device, write))
 	MCFG_PIA_CA2_HANDLER(DEVWRITELINE(CENTRONICS_TAG, centronics_device, write_strobe))
 	MCFG_PIA_CB2_HANDLER(WRITELINE(bw12_state, pia_cb2_w))
-	MCFG_PIA_IRQA_HANDLER(DEVWRITELINE(Z80_TAG, z80_device, irq_line))
-	MCFG_PIA_IRQB_HANDLER(DEVWRITELINE(Z80_TAG, z80_device, irq_line))
+	MCFG_PIA_IRQA_HANDLER(INPUTLINE(Z80_TAG, INPUT_LINE_IRQ0))
+	MCFG_PIA_IRQB_HANDLER(INPUTLINE(Z80_TAG, INPUT_LINE_IRQ0))
 
 	MCFG_Z80SIO0_ADD(Z80SIO_TAG, XTAL_16MHz/4, 0, 0, 0, 0)
 	MCFG_Z80DART_OUT_TXDA_CB(DEVWRITELINE(RS232_A_TAG, rs232_port_device, write_txd))
diff --git a/src/mame/drivers/camplynx.cpp b/src/mame/drivers/camplynx.cpp
index 96cc919dfb9..d5647dfbcde 100644
--- a/src/mame/drivers/camplynx.cpp
+++ b/src/mame/drivers/camplynx.cpp
@@ -831,7 +831,7 @@ static MACHINE_CONFIG_START( lynx48k, camplynx_state )
 	MCFG_MC6845_SHOW_BORDER_AREA(false)
 	MCFG_MC6845_CHAR_WIDTH(8)
 	MCFG_MC6845_UPDATE_ROW_CB(camplynx_state, lynx48k_update_row)
-	MCFG_MC6845_OUT_VSYNC_CB(DEVWRITELINE("maincpu", z80_device, irq_line))
+	MCFG_MC6845_OUT_VSYNC_CB(INPUTLINE("maincpu", INPUT_LINE_IRQ0))
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( lynx96k, lynx48k )
@@ -871,7 +871,7 @@ static MACHINE_CONFIG_START( lynx128k, camplynx_state )
 	MCFG_MC6845_SHOW_BORDER_AREA(false)
 	MCFG_MC6845_CHAR_WIDTH(8)
 	MCFG_MC6845_UPDATE_ROW_CB(camplynx_state, lynx128k_update_row)
-	MCFG_MC6845_OUT_VSYNC_CB(DEVWRITELINE("maincpu", z80_device, irq_line))
+	MCFG_MC6845_OUT_VSYNC_CB(INPUTLINE("maincpu", INPUT_LINE_IRQ0))
 
 	MCFG_FRAGMENT_ADD(lynx_disk)
 MACHINE_CONFIG_END
diff --git a/src/mame/drivers/fantland.cpp b/src/mame/drivers/fantland.cpp
index 4abd445eb35..af10ddd4bd1 100644
--- a/src/mame/drivers/fantland.cpp
+++ b/src/mame/drivers/fantland.cpp
@@ -1047,7 +1047,7 @@ static MACHINE_CONFIG_START( wheelrun, fantland_state )
 	MCFG_SPEAKER_STANDARD_MONO("mono")
 
 	MCFG_SOUND_ADD("ymsnd", YM3526, XTAL_14MHz/4)
-	MCFG_YM3526_IRQ_HANDLER(DEVWRITELINE("audiocpu", z80_device, irq_line))
+	MCFG_YM3526_IRQ_HANDLER(INPUTLINE("audiocpu", INPUT_LINE_IRQ0))
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.0)
 MACHINE_CONFIG_END
 
diff --git a/src/mame/drivers/suna16.cpp b/src/mame/drivers/suna16.cpp
index e2d375bc148..f33d0142f62 100644
--- a/src/mame/drivers/suna16.cpp
+++ b/src/mame/drivers/suna16.cpp
@@ -1021,7 +1021,7 @@ static MACHINE_CONFIG_START( bestbest, suna16_state )
 	MCFG_SOUND_ROUTE(1, "rspeaker", 1.0)
 
 	MCFG_SOUND_ADD("ymsnd", YM3526, XTAL_24MHz/8)   /* 3MHz */
-	MCFG_YM3526_IRQ_HANDLER(DEVWRITELINE("audiocpu", z80_device, irq_line))
+	MCFG_YM3526_IRQ_HANDLER(INPUTLINE("audiocpu", INPUT_LINE_IRQ0))
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "lspeaker", 1.0)
 	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "rspeaker", 1.0)