diff --git a/src/mess/drivers/rmnimbus.c b/src/mess/drivers/rmnimbus.c
index 850d575af50..9971fde990a 100644
--- a/src/mess/drivers/rmnimbus.c
+++ b/src/mess/drivers/rmnimbus.c
@@ -75,7 +75,7 @@ static const ay8910_interface nimbus_ay8910_interface =
 
 static const msm5205_interface msm5205_config =
 {
-	DEVCB_LINE(nimbus_msm5205_vck), /* VCK function */
+	DEVCB_DRIVER_LINE_MEMBER(rmnimbus_state, nimbus_msm5205_vck), /* VCK function */
 	MSM5205_S48_4B      /* 8 kHz */
 };
 
diff --git a/src/mess/includes/rmnimbus.h b/src/mess/includes/rmnimbus.h
index 850ab4a260d..5c04bba99d4 100644
--- a/src/mess/includes/rmnimbus.h
+++ b/src/mess/includes/rmnimbus.h
@@ -344,8 +344,6 @@ extern const wd17xx_interface nimbus_wd17xx_interface;
 
 #define MSM5205_TAG             "msm5205"
 
-void nimbus_msm5205_vck(device_t *device,int st);
-
 /* Mouse / Joystick */
 
 #define JOYSTICK0_TAG           "joystick0"
@@ -483,6 +481,8 @@ public:
 	DECLARE_WRITE_LINE_MEMBER(nimbus_scsi_io_w);
 	DECLARE_WRITE_LINE_MEMBER(nimbus_scsi_msg_w);
 	DECLARE_WRITE_LINE_MEMBER(nimbus_scsi_req_w);
+	DECLARE_WRITE_LINE_MEMBER(nimbus_msm5205_vck);
+
 	void nimbus_scsi_linechange( UINT8 mask, UINT8 state );
 	IRQ_CALLBACK_MEMBER(int_callback);
 	UINT8 get_pixel(UINT16 x, UINT16 y);
diff --git a/src/mess/machine/beta.c b/src/mess/machine/beta.c
index bc7488ab2be..c3e9baf0c6b 100644
--- a/src/mess/machine/beta.c
+++ b/src/mess/machine/beta.c
@@ -72,31 +72,27 @@ void beta_disk_device::clear_status()
 	m_betadisk_status = 0;
 }
 
-static WRITE_LINE_DEVICE_HANDLER(wd179x_intrq_w)
+WRITE_LINE_MEMBER(beta_disk_device::wd179x_intrq_w)
 {
-	beta_disk_device *beta = dynamic_cast<beta_disk_device *>(device->owner());
-	
 	if (state)
-		beta->m_betadisk_status |= (1<<7);
+		m_betadisk_status |= (1<<7);
 	else
-		beta->m_betadisk_status &=~(1<<7);
+		m_betadisk_status &=~(1<<7);
 }
 
-static WRITE_LINE_DEVICE_HANDLER(wd179x_drq_w)
+WRITE_LINE_MEMBER(beta_disk_device::wd179x_drq_w)
 {
-	beta_disk_device *beta = dynamic_cast<beta_disk_device *>(device->owner());
-	
 	if (state)
-		beta->m_betadisk_status |= (1<<6);
+		m_betadisk_status |= (1<<6);
 	else
-		beta->m_betadisk_status &=~(1<<6);
+		m_betadisk_status &=~(1<<6);
 }
 
 static const wd17xx_interface beta_wd17xx_interface =
 {
 	DEVCB_NULL,
-	DEVCB_LINE(wd179x_intrq_w),
-	DEVCB_LINE(wd179x_drq_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, beta_disk_device, wd179x_intrq_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, beta_disk_device, wd179x_drq_w),
 	{FLOPPY_0, FLOPPY_1, FLOPPY_2, FLOPPY_3}
 };
 
diff --git a/src/mess/machine/beta.h b/src/mess/machine/beta.h
index 2acc2c708ef..b96e3ab2ac1 100644
--- a/src/mess/machine/beta.h
+++ b/src/mess/machine/beta.h
@@ -31,6 +31,9 @@ public:
 	DECLARE_WRITE8_MEMBER(sector_w);
 	DECLARE_WRITE8_MEMBER(data_w);
 	
+	DECLARE_WRITE_LINE_MEMBER(wd179x_intrq_w);
+	DECLARE_WRITE_LINE_MEMBER(wd179x_drq_w);
+	
 	int is_active();
 	void enable();
 	void disable();
diff --git a/src/mess/machine/bml3mp1802.c b/src/mess/machine/bml3mp1802.c
index 9f571254888..3d20f77f122 100644
--- a/src/mess/machine/bml3mp1802.c
+++ b/src/mess/machine/bml3mp1802.c
@@ -33,18 +33,17 @@ static const floppy_interface bml3_mp1802_floppy_interface =
 	NULL
 };
 
-static WRITE_LINE_DEVICE_HANDLER( bml3_wd17xx_intrq_w )
+WRITE_LINE_MEMBER( bml3bus_mp1802_device::bml3_wd17xx_intrq_w )
 {
-	bml3bus_mp1802_device *fdc = dynamic_cast<bml3bus_mp1802_device *>(device->owner());
 	if (state) {
-		fdc->m_bml3bus->set_nmi_line(PULSE_LINE);
+		m_bml3bus->set_nmi_line(PULSE_LINE);
 	}
 }
 
 const wd17xx_interface bml3_wd17xx_interface =
 {
 	DEVCB_NULL,
-	DEVCB_LINE(bml3_wd17xx_intrq_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, bml3bus_mp1802_device, bml3_wd17xx_intrq_w),
 	DEVCB_NULL,
 	{FLOPPY_0, FLOPPY_1}
 };
diff --git a/src/mess/machine/bml3mp1802.h b/src/mess/machine/bml3mp1802.h
index 0fbfb67af91..ae6b829fb21 100644
--- a/src/mess/machine/bml3mp1802.h
+++ b/src/mess/machine/bml3mp1802.h
@@ -33,7 +33,7 @@ public:
 
 	DECLARE_READ8_MEMBER(bml3_mp1802_r);
 	DECLARE_WRITE8_MEMBER(bml3_mp1802_w);
-
+	DECLARE_WRITE_LINE_MEMBER(bml3_wd17xx_intrq_w);
 protected:
 	virtual void device_start();
 	virtual void device_reset();
diff --git a/src/mess/machine/coco_fdc.c b/src/mess/machine/coco_fdc.c
index 65730fc5f3f..d8e559c371a 100644
--- a/src/mess/machine/coco_fdc.c
+++ b/src/mess/machine/coco_fdc.c
@@ -130,11 +130,10 @@ coco_rtc_type_t coco_fdc_device::real_time_clock()
     fdc_intrq_w - callback from the FDC
 -------------------------------------------------*/
 
-static WRITE_LINE_DEVICE_HANDLER( fdc_intrq_w )
+WRITE_LINE_MEMBER( coco_fdc_device::fdc_intrq_w )
 {
-	coco_fdc_device *fdc = dynamic_cast<coco_fdc_device *>(device->owner());
-	fdc->set_intrq(state);
-	fdc->update_lines();
+	set_intrq(state);
+	update_lines();
 }
 
 
@@ -142,11 +141,10 @@ static WRITE_LINE_DEVICE_HANDLER( fdc_intrq_w )
     fdc_drq_w - callback from the FDC
 -------------------------------------------------*/
 
-static WRITE_LINE_DEVICE_HANDLER( fdc_drq_w )
+WRITE_LINE_MEMBER( coco_fdc_device::fdc_drq_w )
 {
-	coco_fdc_device *fdc = dynamic_cast<coco_fdc_device *>(device->owner());
-	fdc->set_drq(state);
-	fdc->update_lines();
+	set_drq(state);
+	update_lines();
 }
 
 
@@ -157,8 +155,8 @@ static WRITE_LINE_DEVICE_HANDLER( fdc_drq_w )
 static const wd17xx_interface coco_wd17xx_interface =
 {
 	DEVCB_NULL,
-	DEVCB_LINE(fdc_intrq_w),
-	DEVCB_LINE(fdc_drq_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, coco_fdc_device, fdc_intrq_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, coco_fdc_device, fdc_drq_w),
 	{FLOPPY_0,FLOPPY_1,FLOPPY_2,FLOPPY_3}
 };
 
diff --git a/src/mess/machine/coco_fdc.h b/src/mess/machine/coco_fdc.h
index 9b980ba7cd4..028bf4e39e5 100644
--- a/src/mess/machine/coco_fdc.h
+++ b/src/mess/machine/coco_fdc.h
@@ -44,6 +44,9 @@ public:
 
 		void set_intrq(UINT8 val) { m_intrq = val; }
 		void set_drq(UINT8 val) { m_drq = val; }
+		
+		DECLARE_WRITE_LINE_MEMBER(fdc_intrq_w);
+		DECLARE_WRITE_LINE_MEMBER(fdc_drq_w);
 protected:
 		// device-level overrides
 		virtual void device_start();
diff --git a/src/mess/machine/coco_multi.c b/src/mess/machine/coco_multi.c
index 212735c21d9..0f71766b516 100644
--- a/src/mess/machine/coco_multi.c
+++ b/src/mess/machine/coco_multi.c
@@ -82,29 +82,29 @@ static SLOT_INTERFACE_START(coco_cart_slot4)
 	SLOT_INTERFACE("pak", COCO_PAK)
 SLOT_INTERFACE_END
 
-WRITE_LINE_DEVICE_HANDLER(multi_cart_w)
+WRITE_LINE_MEMBER(coco_multipak_device::multi_cart_w)
 {
-	cococart_slot_device *cart = dynamic_cast<cococart_slot_device *>(device->owner()->owner());
-	cart->m_cart_callback.writeline(device,state);
+	cococart_slot_device *cart = dynamic_cast<cococart_slot_device *>(owner());
+	cart->m_cart_callback.writeline(this,state);
 }
 
-WRITE_LINE_DEVICE_HANDLER(multi_nmi_w)
+WRITE_LINE_MEMBER(coco_multipak_device::multi_nmi_w)
 {
-	cococart_slot_device *cart = dynamic_cast<cococart_slot_device *>(device->owner()->owner());
-	cart->m_nmi_callback.writeline(device,state);
+	cococart_slot_device *cart = dynamic_cast<cococart_slot_device *>(owner());
+	cart->m_nmi_callback.writeline(this,state);
 }
 
-WRITE_LINE_DEVICE_HANDLER(multi_halt_w)
+WRITE_LINE_MEMBER(coco_multipak_device::multi_halt_w)
 {
-	cococart_slot_device *cart = dynamic_cast<cococart_slot_device *>(device->owner()->owner());
-	cart->m_halt_callback.writeline(device,state);
+	cococart_slot_device *cart = dynamic_cast<cococart_slot_device *>(owner());
+	cart->m_halt_callback.writeline(this,state);
 }
 
 static const cococart_interface multi_cococart_interface =
 {
-	DEVCB_LINE(multi_cart_w),
-	DEVCB_LINE(multi_nmi_w),
-	DEVCB_LINE(multi_halt_w)
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, coco_multipak_device, multi_cart_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, coco_multipak_device, multi_nmi_w),
+	DEVCB_DEVICE_LINE_MEMBER(DEVICE_SELF_OWNER, coco_multipak_device, multi_halt_w)
 };
 
 static MACHINE_CONFIG_FRAGMENT(coco_multi)
diff --git a/src/mess/machine/coco_multi.h b/src/mess/machine/coco_multi.h
index a7907f15b64..a6aaf9beff0 100644
--- a/src/mess/machine/coco_multi.h
+++ b/src/mess/machine/coco_multi.h
@@ -35,6 +35,9 @@ public:
 
 	virtual UINT8* get_cart_base();
 
+	DECLARE_WRITE_LINE_MEMBER(multi_cart_w);
+	DECLARE_WRITE_LINE_MEMBER(multi_nmi_w);
+	DECLARE_WRITE_LINE_MEMBER(multi_halt_w);
 protected:
 	// device-level overrides
 	virtual void device_start();
diff --git a/src/mess/machine/rmnimbus.c b/src/mess/machine/rmnimbus.c
index a4153c8e316..80f65e5da3e 100644
--- a/src/mess/machine/rmnimbus.c
+++ b/src/mess/machine/rmnimbus.c
@@ -2765,11 +2765,10 @@ WRITE8_MEMBER(rmnimbus_state::nimbus_sound_ay8910_portb_w)
 	}
 }
 
-void nimbus_msm5205_vck(device_t *device, int st)
+WRITE_LINE_MEMBER(rmnimbus_state::nimbus_msm5205_vck)
 {
-	rmnimbus_state *state = device->machine().driver_data<rmnimbus_state>();
-	if(state->m_iou_reg092 & MSM5205_INT_ENABLE)
-		state->external_int(0,EXTERNAL_INT_MSM5205);
+	if(m_iou_reg092 & MSM5205_INT_ENABLE)
+		external_int(0,EXTERNAL_INT_MSM5205);
 }
 
 static const int MOUSE_XYA[3][4] = { { 0, 0, 0, 0 }, { 1, 1, 0, 0 }, { 0, 1, 1, 0 } };