diff --git a/src/mess/drivers/pc1512.c b/src/mess/drivers/pc1512.c
index ea16a4e64d3..42e4e6c789a 100644
--- a/src/mess/drivers/pc1512.c
+++ b/src/mess/drivers/pc1512.c
@@ -319,7 +319,7 @@ READ8_MEMBER( pc1512_state::printer_r )
 
 		*/
 
-		data |= ioport("LK")->read() & 0x07;
+		data |= m_lk->read() & 0x07;
 
 		data |= m_centronics->fault_r() << 3;
 		data |= m_centronics->vcc_r() << 4;
@@ -404,7 +404,7 @@ READ8_MEMBER( pc1640_state::printer_r )
 		*/
 		data = m_printer_control;
 		data |= m_opt << 5;
-		data |= (ioport("SW")->read() & 0x60) << 1;
+		data |= (m_sw->read() & 0x60) << 1;
 		break;
 
 	default:
@@ -489,7 +489,7 @@ READ8_MEMBER( pc1640_state::io_r )
 	}
 	else if (!BIT(offset, 7))
 	{
-		UINT16 sw = ioport("SW")->read();
+		UINT16 sw = m_sw->read();
 
 		if (!BIT(offset, 14))
 		{
@@ -1084,7 +1084,7 @@ FLOPPY_FORMATS_MEMBER( pc1512_state::floppy_formats )
 FLOPPY_FORMATS_END
 
 static SLOT_INTERFACE_START( ibmpc_floppies )
-		SLOT_INTERFACE( "525dd", FLOPPY_525_DD )
+	SLOT_INTERFACE( "525dd", FLOPPY_525_DD )
 SLOT_INTERFACE_END
 
 
diff --git a/src/mess/drivers/pecom.c b/src/mess/drivers/pecom.c
index f79681693c2..e48979168f4 100644
--- a/src/mess/drivers/pecom.c
+++ b/src/mess/drivers/pecom.c
@@ -49,7 +49,7 @@ mappings, this is another situation where natural keyboard comes very handy!
 
 INPUT_CHANGED_MEMBER(pecom_state::ef_w)
 {
-	machine().device(CDP1802_TAG)->execute().set_input_line((int)(FPTR)param, newval);
+	m_cdp1802->set_input_line((int)(FPTR)param, newval);
 }
 
 static INPUT_PORTS_START( pecom )
@@ -198,13 +198,13 @@ MACHINE_CONFIG_END
 
 /* ROM definition */
 ROM_START( pecom64 )
-		ROM_REGION( 0x10000, CDP1802_TAG, ROMREGION_ERASEFF )
-		ROM_SYSTEM_BIOS(0, "ver4", "version 4")
-		ROMX_LOAD( "pecom64-1.bin", 0x8000, 0x4000, CRC(9a433b47) SHA1(dadb8c399e0a25a2693e10e42a2d7fc2ea9ad427), ROM_BIOS(1) )
-		ROMX_LOAD( "pecom64-2.bin", 0xc000, 0x4000, CRC(2116cadc) SHA1(03f11055cd221d438a40a41874af8fba0fa116d9), ROM_BIOS(1) )
-		ROM_SYSTEM_BIOS(1, "ver1", "version 1")
-		ROMX_LOAD( "170887-rom1.bin", 0x8000, 0x4000, CRC(43710fb4) SHA1(f84f75061c9ac3e34af93141ecabd3c955881aa2), ROM_BIOS(2) )
-		ROMX_LOAD( "170887-rom2.bin", 0xc000, 0x4000, CRC(d0d34f08) SHA1(7baab17d1e68771b8dcef97d0fffc655beabef28), ROM_BIOS(2) )
+	ROM_REGION( 0x10000, CDP1802_TAG, ROMREGION_ERASEFF )
+	ROM_SYSTEM_BIOS(0, "ver4", "version 4")
+	ROMX_LOAD( "pecom64-1.bin", 0x8000, 0x4000, CRC(9a433b47) SHA1(dadb8c399e0a25a2693e10e42a2d7fc2ea9ad427), ROM_BIOS(1) )
+	ROMX_LOAD( "pecom64-2.bin", 0xc000, 0x4000, CRC(2116cadc) SHA1(03f11055cd221d438a40a41874af8fba0fa116d9), ROM_BIOS(1) )
+	ROM_SYSTEM_BIOS(1, "ver1", "version 1")
+	ROMX_LOAD( "170887-rom1.bin", 0x8000, 0x4000, CRC(43710fb4) SHA1(f84f75061c9ac3e34af93141ecabd3c955881aa2), ROM_BIOS(2) )
+	ROMX_LOAD( "170887-rom2.bin", 0xc000, 0x4000, CRC(d0d34f08) SHA1(7baab17d1e68771b8dcef97d0fffc655beabef28), ROM_BIOS(2) )
 ROM_END
 
 /* Driver */
diff --git a/src/mess/drivers/tmc600.c b/src/mess/drivers/tmc600.c
index 34db1ebbe01..1d9df6785fa 100644
--- a/src/mess/drivers/tmc600.c
+++ b/src/mess/drivers/tmc600.c
@@ -206,10 +206,9 @@ READ_LINE_MEMBER( tmc600_state::ef2_r )
 
 READ_LINE_MEMBER( tmc600_state::ef3_r )
 {
-	UINT8 keydata[8] = { m_y0->read(), m_y1->read(), m_y2->read(), m_y3->read(),
-						 m_y4->read(), m_y5->read(), m_y6->read(), m_y7->read() };
+	ioport_port* portnames[8] = { m_y0, m_y1, m_y2, m_y3, m_y4, m_y5, m_y6, m_y7 };
 
-	UINT8 data = ~keydata[m_keylatch / 8];
+	UINT8 data = ~portnames[m_keylatch / 8]->read();
 
 	return BIT(data, m_keylatch % 8);
 }
diff --git a/src/mess/includes/pc1512.h b/src/mess/includes/pc1512.h
index 9735ab70f26..23548dccf3d 100644
--- a/src/mess/includes/pc1512.h
+++ b/src/mess/includes/pc1512.h
@@ -57,7 +57,9 @@ public:
 			m_floppy0(*this, PC_FDC_XT_TAG ":0:525dd" ),
 			m_floppy1(*this, PC_FDC_XT_TAG ":1:525dd" ),
 			m_bus(*this, ISA_BUS_TAG),
+			m_char_rom(*this, AMS40041_TAG),
 			m_video_ram(*this, "video_ram"),
+		    m_lk(*this, "LK"),
 			m_pit1(0),
 			m_pit2(0),
 			m_status1(0),
@@ -93,7 +95,9 @@ public:
 	required_device<floppy_image_device> m_floppy0;
 	optional_device<floppy_image_device> m_floppy1;
 	required_device<isa8_device> m_bus;
+	optional_memory_region m_char_rom;
 	optional_shared_ptr<UINT8> m_video_ram;
+	required_ioport m_lk;
 
 	virtual void machine_start();
 	virtual void machine_reset();
@@ -196,7 +200,6 @@ public:
 	UINT8 m_printer_control;
 
 	// video state
-	const UINT8 *m_char_rom;
 	int m_toggle;
 	int m_lpen;
 	int m_blink;
@@ -210,7 +213,6 @@ public:
 
 	// sound state
 	int m_speaker_drive;
-	UINT32 screen_update_pc1512(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 };
 
 class pc1640_state : public pc1512_state
@@ -218,7 +220,8 @@ class pc1640_state : public pc1512_state
 public:
 	pc1640_state(const machine_config &mconfig, device_type type, const char *tag)
 		: pc1512_state(mconfig, type, tag),
-			m_opt(0)
+		  m_sw(*this, "SW"),
+		  m_opt(0)
 	{ }
 
 	virtual void machine_start();
@@ -236,6 +239,8 @@ public:
 	DECLARE_READ8_MEMBER( printer_r );
 	DECLARE_READ8_MEMBER( io_unmapped_r );
 
+	required_ioport m_sw;
+
 	// video state
 	int m_opt;
 	UINT8 m_egc_ctrl;
diff --git a/src/mess/machine/c64_4cga.c b/src/mess/machine/c64_4cga.c
index f43ae513aa9..ad1771a62ef 100644
--- a/src/mess/machine/c64_4cga.c
+++ b/src/mess/machine/c64_4cga.c
@@ -65,6 +65,9 @@ ioport_constructor c64_4cga_device::device_input_ports() const
 c64_4cga_device::c64_4cga_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
 	device_t(mconfig, C64_4CGA, "C64 Protovision 4 Player Interface", tag, owner, clock),
 	device_c64_user_port_interface(mconfig, *this),
+	m_fire(*this, "FIRE"),
+	m_joy3(*this, "JOY3"),
+	m_joy4(*this, "JOY4"),
 	m_port(0)
 {
 }
@@ -87,15 +90,15 @@ void c64_4cga_device::device_start()
 
 UINT8 c64_4cga_device::c64_pb_r(address_space &space, offs_t offset)
 {
-	UINT8 data = ioport("FIRE")->read();
+	UINT8 data = m_fire->read();
 
 	if (m_port)
 	{
-		data &= ioport("JOY3")->read();
+		data &= m_joy3->read();
 	}
 	else
 	{
-		data &= ioport("JOY4")->read();
+		data &= m_joy4->read();
 	}
 
 	return data;
diff --git a/src/mess/machine/c64_4cga.h b/src/mess/machine/c64_4cga.h
index 6732ac44ff8..f7078a968ba 100644
--- a/src/mess/machine/c64_4cga.h
+++ b/src/mess/machine/c64_4cga.h
@@ -44,6 +44,10 @@ protected:
 	virtual void c64_pb_w(address_space &space, offs_t offset, UINT8 data);
 
 private:
+	required_ioport m_fire;
+	required_ioport m_joy3;
+	required_ioport m_joy4;
+
 	int m_port;
 };
 
diff --git a/src/mess/machine/c64_4dxh.c b/src/mess/machine/c64_4dxh.c
index 0c8900d3a08..0f1563854f1 100644
--- a/src/mess/machine/c64_4dxh.c
+++ b/src/mess/machine/c64_4dxh.c
@@ -65,7 +65,9 @@ ioport_constructor c64_4dxh_device::device_input_ports() const
 
 c64_4dxh_device::c64_4dxh_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
 	device_t(mconfig, C64_4DXH, "C64 DXH 4-Player Adapter", tag, owner, clock),
-	device_c64_user_port_interface(mconfig, *this)
+	device_c64_user_port_interface(mconfig, *this),
+	m_pb(*this, "PB"),
+	m_pa2(*this, "PA2")
 {
 }
 
@@ -85,7 +87,7 @@ void c64_4dxh_device::device_start()
 
 UINT8 c64_4dxh_device::c64_pb_r(address_space &space, offs_t offset)
 {
-	return ioport("PB")->read();
+	return m_pb->read();
 }
 
 
@@ -95,7 +97,7 @@ UINT8 c64_4dxh_device::c64_pb_r(address_space &space, offs_t offset)
 
 int c64_4dxh_device::c64_pa2_r()
 {
-	return BIT(ioport("PA2")->read(), 0);
+	return BIT(m_pa2->read(), 0);
 }
 
 
diff --git a/src/mess/machine/c64_4dxh.h b/src/mess/machine/c64_4dxh.h
index 4cb35313229..06d9c0eeb78 100644
--- a/src/mess/machine/c64_4dxh.h
+++ b/src/mess/machine/c64_4dxh.h
@@ -45,6 +45,10 @@ protected:
 	virtual UINT8 c64_pb_r(address_space &space, offs_t offset);
 	virtual int c64_pa2_r();
 	virtual void c64_cnt1_w(int level);
+
+private:
+	required_ioport m_pb;
+	required_ioport m_pa2;
 };
 
 
diff --git a/src/mess/machine/c64_4ksa.c b/src/mess/machine/c64_4ksa.c
index 437ffb9c45a..de1c2fd3b2f 100644
--- a/src/mess/machine/c64_4ksa.c
+++ b/src/mess/machine/c64_4ksa.c
@@ -65,7 +65,9 @@ ioport_constructor c64_4ksa_device::device_input_ports() const
 
 c64_4ksa_device::c64_4ksa_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
 	device_t(mconfig, C64_4KSA, "C64 Kingsoft 4-Player Adapter", tag, owner, clock),
-	device_c64_user_port_interface(mconfig, *this)
+	device_c64_user_port_interface(mconfig, *this),
+	m_pb(*this, "PB"),
+	m_pa2(*this, "PA2")
 {
 }
 
@@ -85,7 +87,7 @@ void c64_4ksa_device::device_start()
 
 UINT8 c64_4ksa_device::c64_pb_r(address_space &space, offs_t offset)
 {
-	return ioport("PB")->read();
+	return m_pb->read();
 }
 
 
@@ -95,7 +97,7 @@ UINT8 c64_4ksa_device::c64_pb_r(address_space &space, offs_t offset)
 
 int c64_4ksa_device::c64_pa2_r()
 {
-	return BIT(ioport("PA2")->read(), 0);
+	return BIT(m_pa2->read(), 0);
 }
 
 
diff --git a/src/mess/machine/c64_4ksa.h b/src/mess/machine/c64_4ksa.h
index 443e0057ca9..2dfe250fb3e 100644
--- a/src/mess/machine/c64_4ksa.h
+++ b/src/mess/machine/c64_4ksa.h
@@ -45,6 +45,10 @@ protected:
 	virtual UINT8 c64_pb_r(address_space &space, offs_t offset);
 	virtual int c64_pa2_r();
 	virtual void c64_cnt1_w(int level);
+
+private:
+	required_ioport m_pb;
+	required_ioport m_pa2;
 };
 
 
diff --git a/src/mess/machine/c64_4tba.c b/src/mess/machine/c64_4tba.c
index 3e65c272bbd..f3f99f0e0e1 100644
--- a/src/mess/machine/c64_4tba.c
+++ b/src/mess/machine/c64_4tba.c
@@ -65,7 +65,9 @@ ioport_constructor c64_4tba_device::device_input_ports() const
 
 c64_4tba_device::c64_4tba_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
 	device_t(mconfig, C64_4TBA, "C64 Tie Break Adapter", tag, owner, clock),
-	device_c64_user_port_interface(mconfig, *this)
+	device_c64_user_port_interface(mconfig, *this),
+	m_pb(*this, "PB"),
+	m_pa2(*this, "PA2")
 {
 }
 
@@ -85,7 +87,7 @@ void c64_4tba_device::device_start()
 
 UINT8 c64_4tba_device::c64_pb_r(address_space &space, offs_t offset)
 {
-	return ioport("PB")->read();
+	return m_pb->read();
 }
 
 
@@ -95,7 +97,7 @@ UINT8 c64_4tba_device::c64_pb_r(address_space &space, offs_t offset)
 
 int c64_4tba_device::c64_pa2_r()
 {
-	return BIT(ioport("PA2")->read(), 0);
+	return BIT(m_pa2->read(), 0);
 }
 
 
diff --git a/src/mess/machine/c64_4tba.h b/src/mess/machine/c64_4tba.h
index 6de5a8f4053..09f4abd3a69 100644
--- a/src/mess/machine/c64_4tba.h
+++ b/src/mess/machine/c64_4tba.h
@@ -45,6 +45,10 @@ protected:
 	virtual UINT8 c64_pb_r(address_space &space, offs_t offset);
 	virtual int c64_pa2_r();
 	virtual void c64_cnt1_w(int level);
+
+private:
+	required_ioport m_pb;
+	required_ioport m_pa2;
 };
 
 
diff --git a/src/mess/machine/c64_sfx_sound_expander.c b/src/mess/machine/c64_sfx_sound_expander.c
index dde8d3237c4..5dd84b47e84 100644
--- a/src/mess/machine/c64_sfx_sound_expander.c
+++ b/src/mess/machine/c64_sfx_sound_expander.c
@@ -216,7 +216,15 @@ c64_sfx_sound_expander_cartridge_device::c64_sfx_sound_expander_cartridge_device
 	device_t(mconfig, C64_SFX_SOUND_EXPANDER, "C64 SFX Sound Expander cartridge", tag, owner, clock),
 	device_c64_expansion_card_interface(mconfig, *this),
 	m_opl(*this, YM3526_TAG),
-	m_exp(*this, C64_EXPANSION_SLOT_TAG)
+	m_exp(*this, C64_EXPANSION_SLOT_TAG),
+	m_kb0(*this, "KB0"),
+	m_kb1(*this, "KB1"),
+	m_kb2(*this, "KB2"),
+	m_kb3(*this, "KB3"),
+	m_kb4(*this, "KB4"),
+	m_kb5(*this, "KB5"),
+	m_kb6(*this, "KB6"),
+	m_kb7(*this, "KB7")
 {
 }
 
@@ -253,14 +261,14 @@ UINT8 c64_sfx_sound_expander_cartridge_device::c64_cd_r(address_space &space, of
 		{
 			switch (offset & 0x07)
 			{
-			case 0: data = ioport("KB0")->read(); break;
-			case 1: data = ioport("KB1")->read(); break;
-			case 2: data = ioport("KB2")->read(); break;
-			case 3: data = ioport("KB3")->read(); break;
-			case 4: data = ioport("KB4")->read(); break;
-			case 5: data = ioport("KB5")->read(); break;
-			case 6: data = ioport("KB6")->read(); break;
-			case 7: data = ioport("KB7")->read(); break;
+			case 0: data = m_kb0->read(); break;
+			case 1: data = m_kb1->read(); break;
+			case 2: data = m_kb2->read(); break;
+			case 3: data = m_kb3->read(); break;
+			case 4: data = m_kb4->read(); break;
+			case 5: data = m_kb5->read(); break;
+			case 6: data = m_kb6->read(); break;
+			case 7: data = m_kb7->read(); break;
 			}
 		}
 		else if (BIT(offset, 5))
diff --git a/src/mess/machine/c64_sfx_sound_expander.h b/src/mess/machine/c64_sfx_sound_expander.h
index 658a978eac6..be5e00e247b 100644
--- a/src/mess/machine/c64_sfx_sound_expander.h
+++ b/src/mess/machine/c64_sfx_sound_expander.h
@@ -59,6 +59,14 @@ protected:
 private:
 	required_device<ym3526_device> m_opl;
 	required_device<c64_expansion_slot_device> m_exp;
+	required_ioport m_kb0;
+	required_ioport m_kb1;
+	required_ioport m_kb2;
+	required_ioport m_kb3;
+	required_ioport m_kb4;
+	required_ioport m_kb5;
+	required_ioport m_kb6;
+	required_ioport m_kb7;
 };
 
 
diff --git a/src/mess/machine/comx_joy.c b/src/mess/machine/comx_joy.c
index 52960b5a41c..c4728f14ad5 100644
--- a/src/mess/machine/comx_joy.c
+++ b/src/mess/machine/comx_joy.c
@@ -69,7 +69,9 @@ ioport_constructor comx_joy_device::device_input_ports() const
 
 comx_joy_device::comx_joy_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
 	device_t(mconfig, COMX_JOY, "COMX JoyCard", tag, owner, clock),
-	device_comx_expansion_card_interface(mconfig, *this)
+	device_comx_expansion_card_interface(mconfig, *this),
+	m_joy1(*this, "JOY1"),
+	m_joy2(*this, "JOY2")
 {
 }
 
@@ -102,11 +104,11 @@ UINT8 comx_joy_device::comx_io_r(address_space &space, offs_t offset)
 
 	if (offset == 2)
 	{
-		data = ioport("JOY1")->read();
+		data = m_joy1->read();
 	}
 	else if (offset == 4)
 	{
-		data = ioport("JOY2")->read();
+		data = m_joy2->read();
 	}
 
 	return data;
diff --git a/src/mess/machine/comx_joy.h b/src/mess/machine/comx_joy.h
index e368eeac473..ca37e06cd8a 100644
--- a/src/mess/machine/comx_joy.h
+++ b/src/mess/machine/comx_joy.h
@@ -42,6 +42,10 @@ protected:
 
 	// device_comx_expansion_card_interface overrides
 	virtual UINT8 comx_io_r(address_space &space, offs_t offset);
+
+private:
+	required_ioport m_joy1;
+	required_ioport m_joy2;
 };
 
 
diff --git a/src/mess/machine/pc1512kb.c b/src/mess/machine/pc1512kb.c
index 86c8b1a3fb0..5293daf63ce 100644
--- a/src/mess/machine/pc1512kb.c
+++ b/src/mess/machine/pc1512kb.c
@@ -260,6 +260,18 @@ ioport_constructor pc1512_keyboard_device::device_input_ports() const
 pc1512_keyboard_device::pc1512_keyboard_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
 	: device_t(mconfig, PC1512_KEYBOARD, "Amstrad PC1512 Keyboard", tag, owner, clock),
 		m_maincpu(*this, I8048_TAG),
+		m_y1(*this, "Y1"),
+		m_y2(*this, "Y2"),
+		m_y3(*this, "Y3"),
+		m_y4(*this, "Y4"),
+		m_y5(*this, "Y5"),
+		m_y6(*this, "Y6"),
+		m_y7(*this, "Y7"),
+		m_y8(*this, "Y8"),
+		m_y9(*this, "Y9"),
+		m_y10(*this, "Y10"),
+		m_y11(*this, "Y11"),
+		m_com(*this, "COM"),
 		m_data_in(1),
 		m_clock_in(1),
 		m_kb_y(0xffff),
@@ -391,18 +403,18 @@ READ8_MEMBER( pc1512_keyboard_device::kb_bus_r )
 
 	UINT8 data = 0xff;
 
-	if (!BIT(m_kb_y, 0)) data &= ioport("Y1")->read();
-	if (!BIT(m_kb_y, 1)) data &= ioport("Y2")->read();
-	if (!BIT(m_kb_y, 2)) data &= ioport("Y3")->read();
-	if (!BIT(m_kb_y, 3)) data &= ioport("Y4")->read();
-	if (!BIT(m_kb_y, 4)) data &= ioport("Y5")->read();
-	if (!BIT(m_kb_y, 5)) data &= ioport("Y6")->read();
-	if (!BIT(m_kb_y, 6)) data &= ioport("Y7")->read();
-	if (!BIT(m_kb_y, 7)) data &= ioport("Y8")->read();
-	if (!BIT(m_kb_y, 8)) data &= ioport("Y9")->read();
-	if (!BIT(m_kb_y, 9)) data &= ioport("Y10")->read();
-	if (!BIT(m_kb_y, 10)) data &= ioport("Y11")->read();
-	if (!m_joy_com) data &= ioport("COM")->read();
+	if (!BIT(m_kb_y, 0)) data &= m_y1->read();
+	if (!BIT(m_kb_y, 1)) data &= m_y2->read();
+	if (!BIT(m_kb_y, 2)) data &= m_y3->read();
+	if (!BIT(m_kb_y, 3)) data &= m_y4->read();
+	if (!BIT(m_kb_y, 4)) data &= m_y5->read();
+	if (!BIT(m_kb_y, 5)) data &= m_y6->read();
+	if (!BIT(m_kb_y, 6)) data &= m_y7->read();
+	if (!BIT(m_kb_y, 7)) data &= m_y8->read();
+	if (!BIT(m_kb_y, 8)) data &= m_y9->read();
+	if (!BIT(m_kb_y, 9)) data &= m_y10->read();
+	if (!BIT(m_kb_y, 10)) data &= m_y11->read();
+	if (!m_joy_com) data &= m_com->read();
 
 	return data;
 }
diff --git a/src/mess/machine/pc1512kb.h b/src/mess/machine/pc1512kb.h
index aedcef2507f..05487dec773 100644
--- a/src/mess/machine/pc1512kb.h
+++ b/src/mess/machine/pc1512kb.h
@@ -91,6 +91,18 @@ private:
 	devcb_resolved_write_line   m_out_clock_func;
 
 	required_device<cpu_device> m_maincpu;
+	required_ioport m_y1;
+	required_ioport m_y2;
+	required_ioport m_y3;
+	required_ioport m_y4;
+	required_ioport m_y5;
+	required_ioport m_y6;
+	required_ioport m_y7;
+	required_ioport m_y8;
+	required_ioport m_y9;
+	required_ioport m_y10;
+	required_ioport m_y11;
+	required_ioport m_com;
 
 	int m_data_in;
 	int m_clock_in;
diff --git a/src/mess/video/pc1512.c b/src/mess/video/pc1512.c
index c3fd5f695e7..9a6591ef8ca 100644
--- a/src/mess/video/pc1512.c
+++ b/src/mess/video/pc1512.c
@@ -390,7 +390,7 @@ int pc1512_state::get_display_mode(UINT8 mode)
 
 offs_t pc1512_state::get_char_rom_offset()
 {
-	return ((ioport("LK")->read() >> 5) & 0x03) << 11;
+	return ((m_lk->read() >> 5) & 0x03) << 11;
 }
 
 void pc1512_state::draw_alpha(bitmap_rgb32 &bitmap, const rectangle &cliprect, UINT16 ma, UINT8 ra, UINT16 y, UINT8 x_count, INT8 cursor_x, void *param)
@@ -421,7 +421,7 @@ void pc1512_state::draw_alpha(bitmap_rgb32 &bitmap, const rectangle &cliprect, U
 		}
 
 		offs_t addr = char_rom_offset | (code << 3) | (ra & 0x07);
-		UINT8 data = m_char_rom[addr & 0x1fff];
+		UINT8 data = m_char_rom->base()[addr & 0x1fff];
 
 		if ((column == cursor_x) && m_cursor)
 		{
@@ -548,9 +548,6 @@ static MC6845_INTERFACE( crtc_intf )
 
 void pc1512_state::video_start()
 {
-	// find memory regions
-	m_char_rom = memregion(AMS40041_TAG)->base();
-
 	// allocate memory
 	m_video_ram.allocate(0x10000);
 }
diff --git a/src/mess/video/pc1640.c b/src/mess/video/pc1640.c
index fa4d7a123b4..f592b392840 100644
--- a/src/mess/video/pc1640.c
+++ b/src/mess/video/pc1640.c
@@ -128,7 +128,7 @@ READ8_MEMBER( pc1640_state::iga_r )
 		*/
 
 		// switch sense
-		data |= BIT(ioport("SW")->read(), ((m_egc_ctrl >> 2) & 0x03) ^ 0x03);
+		data |= BIT(m_sw->read(), ((m_egc_ctrl >> 2) & 0x03) ^ 0x03);
 		break;
 
 	case 0x15: // Sequencer Data Register
@@ -364,7 +364,7 @@ static MC6845_INTERFACE( crtc_intf )
 
 
 //-------------------------------------------------
-//  VIDEO_START( pc1640 )
+//  VIDEO_START( pc1640 )s
 //-------------------------------------------------
 
 void pc1640_state::video_start()
@@ -380,7 +380,7 @@ void pc1640_state::video_start()
 
 UINT32 pc1640_state::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
 {
-	return false;
+	return 0;
 }
 
 
diff --git a/src/mess/video/pecom.c b/src/mess/video/pecom.c
index 06ddbe2ddd6..4fc959c45ad 100644
--- a/src/mess/video/pecom.c
+++ b/src/mess/video/pecom.c
@@ -74,7 +74,7 @@ WRITE_LINE_MEMBER(pecom_state::pecom_prd_w)
 	// every other PRD triggers a DMAOUT request
 	if (m_dma)
 	{
-		machine().device(CDP1802_TAG)->execute().set_input_line(COSMAC_INPUT_LINE_DMAOUT, HOLD_LINE);
+		m_cdp1802->set_input_line(COSMAC_INPUT_LINE_DMAOUT, HOLD_LINE);
 	}
 
 	m_dma = !m_dma;