diff --git a/.gitattributes b/.gitattributes
index 88fb5b4c83b..f04c2ed132b 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1284,6 +1284,8 @@ src/emu/machine/mb3773.c svneol=native#text/plain
 src/emu/machine/mb3773.h svneol=native#text/plain
 src/emu/machine/mb87078.c svneol=native#text/plain
 src/emu/machine/mb87078.h svneol=native#text/plain
+src/emu/machine/mb89371.c svneol=native#text/plain
+src/emu/machine/mb89371.h svneol=native#text/plain
 src/emu/machine/mc146818.c svneol=native#text/plain
 src/emu/machine/mc146818.h svneol=native#text/plain
 src/emu/machine/mc2661.c svneol=native#text/plain
diff --git a/src/emu/emu.mak b/src/emu/emu.mak
index b5c494bb56d..6adc25c9baa 100644
--- a/src/emu/emu.mak
+++ b/src/emu/emu.mak
@@ -221,6 +221,7 @@ EMUMACHINEOBJS = \
 	$(EMUMACHINE)/mb14241.o     \
 	$(EMUMACHINE)/mb3773.o      \
 	$(EMUMACHINE)/mb87078.o     \
+	$(EMUMACHINE)/mb89371.o     \
 	$(EMUMACHINE)/mc146818.o    \
 	$(EMUMACHINE)/mc2661.o      \
 	$(EMUMACHINE)/mc6843.o      \
diff --git a/src/emu/machine/mb89371.c b/src/emu/machine/mb89371.c
new file mode 100644
index 00000000000..e14eacb0f66
--- /dev/null
+++ b/src/emu/machine/mb89371.c
@@ -0,0 +1,29 @@
+/*
+ * MB89371
+ *
+ * Fujitsu
+ * Dual Serial UART
+ *
+ */
+
+#include "mb89371.h"
+
+const device_type MB89371 = &device_creator<mb89371_device>;
+
+mb89371_device::mb89371_device( const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock )
+	: device_t(mconfig, MB89371, "MB89371", tag, owner, clock)
+{
+}
+
+void mb89371_device::device_start()
+{
+}
+
+WRITE8_MEMBER(mb89371_device::write)
+{
+}
+
+READ8_MEMBER(mb89371_device::read)
+{
+	return 0xff;
+}
diff --git a/src/emu/machine/mb89371.h b/src/emu/machine/mb89371.h
new file mode 100644
index 00000000000..fe2e425784a
--- /dev/null
+++ b/src/emu/machine/mb89371.h
@@ -0,0 +1,33 @@
+/*
+ * MB89371
+ *
+ * Fujitsu
+ * Dual Serial UART
+ *
+ */
+
+#ifndef __MB89371_H__
+#define __MB89371_H__
+
+#include "emu.h"
+
+class mb89371_device : public device_t
+{
+public:
+	// construction/destruction
+	mb89371_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+	DECLARE_WRITE8_MEMBER( write );
+	DECLARE_READ8_MEMBER( read );
+
+protected:
+
+	// device-level overrides
+	virtual void device_start();
+};
+
+
+// device type definition
+extern const device_type MB89371;
+
+#endif
diff --git a/src/mame/drivers/konamigq.c b/src/mame/drivers/konamigq.c
index 6a287d932d1..011e0c1ab98 100644
--- a/src/mame/drivers/konamigq.c
+++ b/src/mame/drivers/konamigq.c
@@ -49,10 +49,11 @@
 #include "cpu/m68000/m68000.h"
 #include "cpu/psx/psx.h"
 #include "video/psx.h"
+#include "machine/am53cf96.h"
 #include "machine/eeprom.h"
+#include "machine/mb89371.h"
 #include "machine/scsibus.h"
 #include "machine/scsihd.h"
-#include "machine/am53cf96.h"
 #include "sound/k054539.h"
 
 class konamigq_state : public driver_device
@@ -74,11 +75,9 @@ public:
 	UINT8 m_sector_buffer[ 512 ];
 	DECLARE_WRITE16_MEMBER(soundr3k_w);
 	DECLARE_READ16_MEMBER(soundr3k_r);
-	DECLARE_WRITE16_MEMBER(mb89371_w);
-	DECLARE_READ16_MEMBER(mb89371_r);
 	DECLARE_WRITE16_MEMBER(eeprom_w);
-	DECLARE_WRITE16_MEMBER(pcmram_w);
-	DECLARE_READ16_MEMBER(pcmram_r);
+	DECLARE_WRITE8_MEMBER(pcmram_w);
+	DECLARE_READ8_MEMBER(pcmram_r);
 	DECLARE_READ16_MEMBER(sndcomm68k_r);
 	DECLARE_WRITE16_MEMBER(sndcomm68k_w);
 	DECLARE_READ16_MEMBER(tms57002_data_word_r);
@@ -116,17 +115,6 @@ READ16_MEMBER(konamigq_state::soundr3k_r)
 	return m_sndtor3k[ offset ];
 }
 
-/* UART */
-
-WRITE16_MEMBER(konamigq_state::mb89371_w)
-{
-}
-
-READ16_MEMBER(konamigq_state::mb89371_r)
-{
-	return 0xffff;
-}
-
 /* EEPROM */
 
 static const UINT16 konamigq_def_eeprom[64] =
@@ -150,12 +138,12 @@ WRITE16_MEMBER(konamigq_state::eeprom_w)
 
 /* PCM RAM */
 
-WRITE16_MEMBER(konamigq_state::pcmram_w)
+WRITE8_MEMBER(konamigq_state::pcmram_w)
 {
 	m_p_n_pcmram[ offset ] = data;
 }
 
-READ16_MEMBER(konamigq_state::pcmram_r)
+READ8_MEMBER(konamigq_state::pcmram_r)
 {
 	return m_p_n_pcmram[ offset ];
 }
@@ -178,8 +166,8 @@ static ADDRESS_MAP_START( konamigq_map, AS_PROGRAM, 32, konamigq_state )
 	AM_RANGE(0x1f230000, 0x1f230003) AM_READ_PORT("P1_P2")
 	AM_RANGE(0x1f230004, 0x1f230007) AM_READ_PORT("P3_SERVICE")
 	AM_RANGE(0x1f238000, 0x1f238003) AM_READ_PORT("DSW")
-	AM_RANGE(0x1f300000, 0x1f5fffff) AM_READWRITE16(pcmram_r, pcmram_w, 0xffffffff)
-	AM_RANGE(0x1f680000, 0x1f68001f) AM_READWRITE16(mb89371_r, mb89371_w, 0xffffffff)
+	AM_RANGE(0x1f300000, 0x1f5fffff) AM_READWRITE8(pcmram_r, pcmram_w, 0x00ff00ff)
+	AM_RANGE(0x1f680000, 0x1f68001f) AM_DEVREADWRITE8("mb89371", mb89371_device, read, write, 0x00ff00ff)
 	AM_RANGE(0x1f780000, 0x1f780003) AM_WRITENOP /* watchdog? */
 ADDRESS_MAP_END
 
@@ -306,6 +294,8 @@ static MACHINE_CONFIG_START( konamigq, konamigq_state )
 
 	MCFG_MACHINE_START_OVERRIDE(konamigq_state, konamigq )
 	MCFG_MACHINE_RESET_OVERRIDE(konamigq_state, konamigq )
+
+	MCFG_DEVICE_ADD("mb89371", MB89371, 0)
 	MCFG_EEPROM_93C46_ADD("eeprom")
 	MCFG_EEPROM_DATA(konamigq_def_eeprom, 128)
 
diff --git a/src/mame/drivers/konamigv.c b/src/mame/drivers/konamigv.c
index d6455011fd2..3d2972e4643 100644
--- a/src/mame/drivers/konamigv.c
+++ b/src/mame/drivers/konamigv.c
@@ -123,11 +123,12 @@ Notes:
 #include "cdrom.h"
 #include "cpu/psx/psx.h"
 #include "video/psx.h"
+#include "machine/am53cf96.h"
 #include "machine/eeprom.h"
 #include "machine/intelfsh.h"
+#include "machine/mb89371.h"
 #include "machine/scsibus.h"
 #include "machine/scsicd.h"
-#include "machine/am53cf96.h"
 #include "sound/spu.h"
 #include "sound/cdda.h"
 
@@ -141,8 +142,6 @@ public:
 	{
 	}
 
-	DECLARE_WRITE16_MEMBER(mb89371_w);
-	DECLARE_READ16_MEMBER(mb89371_r);
 	DECLARE_READ16_MEMBER(flash_r);
 	DECLARE_WRITE16_MEMBER(flash_w);
 	DECLARE_READ16_MEMBER(trackball_r);
@@ -174,22 +173,13 @@ private:
 	required_device<cpu_device> m_maincpu;
 };
 
-WRITE16_MEMBER(konamigv_state::mb89371_w)
-{
-}
-
-READ16_MEMBER(konamigv_state::mb89371_r)
-{
-	return 0xffff;
-}
-
 static ADDRESS_MAP_START( konamigv_map, AS_PROGRAM, 32, konamigv_state )
 	AM_RANGE(0x1f000000, 0x1f00001f) AM_DEVREADWRITE8("scsi:am53cf96", am53cf96_device, read, write, 0x00ff00ff)
 	AM_RANGE(0x1f100000, 0x1f100003) AM_READ_PORT("P1")
 	AM_RANGE(0x1f100004, 0x1f100007) AM_READ_PORT("P2")
 	AM_RANGE(0x1f100008, 0x1f10000b) AM_READ_PORT("P3_P4")
 	AM_RANGE(0x1f180000, 0x1f180003) AM_WRITE_PORT("EEPROMOUT")
-	AM_RANGE(0x1f680000, 0x1f68001f) AM_READWRITE16(mb89371_r, mb89371_w, 0xffffffff)
+	AM_RANGE(0x1f680000, 0x1f68001f) AM_DEVREADWRITE8("mb89371", mb89371_device, read, write, 0x00ff00ff)
 	AM_RANGE(0x1f780000, 0x1f780003) AM_WRITENOP /* watchdog? */
 ADDRESS_MAP_END
 
@@ -330,6 +320,7 @@ static MACHINE_CONFIG_START( konamigv, konamigv_state )
 	MCFG_PSX_DMA_CHANNEL_READ( "maincpu", 5, psx_dma_read_delegate( FUNC( konamigv_state::scsi_dma_read ), (konamigv_state *) owner ) )
 	MCFG_PSX_DMA_CHANNEL_WRITE( "maincpu", 5, psx_dma_write_delegate( FUNC( konamigv_state::scsi_dma_write ), (konamigv_state *) owner ) )
 
+	MCFG_DEVICE_ADD("mb89371", MB89371, 0)
 	MCFG_EEPROM_93C46_ADD("eeprom")
 
 	MCFG_SCSIBUS_ADD("scsi")
diff --git a/src/mame/drivers/ksys573.c b/src/mame/drivers/ksys573.c
index 3125f4b1264..278038d2d03 100644
--- a/src/mame/drivers/ksys573.c
+++ b/src/mame/drivers/ksys573.c
@@ -487,6 +487,7 @@ G: gun mania only, drives air soft gun (this game uses real BB bullet)
 #include "machine/timekpr.h"
 #include "machine/adc083x.h"
 #include "machine/ds2401.h"
+#include "machine/mb89371.h"
 #include "machine/mpeg573.h"
 #include "machine/upd4701.h"
 #include "machine/x76f041.h"
@@ -605,8 +606,6 @@ public:
 	DECLARE_CUSTOM_INPUT_MEMBER(gn845pwbb_read);
 	DECLARE_CUSTOM_INPUT_MEMBER(gunmania_tank_shutter_sensor);
 	DECLARE_CUSTOM_INPUT_MEMBER(gunmania_cable_holder_sensor);
-	DECLARE_WRITE16_MEMBER(mb89371_w);
-	DECLARE_READ16_MEMBER(mb89371_r);
 	DECLARE_READ32_MEMBER(jamma_r);
 	DECLARE_READ16_MEMBER(control_r);
 	DECLARE_WRITE16_MEMBER(control_w);
@@ -680,18 +679,6 @@ void ATTR_PRINTF(3,4)  ksys573_state::verboselog( int n_level, const char *s_fmt
 	}
 }
 
-WRITE16_MEMBER(ksys573_state::mb89371_w)
-{
-	verboselog(2, "mb89371_w %04x %04x %04x\n", offset, mem_mask, data );
-}
-
-READ16_MEMBER(ksys573_state::mb89371_r)
-{
-	UINT32 data = 0xffff;
-	verboselog(2, "mb89371_r %04x %04x %04x\n", offset, mem_mask, data );
-	return data;
-}
-
 READ32_MEMBER(ksys573_state::jamma_r)
 {
 	int security_cart_number = m_security_cart_number;
@@ -1346,7 +1333,7 @@ static ADDRESS_MAP_START( konami573_map, AS_PROGRAM, 32, ksys573_state )
 	AM_RANGE(0x1f560000, 0x1f560003) AM_WRITE16(atapi_reset_w, 0x0000ffff)
 	AM_RANGE(0x1f5c0000, 0x1f5c0003) AM_WRITENOP                // watchdog?
 	AM_RANGE(0x1f620000, 0x1f623fff) AM_DEVREADWRITE8("m48t58", timekeeper_device, read, write, 0x00ff00ff)
-	AM_RANGE(0x1f680000, 0x1f68001f) AM_READWRITE16(mb89371_r, mb89371_w, 0xffffffff)
+	AM_RANGE(0x1f680000, 0x1f68001f) AM_DEVREADWRITE8("mb89371", mb89371_device, read, write, 0x00ff00ff)
 	AM_RANGE(0x1f6a0000, 0x1f6a0003) AM_READWRITE16(security_r, security_w, 0x0000ffff)
 ADDRESS_MAP_END
 
@@ -2699,6 +2686,7 @@ static MACHINE_CONFIG_START( konami573, ksys573_state )
 
 	MCFG_MACHINE_RESET_OVERRIDE(ksys573_state, konami573 )
 
+	MCFG_DEVICE_ADD("mb89371", MB89371, 0)
 	MCFG_DEVICE_ADD("cdrom", CR589, 0)
 
 	// onboard flash