diff --git a/.gitattributes b/.gitattributes
index e57057c8ee8..302d173a64d 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -8683,6 +8683,12 @@ src/mess/machine/mikro80.c svneol=native#text/plain
 src/mess/machine/mm1kb.c svneol=native#text/plain
 src/mess/machine/mm1kb.h svneol=native#text/plain
 src/mess/machine/msx.c svneol=native#text/plain
+src/mess/machine/msx_matsushita.c svneol=native#text/plain
+src/mess/machine/msx_matsushita.h svneol=native#text/plain
+src/mess/machine/msx_s1985.c svneol=native#text/plain
+src/mess/machine/msx_s1985.h svneol=native#text/plain
+src/mess/machine/msx_switched.c svneol=native#text/plain
+src/mess/machine/msx_switched.h svneol=native#text/plain
 src/mess/machine/mtx.c svneol=native#text/plain
 src/mess/machine/mz700.c svneol=native#text/plain
 src/mess/machine/mz80.c svneol=native#text/plain
diff --git a/src/mess/machine/msx_matsushita.c b/src/mess/machine/msx_matsushita.c
new file mode 100644
index 00000000000..a0a70f6bf40
--- /dev/null
+++ b/src/mess/machine/msx_matsushita.c
@@ -0,0 +1,78 @@
+#include "emu.h"
+#include "msx_matsushita.h"
+
+
+const device_type MSX_MATSUSHITA = &device_creator<msx_matsushita_device>;
+
+
+msx_matsushita_device::msx_matsushita_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+	: msx_switched_device(mconfig, MSX_MATSUSHITA, "Matsushita switched device", tag, owner, clock, "msx_matsushita", __FILE__)
+	, m_io_config(*this, "CONFIG")
+	, m_turbo_out_cb(*this)
+{
+}
+
+
+UINT8 msx_matsushita_device::get_id()
+{
+	return 0x08;
+}
+
+
+static INPUT_PORTS_START( matsushita )
+	PORT_START("CONFIG")
+	PORT_CONFNAME( 0x80, 0x00, "Firmware switch")
+	PORT_CONFSETTING( 0x00, "On" )
+	PORT_CONFSETTING( 0x80, "Off" )
+	PORT_BIT(0x7F, IP_ACTIVE_LOW, IPT_UNUSED)
+INPUT_PORTS_END
+
+
+ioport_constructor msx_matsushita_device::device_input_ports() const
+{
+	return INPUT_PORTS_NAME( matsushita );
+}
+
+
+void msx_matsushita_device::device_start()
+{
+	msx_switched_device::device_start();
+	m_turbo_out_cb.resolve_safe();
+}
+
+READ8_MEMBER(msx_matsushita_device::io_read)
+{
+	switch (offset)
+	{
+		case 0:
+			return ~get_id();
+
+		case 1:
+			return m_io_config->read();
+
+		default:
+			printf("msx_matsushita: unhandled read from offset %02x\n", offset);
+			break;
+	}
+
+	return 0xFF;
+}
+
+
+WRITE8_MEMBER(msx_matsushita_device::io_write)
+{
+	switch (offset)
+	{
+		// bit 0: CPU clock select
+		//        0 - 5.369317 MHz
+		//        1 - 3.579545 MHz
+		case 0x01:
+			m_turbo_out_cb((data & 1) ? ASSERT_LINE : CLEAR_LINE);
+			break;
+
+		default:
+			printf("msx_matsushita: unhandled write %02x to offset %02x\n", data, offset);
+			break;
+	}
+}
+
diff --git a/src/mess/machine/msx_matsushita.h b/src/mess/machine/msx_matsushita.h
new file mode 100644
index 00000000000..ae4a823cc1c
--- /dev/null
+++ b/src/mess/machine/msx_matsushita.h
@@ -0,0 +1,39 @@
+#ifndef __MSX_MATSUSHITA_H
+#define __MSX_MATSUSHITA_H
+
+
+#include "msx_switched.h"
+
+
+extern const device_type MSX_MATSUSHITA;
+
+
+#define MCFG_MSX_MATSUSHITA_ADD(_tag) \
+	MCFG_DEVICE_ADD(_tag, MSX_MATSUSHITA, 0)
+
+#define MCFG_MSX_MATSUSHITA_TURBO_CB(_devcb) \
+	devcb = &msx_matsushita_device::set_turbo_callback(*device, DEVCB_##_devcb);
+
+
+class msx_matsushita_device : public msx_switched_device
+{
+public:
+	msx_matsushita_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+	template<class _Object> static devcb_base &set_turbo_callback(device_t &device, _Object object) { return downcast<msx_matsushita_device &>(device).m_turbo_out_cb.set_callback(object); }
+
+	virtual void device_start();
+	virtual ioport_constructor device_input_ports() const;
+
+	virtual UINT8 get_id();
+
+	virtual DECLARE_READ8_MEMBER(io_read);
+	virtual DECLARE_WRITE8_MEMBER(io_write);
+
+private:
+	required_ioport   m_io_config;
+	devcb_write_line  m_turbo_out_cb;
+};
+
+#endif
+
diff --git a/src/mess/machine/msx_s1985.c b/src/mess/machine/msx_s1985.c
new file mode 100644
index 00000000000..588fb668695
--- /dev/null
+++ b/src/mess/machine/msx_s1985.c
@@ -0,0 +1,65 @@
+#include "emu.h"
+#include "msx_s1985.h"
+
+
+const device_type MSX_S1985 = &device_creator<msx_s1985_device>;
+
+
+msx_s1985_device::msx_s1985_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+	: msx_switched_device(mconfig, MSX_S1985, "MSX-Engine S1985", tag, owner, clock, "msx_s1985", __FILE__)
+	, m_6_1(0)
+	, m_6_2(0)
+	, m_7(0)
+{
+}
+
+
+UINT8 msx_s1985_device::get_id()
+{
+	return 0xFE;
+}
+
+
+READ8_MEMBER(msx_s1985_device::io_read)
+{
+	switch (offset)
+	{
+		case 0:
+			return ~get_id();
+
+		case 7:
+			{
+				UINT8 data = (m_7 & 0x80) ? m_6_2 : m_6_1;
+				m_7 = ( m_7 << 1 ) | ( m_7 >> 7 );
+				return data;
+			}
+			break;
+
+		default:
+			printf("msx_s1985: unhandled read from offset %02x\n", offset);
+			break;
+	}
+
+	return 0xFF;
+}
+
+
+WRITE8_MEMBER(msx_s1985_device::io_write)
+{
+	switch (offset)
+	{
+		case 6:
+			m_6_2 = m_6_1;
+			m_6_1 = data;
+			break;
+
+		case 7:
+			m_7 = data;
+			break;
+
+		default:
+			printf("msx_s1985: unhandled write %02x to offset %02x\n", data, offset);
+			break;
+	}
+}
+
diff --git a/src/mess/machine/msx_s1985.h b/src/mess/machine/msx_s1985.h
new file mode 100644
index 00000000000..dbe00b16f44
--- /dev/null
+++ b/src/mess/machine/msx_s1985.h
@@ -0,0 +1,32 @@
+#ifndef __MSX_S1985_H
+#define __MSX_S1985_H
+
+
+#include "msx_switched.h"
+
+
+extern const device_type MSX_S1985;
+
+
+#define MCFG_MSX_S1985_ADD(_tag) \
+	MCFG_DEVICE_ADD(_tag, MSX_S1985, 0)
+
+
+class msx_s1985_device : public msx_switched_device
+{
+public:
+	msx_s1985_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+
+	virtual UINT8 get_id();
+
+	virtual DECLARE_READ8_MEMBER(io_read);
+	virtual DECLARE_WRITE8_MEMBER(io_write);
+
+private:
+	UINT8 m_6_1;
+	UINT8 m_6_2;
+	UINT8 m_7;
+};
+
+#endif
+
diff --git a/src/mess/machine/msx_switched.c b/src/mess/machine/msx_switched.c
new file mode 100644
index 00000000000..9b416c7df7d
--- /dev/null
+++ b/src/mess/machine/msx_switched.c
@@ -0,0 +1,21 @@
+#include "emu.h"
+#include "msx_switched.h"
+
+
+msx_switched_device::msx_switched_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source)
+	: device_t(mconfig, type, name, tag, owner, clock, shortname, source)
+{
+}
+
+
+void msx_switched_device::device_start()
+{
+	address_space &space = dynamic_cast<device_memory_interface*>(owner())->space();
+
+	// Install IO read/write handlers
+	UINT16 start = ( get_id() << 8 ) | 0x00;
+	UINT16 end = ( get_id() << 8 ) | 0x0f;
+	space.install_read_handler(start, end, read8_delegate(FUNC(msx_switched_device::io_read), this));
+	space.install_write_handler(start, end, write8_delegate(FUNC(msx_switched_device::io_write), this));
+}
+
diff --git a/src/mess/machine/msx_switched.h b/src/mess/machine/msx_switched.h
new file mode 100644
index 00000000000..16848c1e3c7
--- /dev/null
+++ b/src/mess/machine/msx_switched.h
@@ -0,0 +1,19 @@
+#ifndef __MSX_SWITCHED_H
+#define __MSX_SWITCHED_H
+
+
+class msx_switched_device : public device_t
+{
+public:
+	msx_switched_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source);
+
+	virtual UINT8 get_id() = 0;
+
+	virtual DECLARE_READ8_MEMBER(io_read) = 0;
+	virtual DECLARE_WRITE8_MEMBER(io_write) = 0;
+
+protected:
+	virtual void device_start();
+};
+
+#endif