diff --git a/src/emu/bus/msx_slot/music.c b/src/emu/bus/msx_slot/music.c
index 77e8369fef4..27ac4cf60a5 100644
--- a/src/emu/bus/msx_slot/music.c
+++ b/src/emu/bus/msx_slot/music.c
@@ -9,8 +9,6 @@ msx_slot_music_device::msx_slot_music_device(const machine_config &mconfig, cons
 	: msx_slot_rom_device(mconfig, MSX_SLOT_MUSIC, "MSX Internal MSX-MUSIC", tag, owner, clock, "msx_slot_music", __FILE__)
 	, m_ym2413(NULL)
 	, m_ym2413_tag(NULL)
-	, m_opll_active(false)
-	, m_unlock(0)
 {
 }
 
@@ -37,33 +35,14 @@ void msx_slot_music_device::device_start()
 }
 
 
-void msx_slot_music_device::device_reset()
-{
-	m_opll_active = false;
-}
-
-
 READ8_MEMBER(msx_slot_music_device::read)
 {
 	return msx_slot_rom_device::read(space, offset);
 }
 
 
-WRITE8_MEMBER(msx_slot_music_device::write)
-{
-	if (m_unlock == 0xbe && data == 0x41)
-	{
-		m_opll_active = true;
-	}
-	m_unlock = data;
-}
-
-
 WRITE8_MEMBER(msx_slot_music_device::write_ym2413)
 {
-	if (m_opll_active)
-	{
-		m_ym2413->write(space, offset & 1, data);
-	}
+	m_ym2413->write(space, offset & 1, data);
 }
 
diff --git a/src/emu/bus/msx_slot/music.h b/src/emu/bus/msx_slot/music.h
index 0dda5bf779c..10e07ae47e6 100644
--- a/src/emu/bus/msx_slot/music.h
+++ b/src/emu/bus/msx_slot/music.h
@@ -24,18 +24,14 @@ public:
 	static void set_ym2413_tag(device_t &device, const char *tag) { dynamic_cast<msx_slot_music_device &>(device).m_ym2413_tag = tag; }
 
 	virtual void device_start();
-	virtual void device_reset();
 
 	virtual DECLARE_READ8_MEMBER(read);
-	virtual DECLARE_WRITE8_MEMBER(write);
 
 	DECLARE_WRITE8_MEMBER(write_ym2413);
 
 private:
 	ym2413_device *m_ym2413;
 	const char *m_ym2413_tag;
-	bool m_opll_active;
-	UINT8 m_unlock;
 };