diff --git a/src/devices/sound/rf5c68.cpp b/src/devices/sound/rf5c68.cpp
index 2567adfe004..9ec522b7d92 100644
--- a/src/devices/sound/rf5c68.cpp
+++ b/src/devices/sound/rf5c68.cpp
@@ -63,10 +63,6 @@ void rf5c68_device::device_start()
 	m_cache = space().cache<0, 0, ENDIANNESS_LITTLE>();
 	m_sample_end_cb.bind_relative_to(*owner());
 
-	// needs to be initialized to 0xff, otherwise f1en has bad sound (MT04531)
-	for (int i = 0; i < 0x10000; i++)
-		m_data->write_byte(i, 0xff);
-
 	/* allocate the stream */
 	m_stream = stream_alloc(0, 2, clock() / 384);
 
diff --git a/src/mame/drivers/segas32.cpp b/src/mame/drivers/segas32.cpp
index f47903b19b7..e9e866c6806 100644
--- a/src/mame/drivers/segas32.cpp
+++ b/src/mame/drivers/segas32.cpp
@@ -1242,7 +1242,7 @@ void segas32_state::system32_sound_portmap(address_map &map)
 void segas32_state::rf5c68_map(address_map &map)
 {
 	map.unmap_value_high();
-	map(0x0000, 0xffff).ram();
+	map(0x0000, 0xffff).ram().share("rf5c68_mem");
 }
 
 
@@ -5432,6 +5432,9 @@ void segas32_state::segas32_common_init()
 	m_sw1_output = nullptr;
 	m_sw2_output = nullptr;
 	m_sw3_output = nullptr;
+
+	// needs to be initialized to 0xff, otherwise f1en has bad sound (MT04531)
+	memset(memshare("rf5c68_mem")->ptr(), 0xff, memshare("rf5c68_mem")->bytes());
 }