diff --git a/src/devices/sound/sn76496.cpp b/src/devices/sound/sn76496.cpp
index 3d59fb62603..83f2d0c5e50 100644
--- a/src/devices/sound/sn76496.cpp
+++ b/src/devices/sound/sn76496.cpp
@@ -178,11 +178,6 @@ sn76496_device::sn76496_device(const machine_config &mconfig, const char *tag, d
 {
 }
 
-u8106_device::u8106_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
-	: sn76496_base_device(mconfig, U8106, tag, 0x4000, 0x01, 0x02, true, false, 8, false, true, owner, clock)
-{
-}
-
 y2404_device::y2404_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
 	: sn76496_base_device(mconfig, Y2404, tag, 0x10000, 0x04, 0x08, false, false, 8, false, true, owner, clock)
 {
@@ -477,7 +472,6 @@ void sn76496_base_device::register_for_save_states()
 }
 
 DEFINE_DEVICE_TYPE(SN76496,  sn76496_device,   "sn76496",      "SN76496")
-DEFINE_DEVICE_TYPE(U8106,    u8106_device,     "u8106",        "U8106")
 DEFINE_DEVICE_TYPE(Y2404,    y2404_device,     "y2404",        "Y2404")
 DEFINE_DEVICE_TYPE(SN76489,  sn76489_device,   "sn76489",      "SN76489")
 DEFINE_DEVICE_TYPE(SN76489A, sn76489a_device,  "sn76489a",     "SN76489A")
diff --git a/src/devices/sound/sn76496.h b/src/devices/sound/sn76496.h
index 07fb3a47932..f58e259b439 100644
--- a/src/devices/sound/sn76496.h
+++ b/src/devices/sound/sn76496.h
@@ -7,7 +7,6 @@
 
 
 DECLARE_DEVICE_TYPE(SN76496,  sn76496_device)
-DECLARE_DEVICE_TYPE(U8106,    u8106_device)
 DECLARE_DEVICE_TYPE(Y2404,    y2404_device)
 DECLARE_DEVICE_TYPE(SN76489,  sn76489_device)
 DECLARE_DEVICE_TYPE(SN76489A, sn76489a_device)
@@ -87,13 +86,6 @@ public:
 	sn76496_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
 };
 
-// U8106 not verified yet. todo: verify; (a custom marked sn76489? only used on mr. do and maybe other universal games)
-class u8106_device : public sn76496_base_device
-{
-public:
-	u8106_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
-};
-
 // Y2404 not verified yet. todo: verify; (don't be fooled by the Y, it's a TI chip, not Yamaha)
 class y2404_device : public sn76496_base_device
 {
diff --git a/src/mame/drivers/mrdo.cpp b/src/mame/drivers/mrdo.cpp
index ae79f9154dd..bf195f52aa6 100644
--- a/src/mame/drivers/mrdo.cpp
+++ b/src/mame/drivers/mrdo.cpp
@@ -5,8 +5,6 @@
 Mr Do!
 driver by Nicola Salmoria
 
-Updated 02/2010 with proper XTAL values thanks to Oliver_A
-
 PCB Model: 8201
 Main Clock: XTAL = 8.2 MHz
 Video clock: XTAL = 19.6 MHz
@@ -18,6 +16,10 @@ VBlank duration: 1/VSYNC * (70/262) = 4457 us
 The manual for this model clearly shows above values in 'Misc' parts listings.
 There's a chance that certain bootlegs might have the different 8/20 MHz XTALS.
 
+Sound chips have custom label "8106", the original label was scratched off.
+They are presumedly SN76489. Note that Lady Bug's PCB S/N is also 8106 and
+has the same sound chips.
+
 ***************************************************************************/
 
 #include "emu.h"
@@ -56,8 +58,8 @@ void mrdo_state::main_map(address_map &map)
 	map(0x8800, 0x8fff).ram().w(FUNC(mrdo_state::mrdo_fgvideoram_w)).share("fgvideoram");
 	map(0x9000, 0x90ff).writeonly().share("spriteram");
 	map(0x9800, 0x9800).w(FUNC(mrdo_state::mrdo_flipscreen_w)); // screen flip + playfield priority
-	map(0x9801, 0x9801).w("u8106_1", FUNC(u8106_device::write));
-	map(0x9802, 0x9802).w("u8106_2", FUNC(u8106_device::write));
+	map(0x9801, 0x9801).w("sn1", FUNC(sn76489_device::write));
+	map(0x9802, 0x9802).w("sn2", FUNC(sn76489_device::write));
 	map(0x9803, 0x9803).r(FUNC(mrdo_state::mrdo_SECRE_r));
 	map(0xa000, 0xa000).portr("P1");
 	map(0xa001, 0xa001).portr("P2");
@@ -177,7 +179,7 @@ GFXDECODE_END
 void mrdo_state::mrdo(machine_config &config)
 {
 	// Basic machine hardware
-	Z80(config, m_maincpu, MAIN_CLOCK/2);  // Verified
+	Z80(config, m_maincpu, MAIN_CLOCK/2); // Verified
 	m_maincpu->set_addrmap(AS_PROGRAM, &mrdo_state::main_map);
 	m_maincpu->set_vblank_int("screen", FUNC(mrdo_state::irq0_line_hold));
 
@@ -193,9 +195,8 @@ void mrdo_state::mrdo(machine_config &config)
 	// Sound hardware
 	SPEAKER(config, "mono").front_center();
 
-	U8106(config, "u8106_1", MAIN_CLOCK/2).add_route(ALL_OUTPUTS, "mono", 0.50); // sn76489-equivalent?, Verified
-
-	U8106(config, "u8106_2", MAIN_CLOCK/2).add_route(ALL_OUTPUTS, "mono", 0.50); // sn76489-equivalent?, Verified
+	SN76489(config, "sn1", MAIN_CLOCK/2).add_route(ALL_OUTPUTS, "mono", 0.50); // Verified
+	SN76489(config, "sn2", MAIN_CLOCK/2).add_route(ALL_OUTPUTS, "mono", 0.50); // Verified
 }
 
 void mrdo_state::mrlo(machine_config &config)