diff --git a/scripts/target/mame/mess.lua b/scripts/target/mame/mess.lua
index a60601cc8b3..62c91167e85 100644
--- a/scripts/target/mame/mess.lua
+++ b/scripts/target/mame/mess.lua
@@ -2044,6 +2044,7 @@ files {
 	MAME_DIR .. "src/mame/drivers/ctk2000.cpp",
 	MAME_DIR .. "src/mame/drivers/ctk551.cpp",
 	MAME_DIR .. "src/mame/drivers/ht6000.cpp",
+	MAME_DIR .. "src/mame/drivers/ld50.cpp",
 	MAME_DIR .. "src/mame/drivers/pb1000.cpp",
 	MAME_DIR .. "src/mame/drivers/pv1000.cpp",
 	MAME_DIR .. "src/mame/drivers/pv2000.cpp",
diff --git a/src/mame/drivers/ld50.cpp b/src/mame/drivers/ld50.cpp
new file mode 100644
index 00000000000..0e27739c69a
--- /dev/null
+++ b/src/mame/drivers/ld50.cpp
@@ -0,0 +1,322 @@
+// license:BSD-3-Clause
+// copyright-holders:Devin Acker
+/*
+	Casio LD-50 electronic drums
+
+	Unlike most Casio instruments, this is either rebranded or outsourced.
+	It's unclear who developed it, or if it was ever sold under other brands,
+	but the data ROM mentions "SharpWin".
+
+	Main board:
+		bottom left:  "DIGITAL DRUM [LD-50] DATE: 2001/07/20"
+		bottom right: "LD50 Main PCB Rev.1"
+
+		IC1:   Burr-Brown PCM1717E DAC
+		IC2:   unknown SOIC8 ("2429 170")
+		IC4:   Philips P87C52UBAA MCU
+		IC5:   AMD AM29F040 ROM
+		IC7/8/9/10: 4x 74HC374
+		IC11:  unknown COB (letter "B" handwritten on epoxy)
+		IC12:  Dream SAM9793
+		XTAL1: 9.6MHz (for SAM9793)
+		XTAL2: 12MHz (for MCU)
+
+	A 10-pin header at the upper left connects to the input matrix and
+	a small plastic LCD assembly on the other side of the board.
+
+	Most of the sound is provided by the SAM9793, which is just a MIDI
+	synth on a chip that takes in serial MIDI input and outputs I2S.
+	The four sound effect pads also trigger PCM samples separately,
+	possibly via the black blob at IC11.
+
+	The external ROM contains the demo and rhythms, which are all stored
+	as standard type 0 MIDI files.
+
+	To activate the test mode, hold "Rhythm" and "Assign" when powering on.
+	From here, hitting the drum pads will display time/velocity measurements.
+
+	TODO:
+	- drum LEDs
+	- LCD artwork
+	- clickable layout?
+	- possibly connect a MIDI out port in lieu of the SAM9793
+	  (MCS51 core needs proper serial output first)
+	- dump/emulate the other PCM device somehow
+ */
+
+#include "emu.h"
+
+#include "bus/midi/midioutport.h"
+#include "cpu/mcs51/mcs51.h"
+#include "video/hd44780.h"
+#include "emupal.h"
+#include "screen.h"
+
+namespace {
+
+class ld50_state : public driver_device
+{
+public:
+	ld50_state(machine_config const &mconfig, device_type type, char const *tag)
+		: driver_device(mconfig, type, tag)
+		, m_maincpu(*this, "maincpu")
+		, m_lcdc(*this, "lcdc")
+		, m_datarom(*this, "datarom")
+		, m_inputs(*this, "IN%u", 0)
+		, m_pads(*this, "PADS")
+		, m_dial(*this, "DIAL")
+	{
+	}
+
+	void ld50(machine_config &config);
+
+	DECLARE_CUSTOM_INPUT_MEMBER(dial_r);
+
+private:
+	u8 port0_r();
+	void port0_w(u8 data);
+	u8 port1_r();
+	void port2_w(u8 data);
+	void port3_w(u8 data);
+
+	virtual void driver_start() override;
+	virtual void driver_reset() override;
+
+	HD44780_PIXEL_UPDATE(lcd_update);
+	void palette_init(palette_device &palette);
+
+	required_device<mcs51_cpu_device> m_maincpu;
+	required_device<hd44780_device> m_lcdc;
+
+	required_memory_region m_datarom;
+	required_ioport_array<5> m_inputs;
+	required_ioport m_pads;
+	required_ioport m_dial;
+
+	u8 m_port[4];
+	u32 m_rom_addr;
+	u16 m_shift_data;
+};
+
+HD44780_PIXEL_UPDATE(ld50_state::lcd_update)
+{
+	if (x < 6 && y < 8 && line < 2 && pos < 8)
+		bitmap.pix(y, line * 48 + pos * 6 + x) = state;
+}
+
+void ld50_state::palette_init(palette_device &palette)
+{
+	palette.set_pen_color(0, rgb_t(255, 255, 255));
+	palette.set_pen_color(1, rgb_t(0, 0, 0));
+}
+
+
+u8 ld50_state::port0_r()
+{
+	u8 data = 0xf0 | (m_lcdc->db_r() >> 4);
+	if (!BIT(m_port[2], 3))
+		data &= m_datarom->base()[m_rom_addr & 0x7ffff];
+
+	return data;
+}
+
+void ld50_state::port0_w(u8 data)
+{
+	m_lcdc->db_w(data << 4);
+	m_port[0] = data;
+}
+
+u8 ld50_state::port1_r()
+{
+	/*
+	bits 0-3: drum pads (active high)
+	bits 4-7: multiplexed inputs (active low)
+
+	The drum pads are read during the timer 0 interrupt.
+	Note velocity is based on the number of timer intervals that the pad remains pressed.
+	*/
+	return (m_port[1] & 0xf0) | m_pads->read();
+}
+
+void ld50_state::port2_w(u8 data)
+{
+	/*
+	bit 0: ?
+	bit 1: ?
+	bit 2: ?
+	bit 3: ROM output enable
+	bit 4: ROM address low byte latch
+	bit 5: ROM address mid byte latch
+	bit 6: ROM address hi byte & input latch
+	bit 7: LCD control latch
+	*/
+
+	const u8 set = data & ~m_port[2];
+	m_port[2] = data;
+
+	if (BIT(set, 4))
+	{
+		m_rom_addr = (m_rom_addr & 0x7ff00) | m_port[0];
+	}
+	if (BIT(set, 5))
+	{
+		m_rom_addr = (m_rom_addr & 0x700ff) | (m_port[0] << 8);
+	}
+	if (BIT(set, 6))
+	{
+		m_rom_addr = (m_rom_addr & 0x0ffff) | ((m_port[0] & 0xe0) << 11);
+
+		m_port[1] |= 0xf0;
+		for (int i = 0; i < 5; i++)
+		{
+			if (!BIT(m_port[0], i))
+				m_port[1] &= (m_inputs[i]->read() << 4);
+		}
+	}
+	if (BIT(set, 7))
+	{
+		m_lcdc->rw_w(BIT(m_port[0], 6));
+		m_lcdc->rs_w(BIT(m_port[0], 7));
+	}
+}
+
+void ld50_state::port3_w(u8 data)
+{
+	/*
+	bit 0: LCD enable
+	bit 1: MIDI Tx (TODO)
+	bit 2: ?
+	bit 3: trigger sound effect
+	bit 4: ?
+	bit 5: shift register data
+	bit 6: shift register clock
+	bit 7: ?
+
+	The LD-50 transmits MIDI both through the UART registers and manually via port 3.
+	Demo/rhythm playback uses the UART, while drum pads, effect values, etc. are
+	bit-banged through the port instead (why?)
+	*/
+
+	const u8 set = data & ~m_port[3];
+	m_port[3] = data;
+
+	m_lcdc->e_w(BIT(data, 0));
+
+	if (BIT(set, 3))
+	{
+		logerror("play sound effect %u\n", m_shift_data & 0x1f);
+	}
+	if (BIT(set, 6))
+	{
+		m_shift_data <<= 1;
+		m_shift_data |= BIT(data, 5);
+	}
+	if (BIT(set, 7))
+	{
+		logerror("unknown serial cmd (data = 0x%4x)\n", m_shift_data);
+	}
+}
+
+CUSTOM_INPUT_MEMBER(ld50_state::dial_r)
+{
+	// return the dial position as a 2-bit gray code
+	const u8 val = m_dial->read();
+	return (val >> 6) ^ (val >> 7);
+}
+
+
+void ld50_state::driver_start()
+{
+	save_item(NAME(m_port));
+	save_item(NAME(m_rom_addr));
+	save_item(NAME(m_shift_data));
+}
+
+void ld50_state::driver_reset()
+{
+	memset(m_port, 0xff, sizeof m_port);
+
+	m_rom_addr = 0;
+	m_shift_data = 0;
+}
+
+void ld50_state::ld50(machine_config &config)
+{
+	// CPU
+	I87C52(config, m_maincpu, 12_MHz_XTAL);
+	m_maincpu->port_in_cb<0>().set(FUNC(ld50_state::port0_r));
+	m_maincpu->port_out_cb<0>().set(FUNC(ld50_state::port0_w));
+	m_maincpu->port_in_cb<1>().set(FUNC(ld50_state::port1_r));
+	m_maincpu->port_out_cb<2>().set(FUNC(ld50_state::port2_w));
+	m_maincpu->port_out_cb<3>().set(FUNC(ld50_state::port3_w));
+
+	// LCD
+	HD44780(config, m_lcdc, 0);
+	m_lcdc->set_lcd_size(2, 8);
+	m_lcdc->set_pixel_update_cb(FUNC(ld50_state::lcd_update));
+
+	// screen (for testing only)
+	// TODO: the actual LCD with custom segments
+	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_LCD));
+	screen.set_refresh_hz(60);
+	screen.set_vblank_time(ATTOSECONDS_IN_USEC(2500)); /* not accurate */
+	screen.set_screen_update("lcdc", FUNC(hd44780_device::screen_update));
+	screen.set_size(6 * 16, 8);
+	screen.set_visarea_full();
+	screen.set_palette("palette");
+
+	PALETTE(config, "palette", FUNC(ld50_state::palette_init), 2);
+}
+
+INPUT_PORTS_START(ld50)
+	PORT_START("PADS")
+	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_BUTTON4 ) PORT_NAME("Drum Pad 4")
+	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_BUTTON3 ) PORT_NAME("Drum Pad 3")
+	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_NAME("Drum Pad 2")
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_NAME("Drum Pad 1")
+
+	PORT_START("DIAL")
+	PORT_BIT( 0xff, 0x00, IPT_DIAL ) PORT_SENSITIVITY(50) PORT_KEYDELTA(50) PORT_REVERSE
+
+	PORT_START("IN0")
+	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_BUTTON8 ) PORT_NAME("SE Pad 4")
+	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_BUTTON7 ) PORT_NAME("SE Pad 3")
+	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_BUTTON6 ) PORT_NAME("SE Pad 2")
+	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_BUTTON5 ) PORT_NAME("SE Pad 1")
+
+	PORT_START("IN1")
+	PORT_BIT( 0x03, IP_ACTIVE_LOW, IPT_CUSTOM ) PORT_CUSTOM_MEMBER(ld50_state, dial_r)
+	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_UNUSED )
+	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_BACKSPACE) PORT_NAME("Effect")
+
+	PORT_START("IN2")
+	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_EQUALS)    PORT_NAME("Assign")
+	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_MINUS)     PORT_NAME("Drum Set")
+	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_0)         PORT_NAME("SE Set")
+	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_9)         PORT_NAME("Rhythm")
+
+	PORT_START("IN3")
+	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_8)         PORT_NAME("Play Level")
+	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_7)         PORT_NAME("Light")
+	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_6)         PORT_NAME("Tempo")
+	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_5)         PORT_NAME("Start/Stop")
+
+	PORT_START("IN4")
+	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_4)         PORT_NAME("Synchro Start")
+	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_3)         PORT_NAME("Demo")
+	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_2)         PORT_NAME("Rhythm Vol.")
+	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYPAD ) PORT_CODE(KEYCODE_1)         PORT_NAME("Main Vol.")
+INPUT_PORTS_END
+
+ROM_START(ld50)
+	ROM_REGION(0x2000, "maincpu", 0)
+	ROM_LOAD("87c52.ic4", 0x0000, 0x2000, CRC(126108cc) SHA1(cb8d7359628f8e519862cec73e38078275c3bd48))
+
+	ROM_REGION(0x80000, "datarom", 0)
+	ROM_LOAD("ld50.ic5", 0x00000, 0x80000, CRC(acaee847) SHA1(7235aefd72260b6d9d1f652c643022515a880781))
+ROM_END
+
+} // anonymous namespace
+
+//    YEAR  NAME     PARENT  COMPAT  MACHINE  INPUT    CLASS          INIT        COMPANY  FULLNAME     FLAGS
+SYST( 2002, ld50,    0,      0,      ld50,    ld50,    ld50_state,    empty_init, "Casio", "LD-50",     MACHINE_NO_SOUND | MACHINE_NOT_WORKING | MACHINE_SUPPORTS_SAVE )
diff --git a/src/mame/mame.lst b/src/mame/mame.lst
index 850cfb03b60..16fdb9474a8 100644
--- a/src/mame/mame.lst
+++ b/src/mame/mame.lst
@@ -19968,6 +19968,9 @@ lckydrawa                       // (c) 1979 Mirco
 @source:lcmate2.cpp
 lcmate2                         //
 
+@source:ld50.cpp
+ld50                            //
+
 @source:leapfrog_iquest.cpp
 iquest
 ttwistfb
diff --git a/src/mame/mess.flt b/src/mame/mess.flt
index f46d9c60f10..307b65f9877 100644
--- a/src/mame/mess.flt
+++ b/src/mame/mess.flt
@@ -537,6 +537,7 @@ lb186.cpp
 lbpc.cpp
 lc80.cpp
 lcmate2.cpp
+ld50.cpp
 leapfrog_iquest.cpp
 leapfrog_leappad.cpp
 leapfrog_leapster_explorer.cpp