diff --git a/scripts/target/mame/arcade.lua b/scripts/target/mame/arcade.lua
index 7d0902de2bd..85342ebe188 100644
--- a/scripts/target/mame/arcade.lua
+++ b/scripts/target/mame/arcade.lua
@@ -3170,6 +3170,7 @@ files {
 	MAME_DIR .. "src/mame/includes/megadrvb.h",
 	MAME_DIR .. "src/mame/drivers/megaplay.cpp",
 	MAME_DIR .. "src/mame/drivers/megatech.cpp",
+	MAME_DIR .. "src/mame/drivers/calcune.cpp",
 	MAME_DIR .. "src/mame/drivers/model1.cpp",
 	MAME_DIR .. "src/mame/includes/model1.h",
 	MAME_DIR .. "src/mame/machine/model1.cpp",
diff --git a/src/mame/drivers/calcune.cpp b/src/mame/drivers/calcune.cpp
new file mode 100644
index 00000000000..fe57bb41aa8
--- /dev/null
+++ b/src/mame/drivers/calcune.cpp
@@ -0,0 +1,322 @@
+// license:BSD-3-Clause
+// copyright-holders:David Haywood
+
+#include "emu.h"
+
+#include "cpu/m68000/m68000.h"
+#include "cpu/z80/z80.h"
+#include "sound/sn76496.h"
+#include "sound/ymz280b.h"
+#include "video/315_5313.h"
+#include "machine/nvram.h"
+#include "speaker.h"
+
+#define MASTER_CLOCK_NTSC 53693175
+
+class calcune_state : public driver_device
+{
+public:
+	calcune_state(const machine_config &mconfig, device_type type, const char *tag)
+		: driver_device(mconfig, type, tag),
+		vdp_state(0),
+		m_maincpu(*this, "maincpu"),
+		m_vdp(*this, "gen_vdp"),
+		m_vdp2(*this, "gen_vdp2"),
+		m_palette(*this, "palette")
+	{ }
+
+	WRITE_LINE_MEMBER(vdp_sndirqline_callback_genesis_z80);
+	WRITE_LINE_MEMBER(vdp_lv6irqline_callback_genesis_68k);
+	WRITE_LINE_MEMBER(vdp_lv4irqline_callback_genesis_68k);
+
+	DECLARE_MACHINE_START(calcune);
+	DECLARE_MACHINE_RESET(calcune);
+
+	IRQ_CALLBACK_MEMBER(genesis_int_callback);
+
+	DECLARE_DRIVER_INIT(calcune);
+
+	DECLARE_READ16_MEMBER(cal_700000_r);
+	DECLARE_WRITE16_MEMBER(cal_770000_w);
+	DECLARE_READ16_MEMBER(cal_vdp_r);
+	DECLARE_WRITE16_MEMBER(cal_vdp_w);
+
+	uint32_t screen_update_calcune(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
+private:
+	int vdp_state;
+
+	required_device<cpu_device> m_maincpu;
+	required_device<sega315_5313_device> m_vdp;
+	required_device<sega315_5313_device> m_vdp2;
+	required_device<palette_device> m_palette;
+};
+
+
+static INPUT_PORTS_START( calcune )
+	PORT_START("710000")
+	PORT_BIT( 0x0001, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_PLAYER(2)
+	PORT_BIT( 0x0002, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_PLAYER(2)
+	PORT_BIT( 0x0004, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_PLAYER(2)
+	PORT_BIT( 0x0008, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(2)
+	PORT_BIT( 0x0010, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(2)
+	PORT_BIT( 0x0020, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(2)
+	PORT_BIT( 0x0040, IP_ACTIVE_HIGH, IPT_UNUSED )
+	PORT_BIT( 0x0080, IP_ACTIVE_HIGH, IPT_UNUSED )
+	PORT_BIT( 0x0100, IP_ACTIVE_HIGH, IPT_SERVICE1 )
+	PORT_SERVICE_NO_TOGGLE( 0x0200, IP_ACTIVE_HIGH )
+	PORT_BIT( 0x0400, IP_ACTIVE_HIGH, IPT_UNUSED )
+	PORT_BIT( 0x0800, IP_ACTIVE_HIGH, IPT_COIN1 )
+	PORT_BIT( 0x1000, IP_ACTIVE_HIGH, IPT_UNUSED )
+	PORT_BIT( 0x2000, IP_ACTIVE_HIGH, IPT_START1 )
+	PORT_BIT( 0x4000, IP_ACTIVE_HIGH, IPT_START2 )
+	PORT_BIT( 0x8000, IP_ACTIVE_HIGH, IPT_UNUSED )
+
+	PORT_START("720000")
+	PORT_BIT( 0x0001, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_PLAYER(1)
+	PORT_BIT( 0x0002, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_PLAYER(1)
+	PORT_BIT( 0x0004, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_PLAYER(1)
+	PORT_BIT( 0x0008, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(1)
+	PORT_BIT( 0x0010, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(1)
+	PORT_BIT( 0x0020, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(1)
+	PORT_BIT( 0xffc0, IP_ACTIVE_HIGH, IPT_UNUSED )
+INPUT_PORTS_END
+
+
+READ16_MEMBER(calcune_state::cal_700000_r)
+{
+	vdp_state = 0;
+	return 0;
+}
+
+WRITE16_MEMBER(calcune_state::cal_770000_w)
+{
+	vdp_state = data;
+}
+
+READ16_MEMBER(calcune_state::cal_vdp_r)
+{
+	if (!vdp_state)
+		return m_vdp->vdp_r(space, offset, mem_mask);
+	else
+		return m_vdp2->vdp_r(space, offset, mem_mask);
+}
+
+WRITE16_MEMBER(calcune_state::cal_vdp_w)
+{
+	if (!vdp_state)
+		m_vdp->vdp_w(space, offset, data, mem_mask);
+	else
+		m_vdp2->vdp_w(space, offset, data, mem_mask);
+}
+
+static ADDRESS_MAP_START( calcune_map, AS_PROGRAM, 16, calcune_state )
+	AM_RANGE(0x000000, 0x1fffff) AM_ROM
+	
+	AM_RANGE(0x700000, 0x700001) AM_READ(cal_700000_r)
+
+	AM_RANGE(0x710000, 0x710001) AM_READ_PORT("710000")
+	AM_RANGE(0x720000, 0x720001) AM_READ_PORT("720000")
+//	AM_RANGE(0x730000, 0x730001) possible Z80 control?
+	AM_RANGE(0x760000, 0x760003) AM_DEVREADWRITE8("ymz", ymz280b_device, read, write, 0xff00)
+
+	AM_RANGE(0x770000, 0x770001) AM_WRITE(cal_770000_w)
+
+	AM_RANGE(0xA14100, 0xA14101) AM_NOP // on startup, possible z80 control
+
+	AM_RANGE(0xc00000, 0xc0001f) AM_READWRITE(cal_vdp_r, cal_vdp_w)
+
+	AM_RANGE(0xff0000, 0xffffff) AM_RAM AM_SHARE("nvram") // battery on PCB
+ADDRESS_MAP_END
+
+
+uint32_t calcune_state::screen_update_calcune(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)
+{
+	const pen_t *paldata = m_palette->pens();
+
+	for (int y = cliprect.min_y; y <= cliprect.max_y; y++)
+	{
+		uint32_t *dst = &bitmap.pix32(y);
+		for (int x = cliprect.min_x; x <= cliprect.max_x; x++)
+		{
+			int pix;
+
+			pix = m_vdp2->m_render_line_raw[x] & 0x3f;
+
+			switch (pix & 0xc0)
+			{
+			case 0x00:
+				dst[x] = paldata[pix + 0x0000 + 0xc0];
+				break;
+			case 0x40:
+			case 0x80:
+				dst[x] = paldata[pix + 0x0040 + 0xc0];
+				break;
+			case 0xc0:
+				dst[x] = paldata[pix + 0x0080 + 0xc0];
+				break;
+
+			}
+
+			if (m_vdp->m_render_line_raw[x] & 0x100)
+			{
+				pix = m_vdp->m_render_line_raw[x] & 0x3f;
+				if (pix & 0xf)
+				{
+					switch (pix & 0xc0)
+					{
+					case 0x00:
+						dst[x] = paldata[pix + 0x0000];
+						break;
+					case 0x40:
+					case 0x80:
+						dst[x] = paldata[pix + 0x0040];
+						break;
+					case 0xc0:
+						dst[x] = paldata[pix + 0x0080];
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+MACHINE_RESET_MEMBER(calcune_state,calcune)
+{
+	m_vdp->device_reset_old();
+	m_vdp2->device_reset_old();
+}
+
+
+IRQ_CALLBACK_MEMBER(calcune_state::genesis_int_callback)
+{
+	if (irqline==4)
+	{
+		m_vdp->vdp_clear_irq4_pending();
+	}
+
+	if (irqline==6)
+	{
+		m_vdp->vdp_clear_irq6_pending();
+	}
+
+	return (0x60+irqline*4)/4; // vector address
+}
+
+WRITE_LINE_MEMBER(calcune_state::vdp_sndirqline_callback_genesis_z80)
+{
+}
+
+WRITE_LINE_MEMBER(calcune_state::vdp_lv6irqline_callback_genesis_68k)
+{
+	// this looks odd but is the logic the Genesis code requires
+	if (state == ASSERT_LINE)
+		m_maincpu->set_input_line(6, HOLD_LINE);
+	else
+		m_maincpu->set_input_line(6, CLEAR_LINE);
+}
+
+WRITE_LINE_MEMBER(calcune_state::vdp_lv4irqline_callback_genesis_68k)
+{
+	// this looks odd but is the logic the Genesis code requires
+	if (state == ASSERT_LINE)
+		m_maincpu->set_input_line(4, HOLD_LINE);
+	else
+		m_maincpu->set_input_line(4, CLEAR_LINE);
+}
+
+MACHINE_START_MEMBER(calcune_state,calcune)
+{
+	m_vdp->stop_timers();
+	m_vdp2->stop_timers();
+}
+
+static MACHINE_CONFIG_START( calcune )
+	MCFG_CPU_ADD("maincpu", M68000, MASTER_CLOCK_NTSC / 7) /* 7.67 MHz */
+	MCFG_CPU_PROGRAM_MAP(calcune_map)
+	MCFG_CPU_IRQ_ACKNOWLEDGE_DRIVER(calcune_state,genesis_int_callback)
+
+	MCFG_CPU_ADD("z80", Z80, MASTER_CLOCK_NTSC / 15) /* 3.58 MHz */
+	MCFG_DEVICE_DISABLE() /* no code is ever uploaded for the Z80, so it's unused here even if it is present on the PCB */
+
+	MCFG_MACHINE_START_OVERRIDE(calcune_state,calcune)
+	MCFG_MACHINE_RESET_OVERRIDE(calcune_state,calcune)
+
+	MCFG_SCREEN_ADD("megadriv", RASTER)
+	MCFG_SCREEN_REFRESH_RATE(60)
+	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(0)) // Vblank handled manually.
+	MCFG_SCREEN_SIZE(64*8, 620)
+	MCFG_SCREEN_VISIBLE_AREA(0, 40*8-1, 0, 28*8-1)
+	MCFG_SCREEN_UPDATE_DRIVER(calcune_state, screen_update_calcune)
+
+	MCFG_DEVICE_ADD("gen_vdp", SEGA315_5313, 0)
+	MCFG_SEGA315_5313_IS_PAL(false)
+	MCFG_SEGA315_5313_SND_IRQ_CALLBACK(WRITELINE(calcune_state, vdp_sndirqline_callback_genesis_z80));
+	MCFG_SEGA315_5313_LV6_IRQ_CALLBACK(WRITELINE(calcune_state, vdp_lv6irqline_callback_genesis_68k));
+	MCFG_SEGA315_5313_LV4_IRQ_CALLBACK(WRITELINE(calcune_state, vdp_lv4irqline_callback_genesis_68k));
+	MCFG_SEGA315_5313_ALT_TIMING(1);
+	MCFG_SEGA315_5313_PAL_WRITE_BASE(0x0000);
+	MCFG_SEGA315_5313_PALETTE("palette")
+
+	MCFG_DEVICE_ADD("gen_vdp2", SEGA315_5313, 0)
+	MCFG_SEGA315_5313_IS_PAL(false)
+//  are these not hooked up or should they OR with the other lines?
+//	MCFG_SEGA315_5313_SND_IRQ_CALLBACK(WRITELINE(calcune_state, vdp_sndirqline_callback_genesis_z80));
+//	MCFG_SEGA315_5313_LV6_IRQ_CALLBACK(WRITELINE(calcune_state, vdp_lv6irqline_callback_genesis_68k));
+//	MCFG_SEGA315_5313_LV4_IRQ_CALLBACK(WRITELINE(calcune_state, vdp_lv4irqline_callback_genesis_68k));
+	MCFG_SEGA315_5313_ALT_TIMING(1);
+	MCFG_SEGA315_5313_PAL_WRITE_BASE(0x0c0);
+	MCFG_SEGA315_5313_PALETTE("palette")
+
+	MCFG_TIMER_DEVICE_ADD_SCANLINE("scantimer", "gen_vdp", sega315_5313_device, megadriv_scanline_timer_callback_alt_timing, "megadriv", 0, 1)
+	MCFG_TIMER_DEVICE_ADD_SCANLINE("scantimer2", "gen_vdp2", sega315_5313_device, megadriv_scanline_timer_callback_alt_timing, "megadriv", 0, 1)
+
+	MCFG_PALETTE_ADD("palette", 0xc0*2)
+
+	MCFG_NVRAM_ADD_0FILL("nvram")
+
+	/* sound hardware */
+	MCFG_SPEAKER_STANDARD_STEREO("lspeaker", "rspeaker")
+
+	MCFG_SOUND_ADD("ymz", YMZ280B, XTAL_16_9344MHz)
+	MCFG_SOUND_ROUTE(0, "lspeaker", 1.0)
+	MCFG_SOUND_ROUTE(1, "rspeaker", 1.0)
+
+	/* sound hardware - VDP */
+	MCFG_SOUND_ADD("snsnd", SEGAPSG, MASTER_CLOCK_NTSC/15)
+	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "lspeaker", 0.25)
+	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "rspeaker",0.25)
+MACHINE_CONFIG_END
+
+DRIVER_INIT_MEMBER(calcune_state,calcune)
+{
+	m_vdp->set_use_cram(1);
+	m_vdp->set_vdp_pal(false);
+	m_vdp->set_framerate(60);
+	m_vdp->set_total_scanlines(262);
+
+	m_vdp2->set_use_cram(1);
+	m_vdp2->set_vdp_pal(false);
+	m_vdp2->set_framerate(60);
+	m_vdp2->set_total_scanlines(262);
+}
+
+ROM_START( calcune )
+	ROM_REGION( 0x400000, "maincpu", 0 ) /* 68000 Code - ROM check fails, but probably due to prototype status, not bad ROM */
+	ROM_LOAD16_BYTE( "1.IC101.27C4001", 0x000001, 0x080000, CRC(2d25544c) SHA1(ef778cbf2aa4fcec43ce2dce9bcefb964f458c0a) )
+	ROM_LOAD16_BYTE( "2.IC102.27C4001", 0x000000, 0x080000, CRC(09330dc9) SHA1(fd888a7469a6290cd372a4b1eed577c2444f0c80) )
+	ROM_LOAD16_BYTE( "3.IC103.27C4001", 0x100001, 0x080000, CRC(736a356d) SHA1(372fa5989a67746efc439d76df1733cf70df57e7) )
+	ROM_LOAD16_BYTE( "4.IC104.27C4001", 0x100000, 0x080000, CRC(0bec031a) SHA1(69b255743f20408b2f14bddf0b85c85a13f29615) )
+
+	ROM_REGION( 0x200000, "ymz", 0 )
+	ROM_LOAD( "Sound1.1C.27C4001", 0x000000, 0x080000, CRC(5fb63e84) SHA1(6fad8e76162c81b2cfa4778effb81b78ed4fa299) )
+	ROM_LOAD( "Sound2.2D.27C4001", 0x080000, 0x080000, CRC(8924c6cc) SHA1(c76e6cfcf92a2c2834de62d7136c69e6edda46cc) )
+	ROM_LOAD( "Sound3.3A.27C4001", 0x100000, 0x080000, CRC(18cfa7f4) SHA1(201ea186eb3af9138db6699c9dcf527795f7c0db) )
+	ROM_LOAD( "Sound4.4B.27C4001", 0x180000, 0x080000, CRC(61a8510b) SHA1(177e56c374aa5697545ede28140cb42b5a4b737b) )
+ROM_END
+
+
+
+GAME( 1996, calcune,  0,        calcune,   calcune,     calcune_state, calcune, ROT0, "Yuvo", "Calcune (Japan, prototype)", 0 )
diff --git a/src/mame/mame.lst b/src/mame/mame.lst
index 11c8bde3372..11ce34f844a 100644
--- a/src/mame/mame.lst
+++ b/src/mame/mame.lst
@@ -9194,6 +9194,9 @@ calchase                        // (c) 1999 The Game Room
 eggsplc                         // (c) 2002 The Game Room
 hostinv                         // (c) 1998 The Game Room
 
+@source:calcune.cpp
+calcune
+
 @source:calomega.cpp
 comg074                         // (c) 1981 Cal Omega Inc.
 comg076                         // (c) 1981 Cal Omega Inc.