diff --git a/src/emu/drivers/xtal.h b/src/emu/drivers/xtal.h
index d6e341dce2e..38d4911d172 100644
--- a/src/emu/drivers/xtal.h
+++ b/src/emu/drivers/xtal.h
@@ -105,6 +105,7 @@ enum
 	XTAL_8_945MHz       = 8945000,      /* Hit Me */
 	XTAL_9_216MHz       = 9216000,      /* Conitec PROF-180X */
 	XTAL_9_828MHz       = 9828000,      /* Universal PCBs */
+	XTAL_9_832MHz       = 9832000,      /* Robotron A7150 */
 	XTAL_9_8304MHz      = 9830400,      /* Epson PX-8 */
 	XTAL_9_987MHz       = 9987000,      /* Crazy Balloon */
 	XTAL_10MHz          = 10000000,
diff --git a/src/mame/drivers/a7150.cpp b/src/mame/drivers/a7150.cpp
index d681f7140d7..83df21b4391 100644
--- a/src/mame/drivers/a7150.cpp
+++ b/src/mame/drivers/a7150.cpp
@@ -1,5 +1,5 @@
 // license:BSD-3-Clause
-// copyright-holders:Miodrag Milanovic
+// copyright-holders:Miodrag Milanovic, Sergey Svishchev
 /***************************************************************************
 
     Robotron A7150
@@ -8,74 +8,502 @@
 
     http://www.robotrontechnik.de/index.htm?/html/computer/a7150.htm
 
+    http://www.tiffe.de/Robotron/MMS16/
+    - Confidence test is documented in A7150_Rechner...pdf, pp. 112-119
+    - Internal test of KGS -- in KGS-K7070.pdf, pp. 19-23
+
+    To do:
+    - MMS16 (Multibus clone) and slot devices
+    - native keyboard
+    - A7100 model
+
 ****************************************************************************/
 
 #include "emu.h"
+
 #include "cpu/i86/i86.h"
+#include "machine/i8251.h"
+#include "machine/i8255.h"
+#include "machine/pit8253.h"
+#include "machine/pic8259.h"
+#include "machine/bankdev.h"
+
+#include "cpu/z80/z80.h"
+#include "machine/z80ctc.h"
+#include "machine/z80sio.h"
+
+#include "bus/rs232/rs232.h"
+#include "machine/isbc_215g.h"
+#include "machine/keyboard.h"
+
 #include "screen.h"
 
 
+#define SCREEN_TAG          "screen"
+#define Z80_TAG             "gfxcpu"
+#define Z80CTC_TAG          "z80ctc"
+#define Z80SIO_TAG          "z80sio"
+#define RS232_A_TAG         "kgsv24"
+#define RS232_B_TAG         "kgsifss"
+
+
 class a7150_state : public driver_device
 {
 public:
 	a7150_state(const machine_config &mconfig, device_type type, const char *tag)
-		: driver_device(mconfig, type, tag) ,
-		m_maincpu(*this, "maincpu") { }
+		: driver_device(mconfig, type, tag)
+		, m_maincpu(*this, "maincpu")
+		, m_uart8251(*this, "uart8251")
+		, m_pit8253(*this, "pit8253")
+		, m_pic8259(*this, "pic8259")
+		, m_gfxcpu(*this, "gfxcpu")
+		, m_ctc(*this, Z80CTC_TAG)
+		, m_video_ram(*this, "video_ram")
+		, m_video_bankdev(*this, "video_bankdev")
+		, m_palette(*this, "palette")
+	{ }
 
 	virtual void machine_reset() override;
-	virtual void video_start() override;
-	uint32_t screen_update_a7150(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
+	virtual void machine_start() override;
+
+	DECLARE_READ8_MEMBER(a7150_kgs_r);
+	DECLARE_WRITE8_MEMBER(a7150_kgs_w);
+
+	DECLARE_WRITE_LINE_MEMBER(a7150_tmr2_w);
+	DECLARE_WRITE8_MEMBER(ppi_c_w);
+
+	DECLARE_READ8_MEMBER(kgs_host_r);
+	DECLARE_WRITE8_MEMBER(kgs_host_w);
+	DECLARE_WRITE_LINE_MEMBER(kgs_iml_w);
+	DECLARE_WRITE8_MEMBER(kbd_put);
+	void kgs_memory_remap();
+
+	bool m_kgs_msel, m_kgs_iml;
+	uint8_t m_kgs_datao, m_kgs_datai, m_kgs_ctrl;
+
+	uint32_t screen_update_k7072(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
+	void screen_eof(screen_device &screen, bool state);
+
 	required_device<cpu_device> m_maincpu;
+	required_device<i8251_device> m_uart8251;
+	required_device<pit8253_device> m_pit8253;
+	required_device<pic8259_device> m_pic8259;
+
+	required_device<z80_device> m_gfxcpu;
+	required_device<z80ctc_device> m_ctc;
+	required_shared_ptr<uint8_t> m_video_ram;
+	required_device<address_map_bank_device> m_video_bankdev;
+	required_device<palette_device> m_palette;
 };
 
 
+uint32_t a7150_state::screen_update_k7072(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
+{
+	int y, x, b;
+	int addr = 0;
+
+	for (y = 0; y < 400; y++)
+	{
+		int horpos = 0;
+		for (x = 0; x < 80; x++)
+		{
+			uint8_t code = m_video_ram[addr++];
+			for (b = 0; b < 8; b++)
+			{
+				bitmap.pix16(y, horpos++) = ((code >> (7 - b)) & 0x01) ? 1 : 0;
+			}
+		}
+	}
+
+	return 0;
+}
+
+WRITE_LINE_MEMBER(a7150_state::kgs_iml_w)
+{
+	m_kgs_iml = !state;
+	kgs_memory_remap();
+}
+
+WRITE_LINE_MEMBER(a7150_state::a7150_tmr2_w)
+{
+	m_uart8251->write_rxc(state);
+	m_uart8251->write_txc(state);
+}
+
+WRITE8_MEMBER(a7150_state::ppi_c_w)
+{
+	// b0 -- INTR(B)
+	// b1 -- /OBF(B)
+	// m_centronics->write_ack(BIT(data, 2));
+	// m_centronics->write_strobe(BIT(data, 3));
+	// b4 -- serial loopback?
+	// b6
+	// b7
+}
+
+#define	KGS_ST_OBF	0x01
+#define	KGS_ST_IBF	0x02
+#define	KGS_ST_INT	0x04
+#define	KGS_ST_ERR	0x80
+
+READ8_MEMBER(a7150_state::kgs_host_r)
+{
+	uint8_t data = 0;
+
+	switch (offset)
+	{
+	case 0:
+		data = m_kgs_datao;
+		m_kgs_ctrl &= ~(KGS_ST_ERR | KGS_ST_IBF);
+		m_pic8259->ir7_w(ASSERT_LINE);
+		break;
+
+	case 2:
+		data = m_kgs_ctrl;
+		break;
+
+	case 6:
+		data = ioport("DSEL0")->read();
+		break;
+
+	case 7:
+		data = ioport("DSEL1")->read();
+		break;
+
+	default:
+		break;
+	}
+
+	if (0 && offset != 2 && offset != 5)
+		logerror("%s: kgs %d == %02x '%c'\n", machine().describe_context(), offset, data,
+				 (data > 0x1f && data < 0x7f) ? data : 0x20);
+
+	return data;
+}
+
+WRITE8_MEMBER(a7150_state::kgs_host_w)
+{
+	if (0) logerror("%s: kgs %d <- %02x '%c', ctrl %02x\n", machine().describe_context(), offset, data,
+			 (data > 0x1f && data < 0x7f) ? data : 0x20, m_kgs_ctrl);
+
+	switch (offset)
+	{
+	case 1:
+		if (m_kgs_ctrl & KGS_ST_OBF)
+		{
+			m_kgs_ctrl |= KGS_ST_ERR;
+		}
+		else
+		{
+			m_kgs_datai = data;
+			m_kgs_ctrl |= KGS_ST_OBF;
+			m_pic8259->ir6_w(ASSERT_LINE);
+		}
+		break;
+
+	case 3:
+		m_kgs_ctrl |= KGS_ST_INT;
+		m_pic8259->ir1_w(ASSERT_LINE);
+		break;
+
+	case 4:
+		m_kgs_ctrl |= KGS_ST_ERR;
+		break;
+
+	case 5:
+		m_kgs_msel = (data != 0);
+		kgs_memory_remap();
+		break;
+	}
+}
+
+WRITE8_MEMBER(a7150_state::kbd_put)
+{
+	m_kgs_datai = data;
+	m_kgs_ctrl |= KGS_ST_OBF | KGS_ST_INT;
+	m_pic8259->ir1_w(ASSERT_LINE);
+}
+
+READ8_MEMBER(a7150_state::a7150_kgs_r)
+{
+	uint8_t data = 0;
+
+	switch (offset)
+	{
+	case 0:
+		data = m_kgs_ctrl;
+		break;
+
+	case 1:
+		data = m_kgs_datai;
+		m_kgs_ctrl &= ~KGS_ST_OBF;
+		break;
+	}
+
+	if (offset)
+	logerror("%s: KGS %d == %02x '%c'\n", machine().describe_context(), offset, data,
+			 (data > 0x1f && data < 0x7f) ? data : 0x20);
+
+	return data;
+}
+
+WRITE8_MEMBER(a7150_state::a7150_kgs_w)
+{
+	logerror("%s: KGS %d <- %02x '%c', ctrl %02x\n", machine().describe_context(), offset, data,
+			 (data > 0x1f && data < 0x7f) ? data : 0x20, m_kgs_ctrl);
+
+	switch (offset)
+	{
+	case 0:
+		m_kgs_ctrl &= ~(KGS_ST_ERR | KGS_ST_INT);
+//		m_pic8259->ir1_w(CLEAR_LINE);
+		break;
+
+	case 1:
+		if (m_kgs_ctrl & KGS_ST_IBF)
+		{
+			m_kgs_ctrl |= KGS_ST_ERR;
+		}
+		else
+		{
+			m_kgs_datao = data;
+			m_kgs_ctrl |= KGS_ST_IBF;
+		}
+		break;
+	}
+}
+
+
 static ADDRESS_MAP_START(a7150_mem, AS_PROGRAM, 16, a7150_state)
 	ADDRESS_MAP_UNMAP_HIGH
-	AM_RANGE(0x00000,0xeffff) AM_RAM
-	AM_RANGE(0xf8000,0xfffff) AM_ROM AM_REGION("user1", 0)
+	AM_RANGE(0x00000, 0xf7fff) AM_RAM
+	AM_RANGE(0xf8000, 0xfffff) AM_ROM AM_REGION("user1", 0)
+ADDRESS_MAP_END
+
+static ADDRESS_MAP_START(a7150_io, AS_IO, 16, a7150_state)
+    ADDRESS_MAP_UNMAP_HIGH
+	AM_RANGE(0x004a, 0x004b) AM_DEVWRITE8("isbc_215g", isbc_215g_device, write, 0x00ff) // KES board
+	AM_RANGE(0x00c0, 0x00c3) AM_DEVREADWRITE8("pic8259", pic8259_device, read, write, 0x00ff)
+	AM_RANGE(0x00c8, 0x00cf) AM_DEVREADWRITE8("ppi8255", i8255_device, read, write, 0x00ff)
+	AM_RANGE(0x00d0, 0x00d7) AM_DEVREADWRITE8("pit8253", pit8253_device, read, write, 0x00ff)
+	AM_RANGE(0x00d8, 0x00d9) AM_DEVREADWRITE8("uart8251", i8251_device, data_r, data_w, 0x00ff)
+	AM_RANGE(0x00da, 0x00db) AM_DEVREADWRITE8("uart8251", i8251_device, status_r, control_w, 0x00ff)
+	AM_RANGE(0x0200, 0x0203) AM_READWRITE8(a7150_kgs_r, a7150_kgs_w, 0x00ff) // ABS/KGS board
+	AM_RANGE(0x0300, 0x031f) AM_UNMAP // ASP board #1
+	AM_RANGE(0x0320, 0x033f) AM_UNMAP // ASP board #2
+ADDRESS_MAP_END
+
+static ADDRESS_MAP_START(k7070_cpu_banked, AS_PROGRAM, 8, a7150_state)
+	ADDRESS_MAP_UNMAP_HIGH
+	// default map: IML=0, MSEL=0.  ROM + local RAM.
+	AM_RANGE(0x00000, 0x01fff) AM_ROM AM_REGION("user2", 0)
+	AM_RANGE(0x02000, 0x07fff) AM_RAMBANK("kgs_ram1")
+	AM_RANGE(0x08000, 0x0ffff) AM_RAMBANK("kgs_ram2")
+	// IML=1, MSEL=0.   local RAM only.
+	AM_RANGE(0x10000, 0x11fff) AM_RAMBANK("kgs_ram0")
+	AM_RANGE(0x12000, 0x17fff) AM_RAMBANK("kgs_ram1")
+	AM_RANGE(0x18000, 0x1ffff) AM_RAMBANK("kgs_ram2")
+	// IML=0, MSEL=1.  ROM + local RAM.
+	AM_RANGE(0x20000, 0x21fff) AM_ROM AM_REGION("user2", 0)
+	AM_RANGE(0x22000, 0x27fff) AM_RAMBANK("kgs_ram1")
+	// IML=1, MSEL=1.   local RAM only.
+	AM_RANGE(0x30000, 0x31fff) AM_RAMBANK("kgs_ram0")
+	AM_RANGE(0x32000, 0x37fff) AM_RAMBANK("kgs_ram1")
+	AM_RANGE(0x38000, 0x3ffff) AM_RAM AM_SHARE("video_ram")
+ADDRESS_MAP_END
+
+static ADDRESS_MAP_START(k7070_cpu_mem, AS_PROGRAM, 8, a7150_state)
+	ADDRESS_MAP_UNMAP_HIGH
+	AM_RANGE(0x0000, 0xffff) AM_DEVREADWRITE("video_bankdev", address_map_bank_device, read8, write8)
+ADDRESS_MAP_END
+
+
+static ADDRESS_MAP_START(k7070_cpu_io, AS_IO, 8, a7150_state)
+	ADDRESS_MAP_UNMAP_HIGH
+	ADDRESS_MAP_GLOBAL_MASK(0xff)
+	AM_RANGE(0x0000, 0x0003) AM_DEVREADWRITE(Z80CTC_TAG, z80ctc_device, read, write)
+	AM_RANGE(0x0008, 0x000b) AM_DEVREADWRITE(Z80SIO_TAG, z80sio_device, ba_cd_r, ba_cd_w)
+	AM_RANGE(0x0010, 0x0017) AM_READWRITE(kgs_host_r, kgs_host_w) // p. 11 of KGS-K7070.pdf
+
+	AM_RANGE(0x0020, 0x0021) AM_NOP // address register
+	AM_RANGE(0x0022, 0x0022) AM_NOP // function register (p. 6 of ABG-K7072.pdf)
+	AM_RANGE(0x0023, 0x0023) AM_NOP // split register
+	AM_RANGE(0x0030, 0x003f) AM_NOP // palette register
 ADDRESS_MAP_END
 
 /* Input ports */
 static INPUT_PORTS_START( a7150 )
+	PORT_START("DSEL0")
+	PORT_DIPNAME(0x01, 0x01, "Codepoint 0x24")
+	PORT_DIPSETTING(0x00, "Currency sign" )
+	PORT_DIPSETTING(0x01, "Dollar sign" )
+	PORT_DIPNAME(0x02, 0x02, "Perform I/O test")
+	PORT_DIPSETTING(0x00, DEF_STR(No) )
+	PORT_DIPSETTING(0x02, DEF_STR(Yes) )
+	PORT_DIPNAME(0x04, 0x00, "Perform VRAM test")
+	PORT_DIPSETTING(0x00, DEF_STR(Yes) )
+	PORT_DIPSETTING(0x04, DEF_STR(No) )
+
+	PORT_START("DSEL1")
+	PORT_DIPNAME(0x03, 0x02, "V.24 Parity")
+	PORT_DIPSETTING(0x00, "No parity" )
+	PORT_DIPSETTING(0x01, "Odd" )
+	PORT_DIPSETTING(0x02, "No parity" )
+	PORT_DIPSETTING(0x03, "Even" )
+	PORT_DIPNAME(0x04, 0x04, "V.24 Character size")
+	PORT_DIPSETTING(0x00, "7 bits")
+	PORT_DIPSETTING(0x04, "8 bits")
+	PORT_DIPNAME(0x38, 0x38, "V.24 Baud rate")
+	PORT_DIPSETTING(0x38, "19200")
+	PORT_DIPSETTING(0x30, "9600")
+	PORT_DIPSETTING(0x28, "4800")
+	PORT_DIPSETTING(0x20, "2400")
+	PORT_DIPSETTING(0x18, "1200")
+	PORT_DIPSETTING(0x10, "600")
+	PORT_DIPSETTING(0x08, "300")
+	PORT_DIPNAME(0x40, 0x40, "IFSS Parity")
+	PORT_DIPSETTING(0x00, "Odd" )
+	PORT_DIPSETTING(0x40, "Even" )
+	PORT_DIPNAME(0x80, 0x80, "IFSS Baud rate")
+	PORT_DIPSETTING(0x00, "9600")
+	PORT_DIPSETTING(0x80, "Same as V.24")
 INPUT_PORTS_END
 
 
+void a7150_state::kgs_memory_remap()
+{
+	int bank = m_kgs_iml + m_kgs_msel + m_kgs_msel;
+
+	logerror("%s: kgs memory: iml %d msel %d bank %d\n", machine().describe_context(), m_kgs_iml, m_kgs_msel, bank);
+
+	m_video_bankdev->set_bank(bank);
+}
+
+void a7150_state::screen_eof(screen_device &screen, bool state)
+{
+	m_gfxcpu->set_input_line(INPUT_LINE_NMI, state);
+}
+
 void a7150_state::machine_reset()
 {
+	m_kgs_ctrl = 3;
+	m_kgs_datao = m_kgs_datai = 0;
+	m_kgs_iml = m_kgs_msel = 0;
+	kgs_memory_remap();
 }
 
-void a7150_state::video_start()
+void a7150_state::machine_start()
 {
 }
 
-uint32_t a7150_state::screen_update_a7150(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
+static const z80_daisy_config k7070_daisy_chain[] =
 {
-	return 0;
-}
+	{ Z80SIO_TAG },
+	{ Z80CTC_TAG },
+	{ nullptr }
+};
 
+/*
+ * K2771.30 ZRE - processor board
+ * K3571    OPS - 256KB RAM board (x4)
+ * K7070    KGS - graphics terminal, running firmware from A7100
+ * K7072    ABG - dumb monochrome framebuffer
+ * K5170    KES - media controller (compatible with iSBC 215A)
+ *
+ * (framebuffer and terminal should be slot devices.)
+ */
 static MACHINE_CONFIG_START( a7150, a7150_state )
-	/* basic machine hardware */
-	MCFG_CPU_ADD("maincpu", I8086, 4915000)
+	MCFG_CPU_ADD("maincpu", I8086, XTAL_9_832MHz/2)
 	MCFG_CPU_PROGRAM_MAP(a7150_mem)
+	MCFG_CPU_IO_MAP(a7150_io)
+	MCFG_CPU_IRQ_ACKNOWLEDGE_DEVICE("pic8259", pic8259_device, inta_cb)
 
+	MCFG_PIC8259_ADD("pic8259", INPUTLINE("maincpu", 0), VCC, NOOP)
 
-	/* video hardware */
-	MCFG_SCREEN_ADD("screen", RASTER)
-	MCFG_SCREEN_REFRESH_RATE(50)
-	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
-	MCFG_SCREEN_SIZE(640, 480)
-	MCFG_SCREEN_VISIBLE_AREA(0, 640-1, 0, 480-1)
-	MCFG_SCREEN_UPDATE_DRIVER(a7150_state, screen_update_a7150)
+	// IFSP port on processor card
+	MCFG_DEVICE_ADD("ppi8255", I8255, 0)
+//	MCFG_I8255_IN_PORTA_CB(DEVREAD8("cent_status_in", input_buffer_device, read))
+//	MCFG_I8255_OUT_PORTB_CB(DEVWRITE8("cent_data_out", output_latch_device, write))
+	MCFG_I8255_OUT_PORTC_CB(WRITE8(a7150_state, ppi_c_w))
+
+	MCFG_DEVICE_ADD("pit8253", PIT8253, 0)
+	MCFG_PIT8253_CLK0(XTAL_14_7456MHz/4)
+	MCFG_PIT8253_OUT0_HANDLER(DEVWRITELINE("pic8259", pic8259_device, ir2_w))
+	MCFG_PIT8253_CLK1(XTAL_14_7456MHz/4)
+	MCFG_PIT8253_CLK2(XTAL_14_7456MHz/4)
+	MCFG_PIT8253_OUT2_HANDLER(WRITELINE(a7150_state, a7150_tmr2_w))
+
+	MCFG_DEVICE_ADD("uart8251", I8251, 0)
+	MCFG_I8251_TXD_HANDLER(DEVWRITELINE("rs232", rs232_port_device, write_txd))
+	MCFG_I8251_DTR_HANDLER(DEVWRITELINE("rs232", rs232_port_device, write_dtr))
+	MCFG_I8251_RTS_HANDLER(DEVWRITELINE("rs232", rs232_port_device, write_rts))
+	MCFG_I8251_RXRDY_HANDLER(DEVWRITELINE("pic8259", pic8259_device, ir4_w))
+	MCFG_I8251_TXRDY_HANDLER(DEVWRITELINE("pic8259", pic8259_device, ir4_w))
+
+	// IFSS port on processor card
+	MCFG_RS232_PORT_ADD("rs232", default_rs232_devices, "loopback") // allows ACT to pass
+	MCFG_RS232_RXD_HANDLER(DEVWRITELINE("uart8251", i8251_device, write_rxd))
+	MCFG_RS232_CTS_HANDLER(DEVWRITELINE("uart8251", i8251_device, write_cts))
+	MCFG_RS232_DSR_HANDLER(DEVWRITELINE("uart8251", i8251_device, write_dsr))
+
+	MCFG_ISBC_215_ADD("isbc_215g", 0x4a, "maincpu")
+	MCFG_ISBC_215_IRQ(DEVWRITELINE("pic8259", pic8259_device, ir5_w))
+
+	// KGS K7070 graphics terminal controlling ABG K7072 framebuffer
+	MCFG_CPU_ADD("gfxcpu", Z80, XTAL_16MHz/4)
+	MCFG_CPU_PROGRAM_MAP(k7070_cpu_mem)
+	MCFG_CPU_IO_MAP(k7070_cpu_io)
+	MCFG_Z80_DAISY_CHAIN(k7070_daisy_chain)
+
+	MCFG_DEVICE_ADD("video_bankdev", ADDRESS_MAP_BANK, 0)
+	MCFG_DEVICE_PROGRAM_MAP(k7070_cpu_banked)
+	MCFG_ADDRESS_MAP_BANK_ENDIANNESS(ENDIANNESS_BIG)
+	MCFG_ADDRESS_MAP_BANK_ADDRBUS_WIDTH(18)
+	MCFG_ADDRESS_MAP_BANK_DATABUS_WIDTH(8)
+	MCFG_ADDRESS_MAP_BANK_STRIDE(0x10000)
+
+	MCFG_DEVICE_ADD(Z80CTC_TAG, Z80CTC, XTAL_16MHz/3)
+	MCFG_Z80CTC_INTR_CB(INPUTLINE("gfxcpu", INPUT_LINE_IRQ0))
+	MCFG_Z80CTC_ZC0_CB(DEVWRITELINE(Z80SIO_TAG, z80sio_device, rxca_w))
+	MCFG_DEVCB_CHAIN_OUTPUT(DEVWRITELINE(Z80SIO_TAG, z80sio_device, txca_w))
+	MCFG_Z80CTC_ZC1_CB(DEVWRITELINE(Z80SIO_TAG, z80sio_device, rxtxcb_w))
+
+	MCFG_Z80SIO_ADD(Z80SIO_TAG, 4800, 0, 0, 0, 0)
+	MCFG_Z80SIO_OUT_INT_CB(INPUTLINE("gfxcpu", INPUT_LINE_IRQ0))
+	MCFG_Z80SIO_OUT_TXDA_CB(DEVWRITELINE(RS232_A_TAG, rs232_port_device, write_txd))
+	MCFG_Z80SIO_OUT_DTRA_CB(DEVWRITELINE(RS232_A_TAG, rs232_port_device, write_dtr))
+	MCFG_Z80SIO_OUT_RTSA_CB(DEVWRITELINE(RS232_A_TAG, rs232_port_device, write_rts))
+	MCFG_Z80SIO_OUT_TXDB_CB(DEVWRITELINE(RS232_B_TAG, rs232_port_device, write_txd))
+	MCFG_Z80SIO_OUT_DTRB_CB(WRITELINE(a7150_state, kgs_iml_w))
+//	MCFG_Z80SIO_OUT_RTSB_CB(WRITELINE(a7150_state, kgs_ifss_loopback_w))
+
+	// V.24 port (graphics tablet)
+	MCFG_RS232_PORT_ADD(RS232_A_TAG, default_rs232_devices, nullptr)
+	MCFG_RS232_RXD_HANDLER(DEVWRITELINE(Z80SIO_TAG, z80sio_device, rxa_w))
+	MCFG_RS232_DCD_HANDLER(DEVWRITELINE(Z80SIO_TAG, z80sio_device, dcda_w))
+	MCFG_RS232_CTS_HANDLER(DEVWRITELINE(Z80SIO_TAG, z80sio_device, ctsa_w))
+
+	// IFSS (current loop) port (keyboard)
+	MCFG_RS232_PORT_ADD(RS232_B_TAG, default_rs232_devices, "keyboard")
+	MCFG_RS232_RXD_HANDLER(DEVWRITELINE(Z80SIO_TAG, z80sio_device, rxb_w))
+
+	MCFG_SCREEN_ADD_MONOCHROME("screen", RASTER, rgb_t::green())
+	MCFG_SCREEN_RAW_PARAMS( XTAL_16MHz, 737,0,640, 431,0,400 )
+	MCFG_SCREEN_UPDATE_DRIVER(a7150_state, screen_update_k7072)
 	MCFG_SCREEN_PALETTE("palette")
-
 	MCFG_PALETTE_ADD_MONOCHROME("palette")
-
 MACHINE_CONFIG_END
 
 /* ROM definition */
 ROM_START( a7150 )
 	ROM_REGION( 0x10000, "user1", ROMREGION_ERASEFF )
 	ROM_LOAD( "a7150.rom", 0x0000, 0x8000, CRC(57855abd) SHA1(b58f1363623d2c3ff1221e449529ecaa22573bff))
+
+	ROM_REGION( 0x10000, "user2", ROMREGION_ERASEFF )
+	// ROM from A7100
+	ROM_LOAD( "KGS7070-152.bin", 0x0000, 0x2000, CRC(403f4235) SHA1(d07ccd40f8b600651d513f588bcf1ea4f15ed094))
+//	ROM_LOAD( "KGS7070-153.rom", 0x0000, 0x2000, CRC(a72fe820) SHA1(4b77ab2b59ea8c3632986847ff359df26b16196b))
+//	ROM_LOAD( "KGS7070-154.rom", 0x0000, 0x2000, CRC(2995ade0) SHA1(62516f2e1cb62698445f80fd823d39a1a78a7807))
 ROM_END
 
 /* Driver */