// license:MAME
// copyright-holders:Angelo Salese, Robbbert
/************************************************************************************************************

    Gundam RX-78 (c) 1983 Bandai

    driver by Angelo Salese & Robbbert.

    TODO:
    - implement printer

    Notes:
    - BS-BASIC v1.0 have a graphic bug with the RX-78 logo, it doesn't set the read bank so all of the color
      info minus plane 1 is lost when the screen scrolls vertically. Almost certainly a btanb.
    - To stop a cmt load, press STOP + SHIFT keys

==============================================================================================================
    Summary of Monitor commands.
    - The monitor is entered at bootup. The prompt is the * character. This is followed by a command
      letter (upper case). Some commands require hex parameters. You must enter all 4 characters of
      these. No spaces allowed except where shown.
    - While in BASIC, you may enter the monitor by using the MON command. After you have finished,
      you can return to BASIC by entering the command *J2005.

    - Tape commands:
    *L Load a tape
    *V Verify a tape
    *S Save a block of memory to tape. You are asked for a filename (blank is allowed), the start address,
       the end address, and the Jump address (where it should begin execution)

    - Memory commands:
    *Dnnnn nnnn Displays a hex dump in the address range entered
    *Mnnnn      Allows you to examine and modify memory. Enter to skip to next, period (.) to quit.
    *Jnnnn      Transfer execution (Jump) to a program in memory at the specified address

    - Other:
    *R          This is a block transfer load from a mystery parallel device, using ports E0 and E1,
                using handshaking similar to a centronics printer. The incoming file is loaded into
                memory and it appears that the operator is not provided any information of what happened.

*************************************************************************************************************/

#include "emu.h"
#include "cpu/z80/z80.h"
#include "sound/sn76496.h"
#include "imagedev/cassette.h"
#include "sound/wave.h"
#include "machine/ram.h"
#include "bus/generic/slot.h"
#include "bus/generic/carts.h"


class rx78_state : public driver_device
{
public:
	rx78_state(const machine_config &mconfig, device_type type, const char *tag)
		: driver_device(mconfig, type, tag),
		m_maincpu(*this, "maincpu"),
		m_cass(*this, "cassette"),
		m_cart(*this, "cartslot"),
		m_ram(*this, RAM_TAG),
		m_palette(*this, "palette")
	{ }

	DECLARE_READ8_MEMBER( key_r );
	DECLARE_READ8_MEMBER( rx78_f0_r );
	DECLARE_READ8_MEMBER( rx78_vram_r );
	DECLARE_WRITE8_MEMBER( rx78_f0_w );
	DECLARE_WRITE8_MEMBER( rx78_vram_w );
	DECLARE_WRITE8_MEMBER( vram_read_bank_w );
	DECLARE_WRITE8_MEMBER( vram_write_bank_w );
	DECLARE_WRITE8_MEMBER( key_w );
	DECLARE_WRITE8_MEMBER( vdp_reg_w );
	DECLARE_WRITE8_MEMBER( vdp_bg_reg_w );
	DECLARE_WRITE8_MEMBER( vdp_pri_mask_w );
	UINT8 m_vram_read_bank;
	UINT8 m_vram_write_bank;
	UINT8 m_pal_reg[7];
	UINT8 m_pri_mask;
	UINT8 m_key_mux;
	virtual void machine_reset();
	virtual void video_start();
	UINT32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
	DECLARE_DRIVER_INIT(rx78);
	required_device<cpu_device> m_maincpu;
	required_device<cassette_image_device> m_cass;
	required_device<generic_slot_device> m_cart;
	required_device<ram_device> m_ram;
	required_device<palette_device> m_palette;
	DECLARE_DEVICE_IMAGE_LOAD_MEMBER( rx78_cart );
};


#define MASTER_CLOCK XTAL_28_63636MHz


WRITE8_MEMBER( rx78_state::rx78_f0_w )
{
	m_cass->output(BIT(data, 0) ? -1.0 : +1.0);
}

READ8_MEMBER( rx78_state::rx78_f0_r )
{
	return (m_cass->input() > 0.03);
}


void rx78_state::video_start()
{
}

UINT32 rx78_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	UINT8 *vram = memregion("vram")->base();
	int x,y,count;

	bitmap.fill(16, cliprect);

	count = 0x2c0; //first 0x2bf bytes aren't used for bitmap drawing apparently

	for(y=0;y<184;y++)
	{
		for(x=0;x<192;x+=8)
		{
			int color,pen[3],i;

			for (i = 0; i < 8; i++)
			{
				/* bg color */
				pen[0] = (m_pri_mask & 0x08) ? (vram[count + 0x6000] >> (i)) : 0x00;
				pen[1] = (m_pri_mask & 0x10) ? (vram[count + 0x8000] >> (i)) : 0x00;
				pen[2] = (m_pri_mask & 0x20) ? (vram[count + 0xa000] >> (i)) : 0x00;

				color  = ((pen[0] & 1) << 0);
				color |= ((pen[1] & 1) << 1);
				color |= ((pen[2] & 1) << 2);

				if(color)
					bitmap.pix16(y, x+i) = color;

				/* fg color */
				pen[0] = (m_pri_mask & 0x01) ? (vram[count + 0x0000] >> (i)) : 0x00;
				pen[1] = (m_pri_mask & 0x02) ? (vram[count + 0x2000] >> (i)) : 0x00;
				pen[2] = (m_pri_mask & 0x04) ? (vram[count + 0x4000] >> (i)) : 0x00;

				color  = ((pen[0] & 1) << 0);
				color |= ((pen[1] & 1) << 1);
				color |= ((pen[2] & 1) << 2);

				if(color)
					bitmap.pix16(y, x+i) = color;
			}
			count++;
		}
	}

	return 0;
}


READ8_MEMBER( rx78_state::key_r )
{
	static const char *const keynames[] = { "KEY0", "KEY1", "KEY2", "KEY3",
											"KEY4", "KEY5", "KEY6", "KEY7",
											"KEY8", "JOY1P_0","JOY1P_1","JOY1P_2",
											"JOY2P_0", "JOY2P_1", "JOY2P_2", "UNUSED" };

	if(m_key_mux == 0x30) //status read
	{
		int res,i;

		res = 0;
		for(i=0;i<15;i++)
			res |= ioport(keynames[i])->read();

		return res;
	}

	if(m_key_mux >= 1 && m_key_mux <= 15)
		return ioport(keynames[m_key_mux - 1])->read();

	return 0;
}

WRITE8_MEMBER( rx78_state::key_w )
{
	m_key_mux = data;
}

READ8_MEMBER( rx78_state::rx78_vram_r )
{
	UINT8 *vram = memregion("vram")->base();

	if(m_vram_read_bank == 0 || m_vram_read_bank > 6)
		return 0xff;

	return vram[offset + ((m_vram_read_bank - 1) * 0x2000)];
}

WRITE8_MEMBER( rx78_state::rx78_vram_w )
{
	UINT8 *vram = memregion("vram")->base();

	if(m_vram_write_bank & 0x01) { vram[offset + 0 * 0x2000] = data; }
	if(m_vram_write_bank & 0x02) { vram[offset + 1 * 0x2000] = data; }
	if(m_vram_write_bank & 0x04) { vram[offset + 2 * 0x2000] = data; }
	if(m_vram_write_bank & 0x08) { vram[offset + 3 * 0x2000] = data; }
	if(m_vram_write_bank & 0x10) { vram[offset + 4 * 0x2000] = data; }
	if(m_vram_write_bank & 0x20) { vram[offset + 5 * 0x2000] = data; }
}

WRITE8_MEMBER( rx78_state::vram_read_bank_w )
{
	m_vram_read_bank = data;
}

WRITE8_MEMBER( rx78_state::vram_write_bank_w )
{
	m_vram_write_bank = data;
}

WRITE8_MEMBER( rx78_state::vdp_reg_w )
{
	UINT8 r,g,b,res,i;

	m_pal_reg[offset] = data;

	for(i=0;i<16;i++)
	{
		res = ((i & 1) ? m_pal_reg[0 + (i & 8 ? 3 : 0)] : 0) | ((i & 2) ? m_pal_reg[1 + (i & 8 ? 3 : 0)] : 0) | ((i & 4) ? m_pal_reg[2 + (i & 8 ? 3 : 0)] : 0);
		if(res & m_pal_reg[6]) //color mask, TODO: check this
			res &= m_pal_reg[6];

		r = (res & 0x11) == 0x11 ? 0xff : ((res & 0x11) == 0x01 ? 0x7f : 0x00);
		g = (res & 0x22) == 0x22 ? 0xff : ((res & 0x22) == 0x02 ? 0x7f : 0x00);
		b = (res & 0x44) == 0x44 ? 0xff : ((res & 0x44) == 0x04 ? 0x7f : 0x00);

		m_palette->set_pen_color(i, rgb_t(r,g,b));
	}
}

WRITE8_MEMBER( rx78_state::vdp_bg_reg_w )
{
	int r,g,b;

	r = (data & 0x11) == 0x11 ? 0xff : ((data & 0x11) == 0x01 ? 0x7f : 0x00);
	g = (data & 0x22) == 0x22 ? 0xff : ((data & 0x22) == 0x02 ? 0x7f : 0x00);
	b = (data & 0x44) == 0x44 ? 0xff : ((data & 0x44) == 0x04 ? 0x7f : 0x00);

	m_palette->set_pen_color(0x10, rgb_t(r,g,b));
}

WRITE8_MEMBER( rx78_state::vdp_pri_mask_w )
{
	m_pri_mask = data;
}


static ADDRESS_MAP_START(rx78_mem, AS_PROGRAM, 8, rx78_state)
	ADDRESS_MAP_UNMAP_HIGH
	AM_RANGE(0x0000, 0x1fff) AM_ROM
	//AM_RANGE(0x2000, 0x5fff)      // mapped by the cartslot
	AM_RANGE(0x6000, 0xafff) AM_RAM //ext RAM
	AM_RANGE(0xb000, 0xebff) AM_RAM
	AM_RANGE(0xec00, 0xffff) AM_READWRITE(rx78_vram_r, rx78_vram_w)
ADDRESS_MAP_END

static ADDRESS_MAP_START(rx78_io, AS_IO, 8, rx78_state)
	ADDRESS_MAP_UNMAP_HIGH
	ADDRESS_MAP_GLOBAL_MASK(0xff)
//  AM_RANGE(0xe2, 0xe2) AM_READNOP AM_WRITENOP //printer
//  AM_RANGE(0xe3, 0xe3) AM_WRITENOP //printer
	AM_RANGE(0xf0, 0xf0) AM_READWRITE(rx78_f0_r,rx78_f0_w) //cmt
	AM_RANGE(0xf1, 0xf1) AM_WRITE(vram_read_bank_w)
	AM_RANGE(0xf2, 0xf2) AM_WRITE(vram_write_bank_w)
	AM_RANGE(0xf4, 0xf4) AM_READWRITE(key_r,key_w) //keyboard
	AM_RANGE(0xf5, 0xfb) AM_WRITE(vdp_reg_w) //vdp
	AM_RANGE(0xfc, 0xfc) AM_WRITE(vdp_bg_reg_w) //vdp
	AM_RANGE(0xfe, 0xfe) AM_WRITE(vdp_pri_mask_w)
	AM_RANGE(0xff, 0xff) AM_DEVWRITE("sn1", sn76489a_device, write) //psg
ADDRESS_MAP_END

/* Input ports */
static INPUT_PORTS_START( rx78 )
	PORT_START("KEY0")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("0") PORT_CODE(KEYCODE_0) PORT_CHAR('0')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("1") PORT_CODE(KEYCODE_1) PORT_CHAR('1') PORT_CHAR('!')
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("2") PORT_CODE(KEYCODE_2) PORT_CHAR('2') PORT_CHAR('"')
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("3") PORT_CODE(KEYCODE_3) PORT_CHAR('3') PORT_CHAR('#')
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("4") PORT_CODE(KEYCODE_4) PORT_CHAR('4') PORT_CHAR('$')
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("5") PORT_CODE(KEYCODE_5) PORT_CHAR('5') PORT_CHAR('%')
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("6") PORT_CODE(KEYCODE_6) PORT_CHAR('6') PORT_CHAR('&')
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("7") PORT_CODE(KEYCODE_7) PORT_CHAR('7') PORT_CHAR('\'')

	PORT_START("KEY1")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("8") PORT_CODE(KEYCODE_8) PORT_CHAR('8') PORT_CHAR('(')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("9") PORT_CODE(KEYCODE_9) PORT_CHAR('9') PORT_CHAR(')')
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME(":") PORT_CODE(KEYCODE_QUOTE) PORT_CHAR(':') PORT_CHAR('*')
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME(";") PORT_CODE(KEYCODE_COLON) PORT_CHAR(';') PORT_CHAR('+')
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME(",") PORT_CODE(KEYCODE_COMMA) PORT_CHAR(',') PORT_CHAR('<')
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("-") PORT_CODE(KEYCODE_MINUS) PORT_CHAR('-') PORT_CHAR('=')
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME(".") PORT_CODE(KEYCODE_STOP) PORT_CHAR('.') PORT_CHAR('>')
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("/") PORT_CODE(KEYCODE_SLASH) PORT_CHAR('/') PORT_CHAR('?')

	PORT_START("KEY2")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("@") PORT_CODE(KEYCODE_TILDE) PORT_CHAR('@') PORT_CHAR('`')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("A") PORT_CODE(KEYCODE_A) PORT_CHAR('A') PORT_CHAR('a')
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("B") PORT_CODE(KEYCODE_B) PORT_CHAR('B') PORT_CHAR('b')
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("C") PORT_CODE(KEYCODE_C) PORT_CHAR('C') PORT_CHAR('c')
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("D") PORT_CODE(KEYCODE_D) PORT_CHAR('D') PORT_CHAR('d')
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("E") PORT_CODE(KEYCODE_E) PORT_CHAR('E') PORT_CHAR('e')
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("F") PORT_CODE(KEYCODE_F) PORT_CHAR('F') PORT_CHAR('f')
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("G") PORT_CODE(KEYCODE_G) PORT_CHAR('G') PORT_CHAR('g')

	PORT_START("KEY3")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("H") PORT_CODE(KEYCODE_H) PORT_CHAR('H') PORT_CHAR('h')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("I") PORT_CODE(KEYCODE_I) PORT_CHAR('I') PORT_CHAR('i')
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("J") PORT_CODE(KEYCODE_J) PORT_CHAR('J') PORT_CHAR('j')
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("K") PORT_CODE(KEYCODE_K) PORT_CHAR('K') PORT_CHAR('k')
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("L") PORT_CODE(KEYCODE_L) PORT_CHAR('L') PORT_CHAR('l')
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("M") PORT_CODE(KEYCODE_M) PORT_CHAR('M') PORT_CHAR('m')
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("N") PORT_CODE(KEYCODE_N) PORT_CHAR('N') PORT_CHAR('n')
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("O") PORT_CODE(KEYCODE_O) PORT_CHAR('O') PORT_CHAR('o')

	PORT_START("KEY4")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("P") PORT_CODE(KEYCODE_P) PORT_CHAR('P') PORT_CHAR('p')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Q") PORT_CODE(KEYCODE_Q) PORT_CHAR('Q') PORT_CHAR('q')
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("R") PORT_CODE(KEYCODE_R) PORT_CHAR('R') PORT_CHAR('r')
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("S") PORT_CODE(KEYCODE_S) PORT_CHAR('S') PORT_CHAR('s')
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("T") PORT_CODE(KEYCODE_T) PORT_CHAR('T') PORT_CHAR('t')
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("U") PORT_CODE(KEYCODE_U) PORT_CHAR('U') PORT_CHAR('u')
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("V") PORT_CODE(KEYCODE_V) PORT_CHAR('V') PORT_CHAR('v')
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("W") PORT_CODE(KEYCODE_W) PORT_CHAR('W') PORT_CHAR('w')

	PORT_START("KEY5")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("X") PORT_CODE(KEYCODE_X) PORT_CHAR('X') PORT_CHAR('x')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Y") PORT_CODE(KEYCODE_Y) PORT_CHAR('Y') PORT_CHAR('y')
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Z") PORT_CODE(KEYCODE_Z) PORT_CHAR('Z') PORT_CHAR('z')
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("[") PORT_CODE(KEYCODE_OPENBRACE) PORT_CHAR('[') PORT_CHAR('{')
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("\\") PORT_CODE(KEYCODE_BACKSLASH) PORT_CHAR('\\') PORT_CHAR('|')
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("]") PORT_CODE(KEYCODE_CLOSEBRACE) PORT_CHAR(']') PORT_CHAR('}')
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Up Down Arrow") PORT_CODE(KEYCODE_PGUP)
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Right Left Arrow") PORT_CODE(KEYCODE_PGDN)

	PORT_START("KEY6")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Space") PORT_CODE(KEYCODE_SPACE) PORT_CHAR(' ')
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Down") PORT_CODE(KEYCODE_DOWN)
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Up") PORT_CODE(KEYCODE_UP)
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Right") PORT_CODE(KEYCODE_RIGHT)
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("Left") PORT_CODE(KEYCODE_LEFT)
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("HOME / CLR") PORT_CODE(KEYCODE_HOME)
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_UNUSED )
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("INST / DEL") PORT_CODE(KEYCODE_BACKSPACE)

	PORT_START("KEY7")
	PORT_BIT(0x07,IP_ACTIVE_HIGH,IPT_UNUSED )
	PORT_BIT(0x08,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("STOP") PORT_CODE(KEYCODE_END)
	PORT_BIT(0x10,IP_ACTIVE_HIGH,IPT_UNUSED )
	PORT_BIT(0x20,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("RETURN") PORT_CODE(KEYCODE_ENTER) PORT_CHAR(13)
	PORT_BIT(0x40,IP_ACTIVE_HIGH,IPT_UNUSED )
	PORT_BIT(0x80,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("SHIFT LOCK") PORT_CODE(KEYCODE_CAPSLOCK)

	PORT_START("KEY8")
	PORT_BIT(0x01,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("CTRL") PORT_CODE(KEYCODE_LCONTROL) //kana shift?
	PORT_BIT(0x02,IP_ACTIVE_HIGH,IPT_UNUSED )
	PORT_BIT(0x04,IP_ACTIVE_HIGH,IPT_KEYBOARD) PORT_NAME("SHIFT") PORT_CODE(KEYCODE_LSHIFT) PORT_CODE(KEYCODE_RSHIFT) PORT_CHAR(UCHAR_SHIFT_1)
	PORT_BIT(0xf8,IP_ACTIVE_HIGH,IPT_UNUSED )

	PORT_START("JOY1P_0")
	PORT_BIT( 0x11, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_8WAY PORT_PLAYER(1)
	PORT_BIT( 0x22, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P1 Up Left") PORT_PLAYER(1)
	PORT_BIT( 0x44, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_8WAY PORT_PLAYER(1)
	PORT_BIT( 0x88, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(1)

	PORT_START("JOY1P_1")
	PORT_BIT( 0x11, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P1 Down Left")  PORT_PLAYER(1)
	PORT_BIT( 0x22, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P1 Up Right") PORT_PLAYER(1)
	PORT_BIT( 0x44, IP_ACTIVE_HIGH, IPT_UNUSED )
	PORT_BIT( 0x88, IP_ACTIVE_HIGH, IPT_UNUSED )

	PORT_START("JOY1P_2")
	PORT_BIT( 0x11, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_8WAY  PORT_PLAYER(1)
	PORT_BIT( 0x22, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P1 Down Right") PORT_PLAYER(1)
	PORT_BIT( 0x44, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_8WAY  PORT_PLAYER(1)
	PORT_BIT( 0x88, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(1)

	PORT_START("JOY2P_0")
	PORT_BIT( 0x11, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_8WAY PORT_PLAYER(2)
	PORT_BIT( 0x22, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P2 Up Left") PORT_PLAYER(2)
	PORT_BIT( 0x44, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_8WAY PORT_PLAYER(2)
	PORT_BIT( 0x88, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(2)

	PORT_START("JOY2P_1")
	PORT_BIT( 0x11, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P2 Down Left")  PORT_PLAYER(2)
	PORT_BIT( 0x22, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P2 Up Right") PORT_PLAYER(2)
	PORT_BIT( 0x44, IP_ACTIVE_HIGH, IPT_UNUSED )
	PORT_BIT( 0x88, IP_ACTIVE_HIGH, IPT_UNUSED )

	PORT_START("JOY2P_2")
	PORT_BIT( 0x11, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_8WAY  PORT_PLAYER(2)
	PORT_BIT( 0x22, IP_ACTIVE_HIGH, IPT_OTHER ) PORT_NAME("P2 Down Right") PORT_PLAYER(2)
	PORT_BIT( 0x44, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_8WAY  PORT_PLAYER(2)
	PORT_BIT( 0x88, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(2)

	PORT_START("UNUSED")
	PORT_BIT( 0xff, IP_ACTIVE_HIGH, IPT_UNUSED )
INPUT_PORTS_END


void rx78_state::machine_reset()
{
	address_space &prg = m_maincpu->space(AS_PROGRAM);
	if (m_cart->exists())
		prg.install_read_handler(0x2000, 0x5fff, read8_delegate(FUNC(generic_slot_device::read_rom),(generic_slot_device*)m_cart));
}

DEVICE_IMAGE_LOAD_MEMBER( rx78_state, rx78_cart )
{
	UINT32 size = m_cart->common_get_size("rom");

	if (size != 0x2000 && size != 0x4000)
	{
		image.seterror(IMAGE_ERROR_UNSPECIFIED, "Unsupported cartridge size");
		return IMAGE_INIT_FAIL;
	}

	m_cart->rom_alloc(size, GENERIC_ROM8_WIDTH, ENDIANNESS_LITTLE);
	m_cart->common_load_rom(m_cart->get_rom_base(), size, "rom");

	return IMAGE_INIT_PASS;
}

/* F4 Character Displayer */
static const gfx_layout rx78_charlayout =
{
	8, 8,                   /* 8 x 8 characters */
	187,                    /* 187 characters */
	1,                  /* 1 bits per pixel */
	{ 0 },                  /* no bitplanes */
	/* x offsets */
	{ 7, 6, 5, 4, 3, 2, 1, 0 },
	/* y offsets */
	{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
	8*8                 /* every char takes 8 bytes */
};

static GFXDECODE_START( rx78 )
	GFXDECODE_ENTRY( "maincpu", 0x1a27, rx78_charlayout, 0, 8 )
GFXDECODE_END


static MACHINE_CONFIG_START( rx78, rx78_state )
	/* basic machine hardware */
	MCFG_CPU_ADD("maincpu",Z80, MASTER_CLOCK/7) // unknown divider
	MCFG_CPU_PROGRAM_MAP(rx78_mem)
	MCFG_CPU_IO_MAP(rx78_io)
	MCFG_CPU_VBLANK_INT_DRIVER("screen", rx78_state, irq0_line_hold)

	/* video hardware */
	MCFG_SCREEN_ADD("screen", RASTER)
	MCFG_SCREEN_REFRESH_RATE(60)
	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
	MCFG_SCREEN_UPDATE_DRIVER(rx78_state, screen_update)
	MCFG_SCREEN_SIZE(192, 184)
	MCFG_SCREEN_VISIBLE_AREA(0, 192-1, 0, 184-1)
	MCFG_SCREEN_PALETTE("palette")

	MCFG_PALETTE_ADD("palette", 16+1) //+1 for the background color
	MCFG_GFXDECODE_ADD("gfxdecode", "palette", rx78)

	MCFG_GENERIC_CARTSLOT_ADD("cartslot", generic_plain_slot, "rx78_cart")
	MCFG_GENERIC_EXTENSIONS("bin,rom")
	MCFG_GENERIC_LOAD(rx78_state, rx78_cart)

	MCFG_RAM_ADD(RAM_TAG)
	MCFG_RAM_DEFAULT_SIZE("32k")
	MCFG_RAM_EXTRA_OPTIONS("16k")

	MCFG_CASSETTE_ADD( "cassette" )

	MCFG_SPEAKER_STANDARD_MONO("mono")

	MCFG_SOUND_WAVE_ADD(WAVE_TAG, "cassette")
	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)

	MCFG_SOUND_ADD("sn1", SN76489A, XTAL_28_63636MHz/8) // unknown divider
	MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.50)

	/* Software lists */
	MCFG_SOFTWARE_LIST_ADD("cart_list","rx78")
MACHINE_CONFIG_END

/* ROM definition */
ROM_START( rx78 )
	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
	ROM_LOAD( "ipl.rom", 0x0000, 0x2000, CRC(a194ea53) SHA1(ba39e73e6eb7cbb8906fff1f81a98964cd62af0d))

	ROM_REGION( 6 * 0x2000, "vram", ROMREGION_ERASE00 )
ROM_END

DRIVER_INIT_MEMBER(rx78_state,rx78)
{
	UINT32 ram_size = m_ram->size();
	address_space &prg = m_maincpu->space(AS_PROGRAM);

	if (ram_size == 0x4000)
		prg.unmap_readwrite(0x6000, 0xafff);
}

/* Driver */

/*    YEAR  NAME    PARENT  COMPAT   MACHINE    INPUT    CLASS       INIT   COMPANY     FULLNAME     FLAGS */
COMP( 1983, rx78,   0,      0,       rx78,      rx78,    rx78_state, rx78,  "Bandai", "Gundam RX-78", 0)
