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

Tank Battalion memory map (preliminary)

driver by Brad Oliver

$0000-$000f : bullet ram, first entry is player's bullet
$0010-$01ff : zero page & stack
$0200-$07ff : RAM
$0800-$0bff : videoram
$0c00-$0c1f : I/O

Read:
	$0c00-$0c03 : p1 joystick
	$0c04
	$0c07       : stop at grid self-test if bit 7 is low
	$0c0f 		: stop at first self-test if bit 7 is low

	$0c18		: Cabinet, 0 = table, 1 = upright
	$0c19-$0c1a	: Coinage, 00 = free play, 01 = 2 coin 1 credit, 10 = 1 coin 2 credits, 11 = 1 coin 1 credit
	$0c1b-$0c1c : Bonus, 00 = 10000, 01 = 15000, 10 = 20000, 11 = none
	$0c1d		: Tanks, 0 = 3, 1 = 2
	$0c1e-$0c1f : ??

Write:
	$0c00-$0c01 : p1/p2 start leds
	$0c02		: ?? written to at end of IRQ, either 0 or 1 - coin counter?
	$0c03		: ?? written to during IRQ if grid test is on
	$0c08		: ?? written to during IRQ if grid test is on
	$0c09		: Sound - coin ding
	$0c0a		: NMI enable (active low) ?? game only ??
	$0c0b		: Sound - background noise, 0 - low rumble, 1 - high rumble
	$0c0c		: Sound - player fire
	$0c0d		: Sound - explosion
	$0c0f		: NMI enable (active high) ?? demo only ??

	$0c10		: IRQ ack ??
	$0c18		: Watchdog ?? Not written to while game screen is up

$2000-$3fff : ROM

TODO:
	. Resistor values on the color prom need to be verified

Changes:
	28 Feb 98 LBO
		. Fixed the coin interrupts
		. Fixed the color issues, should be 100% if I guessed at the resistor values properly
		. Fixed the 2nd player cocktail joystick, had the polarity reversed
		. Hacked the sound sample triggers so they work better

Known issues:
	. The 'moving' tank rumble noise seems to keep playing a second too long
	. Sample support is all a crapshoot. I have no idea how it really works

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

#include "driver.h"
#include "vidhrdw/generic.h"
#include "cpu/m6502/m6502.h"

extern unsigned char *tankbatt_bulletsram;
extern size_t tankbatt_bulletsram_size;

static int tankbatt_nmi_enable; /* No need to init this - the game will set it on reset */
static int tankbatt_sound_enable;

PALETTE_INIT( tankbatt );
VIDEO_UPDATE( tankbatt );

WRITE_HANDLER( tankbatt_led_w )
{
	set_led_status(offset,data & 1);
}

READ_HANDLER( tankbatt_in0_r )
{
	int val;

	val = readinputport(0);
	return ((val << (7-offset)) & 0x80);
}

READ_HANDLER( tankbatt_in1_r )
{
	int val;

	val = readinputport(1);
	return ((val << (7-offset)) & 0x80);
}

READ_HANDLER( tankbatt_dsw_r )
{
	int val;

	val = readinputport(2);
	return ((val << (7-offset)) & 0x80);
}

WRITE_HANDLER( tankbatt_interrupt_enable_w )
{
	tankbatt_nmi_enable = !data;
	tankbatt_sound_enable = !data;
	if (data != 0)
	{
		cpu_set_irq_line(0, 0, CLEAR_LINE);
		cpu_set_nmi_line(0, CLEAR_LINE);
	}
	/* hack - turn off the engine noise if the normal game nmi's are disabled */
	if (data) sample_stop (2);
//	interrupt_enable_w (offset, !data);
}

WRITE_HANDLER( tankbatt_demo_interrupt_enable_w )
{
	tankbatt_nmi_enable = data;
	if (data != 0)
	{
		cpu_set_irq_line(0, 0, CLEAR_LINE);
		cpu_set_nmi_line(0, CLEAR_LINE);
	}
//	interrupt_enable_w (offset, data);
}

WRITE_HANDLER( tankbatt_sh_expl_w )
{
	if (tankbatt_sound_enable)
		sample_start (1, 3, 0);
}

WRITE_HANDLER( tankbatt_sh_engine_w )
{
	if (tankbatt_sound_enable)
	{
		if (data)
			sample_start (2, 2, 1);
		else
			sample_start (2, 1, 1);
	}
	else sample_stop (2);
}

WRITE_HANDLER( tankbatt_sh_fire_w )
{
	if (tankbatt_sound_enable)
		sample_start (0, 0, 0);
}

static MEMORY_READ_START( readmem )
	{ 0x0000, 0x01ff, MRA_RAM },
	{ 0x0c00, 0x0c07, tankbatt_in0_r },
	{ 0x0c08, 0x0c0f, tankbatt_in1_r },
	{ 0x0c18, 0x0c1f, tankbatt_dsw_r },
	{ 0x0200, 0x0bff, MRA_RAM },
	{ 0x6000, 0x7fff, MRA_ROM },
	{ 0xf800, 0xffff, MRA_ROM },	/* for the reset / interrupt vectors */
MEMORY_END

static MEMORY_WRITE_START( writemem )
	{ 0x0010, 0x01ff, MWA_RAM },
	{ 0x0800, 0x0bff, videoram_w, &videoram, &videoram_size },
	{ 0x0000, 0x000f, MWA_RAM, &tankbatt_bulletsram, &tankbatt_bulletsram_size },
	{ 0x0c18, 0x0c18, MWA_NOP }, /* watchdog ?? */
	{ 0x0c00, 0x0c01, tankbatt_led_w },
	{ 0x0c0a, 0x0c0a, tankbatt_interrupt_enable_w },
	{ 0x0c0b, 0x0c0b, tankbatt_sh_engine_w },
	{ 0x0c0c, 0x0c0c, tankbatt_sh_fire_w },
	{ 0x0c0d, 0x0c0d, tankbatt_sh_expl_w },
	{ 0x0c0f, 0x0c0f, tankbatt_demo_interrupt_enable_w },
	{ 0x0200, 0x07ff, MWA_RAM },
	{ 0x2000, 0x3fff, MWA_ROM },
MEMORY_END

INTERRUPT_GEN( tankbatt_interrupt )
{
	if ((readinputport (0) & 0x60) == 0) cpu_set_irq_line(0,0,HOLD_LINE);
	else if (tankbatt_nmi_enable) cpu_set_irq_line(0,IRQ_LINE_NMI,PULSE_LINE);
}

INPUT_PORTS_START( tankbatt )
	PORT_START	/* IN0 */
	PORT_BIT ( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_UP | IPF_4WAY )
	PORT_BIT ( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT | IPF_4WAY )
	PORT_BIT ( 0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN | IPF_4WAY )
	PORT_BIT ( 0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT | IPF_4WAY )
	PORT_BIT ( 0x10, IP_ACTIVE_LOW, IPT_BUTTON1 )
	PORT_BIT_IMPULSE( 0x60, IP_ACTIVE_LOW, IPT_COIN1, 2 )
	PORT_BIT ( 0x80, IP_ACTIVE_LOW, IPT_TILT )

	PORT_START	/* IN1 */
	PORT_BIT ( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_UP | IPF_4WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT | IPF_4WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN | IPF_4WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT | IPF_4WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x10, IP_ACTIVE_LOW, IPT_BUTTON1 | IPF_COCKTAIL )
	PORT_BIT ( 0x20, IP_ACTIVE_LOW, IPT_START1 )
	PORT_BIT ( 0x40, IP_ACTIVE_LOW, IPT_START2 )
	PORT_SERVICE( 0x80, IP_ACTIVE_LOW )

	PORT_START	/* DSW */
	PORT_DIPNAME( 0x01, 0x01, DEF_STR( Cabinet ) )
	PORT_DIPSETTING(    0x01, DEF_STR( Upright ) )
	PORT_DIPSETTING(    0x00, DEF_STR( Cocktail ) )
 	PORT_DIPNAME( 0x06, 0x06, DEF_STR( Coinage ) )
	PORT_DIPSETTING(    0x04, DEF_STR( 2C_1C ) )
	PORT_DIPSETTING(    0x06, DEF_STR( 1C_1C ) )
	PORT_DIPSETTING(    0x02, DEF_STR( 1C_2C ) )
	PORT_DIPSETTING(    0x00, DEF_STR( Free_Play ) )
	PORT_DIPNAME( 0x18, 0x08, DEF_STR( Bonus_Life ) )
	PORT_DIPSETTING(    0x00, "10000" )
	PORT_DIPSETTING(    0x10, "15000" )
	PORT_DIPSETTING(    0x08, "20000" )
	PORT_DIPSETTING(    0x18, "None" )
	PORT_DIPNAME( 0x20, 0x00, DEF_STR( Lives ) )
	PORT_DIPSETTING(    0x20, "2" )
	PORT_DIPSETTING(    0x00, "3" )
	PORT_DIPNAME( 0x40, 0x40, DEF_STR( Unknown ) )
	PORT_DIPSETTING(    0x40, DEF_STR( Off ) )
	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
	PORT_DIPNAME( 0x80, 0x80, DEF_STR( Unknown ) )
	PORT_DIPSETTING(    0x80, DEF_STR( Off ) )
	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
INPUT_PORTS_END


static struct GfxLayout charlayout =
{
	8,8,	/* 8*8 characters */
	256,	/* 256 characters */
	1,	/* 1 bit per pixel */
	{ 0 },	/* only one bitplane */
	{ 0, 1, 2, 3, 4, 5, 6, 7 },
	{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
	8*8	/* every char takes 8 consecutive bytes */
};

static struct GfxLayout bulletlayout =
{
	/* there is no gfx ROM for this one, it is generated by the hardware */
	3,3,	/* 3*3 box */
	1,	/* just one */
	1,	/* 1 bit per pixel */
	{ 8*8 },
	{ 2, 2, 2 },   /* I "know" that this bit of the */
	{ 2, 2, 2 },   /* graphics ROMs is 1 */
	0	/* no use */
};


static struct GfxDecodeInfo gfxdecodeinfo[] =
{
	{ REGION_GFX1, 0, &charlayout,   0, 64 },
	{ REGION_GFX1, 0, &bulletlayout, 0, 64 },
	{ -1 } /* end of array */
};



static const char *tankbatt_sample_names[] =
{
	"*tankbatt",
	"fire.wav",
	"engine1.wav",
	"engine2.wav",
	"explode1.wav",
    0	/* end of array */
};

static struct Samplesinterface samples_interface =
{
	3,	/* 3 channels */
	25,	/* volume */
	tankbatt_sample_names
};



static MACHINE_DRIVER_START( tankbatt )

	/* basic machine hardware */
	MDRV_CPU_ADD(M6502, 1000000)	/* 1 MHz ???? */
	MDRV_CPU_MEMORY(readmem,writemem)
	MDRV_CPU_VBLANK_INT(tankbatt_interrupt,1)

	MDRV_FRAMES_PER_SECOND(60)
	MDRV_VBLANK_DURATION(DEFAULT_60HZ_VBLANK_DURATION)

	/* video hardware */
	MDRV_VIDEO_ATTRIBUTES(VIDEO_TYPE_RASTER)
	MDRV_SCREEN_SIZE(32*8, 32*8)
	MDRV_VISIBLE_AREA(0*8, 32*8-1, 2*8, 30*8-1)
	MDRV_GFXDECODE(gfxdecodeinfo)
	MDRV_PALETTE_LENGTH(65)
	MDRV_COLORTABLE_LENGTH(128)

	MDRV_PALETTE_INIT(tankbatt)
	MDRV_VIDEO_START(generic)
	MDRV_VIDEO_UPDATE(tankbatt)

	/* sound hardware */
	MDRV_SOUND_ADD(SAMPLES, samples_interface)
MACHINE_DRIVER_END



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

  Game driver(s)

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

ROM_START( tankbatt )
	ROM_REGION( 0x10000, REGION_CPU1, 0 )	/* 64k for code */
	ROM_LOAD( "tb1-1.bin",    0x6000, 0x0800, 0x278a0b8c )
	ROM_LOAD( "tb1-2.bin",    0x6800, 0x0800, 0xe0923370 )
	ROM_LOAD( "tb1-3.bin",    0x7000, 0x0800, 0x85005ea4 )
	ROM_LOAD( "tb1-4.bin",    0x7800, 0x0800, 0x3dfb5bcf )
	ROM_RELOAD(               0xf800, 0x0800 )	/* for the reset and interrupt vectors */

	ROM_REGION( 0x0800, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "tb1-5.bin",    0x0000, 0x0800, 0xaabd4fb1 )

	ROM_REGION( 0x0100, REGION_PROMS, 0 )
	ROM_LOAD( "tankbatt.clr", 0x0000, 0x0100, 0x1150d613 )
ROM_END



GAME( 1980, tankbatt, 0, tankbatt, tankbatt, 0, ROT90, "Namco", "Tank Battalion" )
