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

	Atari Millipede hardware

	Games supported:
		* Millipede

	Known bugs:
		* none at this time

****************************************************************************

	Millipede memory map (preliminary)

	driver by Ivan Mackintosh

	0400-040F		POKEY 1
	0800-080F		POKEY 2
	1000-13BF		SCREEN RAM (8x8 TILES, 32x30 SCREEN)
	13C0-13CF		SPRITE IMAGE OFFSETS
	13D0-13DF		SPRITE HORIZONTAL OFFSETS
	13E0-13EF		SPRITE VERTICAL OFFSETS
	13F0-13FF		SPRITE COLOR OFFSETS

	2000			BIT 1-4 trackball
					BIT 5 IS P1 FIRE
					BIT 6 IS P1 START
					BIT 7 IS VBLANK

	2001			BIT 1-4 trackball
					BIT 5 IS P2 FIRE
					BIT 6 IS P2 START
					BIT 7,8 (?)

	2010			BIT 1 IS P1 RIGHT
					BIT 2 IS P1 LEFT
					BIT 3 IS P1 DOWN
					BIT 4 IS P1 UP
					BIT 5 IS SLAM, LEFT COIN, AND UTIL COIN
					BIT 6,7 (?)
					BIT 8 IS RIGHT COIN
	2030			earom read
	2480-249F		COLOR RAM
	2500-2502		Coin counters
	2503-2504		LEDs
	2505-2507		Coin door lights ??
	2600			INTERRUPT ACKNOWLEDGE
	2680			CLEAR WATCHDOG
	2700			earom control
	2780			earom write
	4000-7FFF		GAME CODE

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

#include "driver.h"
#include "vidhrdw/generic.h"
#include "machine/atari_vg.h"
#include "milliped.h"



/*************************************
 *
 *	Input ports
 *
 *************************************/

/*
 * This wrapper routine is necessary because Millipede requires a direction bit
 * to be set or cleared. The direction bit is held until the mouse is moved
 * again. We still don't understand why the difference between
 * two consecutive reads must not exceed 7. After all, the input is 4 bits
 * wide, and we have a fifth bit for the sign...
 *
 * The other reason it is necessary is that Millipede uses the same address to
 * read the dipswitches.
 */

static UINT8 dsw_select;

static WRITE_HANDLER( milliped_input_select_w )
{
	dsw_select = (data == 0);
}


static READ_HANDLER( milliped_IN0_r )
{
	static int oldpos,sign;
	int newpos;

	if (dsw_select)
		return (readinputport(0) | sign);

	newpos = readinputport(6);
	if (newpos != oldpos)
	{
		sign = (newpos - oldpos) & 0x80;
		oldpos = newpos;
	}

	return ((readinputport(0) & 0x70) | (oldpos & 0x0f) | sign );
}


static READ_HANDLER( milliped_IN1_r )
{
	static int oldpos,sign;
	int newpos;

	if (dsw_select)
		return (readinputport(1) | sign);

	newpos = readinputport(7);
	if (newpos != oldpos)
	{
		sign = (newpos - oldpos) & 0x80;
		oldpos = newpos;
	}

	return ((readinputport(1) & 0x70) | (oldpos & 0x0f) | sign );
}



/*************************************
 *
 *	Output ports
 *
 *************************************/

static WRITE_HANDLER( milliped_led_w )
{
	set_led_status(offset,~data & 0x80);
}


static WRITE_HANDLER( milliped_coin_counter_w )
{
	coin_counter_w(offset,data);
}




/*************************************
 *
 *	Main CPU memory handlers
 *
 *************************************/

static MEMORY_READ_START( readmem )
	{ 0x0000, 0x03ff, MRA_RAM },
	{ 0x0400, 0x040f, pokey1_r },
	{ 0x0800, 0x080f, pokey2_r },
	{ 0x1000, 0x13ff, MRA_RAM },
	{ 0x2000, 0x2000, milliped_IN0_r },
	{ 0x2001, 0x2001, milliped_IN1_r },
	{ 0x2010, 0x2010, input_port_2_r },
	{ 0x2011, 0x2011, input_port_3_r },
	{ 0x2030, 0x2030, atari_vg_earom_r },
	{ 0x4000, 0x7fff, MRA_ROM },
	{ 0xf000, 0xffff, MRA_ROM },		/* for the reset / interrupt vectors */
MEMORY_END


static MEMORY_WRITE_START( writemem )
	{ 0x0000, 0x03ff, MWA_RAM },
	{ 0x0400, 0x040f, pokey1_w },
	{ 0x0800, 0x080f, pokey2_w },
	{ 0x1000, 0x13ff, videoram_w, &videoram, &videoram_size },
	{ 0x13c0, 0x13ff, MWA_RAM, &spriteram },
	{ 0x2480, 0x249f, milliped_paletteram_w, &paletteram },
	{ 0x2500, 0x2502, milliped_coin_counter_w },
	{ 0x2503, 0x2504, milliped_led_w },
	{ 0x2505, 0x2505, milliped_input_select_w },
//	{ 0x2506, 0x2507, MWA_NOP }, /* ? */
	{ 0x2600, 0x2600, MWA_NOP }, /* IRQ ack */
	{ 0x2680, 0x2680, watchdog_reset_w },
	{ 0x2700, 0x2700, atari_vg_earom_ctrl_w },
	{ 0x2780, 0x27bf, atari_vg_earom_w },
	{ 0x4000, 0x73ff, MWA_ROM },
MEMORY_END



/*************************************
 *
 *	Port definitions
 *
 *************************************/

INPUT_PORTS_START( milliped )
	PORT_START	/* IN0 $2000 */ /* see port 6 for x trackball */
	PORT_DIPNAME(0x03, 0x00, "Language" )
	PORT_DIPSETTING(   0x00, "English" )
	PORT_DIPSETTING(   0x01, "German" )
	PORT_DIPSETTING(   0x02, "French" )
	PORT_DIPSETTING(   0x03, "Spanish" )
	PORT_DIPNAME(0x0c, 0x04, "Bonus" )
	PORT_DIPSETTING(   0x00, "0" )
	PORT_DIPSETTING(   0x04, "0 1x" )
	PORT_DIPSETTING(   0x08, "0 1x 2x" )
	PORT_DIPSETTING(   0x0c, "0 1x 2x 3x" )
	PORT_BIT ( 0x10, IP_ACTIVE_LOW, IPT_BUTTON1 )
	PORT_BIT ( 0x20, IP_ACTIVE_LOW, IPT_START1 )
	PORT_BIT ( 0x40, IP_ACTIVE_HIGH, IPT_VBLANK )
	PORT_BIT ( 0x80, IP_ACTIVE_HIGH, IPT_UNKNOWN )	/* trackball sign bit */

	PORT_START	/* IN1 $2001 */ /* see port 7 for y trackball */
	PORT_DIPNAME(0x01, 0x00, DEF_STR( Unknown ) )
	PORT_DIPSETTING(   0x00, DEF_STR( Off ) )
	PORT_DIPSETTING(   0x01, DEF_STR( On ) )
	PORT_DIPNAME(0x02, 0x00, DEF_STR( Unknown ) )
	PORT_DIPSETTING(   0x00, DEF_STR( Off ) )
	PORT_DIPSETTING(   0x02, DEF_STR( On ) )
	PORT_DIPNAME(0x04, 0x00, "Credit Minimum" )
	PORT_DIPSETTING(   0x00, "1" )
	PORT_DIPSETTING(   0x04, "2" )
	PORT_DIPNAME(0x08, 0x00, "Coin Counters" )
	PORT_DIPSETTING(   0x00, "1" )
	PORT_DIPSETTING(   0x08, "2" )
	PORT_BIT ( 0x10, IP_ACTIVE_LOW, IPT_BUTTON1 | IPF_COCKTAIL )
	PORT_BIT ( 0x20, IP_ACTIVE_LOW, IPT_START2 )
	PORT_BIT ( 0x40, IP_ACTIVE_LOW, IPT_UNKNOWN )
	PORT_BIT ( 0x80, IP_ACTIVE_HIGH, IPT_UNKNOWN )	/* trackball sign bit */

	PORT_START	/* IN2 $2010 */
	PORT_BIT ( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT | IPF_8WAY )
	PORT_BIT ( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT | IPF_8WAY )
	PORT_BIT ( 0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN | IPF_8WAY )
	PORT_BIT ( 0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_UP | IPF_8WAY )
	PORT_BIT ( 0x10, IP_ACTIVE_LOW, IPT_TILT )
	PORT_BIT ( 0x20, IP_ACTIVE_LOW, IPT_COIN1 )
	PORT_BIT ( 0x40, IP_ACTIVE_LOW, IPT_COIN2 )
	PORT_BIT ( 0x80, IP_ACTIVE_LOW, IPT_COIN3 )

	PORT_START	/* IN3 $2011 */
	PORT_BIT ( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT | IPF_8WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT | IPF_8WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN | IPF_8WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_UP | IPF_8WAY | IPF_COCKTAIL )
	PORT_BIT ( 0x10, IP_ACTIVE_LOW, IPT_UNKNOWN )
	PORT_BIT ( 0x20, IP_ACTIVE_LOW, IPT_UNKNOWN )
	PORT_BIT ( 0x40, IP_ACTIVE_LOW, IPT_UNKNOWN )
	PORT_SERVICE( 0x80, IP_ACTIVE_LOW )

	PORT_START	/* 4 */ /* DSW1 $0408 */
	PORT_DIPNAME(0x01, 0x00, "Millipede Head" )
	PORT_DIPSETTING(   0x00, "Easy" )
	PORT_DIPSETTING(   0x01, "Hard" )
	PORT_DIPNAME(0x02, 0x00, "Beetle" )
	PORT_DIPSETTING(   0x00, "Easy" )
	PORT_DIPSETTING(   0x02, "Hard" )
	PORT_DIPNAME(0x0c, 0x04, DEF_STR( Lives ) )
	PORT_DIPSETTING(   0x00, "2" )
	PORT_DIPSETTING(   0x04, "3" )
	PORT_DIPSETTING(   0x08, "4" )
	PORT_DIPSETTING(   0x0c, "5" )
	PORT_DIPNAME(0x30, 0x10, DEF_STR( Bonus_Life ) )
	PORT_DIPSETTING(   0x00, "12000" )
	PORT_DIPSETTING(   0x10, "15000" )
	PORT_DIPSETTING(   0x20, "20000" )
	PORT_DIPSETTING(   0x30, "None" )
	PORT_DIPNAME(0x40, 0x00, "Spider" )
	PORT_DIPSETTING(   0x00, "Easy" )
	PORT_DIPSETTING(   0x40, "Hard" )
	PORT_DIPNAME(0x80, 0x00, "Starting Score Select" )
	PORT_DIPSETTING(   0x80, DEF_STR( Off ) )
	PORT_DIPSETTING(   0x00, DEF_STR( On ) )

	PORT_START	/* 5 */ /* DSW2 $0808 */
	PORT_DIPNAME(0x03, 0x02, DEF_STR( Coinage ) )
	PORT_DIPSETTING(   0x03, DEF_STR( 2C_1C ) )
	PORT_DIPSETTING(   0x02, DEF_STR( 1C_1C ) )
	PORT_DIPSETTING(   0x01, DEF_STR( 1C_2C ) )
	PORT_DIPSETTING(   0x00, DEF_STR( Free_Play ) )
	PORT_DIPNAME(0x0c, 0x00, "Right Coin" )
	PORT_DIPSETTING(   0x00, "*1" )
	PORT_DIPSETTING(   0x04, "*4" )
	PORT_DIPSETTING(   0x08, "*5" )
	PORT_DIPSETTING(   0x0c, "*6" )
	PORT_DIPNAME(0x10, 0x00, "Left Coin" )
	PORT_DIPSETTING(   0x00, "*1" )
	PORT_DIPSETTING(   0x10, "*2" )
	PORT_DIPNAME(0xe0, 0x00, "Bonus Coins" )
	PORT_DIPSETTING(   0x00, "None" )
	PORT_DIPSETTING(   0x20, "3 credits/2 coins" )
	PORT_DIPSETTING(   0x40, "5 credits/4 coins" )
	PORT_DIPSETTING(   0x60, "6 credits/4 coins" )
	PORT_DIPSETTING(   0x80, "6 credits/5 coins" )
	PORT_DIPSETTING(   0xa0, "4 credits/3 coins" )
	PORT_DIPSETTING(   0xc0, "Demo mode" )

	PORT_START	/* IN6: FAKE - used for trackball-x at $2000 */
	PORT_ANALOGX( 0xff, 0x00, IPT_TRACKBALL_X | IPF_REVERSE, 50, 10, 0, 0, IP_KEY_NONE, IP_KEY_NONE, IP_JOY_NONE, IP_JOY_NONE )

	PORT_START	/* IN7: FAKE - used for trackball-y at $2001 */
	PORT_ANALOGX( 0xff, 0x00, IPT_TRACKBALL_Y, 50, 10, 0, 0, IP_KEY_NONE, IP_KEY_NONE, IP_JOY_NONE, IP_JOY_NONE )
INPUT_PORTS_END



/*************************************
 *
 *	Graphics layouts
 *
 *************************************/

static struct GfxLayout charlayout =
{
	8,8,	/* 8*8 characters */
	256,	/* 256 characters */
	2,	/* 2 bits per pixel */
	{ 0, 256*8*8 }, /* the two bitplanes are separated */
	{ 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 spritelayout =
{
	8,16,	/* 16*8 sprites */
	128,	/* 64 sprites */
	2,	/* 2 bits per pixel */
	{ 0, 128*16*8 },	/* the two bitplanes are separated */
	{ 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, 9*8, 10*8, 11*8, 12*8, 13*8, 14*8, 15*8 },
	16*8	/* every sprite takes 16 consecutive bytes */
};


static struct GfxDecodeInfo gfxdecodeinfo[] =
{
	{ REGION_GFX1, 0, &charlayout,     0, 4 },
	{ REGION_GFX1, 0, &spritelayout, 4*4, 4*4*4*4 },
	{ -1 } /* end of array */
};



/*************************************
 *
 *	Sound interfaces
 *
 *************************************/

static struct POKEYinterface pokey_interface =
{
	2,	/* 2 chips */
	1500000,	/* 1.5 MHz??? */
	{ 50, 50 },
	/* The 8 pot handlers */
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	/* The allpot handler */
	{ input_port_4_r, input_port_5_r },
};



/*************************************
 *
 *	Machine driver
 *
 *************************************/

static MACHINE_DRIVER_START( milliped )

	/* basic machine hardware */
	MDRV_CPU_ADD(M6502, 1500000)
	MDRV_CPU_MEMORY(readmem,writemem)
	MDRV_CPU_VBLANK_INT(irq0_line_hold,4)

	MDRV_FRAMES_PER_SECOND(60)
	MDRV_VBLANK_DURATION(DEFAULT_REAL_60HZ_VBLANK_DURATION)
	
	MDRV_NVRAM_HANDLER(atari_vg)

	/* video hardware */
	MDRV_VIDEO_ATTRIBUTES(VIDEO_TYPE_RASTER | VIDEO_SUPPORTS_DIRTY)
	MDRV_SCREEN_SIZE(32*8, 32*8)
	MDRV_VISIBLE_AREA(0*8, 32*8-1, 0*8, 30*8-1)
	MDRV_GFXDECODE(gfxdecodeinfo)
	MDRV_PALETTE_LENGTH(32)
	MDRV_COLORTABLE_LENGTH(4*4+4*4*4*4*4)
	
	MDRV_PALETTE_INIT(milliped)
	MDRV_VIDEO_START(generic)
	MDRV_VIDEO_UPDATE(milliped)

	/* sound hardware */
	MDRV_SOUND_ADD(POKEY, pokey_interface)
MACHINE_DRIVER_END



/*************************************
 *
 *	ROM definitions
 *
 *************************************/

ROM_START( milliped )
	ROM_REGION( 0x10000, REGION_CPU1, 0 )	/* 64k for code */
	ROM_LOAD( "milliped.104", 0x4000, 0x1000, 0x40711675 )
	ROM_LOAD( "milliped.103", 0x5000, 0x1000, 0xfb01baf2 )
	ROM_LOAD( "milliped.102", 0x6000, 0x1000, 0x62e137e0 )
	ROM_LOAD( "milliped.101", 0x7000, 0x1000, 0x46752c7d )
	ROM_RELOAD( 			  0xf000, 0x1000 )	/* for the reset and interrupt vectors */

	ROM_REGION( 0x1000, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "milliped.106", 0x0000, 0x0800, 0xf4468045 )
	ROM_LOAD( "milliped.107", 0x0800, 0x0800, 0x68c3437a )
ROM_END



/*************************************
 *
 *	Game drivers
 *
 *************************************/

GAME( 1982, milliped, 0, milliped, milliped, 0, ROT270, "Atari", "Millipede" )

