#include "driver.h"
#include "vidhrdw/generic.h"
#include "cpu/m6809/m6809.h"
#include "homedata.h"


data8_t *homedata_vreg;	/* pointer to RAM associated with 0x7ffx */

int homedata_visible_page;

static int homedata_flipscreen;

static data8_t	reikaids_gfx_bank[2];
static data8_t	pteacher_gfx_bank;
static data8_t	blitter_bank;
static int		blitter_param_count;
static data8_t	blitter_param[4];		/* buffers last 4 writes to 0x8006 */

static struct tilemap *tilemap[2][4];


/*
	video control registers:
	0 xxxxxxxx  unknown
	1 x-------  flip screen
	  -xxxxxxx  unknown
	2 xxxxxxxx  unknown
	3 xxxxxxxx  related to visible area?
	4 ----xxxx	fine horiz scroll (sub-character, 8 or 12 pixels)
	  xxxx----  unknown
	5 xxxxxxxx  related to visible area?
	6 xxxxxxxx  related to visible area?
	7 xxxxxxxx  unknown
	8 xxxxxxxx  unknown
	9 xxxxxxxx  unknown
	a xxxxxxxx  unknown
	b xxxxxx--  horiz scroll (character resolution)
	c xxxxxxxx  might be bg layer horiz scroll (always 0 here but used by the older games)
	d xxxxxxxx  might be fg layer horiz scroll (always 0 here but always 4 in the older games)
 */


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

  Blitter

  This is probably work done by the GX61A01 custom chip found on all boards,
  however the way it works is not exactly the same in all games.

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

static void mrokumei_handleblit( int rom_base )
{
	int i;
	int DestParam;
	int SourceAddr;
	int DestAddr;
	int BaseAddr;
	int opcode,data,NumTiles;
	data8_t *pBlitData = memory_region(REGION_USER1) + rom_base;

	DestParam =
		blitter_param[(blitter_param_count-4)&3]*256+
		blitter_param[(blitter_param_count-3)&3];

	SourceAddr =
		blitter_param[(blitter_param_count-2)&3]*256+
		blitter_param[(blitter_param_count-1)&3];

	/*  xxx-.----.----.---- not used?
	 *	---x.----.----.---- layer
	 *	----.xxxx.xxxx.xxxx addr
	 */
	BaseAddr= (DestParam&0x1000);
	DestAddr= (DestParam&0x0fff);

//	logerror( "[blit bank %02x src %04x dst %04x]\n",blitter_bank,SourceAddr,DestParam);

	if( homedata_visible_page == 0 )
	{
		BaseAddr += 0x2000;
	}

	for(;;)
	{
		opcode = pBlitData[SourceAddr++];
		/* 00xxxxxx	RLE incrementing
		 * 01xxxxxx	Raw Run
		 * 1xxxxxxx	RLE constant data
		 */
		if( opcode == 0x00 )
		{
 			/* end-of-graphic */
 			goto finish;
		}
		data  = pBlitData[SourceAddr++];

		if (opcode&0x80)
			NumTiles = 0x80-(opcode&0x7f);
		else
			NumTiles = 0x40-(opcode&0x3f);

		for( i=0; i<NumTiles; i++ )
		{
			if( i!=0 )
			{
				switch( opcode&0xc0 )
				{
				case 0x40: // Raw Run
					data  = pBlitData[SourceAddr++];
					break;

				case 0x00: // RLE incrementing
					data++;
					break;
				}
			} /* i!=0 */

			if (data)	/* 00 is a nop */
				mrokumei_videoram_w( BaseAddr + DestAddr, data );

			if (homedata_vreg[1] & 0x80)	/* flip screen */
			{
				DestAddr-=2;
				if (DestAddr < 0) goto finish;
			}
			else
			{
				DestAddr+=2;
				if (DestAddr >= 0x1000) goto finish;
			}
		} /* for( i=0; i<NumTiles; i++ ) */
	} /* for(;;) */

finish:
	cpu_set_irq_line(0,M6809_FIRQ_LINE,HOLD_LINE);
}

static void reikaids_handleblit( int rom_base )
{
	int i;
	UINT16 DestParam;
	int flipx;
	int SourceAddr, BaseAddr;
	int DestAddr;
	data8_t *pBlitData = memory_region(REGION_USER1) + rom_base;

	int opcode,data,NumTiles;

	DestParam =
		blitter_param[(blitter_param_count-4)&3]*256+
		blitter_param[(blitter_param_count-3)&3];

	SourceAddr =
		blitter_param[(blitter_param_count-2)&3]*256+
		blitter_param[(blitter_param_count-1)&3];

	/*	x---.----.----.---- flipx
	 * 	-x--.----.----.---- select: attr/tile
	 *	--*x.xxxx.*xxx.xxxx addr
	 */
	BaseAddr= (DestParam&0x4000);
	DestAddr= (DestParam&0x3fff);
	flipx	= (DestParam&0x8000);

//	logerror( "[blit %02x %04x %04x]\n",blitter_bank,SourceAddr,DestParam);

	if( homedata_visible_page == 0 )
	{
		BaseAddr += 0x2000<<2;
	}

	for(;;)
	{
		opcode = pBlitData[SourceAddr++];
		/* 00xxxxxx	Raw Run
		 * 01xxxxxx	RLE incrementing
		 * 1xxxxxxx	RLE constant data
		 */
		if( opcode == 0x00 )
		{
			/* end-of-graphic */
			goto finish;
		}

		data  = pBlitData[SourceAddr++];

		if( (opcode&0xc0)==0x80 )
			NumTiles = 0x80 - (opcode&0x7f);
		else
			NumTiles = 0x40 - (opcode&0x3f);

		for( i=0; i<NumTiles; i++ )
		{
			if( i!=0 )
			{
				switch( opcode&0xc0 )
				{
				case 0x00: // Raw Run
					data  = pBlitData[SourceAddr++];
					break;

				case 0x40: // RLE incrementing
					data++;
					break;
				}
			} /* i!=0 */

			if (data)	/* 00 is a nop */
			{
				int addr = BaseAddr + (DestAddr & 0x3fff);
				int dat = data;

				if ((addr & 0x2080) == 0)
				{
					addr = ((addr & 0xc000) >> 2) | ((addr & 0x1f00) >> 1) | (addr & 0x7f);

					if( flipx )
					{
						if ((BaseAddr & 0x4000) == 0) dat |= 0x80;
						addr ^= 0x007c;
					}

					reikaids_videoram_w( addr, dat );
				}
			}

			if (homedata_vreg[1] & 0x80)	/* flip screen */
				DestAddr-=4;
			else
				DestAddr+=4;
		} /* for( i=0; i<NumTiles; i++ ) */
	}

finish:
	cpu_set_irq_line(0,M6809_FIRQ_LINE,HOLD_LINE);
}

static void pteacher_handleblit( int rom_base )
{
	int i;
	int DestParam;
	int SourceAddr;
	int DestAddr, BaseAddr;
	int opcode,data,NumTiles;
	data8_t *pBlitData = memory_region(REGION_USER1) + rom_base;

	DestParam =
		blitter_param[(blitter_param_count-4)&3]*256+
		blitter_param[(blitter_param_count-3)&3];

	SourceAddr =
		blitter_param[(blitter_param_count-2)&3]*256+
		blitter_param[(blitter_param_count-1)&3];

	/*  x---.----.----.---- not used?
	 *  -x--.----.----.---- layer	(0..1)
	 *	--*x.xxxx.*xxx.xxxx addr
	 */
	BaseAddr= (DestParam&0x4000);
	DestAddr= (DestParam&0x3fff);

//	logerror( "[blit %02x %04x %04x]->%d\n",blitter_bank,SourceAddr,DestParam,homedata_visible_page);

	if( homedata_visible_page == 0 )
	{
		BaseAddr += 0x2000<<2;
	}

	for(;;)
	{
		opcode = pBlitData[SourceAddr++];
		/* 00xxxxxx	Raw Run
		 * 01xxxxxx	RLE incrementing
		 * 1xxxxxxx	RLE constant data
		 */
		if( opcode == 0x00 )
		{
 			/* end-of-graphic */
 			goto finish;
		}
		data  = pBlitData[SourceAddr++];

		if (opcode & 0x80)
			NumTiles = 0x80-(opcode&0x7f);
		else
			NumTiles = 0x40-(opcode&0x3f);

		for( i=0; i<NumTiles; i++ )
		{
			if( i!=0 )
			{
				switch( opcode&0xc0 )
				{
				case 0x00: // Raw Run
					data  = pBlitData[SourceAddr++];
					break;

				case 0x40: // RLE incrementing
					data++;
					break;
				}
			} /* i!=0 */

			if (data)	/* 00 is a nop */
			{
				int addr = BaseAddr + (DestAddr & 0x3fff);

				if ((addr & 0x2080) == 0)
				{
					addr = ((addr & 0xc000) >> 2) | ((addr & 0x1f00) >> 1) | (addr & 0x7f);
					pteacher_videoram_w( addr, data );
				}
			}

			if (homedata_vreg[1] & 0x80)	/* flip screen */
				DestAddr-=2;
			else
				DestAddr+=2;
		} /* for( i=0; i<NumTiles; i++ ) */
	} /* for(;;) */

finish:
	cpu_set_irq_line(0,M6809_FIRQ_LINE,HOLD_LINE);
}




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

  Palette setup

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

PALETTE_INIT( mrokumei )
{
	int i;

	/* initialize 555 RGB palette */
	for (i = 0; i < 0x8000; i++)
	{
		int r,g,b;
		int color = color_prom[i*2] * 256 + color_prom[i*2+1];
		/* xxxx--------x--- red
		 * ----xxxx-----x-- green
		 * --------xxxx--x- blue
		 * ---------------x unused
		 */
		r = ((color >> 11) & 0x1e) | ((color >> 3) & 1);
		g = ((color >>  7) & 0x1e) | ((color >> 2) & 1);
		b = ((color >>  3) & 0x1e) | ((color >> 1) & 1);

		r = (r << 3) | (r >> 2);
		g = (g << 3) | (g >> 2);
		b = (b << 3) | (b >> 2);

		palette_set_color(i,r,g,b);
	}
}

PALETTE_INIT( reikaids )
{
	int i;

	/* initialize 555 RGB palette */
	for (i = 0; i < 0x8000; i++)
	{
		int r,g,b;
		int color = color_prom[i*2] * 256 + color_prom[i*2+1];
		/* xxxx--------x--- green
		 * ----xxxx-----x-- red
		 * --------xxxx--x- blue
		 * ---------------x unused
		 */
		g = ((color >> 11) & 0x1e) | ((color >> 3) & 1);
		r = ((color >>  7) & 0x1e) | ((color >> 2) & 1);
		b = ((color >>  3) & 0x1e) | ((color >> 1) & 1);

		r = (r << 3) | (r >> 2);
		g = (g << 3) | (g >> 2);
		b = (b << 3) | (b >> 2);

		palette_set_color(i,r,g,b);
	}
}

PALETTE_INIT( pteacher )
{
	int i;

	/* initialize 555 RGB palette */
	for (i = 0; i < 0x8000; i++)
	{
		int r,g,b;
		int color = color_prom[i*2] * 256 + color_prom[i*2+1];
		/* xxxxx----------- green
		 * -----xxxxx------ red
		 * ----------xxxxx- blue
		 * ---------------x unused
		 */
		g = ((color >> 11) & 0x1f);
		r = ((color >>  6) & 0x1f);
		b = ((color >>  1) & 0x1f);

		r = (r << 3) | (r >> 2);
		g = (g << 3) | (g >> 2);
		b = (b << 3) | (b >> 2);

		palette_set_color(i,r,g,b);
	}
}



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

  Callbacks for the TileMap code

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

INLINE void mrokumei_info0( int tile_index, int page, int gfxbank )
{
	int addr  = tile_index * 2 + 0x2000 * page;
	int attr  = videoram[addr];
	int code  = videoram[addr + 1] + ((attr & 0x03) << 8) + (gfxbank << 10);
	int color = (attr >> 2) + (gfxbank << 6);

	SET_TILE_INFO( 0, code, color, homedata_flipscreen );
}
INLINE void mrokumei_info1( int tile_index, int page, int gfxbank )
{
	int addr  = tile_index * 2 + 0x1000 + 0x2000 * page;
	int attr  = videoram[addr];
	int code  = videoram[addr + 1] + ((attr & 0x07) << 8) + (gfxbank << 11);
	int color = (attr >> 3) + ((gfxbank & 3) << 6);

	SET_TILE_INFO( 1, code, color, homedata_flipscreen );
}

static void mrokumei_get_info0_0(int tile_index) { mrokumei_info0( tile_index, 0,  blitter_bank & 0x03 ); }
static void mrokumei_get_info1_0(int tile_index) { mrokumei_info0( tile_index, 1,  blitter_bank & 0x03 ); }
static void mrokumei_get_info0_1(int tile_index) { mrokumei_info1( tile_index, 0, (blitter_bank & 0x38) >> 3 ); }
static void mrokumei_get_info1_1(int tile_index) { mrokumei_info1( tile_index, 1, (blitter_bank & 0x38) >> 3 ); }


INLINE void reikaids_info( int tile_index, int page, int layer, int gfxbank )
{
	int addr  = tile_index * 4 + layer + 0x2000 * page;
	int attr  = videoram[addr];
	int code  = videoram[addr + 0x1000] + ((attr & 0x03) << 8) + (gfxbank << 10);
	int color = (attr & 0x7c) >> 2;
	int flags = homedata_flipscreen;

	if (attr & 0x80) flags ^= TILE_FLIPX;

	SET_TILE_INFO( layer, code, color, flags );
}

	/* reikaids_gfx_bank[0]:
	 *		-xxx.x---	layer#1
	 *		----.-xxx	layer#3
	 *
	 * reikaids_gfx_bank[1]:
	 *		xxxx.x---	layer#0
	 *		----.-xxx	layer#2
	 */
static void reikaids_get_info0_0(int tile_index) { reikaids_info( tile_index, 0, 0,  (reikaids_gfx_bank[1]>>3)); }
static void reikaids_get_info1_0(int tile_index) { reikaids_info( tile_index, 1, 0,  (reikaids_gfx_bank[1]>>3)); }
static void reikaids_get_info0_1(int tile_index) { reikaids_info( tile_index, 0, 1, ((reikaids_gfx_bank[0]&0x78)>>3)); }
static void reikaids_get_info1_1(int tile_index) { reikaids_info( tile_index, 1, 1, ((reikaids_gfx_bank[0]&0x78)>>3)); }
static void reikaids_get_info0_2(int tile_index) { reikaids_info( tile_index, 0, 2,  (reikaids_gfx_bank[1]&0x7)); }
static void reikaids_get_info1_2(int tile_index) { reikaids_info( tile_index, 1, 2,  (reikaids_gfx_bank[1]&0x7)); }
static void reikaids_get_info0_3(int tile_index) { reikaids_info( tile_index, 0, 3,  (reikaids_gfx_bank[0]&0x7)); }
static void reikaids_get_info1_3(int tile_index) { reikaids_info( tile_index, 1, 3,  (reikaids_gfx_bank[0]&0x7)); }


INLINE void pteacher_info( int tile_index, int page, int layer, int gfxbank )
{
	int addr  = tile_index * 2 + 0x1000 * layer + 0x2000 * page;
	int attr  = videoram[addr];
	int code  = videoram[addr + 1] + ((attr & 0x07) << 8) + (gfxbank << 11);
	int color = (attr >> 3) + ((gfxbank & 1) << 5);

	SET_TILE_INFO( layer, code, color, homedata_flipscreen );
}

static void pteacher_get_info0_0(int tile_index) { pteacher_info( tile_index, 0, 0, pteacher_gfx_bank & 0x0f ); }
static void pteacher_get_info1_0(int tile_index) { pteacher_info( tile_index, 1, 0, pteacher_gfx_bank & 0x0f ); }
static void pteacher_get_info0_1(int tile_index) { pteacher_info( tile_index, 0, 1, pteacher_gfx_bank >> 4 ); }
static void pteacher_get_info1_1(int tile_index) { pteacher_info( tile_index, 1, 1, pteacher_gfx_bank >> 4 ); }


INLINE void lemnangl_info( int tile_index, int page, int layer, int gfxset, int gfxbank )
{
	int addr  = tile_index * 2 + 0x1000 * layer + 0x2000 * page;
	int attr  = videoram[addr];
	int code  = videoram[addr + 1] + ((attr & 0x07) << 8) + (gfxbank << 11);
	int color = 16 * (attr >> 3) + gfxbank;

	SET_TILE_INFO( 2*layer + gfxset, code, color, homedata_flipscreen );
}

static void lemnangl_get_info0_0(int tile_index) { lemnangl_info( tile_index, 0, 0,  blitter_bank & 1,       pteacher_gfx_bank & 0x0f ); }
static void lemnangl_get_info1_0(int tile_index) { lemnangl_info( tile_index, 1, 0,  blitter_bank & 1,       pteacher_gfx_bank & 0x0f ); }
static void lemnangl_get_info0_1(int tile_index) { lemnangl_info( tile_index, 0, 1, (blitter_bank & 2) >> 1, pteacher_gfx_bank >> 4 ); }
static void lemnangl_get_info1_1(int tile_index) { lemnangl_info( tile_index, 1, 1, (blitter_bank & 2) >> 1, pteacher_gfx_bank >> 4 ); }


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

  Start the video hardware emulation.

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

VIDEO_START( mrokumei )
{
	tilemap[0][0] = tilemap_create( mrokumei_get_info0_0, tilemap_scan_rows, TILEMAP_OPAQUE,      8, 8, 64,32 );
	tilemap[0][1] = tilemap_create( mrokumei_get_info0_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 64,32 );
	tilemap[1][0] = tilemap_create( mrokumei_get_info1_0, tilemap_scan_rows, TILEMAP_OPAQUE,      8, 8, 64,32 );
	tilemap[1][1] = tilemap_create( mrokumei_get_info1_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 64,32 );

	if (!tilemap[0][0] || !tilemap[0][1] || !tilemap[1][0] || !tilemap[1][1])
		return 1;

	tilemap_set_transparent_pen(tilemap[0][1],0);
	tilemap_set_transparent_pen(tilemap[1][1],0);

	return 0;
}

VIDEO_START( reikaids )
{
	tilemap[0][0] = tilemap_create( reikaids_get_info0_0, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[0][1] = tilemap_create( reikaids_get_info0_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[0][2] = tilemap_create( reikaids_get_info0_2, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[0][3] = tilemap_create( reikaids_get_info0_3, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[1][0] = tilemap_create( reikaids_get_info1_0, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[1][1] = tilemap_create( reikaids_get_info1_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[1][2] = tilemap_create( reikaids_get_info1_2, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );
	tilemap[1][3] = tilemap_create( reikaids_get_info1_3, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 32, 32 );

	if (!tilemap[0][0] || !tilemap[0][1] || !tilemap[0][2] || !tilemap[0][3] ||
		!tilemap[1][0] || !tilemap[1][1] || !tilemap[1][2] || !tilemap[1][3])
		return 1;

	tilemap_set_transparent_pen(tilemap[0][0],0xff);
	tilemap_set_transparent_pen(tilemap[0][1],0xff);
	tilemap_set_transparent_pen(tilemap[0][2],0xff);
	tilemap_set_transparent_pen(tilemap[0][3],0xff);
	tilemap_set_transparent_pen(tilemap[1][0],0xff);
	tilemap_set_transparent_pen(tilemap[1][1],0xff);
	tilemap_set_transparent_pen(tilemap[1][2],0xff);
	tilemap_set_transparent_pen(tilemap[1][3],0xff);

	return 0;
}

VIDEO_START( pteacher )
{
	tilemap[0][0] = tilemap_create( pteacher_get_info0_0, tilemap_scan_rows, TILEMAP_OPAQUE,      8, 8, 64,32 );
	tilemap[0][1] = tilemap_create( pteacher_get_info0_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 64,32 );
	tilemap[1][0] = tilemap_create( pteacher_get_info1_0, tilemap_scan_rows, TILEMAP_OPAQUE,      8, 8, 64,32 );
	tilemap[1][1] = tilemap_create( pteacher_get_info1_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 64,32 );

	if (!tilemap[0][0] || !tilemap[0][1] || !tilemap[1][0] || !tilemap[1][1])
		return 1;

	tilemap_set_transparent_pen(tilemap[0][1],0xff);
	tilemap_set_transparent_pen(tilemap[1][1],0xff);

	return 0;
}

VIDEO_START( lemnangl )
{
	tilemap[0][0] = tilemap_create( lemnangl_get_info0_0, tilemap_scan_rows, TILEMAP_OPAQUE,      8, 8, 64,32 );
	tilemap[0][1] = tilemap_create( lemnangl_get_info0_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 64,32 );
	tilemap[1][0] = tilemap_create( lemnangl_get_info1_0, tilemap_scan_rows, TILEMAP_OPAQUE,      8, 8, 64,32 );
	tilemap[1][1] = tilemap_create( lemnangl_get_info1_1, tilemap_scan_rows, TILEMAP_TRANSPARENT, 8, 8, 64,32 );

	if (!tilemap[0][0] || !tilemap[0][1] || !tilemap[1][0] || !tilemap[1][1])
		return 1;

	tilemap_set_transparent_pen(tilemap[0][1],0x0f);
	tilemap_set_transparent_pen(tilemap[1][1],0x0f);

	return 0;
}



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

  Memory handlers

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

WRITE_HANDLER( mrokumei_videoram_w )
{
	if( videoram[offset] != data )
	{
		videoram[offset] = data;
		tilemap_mark_tile_dirty( tilemap[(offset & 0x2000) >> 13][(offset & 0x1000) >> 12], (offset & 0xffe) >> 1 );
	}
}

WRITE_HANDLER( reikaids_videoram_w )
{
	if (videoram[offset] != data)
	{
		videoram[offset] = data;
		tilemap_mark_tile_dirty( tilemap[(offset & 0x2000) >> 13][offset & 3], (offset & 0xffc) >> 2 );
	}
}

WRITE_HANDLER( pteacher_videoram_w )
{
	if( videoram[offset] != data )
	{
		videoram[offset] = data;
		tilemap_mark_tile_dirty( tilemap[(offset & 0x2000) >> 13][(offset & 0x1000) >> 12], (offset & 0xffe) >> 1 );
	}
}

WRITE_HANDLER( reikaids_gfx_bank_w )
{
	static int which;

//logerror( "%04x: [setbank %02x]\n",activecpu_get_pc(),data);

	if (reikaids_gfx_bank[which] != data)
	{
		reikaids_gfx_bank[which] = data;
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS );
	}

	which ^= 1;
}

WRITE_HANDLER( pteacher_gfx_bank_w )
{
//	logerror( "%04x: gfxbank:=%02x\n", activecpu_get_pc(), data );
	if (pteacher_gfx_bank != data)
	{
		pteacher_gfx_bank = data;
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS );
	}
}

WRITE_HANDLER( homedata_blitter_param_w )
{
//logerror("%04x: blitter_param_w %02x\n",activecpu_get_pc(),data);
	blitter_param[blitter_param_count] = data;
	blitter_param_count++;
	blitter_param_count&=3;
}

WRITE_HANDLER( mrokumei_blitter_bank_w )
{
	/* --xxx--- layer 1 gfx bank
	   -----x-- blitter ROM bank
	   ------xx layer 0 gfx bank
	 */

	if ((blitter_bank ^ data) & 0x3b)
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS);

	blitter_bank = data;
}

WRITE_HANDLER( reikaids_blitter_bank_w )
{
	/* xxx----- priority control
	   ----x--- target page? what's this for?
	   ------xx blitter ROM bank
	 */
	blitter_bank = data;
}

WRITE_HANDLER( pteacher_blitter_bank_w )
{
	/* xxx----- blitter ROM bank
	   -----x-- pixel clock (normal/slow)
	   ------x- layer #1 gfx charset (lemnangl only)
	   -------x layer #0 gfx charset (lemnangl only)
	 */

	if ((blitter_bank ^ data) & 0x03)
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS);

	blitter_bank = data;
}

WRITE_HANDLER( mrokumei_blitter_start_w )
{
	if (data & 0x80) mrokumei_handleblit(((blitter_bank & 0x04) >> 2) * 0x10000);

	/* bit 0 = bank switch; used by hourouki to access the
	   optional service mode ROM (not available in current dump) */
}

WRITE_HANDLER( reikaids_blitter_start_w )
{
	reikaids_handleblit((blitter_bank & 3) * 0x10000);
}

WRITE_HANDLER( pteacher_blitter_start_w )
{
	pteacher_handleblit((blitter_bank >> 5) * 0x10000 & (memory_region_length(REGION_USER1) - 1));
}



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

  Display refresh

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

VIDEO_UPDATE( mrokumei )
{
	int flags,width;

	/* blank screen */
	if (homedata_vreg[0x3] == 0xc1 && homedata_vreg[0x4] == 0xc0 && homedata_vreg[0x5] == 0xff)
	{
		fillbitmap(bitmap,get_black_pen(),cliprect);
		return;
	}

	flags = (homedata_vreg[1] & 0x80) ? (TILE_FLIPX | TILE_FLIPY) : 0;
	if (flags != homedata_flipscreen)
	{
		homedata_flipscreen = flags;
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS );
	}

	switch (homedata_vreg[0x3])
	{
		case 0xb7: width = 54; break;	// mjclinic
		case 0xae: width = 52; break;	// mrokumei
		case 0x9f: width = 49; break;	// hourouki, mhgaiden, mjhokite
		case 0x96: width = 49; break;	// mjclinic
		default:
			if (homedata_vreg[0x3])
				usrintf_showmessage("unknown video control %02x %02x %02x %02x",
					homedata_vreg[0x3],
					homedata_vreg[0x4],
					homedata_vreg[0x5],
					homedata_vreg[0x6]);
			width = 54;
			break;
	}
	set_visible_area(0*8, width*8-1, 2*8, 30*8-1);

	tilemap_set_scrollx(tilemap[homedata_visible_page][0],0,homedata_vreg[0xc] << 1);

	tilemap_draw(bitmap, cliprect, tilemap[homedata_visible_page][0], 0, 0);
	tilemap_draw(bitmap, cliprect, tilemap[homedata_visible_page][1], 0, 0);
}

VIDEO_UPDATE( reikaids )
{
	int flags;
	static int pritable[8][4] =	/* table of priorities derived from the PROM */
	{
		{ 3,1,0,2 },
		{ 1,3,0,2 },
		{ 0,3,1,2 },
		{ 0,1,3,2 },
		{ 3,0,1,2 },
		{ 1,0,3,2 },
		{ 2,3,1,0 },	// (bg color should be taken from 1)
		{ 3,1,2,0 },	// (bg color should be taken from 1)
	};
	int pri,i;


	flags = (homedata_vreg[1] & 0x80) ? (TILE_FLIPX | TILE_FLIPY) : 0;
	if (flags != homedata_flipscreen)
	{
		homedata_flipscreen = flags;
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS );
	}


	fillbitmap(bitmap,get_black_pen(),cliprect);

	pri = (blitter_bank & 0x70) >> 4;
	for (i = 0;i < 4;i++)
		tilemap_draw(bitmap, cliprect, tilemap[homedata_visible_page][pritable[pri][3-i]], 0, 0);
}

VIDEO_UPDATE( pteacher )
{
	int flags,scroll_low,scroll_high;


	/* blank screen */
	if (homedata_vreg[0x3] == 0xc1 && homedata_vreg[0x4] == 0xc0 && homedata_vreg[0x5] == 0xff)
	{
		fillbitmap(bitmap,get_black_pen(),cliprect);
		return;
	}

	flags = (homedata_vreg[1] & 0x80) ? (TILE_FLIPX | TILE_FLIPY) : 0;
	if (flags != homedata_flipscreen)
	{
		homedata_flipscreen = flags;
		tilemap_mark_all_tiles_dirty( ALL_TILEMAPS );
	}

	/* bit 2 of blitter_bank stretches characters horizontally by 3/2,
	   so they look as if they were 12x8 instead of 8x8.

	   However, the visible area can be further reduced by fudging with the video
	   registers, but I haven't figured out how they work exactly.
	   In most games it's like this (note that register 4 controls fine
	   scrolling):

	   width      3  4  5  6
	   33*8    = a6 00 ef db (mjikaga)
	   35*8    = bc 0b ef f0
	   51*8    = a6 07 ef db (mjikaga)
	   54*8    = bc 07 ef e8

       but in mjkinjas it's
	   42*8    = f0 ae df cc

	   note that mjkinjas has a 11MHz xtal instead of the 9MHz of all the others:
	   the two things are probably related, in fact 35 * 11 / 9 = 42.7777777.

	   and it also seems that
	   blanked = c1 c0 ff --
	  */

	if (blitter_bank & 0x04)
	{
		if (homedata_vreg[0x4] == 0xae || homedata_vreg[0x4] == 0xb8)
		{
			/* kludge for mjkinjas */
			set_visible_area(0*8, 42*8-1, 2*8, 30*8-1);
			scroll_low = 0;
		}
		else
		{
			if (homedata_vreg[0x3] == 0xa6)
				set_visible_area(0*8, 33*8-1, 2*8, 30*8-1);
			else
				set_visible_area(0*8, 35*8-1, 2*8, 30*8-1);
			scroll_low = (11 - (homedata_vreg[0x4] & 0x0f)) * 8 / 12;
		}
	}
	else
	{
		if (homedata_vreg[0x3] == 0xa6)
			set_visible_area(0*8, 51*8-1, 2*8, 30*8-1);
		else
			set_visible_area(0*8, 54*8-1, 2*8, 30*8-1);
		scroll_low = 7 - (homedata_vreg[0x4] & 0x0f);
	}
	scroll_high = homedata_vreg[0xb] >> 2;

	tilemap_set_scrollx(tilemap[homedata_visible_page][0],0,scroll_high*8 + scroll_low);
	tilemap_set_scrollx(tilemap[homedata_visible_page][1],0,scroll_high*8 + scroll_low);

	tilemap_draw(bitmap, cliprect, tilemap[homedata_visible_page][0], 0, 0);
	tilemap_draw(bitmap, cliprect, tilemap[homedata_visible_page][1], 0, 0);
}


VIDEO_EOF( homedata )
{
	homedata_visible_page ^= 1;
}
