text: /***************************************************************************
  
  Minivader (Space Invaders's mini game)
  (c)1990 Taito Corporation
  
  Driver by Takahiro Nogi (nogi@kt.rim.or.jp) 1999/12/19 -
  
  This is a test board sold together with the cabinet (as required by law in
  Japan). It has no sound.
  
  ***************************************************************************/
  
  #include "emu.h"
  #include "cpu/z80/z80.h"
  
  
  class minivadr_state : public driver_device
  {
  public:
  	minivadr_state(const machine_config &mconfig, device_type type, const char *tag)
  		: driver_device(mconfig, type, tag) { }
  
  	/* memory pointers */
  	UINT8 *  m_videoram;
  	size_t   m_videoram_size;
  };
  
  /*************************************
   *
   *  Video update
   *
   *************************************/
  
  static SCREEN_UPDATE( minivadr )
  {
  	minivadr_state *state = screen->machine().driver_data<minivadr_state>();
  	offs_t offs;
  
  	for (offs = 0; offs < state->m_videoram_size; offs++)
  	{
  		int i;
  
  		UINT8 x = offs << 3;
  		int y = offs >> 5;
  		UINT8 data = state->m_videoram[offs];
  
  		for (i = 0; i < 8; i++)
  		{
  			pen_t pen = (data & 0x80) ? RGB_WHITE : RGB_BLACK;
  			*BITMAP_ADDR32(bitmap, y, x) = pen;
  
  			data = data << 1;
  			x = x + 1;
  		}
  	}
  
  	return 0;
  }
  
  
  static ADDRESS_MAP_START( minivadr_map, AS_PROGRAM, 8 )
  	AM_RANGE(0x0000, 0x1fff) AM_ROM
  	AM_RANGE(0xa000, 0xbfff) AM_RAM AM_BASE_SIZE_MEMBER(minivadr_state, m_videoram, m_videoram_size)
  	AM_RANGE(0xe008, 0xe008) AM_READ_PORT("INPUTS") AM_WRITENOP		// W - ???
  ADDRESS_MAP_END
  
  
  static INPUT_PORTS_START( minivadr )
  	PORT_START("INPUTS")
  	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT )
  	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT )
  	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_BUTTON1 )
  	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_COIN1 )
  	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_BIT( 0x80, IP_ACTIVE_LOW, IPT_UNKNOWN )
  INPUT_PORTS_END
  
  
  static MACHINE_CONFIG_START( minivadr, minivadr_state )
  
  	/* basic machine hardware */
  	MCFG_CPU_ADD("maincpu", Z80,24000000 / 6)		 /* 4 MHz ? */
  	MCFG_CPU_PROGRAM_MAP(minivadr_map)
  	MCFG_CPU_VBLANK_INT("screen", irq0_line_hold)
  
  	/* video hardware */
  	MCFG_SCREEN_ADD("screen", RASTER)
  	MCFG_SCREEN_REFRESH_RATE(60)
  	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(0))
  	MCFG_SCREEN_FORMAT(BITMAP_FORMAT_RGB32)
  	MCFG_SCREEN_SIZE(256, 256)
  	MCFG_SCREEN_VISIBLE_AREA(0, 256-1, 16, 240-1)
  	MCFG_SCREEN_UPDATE(minivadr)
  
  	/* the board has no sound hardware */
  MACHINE_CONFIG_END
  
  
  /***************************************************************************
  
    Game driver(s)
  
  ***************************************************************************/
  
  ROM_START( minivadr )
  	ROM_REGION( 0x10000, "maincpu", 0 )
  	ROM_LOAD( "d26-01.bin",	0x0000, 0x2000, CRC(a96c823d) SHA1(aa9969ff80e94b0fff0f3530863f6b300510162e) )
  ROM_END
  
  
  GAME( 1990, minivadr, 0, minivadr, minivadr, 0, ROT0, "Taito Corporation", "Minivader", GAME_SUPPORTS_SAVE | GAME_NO_SOUND_HW )
  