text: /*************************************************************************
  
      Driver for Midway T-unit games.
  
  **************************************************************************/
  
  #include "driver.h"
  #include "cpu/tms34010/tms34010.h"
  #include "cpu/m6809/m6809.h"
  #include "audio/williams.h"
  #include "audio/dcs.h"
  #include "midtunit.h"
  
  
  /* compile-time constants */
  #define ENABLE_ALL_JDREDD_LEVELS	0
  
  
  /* constant definitions */
  #define SOUND_ADPCM					1
  #define SOUND_ADPCM_LARGE			2
  #define SOUND_DCS					3
  
  
  /* CMOS-related variables */
  static UINT8	cmos_write_enable;
  
  /* sound-related variables */
  static UINT8	sound_type;
  static UINT8	fake_sound_state;
  
  /* protection */
  static UINT8 	mk_prot_index;
  static UINT16 	mk2_prot_data;
  
  static const UINT32 *nbajam_prot_table;
  static UINT16	nbajam_prot_queue[5];
  static UINT8	nbajam_prot_index;
  
  static const UINT8 *jdredd_prot_table;
  static UINT8 	jdredd_prot_index;
  static UINT8 	jdredd_prot_max;
  
  
  
  /*************************************
   *
   *  State saving
   *
   *************************************/
  
  static void register_state_saving(void)
  {
  	state_save_register_global(cmos_write_enable);
  	state_save_register_global(fake_sound_state);
  	state_save_register_global(mk_prot_index);
  	state_save_register_global(mk2_prot_data);
  	state_save_register_global_array(nbajam_prot_queue);
  	state_save_register_global(nbajam_prot_index);
  	state_save_register_global(jdredd_prot_index);
  	state_save_register_global(jdredd_prot_max);
  }
  
  
  
  /*************************************
   *
   *  CMOS reads/writes
   *
   *************************************/
  
  WRITE16_HANDLER( midtunit_cmos_enable_w )
  {
  	cmos_write_enable = 1;
  }
  
  
  WRITE16_HANDLER( midtunit_cmos_w )
  {
  	if (1)/*cmos_write_enable)*/
  	{
  		COMBINE_DATA(generic_nvram16+offset);
  		cmos_write_enable = 0;
  	}
  	else
  	{
  		logerror("%08X:Unexpected CMOS W @ %05X\n", activecpu_get_pc(), offset);
  		popmessage("Bad CMOS write");
  	}
  }
  
  
  READ16_HANDLER( midtunit_cmos_r )
  {
  	return generic_nvram16[offset];
  }
  
  
  
  /*************************************
   *
   *  Generic input ports
   *
   *************************************/
  
  READ16_HANDLER( midtunit_input_r )
  {
  	return readinputport(offset);
  }
  
  
  
  /*************************************
   *
   *  Mortal Kombat (T-unit) protection
   *
   *************************************/
  
  static const UINT8 mk_prot_values[] =
  {
  	0x13, 0x27, 0x0f, 0x1f, 0x3e, 0x3d, 0x3b, 0x37,
  	0x2e, 0x1c, 0x38, 0x31, 0x22, 0x05, 0x0a, 0x15,
  	0x2b, 0x16, 0x2d, 0x1a, 0x34, 0x28, 0x10, 0x21,
  	0x03, 0x06, 0x0c, 0x19, 0x32, 0x24, 0x09, 0x13,
  	0x27, 0x0f, 0x1f, 0x3e, 0x3d, 0x3b, 0x37, 0x2e,
  	0x1c, 0x38, 0x31, 0x22, 0x05, 0x0a, 0x15, 0x2b,
  	0x16, 0x2d, 0x1a, 0x34, 0x28, 0x10, 0x21, 0x03,
  	0xff
  };
  
  static READ16_HANDLER( mk_prot_r )
  {
  	logerror("%08X:Protection R @ %05X = %04X\n", activecpu_get_pc(), offset, mk_prot_values[mk_prot_index] << 9);
  
  	/* just in case */
  	if (mk_prot_index >= sizeof(mk_prot_values))
  	{
  		logerror("%08X:Unexpected protection R @ %05X\n", activecpu_get_pc(), offset);
  		mk_prot_index = 0;
  	}
  
  	return mk_prot_values[mk_prot_index++] << 9;
  }
  
  static WRITE16_HANDLER( mk_prot_w )
  {
  	if (ACCESSING_MSB)
  	{
  		int first_val = (data >> 9) & 0x3f;
  		int i;
  
  		/* find the desired first value and stop then */
  		for (i = 0; i < sizeof(mk_prot_values); i++)
  			if (mk_prot_values[i] == first_val)
  			{
  				mk_prot_index = i;
  				break;
  			}
  
  		/* just in case */
  		if (i == sizeof(mk_prot_values))
  		{
  			logerror("%08X:Unhandled protection W @ %05X = %04X\n", activecpu_get_pc(), offset, data);
  			mk_prot_index = 0;
  		}
  
  		logerror("%08X:Protection W @ %05X = %04X\n", activecpu_get_pc(), offset, data);
  	}
  }
  
  
  
  /*************************************
   *
   *  Mortal Kombat 2 protection
   *
   *************************************/
  
  static READ16_HANDLER( mk2_prot_const_r )
  {
  	return 2;
  }
  
  static READ16_HANDLER( mk2_prot_r )
  {
  	return mk2_prot_data;
  }
  
  static READ16_HANDLER( mk2_prot_shift_r )
  {
  	return mk2_prot_data >> 1;
  }
  
  static WRITE16_HANDLER( mk2_prot_w )
  {
  	COMBINE_DATA(&mk2_prot_data);
  }
  
  
  
  /*************************************
   *
   *  NBA Jam protection
   *
   *************************************/
  
  static const UINT32 nbajam_prot_values[128] =
  {
  	0x21283b3b, 0x2439383b, 0x31283b3b, 0x302b3938, 0x31283b3b, 0x302b3938, 0x232f2f2f, 0x26383b3b,
  	0x21283b3b, 0x2439383b, 0x312a1224, 0x302b1120, 0x312a1224, 0x302b1120, 0x232d283b, 0x26383b3b,
  	0x2b3b3b3b, 0x2e2e2e2e, 0x39383b1b, 0x383b3b1b, 0x3b3b3b1b, 0x3a3a3a1a, 0x2b3b3b3b, 0x2e2e2e2e,
  	0x2b39383b, 0x2e2e2e2e, 0x393a1a18, 0x383b1b1b, 0x3b3b1b1b, 0x3a3a1a18, 0x2b39383b, 0x2e2e2e2e,
  	0x01202b3b, 0x0431283b, 0x11202b3b, 0x1021283b, 0x11202b3b, 0x1021283b, 0x03273b3b, 0x06302b39,
  	0x09302b39, 0x0c232f2f, 0x19322e06, 0x18312a12, 0x19322e06, 0x18312a12, 0x0b31283b, 0x0e26383b,
  	0x03273b3b, 0x06302b39, 0x11202b3b, 0x1021283b, 0x13273938, 0x12243938, 0x03273b3b, 0x06302b39,
  	0x0b31283b, 0x0e26383b, 0x19322e06, 0x18312a12, 0x1b332f05, 0x1a302b11, 0x0b31283b,	0x0e26383b,
  	0x21283b3b, 0x2439383b, 0x31283b3b, 0x302b3938, 0x31283b3b, 0x302b3938, 0x232f2f2f, 0x26383b3b,
  	0x21283b3b, 0x2439383b, 0x312a1224, 0x302b1120, 0x312a1224, 0x302b1120, 0x232d283b, 0x26383b3b,
  	0x2b3b3b3b, 0x2e2e2e2e, 0x39383b1b, 0x383b3b1b, 0x3b3b3b1b, 0x3a3a3a1a, 0x2b3b3b3b, 0x2e2e2e2e,
  	0x2b39383b, 0x2e2e2e2e, 0x393a1a18, 0x383b1b1b, 0x3b3b1b1b, 0x3a3a1a18, 0x2b39383b, 0x2e2e2e2e,
  	0x01202b3b, 0x0431283b, 0x11202b3b, 0x1021283b, 0x11202b3b, 0x1021283b, 0x03273b3b, 0x06302b39,
  	0x09302b39, 0x0c232f2f, 0x19322e06, 0x18312a12, 0x19322e06, 0x18312a12, 0x0b31283b, 0x0e26383b,
  	0x03273b3b, 0x06302b39, 0x11202b3b, 0x1021283b, 0x13273938, 0x12243938, 0x03273b3b, 0x06302b39,
  	0x0b31283b, 0x0e26383b, 0x19322e06, 0x18312a12, 0x1b332f05, 0x1a302b11, 0x0b31283b,	0x0e26383b
  };
  
  static const UINT32 nbajamte_prot_values[128] =
  {
  	0x00000000, 0x04081020, 0x08102000, 0x0c183122, 0x10200000, 0x14281020, 0x18312204, 0x1c393326,
  	0x20000001, 0x24081021, 0x28102000, 0x2c183122, 0x30200001, 0x34281021, 0x38312204, 0x3c393326,
  	0x00000102, 0x04081122, 0x08102102, 0x0c183122, 0x10200000, 0x14281020, 0x18312204, 0x1c393326,
  	0x20000103, 0x24081123, 0x28102102, 0x2c183122, 0x30200001, 0x34281021, 0x38312204, 0x3c393326,
  	0x00010204, 0x04091224, 0x08112204, 0x0c193326, 0x10210204, 0x14291224, 0x18312204, 0x1c393326,
  	0x20000001, 0x24081021, 0x28102000, 0x2c183122, 0x30200001, 0x34281021, 0x38312204, 0x3c393326,
  	0x00010306, 0x04091326, 0x08112306, 0x0c193326, 0x10210204, 0x14291224, 0x18312204, 0x1c393326,
  	0x20000103, 0x24081123, 0x28102102, 0x2c183122, 0x30200001, 0x34281021, 0x38312204, 0x3c393326,
  	0x00000000, 0x01201028, 0x02213018, 0x03012030, 0x04223138, 0x05022110, 0x06030120, 0x07231108,
  	0x08042231, 0x09243219, 0x0a251229, 0x0b050201, 0x0c261309, 0x0d060321, 0x0e072311, 0x0f273339,
  	0x10080422, 0x1128140a, 0x1229343a, 0x13092412, 0x142a351a, 0x150a2532, 0x160b0502, 0x172b152a,
  	0x180c2613, 0x192c363b, 0x1a2d160b, 0x1b0d0623, 0x1c2e172b, 0x1d0e0703, 0x1e0f2733, 0x1f2f371b,
  	0x20100804, 0x2130182c, 0x2231381c, 0x23112834, 0x2432393c, 0x25122914, 0x26130924, 0x2733190c,
  	0x28142a35, 0x29343a1d, 0x2a351a2d, 0x2b150a05, 0x2c361b0d, 0x2d160b25, 0x2e172b15, 0x2f373b3d,
  	0x30180c26, 0x31381c0e, 0x32393c3e, 0x33192c16, 0x343a3d1e, 0x351a2d36, 0x361b0d06, 0x373b1d2e,
  	0x381c2e17, 0x393c3e3f, 0x3a3d1e0f, 0x3b1d0e27, 0x3c3e1f2f, 0x3d1e0f07, 0x3e1f2f37, 0x3f3f3f1f
  };
  
  static READ16_HANDLER( nbajam_prot_r )
  {
  	int result = nbajam_prot_queue[nbajam_prot_index];
  	if (nbajam_prot_index < 4)
  		nbajam_prot_index++;
  	return result;
  }
  
  static WRITE16_HANDLER( nbajam_prot_w )
  {
  	int table_index = (offset >> 6) & 0x7f;
  	UINT32 protval = nbajam_prot_table[table_index];
  
  	nbajam_prot_queue[0] = data;
  	nbajam_prot_queue[1] = ((protval >> 24) & 0xff) << 9;
  	nbajam_prot_queue[2] = ((protval >> 16) & 0xff) << 9;
  	nbajam_prot_queue[3] = ((protval >> 8) & 0xff) << 9;
  	nbajam_prot_queue[4] = ((protval >> 0) & 0xff) << 9;
  	nbajam_prot_index = 0;
  }
  
  
  
  /*************************************
   *
   *  Judge Dredd protection
   *
   *************************************/
  
  static const UINT8 jdredd_prot_values_10740[] =
  {
  	0x14,0x2A,0x15,0x0A,0x25,0x32,0x39,0x1C,
  	0x2E,0x37,0x3B,0x1D,0x2E,0x37,0x1B,0x0D,
  	0x26,0x33,0x39,0x3C,0x1E,0x2F,0x37,0x3B,
  	0x3D,0x3E,0x3F,0x1F,0x2F,0x17,0x0B,0x25,
  	0x32,0x19,0x0C,0x26,0x33,0x19,0x2C,0x16,
  	0x2B,0x15,0x0A,0x05,0x22,0x00
  };
  
  static const UINT8 jdredd_prot_values_13240[] =
  {
  	0x28
  };
  
  static const UINT8 jdredd_prot_values_76540[] =
  {
  	0x04,0x08
  };
  
  static const UINT8 jdredd_prot_values_77760[] =
  {
  	0x14,0x2A,0x14,0x2A,0x35,0x2A,0x35,0x1A,
  	0x35,0x1A,0x2D,0x1A,0x2D,0x36,0x2D,0x36,
  	0x1B,0x36,0x1B,0x36,0x2C,0x36,0x2C,0x18,
  	0x2C,0x18,0x31,0x18,0x31,0x22,0x31,0x22,
  	0x04,0x22,0x04,0x08,0x04,0x08,0x10,0x08,
  	0x10,0x20,0x10,0x20,0x00,0x20,0x00,0x00,
  	0x00,0x00,0x01,0x00,0x01,0x02,0x01,0x02,
  	0x05,0x02,0x05,0x0B,0x05,0x0B,0x16,0x0B,
  	0x16,0x2C,0x16,0x2C,0x18,0x2C,0x18,0x31,
  	0x18,0x31,0x22,0x31,0x22,0x04,0x22,0x04,
  	0x08,0x04,0x08,0x10,0x08,0x10,0x20,0x10,
  	0x20,0x00,0x00
  };
  
  static const UINT8 jdredd_prot_values_80020[] =
  {
  	0x3A,0x1D,0x2E,0x37,0x00,0x00,0x2C,0x1C,
  	0x39,0x33,0x00,0x00,0x00,0x00,0x00,0x00
  };
  
  static WRITE16_HANDLER( jdredd_prot_w )
  {
  	logerror("%08X:jdredd_prot_w(%04X,%04X)\n", activecpu_get_previouspc(), offset*16, data);
  
  	switch (offset)
  	{
  		case TOWORD(0x10740):
  			jdredd_prot_index = 0;
  			jdredd_prot_table = jdredd_prot_values_10740;
  			jdredd_prot_max = sizeof(jdredd_prot_values_10740);
  			logerror("-- reset prot table 10740\n");
  			break;
  
  		case TOWORD(0x13240):
  			jdredd_prot_index = 0;
  			jdredd_prot_table = jdredd_prot_values_13240;
  			jdredd_prot_max = sizeof(jdredd_prot_values_13240);
  			logerror("-- reset prot table 13240\n");
  			break;
  
  		case TOWORD(0x76540):
  			jdredd_prot_index = 0;
  			jdredd_prot_table = jdredd_prot_values_76540;
  			jdredd_prot_max = sizeof(jdredd_prot_values_76540);
  			logerror("-- reset prot table 76540\n");
  			break;
  
  		case TOWORD(0x77760):
  			jdredd_prot_index = 0;
  			jdredd_prot_table = jdredd_prot_values_77760;
  			jdredd_prot_max = sizeof(jdredd_prot_values_77760);
  			logerror("-- reset prot table 77760\n");
  			break;
  
  		case TOWORD(0x80020):
  			jdredd_prot_index = 0;
  			jdredd_prot_table = jdredd_prot_values_80020;
  			jdredd_prot_max = sizeof(jdredd_prot_values_80020);
  			logerror("-- reset prot table 80020\n");
  			break;
  	}
  }
  
  static READ16_HANDLER( jdredd_prot_r )
  {
  	UINT16 result = 0xffff;
  
  	if (jdredd_prot_table && jdredd_prot_index < jdredd_prot_max)
  		result = jdredd_prot_table[jdredd_prot_index++] << 9;
  
  	logerror("%08X:jdredd_prot_r(%04X) = %04X\n", activecpu_get_previouspc(), offset*16, result);
  	return result;
  }
  
  
  #if ENABLE_ALL_JDREDD_LEVELS
  static UINT16 *jdredd_hack;
  static READ16_HANDLER( jdredd_hack_r )
  {
  	if (activecpu_get_pc() == 0xFFBA7EB0)
  	{
  		fprintf(stderr, "jdredd_hack_r\n");
  		return 0;
  	}
  
  	return jdredd_hack[offset];
  }
  #endif
  
  
  
  /*************************************
   *
   *  Generic driver init
   *
   *************************************/
  
  static void init_tunit_generic(int sound)
  {
  	offs_t gfx_chunk = midyunit_gfx_rom_size / 4;
  	UINT8 *base;
  	int i;
  
  	/* register for state saving */
  	register_state_saving();
  
  	/* load the graphics ROMs -- quadruples */
  	base = memory_region(REGION_GFX1);
  	for (i = 0; i < midyunit_gfx_rom_size; i += 4)
  	{
  		midyunit_gfx_rom[i + 0] = base[0 * gfx_chunk + i / 4];
  		midyunit_gfx_rom[i + 1] = base[1 * gfx_chunk + i / 4];
  		midyunit_gfx_rom[i + 2] = base[2 * gfx_chunk + i / 4];
  		midyunit_gfx_rom[i + 3] = base[3 * gfx_chunk + i / 4];
  	}
  
  	/* load sound ROMs and set up sound handlers */
  	sound_type = sound;
  	switch (sound)
  	{
  		case SOUND_ADPCM:
  		case SOUND_ADPCM_LARGE:
  			williams_adpcm_init();
  			break;
  
  		case SOUND_DCS:
  			dcs_init();
  			break;
  	}
  
  	/* default graphics functionality */
  	midtunit_gfx_rom_large = 0;
  }
  
  
  
  /*************************************
   *
   *  T-unit init (ADPCM)
   *
   *  music: 6809 driving YM2151, DAC, and OKIM6295
   *
   *************************************/
  
  DRIVER_INIT( mktunit )
  {
  	/* common init */
  	init_tunit_generic(SOUND_ADPCM);
  
  	/* protection */
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b00000, 0x1b6ffff, 0, 0, mk_prot_r);
  	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b00000, 0x1b6ffff, 0, 0, mk_prot_w);
  
  	/* sound chip protection (hidden RAM) */
  	memory_install_write8_handler(1, ADDRESS_SPACE_PROGRAM, 0xfb9c, 0xfbc6, 0, 0, MWA8_RAM);
  }
  
  static void init_nbajam_common(int te_protection)
  {
  	/* common init */
  	init_tunit_generic(SOUND_ADPCM_LARGE);
  
  	/* protection */
  	if (!te_protection)
  	{
  		nbajam_prot_table = nbajam_prot_values;
  		memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b14020, 0x1b2503f, 0, 0, nbajam_prot_r);
  		memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b14020, 0x1b2503f, 0, 0, nbajam_prot_w);
  	}
  	else
  	{
  		nbajam_prot_table = nbajamte_prot_values;
  		memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b15f40, 0x1b37f5f, 0, 0, nbajam_prot_r);
  		memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b95f40, 0x1bb7f5f, 0, 0, nbajam_prot_r);
  		memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b15f40, 0x1b37f5f, 0, 0, nbajam_prot_w);
  		memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b95f40, 0x1bb7f5f, 0, 0, nbajam_prot_w);
  	}
  
  	/* sound chip protection (hidden RAM) */
  	if (!te_protection)
  		memory_install_write8_handler(1, ADDRESS_SPACE_PROGRAM, 0xfbaa, 0xfbd4, 0, 0, MWA8_RAM);
  	else
  		memory_install_write8_handler(1, ADDRESS_SPACE_PROGRAM, 0xfbec, 0xfc16, 0, 0, MWA8_RAM);
  }
  
  DRIVER_INIT( nbajam )
  {
  	init_nbajam_common(0);
  }
  
  DRIVER_INIT( nbajamte )
  {
  	init_nbajam_common(1);
  }
  
  DRIVER_INIT( jdreddp )
  {
  	/* common init */
  	init_tunit_generic(SOUND_ADPCM_LARGE);
  
  	/* looks like the watchdog needs to be disabled */
  	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x01d81060, 0x01d8107f, 0, 0, MWA16_NOP);
  
  	/* protection */
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b00000, 0x1bfffff, 0, 0, jdredd_prot_r);
  	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x1b00000, 0x1bfffff, 0, 0, jdredd_prot_w);
  
  	/* sound chip protection (hidden RAM) */
  	memory_install_write8_handler(1, ADDRESS_SPACE_PROGRAM, 0xfbcf, 0xfbf9, 0, 0, MWA8_RAM);
  
  #if ENABLE_ALL_JDREDD_LEVELS
  	/* how about the final levels? */
  	jdredd_hack = memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0xFFBA7FF0, 0xFFBA7FFf, 0, 0, jdredd_hack_r);
  #endif
  }
  
  
  
  /*************************************
   *
   *  T-unit init (DCS)
   *
   *  music: ADSP2105
   *
   *************************************/
  
  DRIVER_INIT( mk2 )
  {
  	/* common init */
  	init_tunit_generic(SOUND_DCS);
  	midtunit_gfx_rom_large = 1;
  
  	/* protection */
  	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x00f20c60, 0x00f20c7f, 0, 0, mk2_prot_w);
  	memory_install_write16_handler(0, ADDRESS_SPACE_PROGRAM, 0x00f42820, 0x00f4283f, 0, 0, mk2_prot_w);
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x01a190e0, 0x01a190ff, 0, 0, mk2_prot_r);
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x01a191c0, 0x01a191df, 0, 0, mk2_prot_shift_r);
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x01a3d0c0, 0x01a3d0ff, 0, 0, mk2_prot_r);
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x01d9d1e0, 0x01d9d1ff, 0, 0, mk2_prot_const_r);
  	memory_install_read16_handler(0, ADDRESS_SPACE_PROGRAM, 0x01def920, 0x01def93f, 0, 0, mk2_prot_const_r);
  }
  
  
  
  /*************************************
   *
   *  Machine init
   *
   *************************************/
  
  MACHINE_RESET( midtunit )
  {
  	/* reset sound */
  	switch (sound_type)
  	{
  		case SOUND_ADPCM:
  		case SOUND_ADPCM_LARGE:
  			williams_adpcm_reset_w(1);
  			williams_adpcm_reset_w(0);
  			break;
  
  		case SOUND_DCS:
  			dcs_reset_w(1);
  			dcs_reset_w(0);
  			break;
  	}
  }
  
  
  
  /*************************************
   *
   *  Sound write handlers
   *
   *************************************/
  
  READ16_HANDLER( midtunit_sound_state_r )
  {
  /*  logerror("%08X:Sound status read\n", activecpu_get_pc());*/
  
  	if (sound_type == SOUND_DCS)
  		return dcs_control_r() >> 4;
  
  	if (fake_sound_state)
  	{
  		fake_sound_state--;
  		return 0;
  	}
  	return ~0;
  }
  
  READ16_HANDLER( midtunit_sound_r )
  {
  	logerror("%08X:Sound data read\n", activecpu_get_pc());
  
  	if (sound_type == SOUND_DCS)
  		return dcs_data_r() & 0xff;
  
  	return ~0;
  }
  
  WRITE16_HANDLER( midtunit_sound_w )
  {
  	/* check for out-of-bounds accesses */
  	if (!offset)
  	{
  		logerror("%08X:Unexpected write to sound (lo) = %04X\n", activecpu_get_pc(), data);
  		return;
  	}
  
  	/* call through based on the sound type */
  	if (ACCESSING_LSB && ACCESSING_MSB)
  		switch (sound_type)
  		{
  			case SOUND_ADPCM:
  			case SOUND_ADPCM_LARGE:
  				williams_adpcm_reset_w(~data & 0x100);
  				williams_adpcm_data_w(data & 0xff);
  
  				/* the games seem to check for $82 loops, so this should be just barely enough */
  				fake_sound_state = 128;
  				break;
  
  			case SOUND_DCS:
  				logerror("%08X:Sound write = %04X\n", activecpu_get_pc(), data);
  				dcs_reset_w(~data & 0x100);
  				dcs_data_w(data & 0xff);
  				/* the games seem to check for $82 loops, so this should be just barely enough */
  				fake_sound_state = 128;
  				break;
  		}
  }
  