diff --git a/src/mame/drivers/taito_f3.c b/src/mame/drivers/taito_f3.c
index ab26bc4d26e..4b9f2a4b6f9 100644
--- a/src/mame/drivers/taito_f3.c
+++ b/src/mame/drivers/taito_f3.c
@@ -348,7 +348,7 @@ static const gfx_layout spriteram_layout =
 {
 	16,16,
 	RGN_FRAC(1,2),
-	6,
+	6,	/* Palettes have 4 bpp indexes despite up to 6 bpp data */
 	{ RGN_FRAC(1,2)+0, RGN_FRAC(1,2)+1, 0, 1, 2, 3 },
 	{
 	4, 0, 12, 8,
@@ -364,7 +364,7 @@ static const gfx_layout tile_layout =
 {
 	16,16,
 	RGN_FRAC(1,2),
-	6,
+	6,	/* Palettes have 4 bpp indexes despite up to 6 bpp data */
 	{ RGN_FRAC(1,2)+2, RGN_FRAC(1,2)+3, 0, 1, 2, 3 },
 	{
 	4, 0, 16+4, 16+0,
@@ -378,10 +378,10 @@ static const gfx_layout tile_layout =
 };
 
 static GFXDECODE_START( taito_f3 )
-	GFXDECODE_ENTRY( 0,           0x000000, charlayout,          0,  64 ) /* Dynamically modified */
-	GFXDECODE_ENTRY( REGION_GFX2, 0x000000, tile_layout, 	       0, 512 ) /* Tiles area */
-	GFXDECODE_ENTRY( REGION_GFX1, 0x000000, spriteram_layout, 4096, 256 ) /* Sprites area */
-	GFXDECODE_ENTRY( 0,           0x000000, pivotlayout,         0,  64 ) /* Dynamically modified */
+	GFXDECODE_ENTRY( 0,           0x000000, charlayout,       0x0000,  0x400>>4 ) /* Dynamically modified */
+	GFXDECODE_ENTRY( REGION_GFX2, 0x000000, tile_layout, 	    0x0000, 0x2000>>4 ) /* Tiles area */
+	GFXDECODE_ENTRY( REGION_GFX1, 0x000000, spriteram_layout, 0x1000, 0x1000>>4 ) /* Sprites area */
+	GFXDECODE_ENTRY( 0,           0x000000, pivotlayout,      0x0000,  0x400>>4 ) /* Dynamically modified */
 GFXDECODE_END
 
 /******************************************************************************/
@@ -462,7 +462,7 @@ static MACHINE_DRIVER_START( f3 )
 	MDRV_SCREEN_VISIBLE_AREA(46, 40*8-1 + 46, 24, 24+232-1)
 
 	MDRV_GFXDECODE(taito_f3)
-	MDRV_PALETTE_LENGTH(8192)
+	MDRV_PALETTE_LENGTH(0x2000)
 
 	MDRV_VIDEO_START(f3)
 	MDRV_VIDEO_EOF(f3)
@@ -3251,13 +3251,13 @@ ROM_END
 
 /******************************************************************************/
 
-static void tile_decode(running_machine *machine, int uses_5bpp_tiles)
+static void tile_decode(running_machine *machine)
 {
 	UINT8 lsb,msb;
 	UINT32 offset,i;
 	UINT8 *gfx = memory_region(machine, REGION_GFX2);
 	int size=memory_region_length(machine, REGION_GFX2);
-	int half=size/2,data;
+	int data;
 
 	/* Setup ROM formats:
 
@@ -3266,10 +3266,12 @@ static void tile_decode(running_machine *machine, int uses_5bpp_tiles)
         are tied low on the game board if unused.  This is backed up by the fact the palette
         indices are always related to 4 bpp data, even in 6 bpp games.
 
+        Most (all?) games with 5bpp tiles have the sixth bit set. Also, in Arabian Magic
+        sprites 1200-120f contain 6bpp data which is probably bogus.
+        VIDEO_START( f3 ) clears the fifth and sixth bit of the decoded graphics according
+        to the bit depth specified in f3_config_table.
+
     */
-	if (uses_5bpp_tiles)
-		for (i=half; i<size; i+=2)
-			gfx[i+1]=0;
 
 	offset = size/2;
 	for (i = size/2+size/4; i<size; i+=2)
@@ -3368,54 +3370,54 @@ F3_IRQ_SPEEDUP_2_R(kirameki, 0x12fc6,  0x0414/4, 0x0000ff00 )
 static DRIVER_INIT( ringrage )
 {
 	f3_game=RINGRAGE;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( arabianm )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408124, 0x408127, 0, 0, irq_speedup_r_arabianm );
 	f3_game=ARABIANM;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( ridingf )
 {
 	f3_game=RIDINGF;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( gseeker )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x40ad94, 0x40ad97, 0, 0, irq_speedup_r_gseeker );
 	f3_game=GSEEKER;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( gunlock )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400004, 0x400007, 0, 0, irq_speedup_r_gunlock );
 	f3_game=GUNLOCK;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( elvactr )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x4007a0, 0x4007a3, 0, 0, irq_speedup_r_eaction2 );
 	f3_game=EACTION2;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( cupfinal )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408114, 0x408117, 0, 0, irq_speedup_r_cupfinal );
 	f3_game=SCFINALS;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( trstaroj )
 {
 	f3_game=TRSTAR;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( scfinals )
@@ -3430,69 +3432,69 @@ static DRIVER_INIT( scfinals )
 
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408114, 0x408117, 0, 0, irq_speedup_r_scfinals );
 	f3_game=SCFINALS;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( lightbr )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400130, 0x400133, 0, 0, irq_speedup_r_lightbr );
 	f3_game=LIGHTBR;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( kaiserkn )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408110, 0x408113, 0, 0, irq_speedup_r_kaiserkn );
 	f3_game=KAISERKN;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( dariusg )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x406ba8, 0x406bab, 0, 0, irq_speedup_r_dariusg );
 	f3_game=DARIUSG;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( spcinvdj )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400230, 0x400233, 0, 0, irq_speedup_r_spcinvdj );
 	f3_game=SPCINVDX;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( qtheater )
 {
 	f3_game=QTHEATER;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( spcinv95 )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408114, 0x408117, 0, 0, irq_speedup_r_spcinv95 );
 	f3_game=SPCINV95;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( gekirido )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x406bb0, 0x406bb3, 0, 0, irq_speedup_r_gekirido );
 	f3_game=GEKIRIDO;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( ktiger2 )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400570, 0x400573, 0, 0, irq_speedup_r_ktiger2 );
 	f3_game=KTIGER2;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( bubsymph )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400134, 0x400137, 0, 0, irq_speedup_r_bubsymph );
 	f3_game=BUBSYMPH;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 
@@ -3523,7 +3525,7 @@ static DRIVER_INIT( bubsympb )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400134, 0x400137, 0, 0, irq_speedup_r_bubsymph );
 	f3_game=BUBSYMPH;
-	//tile_decode(machine, 1);
+	//tile_decode(machine);
 
 	/* expand gfx rom */
 	{
@@ -3553,28 +3555,28 @@ static DRIVER_INIT( bubblem )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400134, 0x400137, 0, 0, irq_speedup_r_bubblem );
 	f3_game=BUBBLEM;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( cleopatr )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408114, 0x408117, 0, 0, irq_speedup_r_cleopatr );
 	f3_game=CLEOPATR;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( popnpop )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x401cf8, 0x401cfb, 0, 0, irq_speedup_r_popnpop );
 	f3_game=POPNPOP;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( landmakr )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400824, 0x400827, 0, 0, irq_speedup_r_landmakr );
 	f3_game=LANDMAKR;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( landmkrp )
@@ -3590,94 +3592,94 @@ static DRIVER_INIT( landmkrp )
 
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400824, 0x400827, 0, 0, irq_speedup_r_landmakr );
 	f3_game=LANDMAKR;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( pbobble3 )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x405af4, 0x405af7, 0, 0, irq_speedup_r_pbobble3 );
 	f3_game=PBOBBLE3;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( pbobble4 )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x4058f4, 0x4058f7, 0, 0, irq_speedup_r_pbobble4 );
 	f3_game=PBOBBLE4;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( quizhuhu )
 {
 	f3_game=QUIZHUHU;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( pbobble2 )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x404a50, 0x404a53, 0, 0, irq_speedup_r_pbobble2 );
 	f3_game=PBOBBLE2;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( pbobbl2x )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x405c58, 0x405c5b, 0, 0, irq_speedup_r_pbobbl2x );
 	f3_game=PBOBBLE2;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( hthero95 )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x408114, 0x408117, 0, 0, irq_speedup_r_pwrgoal );
 	f3_game=HTHERO95;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( kirameki )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400414, 0x400417, 0, 0, irq_speedup_r_kirameki );
 	f3_game=KIRAMEKI;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( puchicar )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x4024d8, 0x4024db, 0, 0, irq_speedup_r_puchicar );
 	f3_game=PUCHICAR;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( twinqix )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x400134, 0x400137, 0, 0, irq_speedup_r_twinqix );
 	f3_game=TWINQIX;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( arkretrn )
 {
 	memory_install_read32_handler(machine, 0, ADDRESS_SPACE_PROGRAM, 0x402154, 0x402157, 0, 0, irq_speedup_r_arkretrn );
 	f3_game=ARKRETRN;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( intcup94 )
 {
 	f3_game=SCFINALS;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( recalh )
 {
 	f3_game=RECALH;
-	tile_decode(machine, 0);
+	tile_decode(machine);
 }
 
 static DRIVER_INIT( commandw )
 {
 	f3_game=COMMANDW;
-	tile_decode(machine, 1);
+	tile_decode(machine);
 }
 
 /******************************************************************************/
diff --git a/src/mame/video/taito_f3.c b/src/mame/video/taito_f3.c
index d4633945381..55316039d62 100644
--- a/src/mame/video/taito_f3.c
+++ b/src/mame/video/taito_f3.c
@@ -236,45 +236,47 @@ struct F3config
 	int name;
 	int extend;
 	int sprite_lag;
+	int sprite_bpp;
+	int tile_bpp;
 };
 
 static const struct F3config *f3_game_config;
 
 static const struct F3config f3_config_table[] =
 {
-	/* Name    Extend  Sprite Lag */
-	{ RINGRAGE,  0,       2 },
-	{ ARABIANM,  0,       2 },
-	{ RIDINGF,   1,       1 },
-	{ GSEEKER,   0,       1 },
-	{ TRSTAR,    1,       0 },
-	{ GUNLOCK,   1,       2 },
-	{ TWINQIX,   1,       1 },
-	{ SCFINALS,  0,       1 },
-	{ LIGHTBR,   1,       2 },
-	{ KAISERKN,  0,       2 },
-	{ DARIUSG,   0,       2 },
-	{ BUBSYMPH,  1,       1 },
-	{ SPCINVDX,  1,       1 },
-	{ QTHEATER,  1,       1 },
-	{ HTHERO95,  0,       1 },
-	{ SPCINV95,  0,       1 },
-	{ EACTION2,  1,       2 },
-	{ QUIZHUHU,  1,       1 },
-	{ PBOBBLE2,  0,       1 },
-	{ GEKIRIDO,  0,       1 },
-	{ KTIGER2,   0,       0 },
-	{ BUBBLEM,   1,       1 },
-	{ CLEOPATR,  0,       1 },
-	{ PBOBBLE3,  0,       1 },
-	{ ARKRETRN,  1,       1 },
-	{ KIRAMEKI,  0,       1 },
-	{ PUCHICAR,  1,       1 },
-	{ PBOBBLE4,  0,       1 },
-	{ POPNPOP,   1,       1 },
-	{ LANDMAKR,  1,       1 },
-	{ RECALH,    1,       1 },
-	{ COMMANDW,  1,       1 },
+	/* Name    Extend  Lag   Bpp */
+	{ RINGRAGE,  0,     2,   5, 6 },
+	{ ARABIANM,  0,     2,   5, 5 },	/* sprites 1200-120F contain 6bpp pixels but this seems to be a data error */
+	{ RIDINGF,   1,     1,   4, 4 },
+	{ GSEEKER,   0,     1,   4, 4 },
+	{ COMMANDW,  1,     1,   5, 5 },
+	{ SCFINALS,  0,     1,   5, 5 },
+	{ TRSTAR,    1,     0,   5, 5 },
+	{ GUNLOCK,   1,     2,   5, 5 },
+	{ LIGHTBR,   1,     2,   5, 5 },
+	{ KAISERKN,  0,     2,   5, 5 },
+	{ DARIUSG,   0,     2,   5, 5 },
+	{ BUBSYMPH,  1,     1,   5, 5 },
+	{ SPCINVDX,  1,     1,   4, 4 },
+	{ HTHERO95,  0,     1,   6, 6 },
+	{ QTHEATER,  1,     1,   4, 4 },
+	{ EACTION2,  1,     2,   5, 5 },
+	{ RECALH,    1,     1,   4, 4 },
+	{ SPCINV95,  0,     1,   5, 5 },
+	{ TWINQIX,   1,     1,   4, 6 },
+	{ QUIZHUHU,  1,     1,   6, 6 },
+	{ PBOBBLE2,  0,     1,   4, 6 },
+	{ GEKIRIDO,  0,     1,   5, 5 },
+	{ KTIGER2,   0,     0,   4, 4 },
+	{ BUBBLEM,   1,     1,   4, 5 },
+	{ CLEOPATR,  0,     1,   4, 6 },
+	{ PBOBBLE3,  0,     1,   4, 6 },
+	{ ARKRETRN,  1,     1,   5, 6 },
+	{ KIRAMEKI,  0,     1,   5, 6 },
+	{ PUCHICAR,  1,     1,   5, 6 },
+	{ PBOBBLE4,  0,     1,   4, 6 },
+	{ POPNPOP,   1,     1,   6, 6 },
+	{ LANDMAKR,  1,     1,   5, 6 },
 	{0}
 };
 
@@ -443,11 +445,16 @@ INLINE void get_tile_info(running_machine *machine, tile_data *tileinfo, int til
 {
 	UINT32 tile=gfx_base[tile_index];
 	UINT8 abtype=(tile>>(16+9))&0x1f;
+	int color_mask;
+
+	// if tiles use more than 4bpp, the bottom bits of the color code must be masked out.
+	// This fixes (at least) the rain in round 6 of Arabian Magic.
+	color_mask = ~((1 << (f3_game_config->tile_bpp - 4)) - 1);
 
 	SET_TILE_INFO(
 			1,
 			tile&0xffff,
-			(tile>>16)&0x1ff,
+			(tile>>16) & 0x1ff & color_mask,
 			TILE_FLIPYX( tile >> 30 ));
 	tileinfo->category =  abtype&1;		/* alpha blending type */
 }
@@ -617,10 +624,14 @@ VIDEO_START( f3 )
 	tilemap_set_transparent_pen(vram_layer,0);
 	tilemap_set_transparent_pen(pixel_layer,0);
 
-	/* Palettes have 4 bpp indexes despite up to 6 bpp data */
+	// Palettes have 4 bpp indexes despite up to 6 bpp data. The unused
+	// top bits in the gfx data are cleared later.
 	machine->gfx[1]->color_granularity=16;
 	machine->gfx[2]->color_granularity=16;
 
+	assert(f3_game_config->tile_bpp >= 4 && f3_game_config->tile_bpp <= 6);
+	assert(f3_game_config->sprite_bpp >= 4 && f3_game_config->sprite_bpp <= 6);
+
 	flipscreen = 0;
 	memset(spriteram32_buffered,0,spriteram_size);
 	memset(spriteram32,0,spriteram_size);
@@ -642,6 +653,7 @@ VIDEO_START( f3 )
 	{
 		const gfx_element *sprite_gfx = machine->gfx[2];
 		int c;
+		int bpp_mask = (1 << f3_game_config->sprite_bpp) - 1;
 
 		for (c = 0;c < sprite_gfx->total_elements;c++)
 		{
@@ -652,6 +664,9 @@ VIDEO_START( f3 )
 			{
 				for (x = 0;x < sprite_gfx->width;x++)
 				{
+					// clear unused top bits from gfx data
+					dp[x] &= bpp_mask;
+
 					if(!dp[x]) chk_trans_or_opa|=2;
 					else	   chk_trans_or_opa|=1;
 				}
@@ -666,6 +681,7 @@ VIDEO_START( f3 )
 	{
 		const gfx_element *pf_gfx = machine->gfx[1];
 		int c;
+		int bpp_mask = (1 << f3_game_config->tile_bpp) - 1;
 
 		for (c = 0;c < pf_gfx->total_elements;c++)
 		{
@@ -676,6 +692,9 @@ VIDEO_START( f3 )
 			{
 				for (x = 0;x < pf_gfx->width;x++)
 				{
+					// clear unused top bits from gfx data
+					dp[x] &= bpp_mask;
+
 					if(!dp[x]) chk_trans_or_opa|=2;
 					else	   chk_trans_or_opa|=1;
 				}
@@ -3157,9 +3176,15 @@ static void draw_sprites(running_machine *machine, bitmap_t *bitmap, const recta
 {
 	const struct tempsprite *sprite_ptr;
 	const gfx_element *sprite_gfx = machine->gfx[2];
+	int color_mask;
 
 	sprite_ptr = sprite_end;
 	sprite_pri_usage=0;
+
+	// if sprites use more than 4bpp, the bottom bits of the color code must be masked out.
+	// This fixes (at least) stage 1 battle ships and attract mode explosions in Ray Force.
+	color_mask = ~((1 << (f3_game_config->sprite_bpp - 4)) - 1);
+
 	while (sprite_ptr != spritelist)
 	{
 		int pri;
@@ -3172,7 +3197,7 @@ static void draw_sprites(running_machine *machine, bitmap_t *bitmap, const recta
 			f3_drawgfx(machine,
 					bitmap,sprite_gfx,
 					sprite_ptr->code,
-					sprite_ptr->color,
+					sprite_ptr->color & color_mask,
 					sprite_ptr->flipx,sprite_ptr->flipy,
 					sprite_ptr->x,sprite_ptr->y,
 					cliprect,
@@ -3181,7 +3206,7 @@ static void draw_sprites(running_machine *machine, bitmap_t *bitmap, const recta
 			f3_drawgfxzoom(machine,
 					bitmap,sprite_gfx,
 					sprite_ptr->code,
-					sprite_ptr->color,
+					sprite_ptr->color & color_mask,
 					sprite_ptr->flipx,sprite_ptr->flipy,
 					sprite_ptr->x,sprite_ptr->y,
 					cliprect,