A little more cleaning in the irem games.

.gitattributes

@@ -2207,6 +2207,7 @@ src/mame/includes/lwings.h svneol=native#text/plain
 src/mame/includes/m107.h svneol=native#text/plain
 src/mame/includes/m52.h svneol=native#text/plain
 src/mame/includes/m57.h svneol=native#text/plain
+src/mame/includes/m58.h svneol=native#text/plain
 src/mame/includes/m62.h svneol=native#text/plain
 src/mame/includes/m72.h svneol=native#text/plain
 src/mame/includes/m92.h svneol=native#text/plain

src/mame/drivers/gberet.c

@@ -84,7 +84,25 @@ extern VIDEO_UPDATE( gberet );
 extern VIDEO_UPDATE( gberetb );
 
 
-static int enable_NMI, enable_IRQ;
+static UINT8 nmi_enable, irq_enable;
+
+
+/* Interrupt Generators */
+
+static INTERRUPT_GEN( gberet_interrupt )
+{
+	if (cpu_getiloops() == 0)
+	{
+		if (irq_enable)
+			cpunum_set_input_line(machine, 0, 0, HOLD_LINE);
+	}
+
+	if (cpu_getiloops() % 2)
+	{
+		if (nmi_enable)
+			cpunum_set_input_line(machine, 0, INPUT_LINE_NMI, PULSE_LINE);
+	}
+}
 
 
 /* Read/Write Handlers */
@@ -98,8 +116,8 @@ static WRITE8_HANDLER( gberet_coin_counter_w )
 
 static WRITE8_HANDLER( gberet_flipscreen_w )
 {
-	enable_NMI = data & 0x01;
+	nmi_enable = data & 0x01;
-	enable_IRQ = data & 0x04;
+	irq_enable = data & 0x04;
 
 	flip_screen_set(data & 0x08);
 }
@@ -119,8 +137,8 @@ static WRITE8_HANDLER( mrgoemon_coin_counter_w )
 
 static WRITE8_HANDLER( mrgoemon_flipscreen_w )
 {
-	enable_NMI = data & 0x01;
+	nmi_enable = data & 0x01;
-	enable_IRQ = data & 0x02;
+	irq_enable = data & 0x02;
 
 	flip_screen_set(data & 0x08);
 }
@@ -528,23 +546,6 @@ static GFXDECODE_START( gberetb )
 	GFXDECODE_ENTRY( REGION_GFX2, 0, gberetb_spritelayout, 16*16, 16 )
 GFXDECODE_END
 
-/* Interrupt Generators */
-
-static INTERRUPT_GEN( gberet_interrupt )
-{
-	if (cpu_getiloops() == 0)
-	{
-		if (enable_IRQ)
-			cpunum_set_input_line(machine, 0, 0, HOLD_LINE);
-	}
-
-	if (cpu_getiloops() % 2)
-	{
-		if (enable_NMI)
-			cpunum_set_input_line(machine, 0, INPUT_LINE_NMI, PULSE_LINE);
-	}
-}
-
 /* Machine Drivers */
 
 static MACHINE_DRIVER_START( gberet )

src/mame/drivers/yard.c

@@ -1,5 +1,6 @@
 /****************************************************************************
-10 Yard Fight Driver.
+
+	Irem M58 hardware
 
 	L Taylor
 	J Clegg
@@ -9,24 +10,18 @@ Loosely based on the Kung Fu Master driver.
 ****************************************************************************/
 
 #include "driver.h"
+#include "m58.h"
 #include "audio/irem.h"
 
 #define MASTER_CLOCK		XTAL_18_432MHz
 
 
-extern UINT8 *yard_scroll_x_low;
-extern UINT8 *yard_scroll_x_high;
-extern UINT8 *yard_scroll_y_low;
-extern UINT8 *yard_score_panel_disabled;
 
-extern WRITE8_HANDLER( yard_videoram_w );
+/*************************************
-extern WRITE8_HANDLER( yard_scroll_panel_w );
+ *
-
+ *  Outputs
-extern PALETTE_INIT( yard );
+ *
-extern VIDEO_START( yard );
+ *************************************/
-extern VIDEO_UPDATE( yard );
-
-/* Read/Write Handlers */
 
 static WRITE8_HANDLER( yard_flipscreen_w )
 {
@@ -36,7 +31,13 @@ static WRITE8_HANDLER( yard_flipscreen_w )
 	coin_counter_w(1, data & 0x20);
 }
 
-/* Memory Map */
+
+
+/*************************************
+ *
+ *  Memory maps
+ *
+ *************************************/
 
 static ADDRESS_MAP_START( yard_map, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x0000, 0x5fff) AM_ROM
@@ -55,7 +56,13 @@ static ADDRESS_MAP_START( yard_map, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0xe000, 0xefff) AM_RAM
 ADDRESS_MAP_END
 
-/* Input Ports */
+
+
+/*************************************
+ *
+ *  Port definitions
+ *
+ *************************************/
 
 static INPUT_PORTS_START( yard )
 	PORT_START_TAG("IN0")
@@ -160,18 +167,13 @@ static INPUT_PORTS_START( vsyard )
 	PORT_DIPSETTING( 0x00, DEF_STR( Yes ) )
 INPUT_PORTS_END
 
-/* Graphics Layouts */
 
-static const gfx_layout charlayout =
+
-{
+/*************************************
-	8, 8,
+ *
-	RGN_FRAC(1,3),
+ *  Graphics layouts
-	3,
+ *
-	{ RGN_FRAC(2,3), RGN_FRAC(1,3), RGN_FRAC(0,3) },
+ *************************************/
-	{ 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
-};
 
 static const gfx_layout spritelayout =
 {
@@ -179,22 +181,24 @@ static const gfx_layout spritelayout =
 	RGN_FRAC(1,3),
 	3,
 	{ RGN_FRAC(2,3), RGN_FRAC(1,3), RGN_FRAC(0,3) },
-	{ 0, 1, 2, 3, 4, 5, 6, 7,
+	{ STEP8(0,1), STEP8(16*8,1) },
-	  16*8+0, 16*8+1, 16*8+2, 16*8+3, 16*8+4, 16*8+5, 16*8+6, 16*8+7 },
+	{ STEP16(0,8) },
-	{ 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 },
 	32*8
 };
 
-/* Graphics Decode Information */
 
 static GFXDECODE_START( yard )
-	GFXDECODE_ENTRY( REGION_GFX1, 0, charlayout,     0, 32 )
+	GFXDECODE_ENTRY( REGION_GFX1, 0, gfx_8x8x3_planar,   0, 32 )
-	GFXDECODE_ENTRY( REGION_GFX2, 0, spritelayout, 256, 32 )
+	GFXDECODE_ENTRY( REGION_GFX2, 0, spritelayout,     512, 32 )
 GFXDECODE_END
 
 
-/* Machine Driver */
+
+/*************************************
+ *
+ *  Machine drivers
+ *
+ *************************************/
 
 static MACHINE_DRIVER_START( yard )
 
@@ -221,7 +225,13 @@ static MACHINE_DRIVER_START( yard )
 MACHINE_DRIVER_END
 
 
-/* ROMs */
+
+/*************************************
+ *
+ *  ROM definitions
+ *
+ *************************************/
+
 ROM_START( 10yard )
 	ROM_REGION( 0x10000, REGION_CPU1, 0 )
 	ROM_LOAD( "yf-a-3p-b",    0x0000, 0x2000, CRC(2e205ec2) SHA1(fcfa08f45423b35f2c99d4e6b5474ab1b3a84fec) )
@@ -358,7 +368,13 @@ ROM_START( vs10yarj )
 	ROM_LOAD( "yard.2m",      0x0420, 0x0100, CRC(45384397) SHA1(e4c662ee81aef63efd8b4a45f85c4a78dc2d419e) ) /* radar palette high 4 bits */
 ROM_END
 
-/* Game Drivers */
+
+
+/*************************************
+ *
+ *  Game drivers
+ *
+ *************************************/
 
 GAME( 1983, 10yard,        0, yard, yard,   0, ROT0, "Irem", "10-Yard Fight (World)", 0 )
 GAME( 1983, 10yardj,  10yard, yard, yard,   0, ROT0, "Irem", "10-Yard Fight (Japan)", 0 )

src/mame/includes/m58.h

@@ -0,0 +1,19 @@
+/*************************************************************************
+
+	Irem M58 hardware
+
+*************************************************************************/
+
+/*----------- defined in video/m58.c -----------*/
+
+extern UINT8 *yard_scroll_x_low;
+extern UINT8 *yard_scroll_x_high;
+extern UINT8 *yard_scroll_y_low;
+extern UINT8 *yard_score_panel_disabled;
+
+WRITE8_HANDLER( yard_videoram_w );
+WRITE8_HANDLER( yard_scroll_panel_w );
+
+PALETTE_INIT( yard );
+VIDEO_START( yard );
+VIDEO_UPDATE( yard );

src/mame/video/m52.c

@@ -27,15 +27,19 @@ static tilemap* bg_tilemap;
 
 PALETTE_INIT( m52 )
 {
+	const UINT8 *char_pal = color_prom + 0x000;
+	const UINT8 *back_pal = color_prom + 0x200;
+	const UINT8 *sprite_pal = color_prom + 0x220;
+	const UINT8 *sprite_table = color_prom + 0x240;
 	static const int resistances_3[3] = { 1000, 470, 220 };
 	static const int resistances_2[2]  = { 470, 220 };
-	double weights_r[3], weights_g[3], weights_b[3];
+	double weights_r[3], weights_g[3], weights_b[3], scale;
 	int i;
 
 	machine->colortable = colortable_alloc(machine, 512+32+32);
 
 	/* compute palette information for characters/backgrounds */
-	compute_resistor_weights(0,	255, -1.0,
+	scale = compute_resistor_weights(0,	255, -1.0,
 			3, resistances_3, weights_r, 0, 0,
 			3, resistances_3, weights_g, 0, 0,
 			2, resistances_2, weights_b, 0, 0);
@@ -43,7 +47,7 @@ PALETTE_INIT( m52 )
 	/* character palette */
 	for (i = 0; i < 512; i++)
 	{
-		UINT8 promval = color_prom[i];
+		UINT8 promval = char_pal[i];
 		int r = combine_3_weights(weights_r, BIT(promval,0), BIT(promval,1), BIT(promval,2));
 		int g = combine_3_weights(weights_g, BIT(promval,3), BIT(promval,4), BIT(promval,5));
 		int b = combine_2_weights(weights_b, BIT(promval,6), BIT(promval,7));
@@ -54,16 +58,16 @@ PALETTE_INIT( m52 )
 	/* background palette */
 	for (i = 0; i < 32; i++)
 	{
-		UINT8 promval = color_prom[512+i];
+		UINT8 promval = back_pal[i];
 		int r = combine_3_weights(weights_r, BIT(promval,0), BIT(promval,1), BIT(promval,2));
 		int g = combine_3_weights(weights_g, BIT(promval,3), BIT(promval,4), BIT(promval,5));
 		int b = combine_2_weights(weights_b, BIT(promval,6), BIT(promval,7));
 
-		colortable_palette_set_color(machine->colortable,i+512,MAKE_RGB(r,g,b));
+		colortable_palette_set_color(machine->colortable, 512+i, MAKE_RGB(r,g,b));
 	}
 
 	/* compute palette information for sprites */
-	compute_resistor_weights(0,	255, -1.0,
+	compute_resistor_weights(0,	255, scale,
 			2, resistances_2, weights_r, 470, 0,
 			3, resistances_3, weights_g, 470, 0,
 			3, resistances_3, weights_b, 470, 0);
@@ -71,12 +75,12 @@ PALETTE_INIT( m52 )
 	/* sprite palette */
 	for (i = 0; i < 32; i++)
 	{
-		UINT8 promval = color_prom[512+32+i];
+		UINT8 promval = sprite_pal[i];
 		int r = combine_2_weights(weights_r, BIT(promval,6), BIT(promval,7));
 		int g = combine_3_weights(weights_g, BIT(promval,3), BIT(promval,4), BIT(promval,5));
 		int b = combine_3_weights(weights_b, BIT(promval,0), BIT(promval,1), BIT(promval,2));
 
-		colortable_palette_set_color(machine->colortable,i+512+32,MAKE_RGB(r,g,b));
+		colortable_palette_set_color(machine->colortable, 512+32+i, MAKE_RGB(r,g,b));
 	}
 
 	/* character lookup table */
@@ -86,7 +90,7 @@ PALETTE_INIT( m52 )
 	/* sprite lookup table */
 	for (i = 0; i < 16*4; i++)
 	{
-		UINT8 promval = color_prom[512+32+32+((i & 3) | ((i & ~3) << 1))];
+		UINT8 promval = sprite_table[(i & 3) | ((i & ~3) << 1)];
 		colortable_entry_set_value(machine->colortable, 512+i, 512+32+promval);
 	}
 

src/mame/video/williams.c

@@ -349,24 +349,9 @@ static void create_palette_lookup(void)
 	palette_lookup = auto_malloc(256 * sizeof(*palette_lookup));
 	for (i = 0; i < 256; i++)
 	{
-		int bit0,bit1,bit2,r,g,b;
+		int r = combine_3_weights(weights_r, BIT(i,0), BIT(i,1), BIT(i,2));
-
+		int g = combine_3_weights(weights_g, BIT(i,3), BIT(i,4), BIT(i,5));
-		/* red component */
+		int b = combine_2_weights(weights_b, BIT(i,6), BIT(i,7));
-		bit0 = (i >> 0) & 0x01;
-		bit1 = (i >> 1) & 0x01;
-		bit2 = (i >> 2) & 0x01;
-		r = combine_3_weights(weights_r, bit0, bit1, bit2);
-
-		/* green component */
-		bit0 = (i >> 3) & 0x01;
-		bit1 = (i >> 4) & 0x01;
-		bit2 = (i >> 5) & 0x01;
-		g = combine_3_weights(weights_g, bit0, bit1, bit2);
-
-		/* blue component */
-		bit0 = (i >> 6) & 0x01;
-		bit1 = (i >> 7) & 0x01;
-		b = combine_2_weights(weights_b, bit0, bit1);
 
 		palette_lookup[i] = MAKE_RGB(r, g, b);
 	}

src/mame/video/yard.c

@@ -1,18 +1,13 @@
 /***************************************************************************
 
-  video.c
+	Irem M58 hardware
-
-  10 Yard Fight
-
-L Taylor
-J Clegg
-
-  Functions to emulate the video hardware of the machine.
 
 ***************************************************************************/
 
 #include "driver.h"
 #include "deprecat.h"
+#include "m58.h"
+#include "video/resnet.h"
 
 UINT8 *yard_scroll_x_low;
 UINT8 *yard_scroll_x_high;
@@ -23,136 +18,107 @@ static mame_bitmap *scroll_panel_bitmap;
 static tilemap *bg_tilemap;
 
 #define SCROLL_PANEL_WIDTH  (14*4)
-#define RADAR_PALETTE_BASE (256+256)
+#define RADAR_PALETTE_BASE	(256)
 
 
-/***************************************************************************
 
-  Convert the color PROMs into a more useable format.
+/*************************************
+ *
+ *  Palette configuration
+ *
+ *************************************/
 
-  10 Yard Fight has two 256x4 character palette PROMs, one 32x8 sprite
-  palette PROM, one 256x4 sprite color lookup table PROM, and two 256x4
-  radar palette PROMs.
-
-  I don't know for sure how the palette PROMs are connected to the RGB
-  output, but it's probably something like this; note that RED and BLUE
-  are swapped wrt the usual configuration.
-
-  bit 7 -- 220 ohm resistor  -- RED
-        -- 470 ohm resistor  -- RED
-        -- 220 ohm resistor  -- GREEN
-        -- 470 ohm resistor  -- GREEN
-        -- 1  kohm resistor  -- GREEN
-        -- 220 ohm resistor  -- BLUE
-        -- 470 ohm resistor  -- BLUE
-  bit 0 -- 1  kohm resistor  -- BLUE
-
-***************************************************************************/
 PALETTE_INIT( yard )
 {
+	const UINT8 *char_lopal = color_prom + 0x000;
+	const UINT8 *char_hipal = color_prom + 0x100;
+	const UINT8 *sprite_pal = color_prom + 0x200;
+	const UINT8 *sprite_table = color_prom + 0x220;
+	const UINT8 *radar_lopal = color_prom + 0x320;
+	const UINT8 *radar_hipal = color_prom + 0x420;
+	static const int resistances_3[3] = { 1000, 470, 220 };
+	static const int resistances_2[2]  = { 470, 220 };
+	double weights_r[3], weights_g[3], weights_b[3], scale;
 	int i;
 
-	machine->colortable = colortable_alloc(machine, 256+16+256);
+	machine->colortable = colortable_alloc(machine, 256+256+16);
+
+	/* compute palette information for characters/radar */
+	scale = compute_resistor_weights(0,	255, -1.0,
+			2, resistances_2, weights_r, 0, 0,
+			3, resistances_3, weights_g, 0, 0,
+			3, resistances_3, weights_b, 0, 0);
 
 	/* character palette */
 	for (i = 0; i < 256; i++)
 	{
-		int bit0,bit1,bit2,r,g,b;
+		UINT8 promval = (char_lopal[i] & 0x0f) | (char_hipal[i] << 4);
-
+		int r = combine_2_weights(weights_r, BIT(promval,6), BIT(promval,7));
-		/* red component */
+		int g = combine_3_weights(weights_g, BIT(promval,3), BIT(promval,4), BIT(promval,5));
-		bit0 = 0;
+		int b = combine_3_weights(weights_b, BIT(promval,0), BIT(promval,1), BIT(promval,2));
-		bit1 = (color_prom[256] >> 2) & 0x01;
-		bit2 = (color_prom[256] >> 3) & 0x01;
-		r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-		/* green component */
-		bit0 = (color_prom[0] >> 3) & 0x01;
-		bit1 = (color_prom[256] >> 0) & 0x01;
-		bit2 = (color_prom[256] >> 1) & 0x01;
-		g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-		/* blue component */
-		bit0 = (color_prom[0] >> 0) & 0x01;
-		bit1 = (color_prom[0] >> 1) & 0x01;
-		bit2 = (color_prom[0] >> 2) & 0x01;
-		b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
 
 		colortable_palette_set_color(machine->colortable, i, MAKE_RGB(r,g,b));
-		colortable_entry_set_value(machine->colortable,i,i);
-
-		color_prom++;
 	}
 
-	color_prom += 256;
-	/* color_prom now points to the beginning of the sprite palette */
-
-	/* sprite palette */
-	for (i = 0;i < 16;i++)
-	{
-		int bit0,bit1,bit2,r,g,b;
-
-		/* red component */
-		bit0 = 0;
-		bit1 = (*color_prom >> 6) & 0x01;
-		bit2 = (*color_prom >> 7) & 0x01;
-		r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-		/* green component */
-		bit0 = (*color_prom >> 3) & 0x01;
-		bit1 = (*color_prom >> 4) & 0x01;
-		bit2 = (*color_prom >> 5) & 0x01;
-		g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-		/* blue component */
-		bit0 = (*color_prom >> 0) & 0x01;
-		bit1 = (*color_prom >> 1) & 0x01;
-		bit2 = (*color_prom >> 2) & 0x01;
-		b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-
-		colortable_palette_set_color(machine->colortable,256+i,MAKE_RGB(r,g,b));
-
-		color_prom++;
-	}
-
-	color_prom += 16;
-	/* color_prom now points to the beginning of the sprite lookup table */
-
-	/* sprite lookup table */
-	for (i = 0;i < 256;i++)
-		colortable_entry_set_value(machine->colortable,256+i,256+(*color_prom++ & 0x0f));
-
-	/* color_prom now points to the beginning of the radar palette */
-
 	/* radar palette */
 	for (i = 0; i < 256; i++)
 	{
-		int bit0,bit1,bit2,r,g,b;
+		UINT8 promval = (radar_lopal[i] & 0x0f) | (radar_hipal[i] << 4);
+		int r = combine_2_weights(weights_r, BIT(promval,6), BIT(promval,7));
+		int g = combine_3_weights(weights_g, BIT(promval,3), BIT(promval,4), BIT(promval,5));
+		int b = combine_3_weights(weights_b, BIT(promval,0), BIT(promval,1), BIT(promval,2));
 
-		/* red component */
+		colortable_palette_set_color(machine->colortable, 256+i, MAKE_RGB(r,g,b));
-		bit0 = 0;
+	}
-		bit1 = (color_prom[256] >> 2) & 0x01;
-		bit2 = (color_prom[256] >> 3) & 0x01;
-		r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-		/* green component */
-		bit0 = (color_prom[0] >> 3) & 0x01;
-		bit1 = (color_prom[256] >> 0) & 0x01;
-		bit2 = (color_prom[256] >> 1) & 0x01;
-		g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
-		/* blue component */
-		bit0 = (color_prom[0] >> 0) & 0x01;
-		bit1 = (color_prom[0] >> 1) & 0x01;
-		bit2 = (color_prom[0] >> 2) & 0x01;
-		b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
 
-		colortable_palette_set_color(machine->colortable,256+16+i,MAKE_RGB(r,g,b));
+	/* compute palette information for sprites */
-		colortable_entry_set_value(machine->colortable,256+256+i,256+16+i);
+	scale = compute_resistor_weights(0,	255, scale,
+			2, resistances_2, weights_r, 470, 0,
+			3, resistances_3, weights_g, 470, 0,
+			3, resistances_3, weights_b, 470, 0);
 
-		color_prom++;
+	/* sprite palette */
+	for (i = 0; i < 16; i++)
+	{
+		UINT8 promval = sprite_pal[i];
+		int r = combine_2_weights(weights_r, BIT(promval,6), BIT(promval,7));
+		int g = combine_3_weights(weights_g, BIT(promval,3), BIT(promval,4), BIT(promval,5));
+		int b = combine_3_weights(weights_b, BIT(promval,0), BIT(promval,1), BIT(promval,2));
+
+		colortable_palette_set_color(machine->colortable, 256+256+i, MAKE_RGB(r,g,b));
+	}
+
+	/* character lookup table */
+	for (i = 0; i < 256; i++)
+		colortable_entry_set_value(machine->colortable, i, i);
+
+	/* radar lookup table */
+	for (i = 0; i < 256; i++)
+		colortable_entry_set_value(machine->colortable, 256+i, 256+i);
+
+	/* sprite lookup table */
+	for (i = 0; i < 256; i++)
+	{
+		UINT8 promval = sprite_table[i] & 0x0f;
+		colortable_entry_set_value(machine->colortable, 256+256+i, 256+256+promval);
 	}
 }
 
+
+
+/*************************************
+ *
+ *  Video RAM access
+ *
+ *************************************/
+
 WRITE8_HANDLER( yard_videoram_w )
 {
 	videoram[offset] = data;
 	tilemap_mark_tile_dirty(bg_tilemap, offset / 2);
 }
 
+
 WRITE8_HANDLER( yard_scroll_panel_w )
 {
 	int sx,sy,i;
@@ -175,6 +141,14 @@ WRITE8_HANDLER( yard_scroll_panel_w )
 	}
 }
 
+
+
+/*************************************
+ *
+ *  Tilemap info callback
+ *
+ *************************************/
+
 static TILE_GET_INFO( yard_get_bg_tile_info )
 {
 	int offs = tile_index * 2;
@@ -186,6 +160,7 @@ static TILE_GET_INFO( yard_get_bg_tile_info )
 	SET_TILE_INFO(0, code, color, flags);
 }
 
+
 static UINT32 yard_tilemap_scan_rows( UINT32 col, UINT32 row, UINT32 num_cols, UINT32 num_rows )
 {
 	/* logical (col,row) -> memory offset */
@@ -195,6 +170,14 @@ static UINT32 yard_tilemap_scan_rows( UINT32 col, UINT32 row, UINT32 num_cols, U
 		return row*32 + col;
 }
 
+
+
+/*************************************
+ *
+ *  Video startup
+ *
+ *************************************/
+
 VIDEO_START( yard )
 {
 	bg_tilemap = tilemap_create(yard_get_bg_tile_info, yard_tilemap_scan_rows, TILEMAP_TYPE_PEN, 8, 8, 64, 32);
@@ -204,7 +187,15 @@ VIDEO_START( yard )
 	scroll_panel_bitmap = auto_bitmap_alloc(SCROLL_PANEL_WIDTH, machine->screen[0].height, machine->screen[0].format);
 }
 
-#define DRAW_SPRITE(code, sy) drawgfx(bitmap, machine->gfx[1], code, color, flipx, flipy, sx, sy, cliprect, TRANSPARENCY_PENS, colortable_get_transpen_mask(machine->colortable, machine->gfx[1], color, 256));
+
+
+/*************************************
+ *
+ *  Sprite rendering
+ *
+ *************************************/
+
+#define DRAW_SPRITE(code, sy) drawgfx(bitmap, machine->gfx[1], code, color, flipx, flipy, sx, sy, cliprect, TRANSPARENCY_PENS, colortable_get_transpen_mask(machine->colortable, machine->gfx[1], color, 512));
 
 static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect )
 {
@@ -251,6 +242,14 @@ static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const re
 	}
 }
 
+
+
+/*************************************
+ *
+ *  Radar panel rendering
+ *
+ *************************************/
+
 static void draw_panel( running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect )
 {
 	if (! *yard_score_panel_disabled)
@@ -277,6 +276,14 @@ static void draw_panel( running_machine *machine, mame_bitmap *bitmap, const rec
 	}
 }
 
+
+
+/*************************************
+ *
+ *  Video update
+ *
+ *************************************/
+
 VIDEO_UPDATE( yard )
 {
 	tilemap_set_scrollx(bg_tilemap, 0, (*yard_scroll_x_high * 0x100) + *yard_scroll_x_low);