(MESS) sms.c: Misc fixes: [Enik Land]

- Disable gamegear sio register when in ggsms mode.
- Fixed tilemap mirroring on sms1 vdp needed for Japanese version of Ys.
- Fixed BIOS support in the gamegear driver.
- Fixed collisions when column #0 is disabled.

src/emu/video/315_5124.c

@@ -748,65 +748,31 @@ WRITE8_MEMBER( sega315_5124_device::register_write )
 }
 
 
-UINT16 sega315_5124_device::get_name_table_address()
+UINT16 sega315_5124_device::get_name_table_row(int row)
 {
-	UINT16 result;
-
-	if ( m_y_pixels != 192 )
-	{
-		result = ((m_reg[0x02] & 0x0c) << 10) | 0x0700;
-	}
-	else
-	{
-		result = (m_reg[0x02] << 10) & 0x3800;
-	}
-
-	return result & (((m_reg[0x02] & 0x01) << 10) | 0x3bff);
+	return ((row >> 3) << 6) & (((m_reg[0x02] & 0x01) << 10) | 0x3bff);
 }
 
 
-UINT16 sega315_5246_device::get_name_table_address()
+UINT16 sega315_5246_device::get_name_table_row(int row)
 {
-	UINT16 result;
-
-	if ( m_y_pixels != 192 )
-	{
-		result = ((m_reg[0x02] & 0x0c) << 10) | 0x0700;
-	}
-	else
-	{
-		result = (m_reg[0x02] << 10) & 0x3800;
-	}
-
-	return result;
+	return (row >> 3) << 6;
 }
 
 
-UINT16 sega315_5378_device::get_name_table_address()
+UINT16 sega315_5378_device::get_name_table_row(int row)
 {
-	UINT16 result;
-
-	if ( m_y_pixels != 192 )
-	{
-		result = ((m_reg[0x02] & 0x0c) << 10) | 0x0700;
-	}
-	else
-	{
-		result = (m_reg[0x02] << 10) & 0x3800;
-	}
-
-	return result;
+	return (row >> 3) << 6;
 }
 
 
 void sega315_5124_device::draw_scanline_mode4( int *line_buffer, int *priority_selected, int line )
 {
 	int tile_column;
-	int y_scroll;
+	int y_scroll, scroll_mod;
 	int pixel_x, pixel_plot_x;
 	int bit_plane_0, bit_plane_1, bit_plane_2, bit_plane_3;
-	const int scroll_mod = ( m_y_pixels != 192 ) ? 256 : 224;
-	const UINT16 name_table_address = get_name_table_address();
+	UINT16 name_table_address;
 
 	/* if top 2 rows of screen not affected by horizontal scrolling, then x_scroll = 0 */
 	/* else x_scroll = m_reg8copy                                                      */
@@ -814,6 +780,17 @@ void sega315_5124_device::draw_scanline_mode4( int *line_buffer, int *priority_s
 
 	const int x_scroll_start_column = (x_scroll >> 3);             /* x starting column tile */
 
+	if ( m_y_pixels != 192 )
+	{
+		name_table_address = ((m_reg[0x02] & 0x0c) << 10) | 0x0700;
+		scroll_mod = 256;
+	}
+	else
+	{
+		name_table_address = (m_reg[0x02] << 10) & 0x3800;
+		scroll_mod = 224;
+	}
+
 	/* Draw background layer */
 	for (tile_column = 0; tile_column < 33; tile_column++)
 	{
@@ -825,8 +802,8 @@ void sega315_5124_device::draw_scanline_mode4( int *line_buffer, int *priority_s
 		/* vertical scrolling when bit 7 of reg[0x00] is set */
 		y_scroll = ((m_reg[0x00] & 0x80) && (tile_column > 23)) ? 0 : m_reg9copy;
 
-		tile_line = ((tile_column + x_scroll_start_column) & 0x1f) * 2;
-		tile_data = space().read_word(name_table_address + ((((line + y_scroll) % scroll_mod) >> 3) << 6) + tile_line);
+		tile_line = ((tile_column + x_scroll_start_column) & 0x1f) << 1;
+		tile_data = space().read_word(name_table_address + get_name_table_row((line + y_scroll) % scroll_mod) + tile_line);
 
 		tile_selected = (tile_data & 0x01ff);
 		priority_select = tile_data & PRIORITY_BIT;
@@ -891,7 +868,7 @@ void sega315_5124_device::select_sprites( int line )
 	/* Check if MAG is set */
 	m_sprite_zoom = (m_reg[0x01] & 0x01) ? 2 : 1;
 
-	if (m_sprite_zoom == 2)
+	if (m_sprite_zoom > 1)
 	{
 		/* Divide before use the value for comparison, same later with sprite_y, or
 		   else an off-by-one bug could occur, as seen with Tarzan, for Game Gear */
@@ -1041,10 +1018,15 @@ void sega315_5124_device::draw_sprites_mode4( int *line_buffer, int *priority_se
 	bool sprite_col_occurred = false;
 	int sprite_col_x = SEGA315_5124_WIDTH;
 	UINT8 collision_buffer[SEGA315_5124_WIDTH];
+	int plot_min_x = 0;
 
 	if (m_display_disabled || m_sprite_count == 0)
 		return;
 
+	/* Sprites aren't drawn and collisions don't occur on column 0 if it is disabled */
+	if (m_reg[0x00] & 0x20)
+		plot_min_x = 8;
+
 	memset(collision_buffer, 0, SEGA315_5124_WIDTH);
 
 	/* Draw sprite layer */
@@ -1078,7 +1060,7 @@ void sega315_5124_device::draw_sprites_mode4( int *line_buffer, int *priority_se
 				int pixel_plot_x = sprite_x + (pixel_x << 1);
 
 				/* check to prevent going outside of active display area */
-				if (pixel_plot_x < 0 || pixel_plot_x > 255)
+				if (pixel_plot_x < plot_min_x || pixel_plot_x > 255)
 				{
 					continue;
 				}
@@ -1127,7 +1109,7 @@ void sega315_5124_device::draw_sprites_mode4( int *line_buffer, int *priority_se
 				int pixel_plot_x = sprite_x + pixel_x;
 
 				/* check to prevent going outside of active display area */
-				if (pixel_plot_x < 0 || pixel_plot_x > 255)
+				if (pixel_plot_x < plot_min_x || pixel_plot_x > 255)
 				{
 					continue;
 				}
@@ -1256,7 +1238,7 @@ void sega315_5124_device::draw_sprites_tms9918_mode( int *line_buffer, int line
 		{
 			sprite_tile_selected += 2;
 			pattern = space().read_byte( sprite_pattern_line + sprite_tile_selected * 8 );
-			sprite_x += (m_sprite_zoom == 2 ? 16 : 8);
+			sprite_x += (m_sprite_zoom > 1 ? 16 : 8);
 
 			for (int pixel_x = 0; pixel_x < 8; pixel_x++)
 			{

src/emu/video/315_5124.h

@@ -88,13 +88,13 @@ public:
 
 protected:
 	static const int X_SCROLL_HPOS_5124 = 21;
-	static const int X_SCROLL_HPOS_5378 = 35;  // Not verified
+	static const int X_SCROLL_HPOS_5378 = 41;  // Not verified, needed for Chicago Syndicate
 
 	void set_display_settings();
 	virtual void update_palette();
 	virtual void cram_write(UINT8 data);
 	virtual void draw_scanline( int pixel_offset_x, int pixel_plot_y, int line );
-	virtual UINT16 get_name_table_address();
+	virtual UINT16 get_name_table_row(int row);
 	void process_line_timer();
 	void draw_scanline_mode4( int *line_buffer, int *priority_selected, int line );
 	void draw_sprites_mode4( int *line_buffer, int *priority_selected, int line );
@@ -190,7 +190,7 @@ public:
 	sega315_5246_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
 
 protected:
-	virtual UINT16 get_name_table_address();
+	virtual UINT16 get_name_table_row(int row);
 };
 
 
@@ -210,7 +210,7 @@ protected:
 	virtual void update_palette();
 	virtual void cram_write(UINT8 data);
 	virtual void draw_scanline( int pixel_offset_x, int pixel_plot_y, int line );
-	virtual UINT16 get_name_table_address();
+	virtual UINT16 get_name_table_row(int row);
 };
 
 

src/mess/drivers/sms.c

@@ -16,7 +16,6 @@
  - Gear to Gear Port SMS Controller Adaptor
  - Sega Demo Unit II (kiosk expansion device)
  - SMS Disk System (floppy disk drive expansion device) - unreleased
- - Sega Graphic Board (black version) - unreleased
  - Rapid button of Japanese Master System
  - Keyboard support for Sega Mark III (sg1000m3 driver)
  - Link between two Mark III's through keyboard, supported by F-16 Fighting Falcon

src/mess/machine/sms.c

@@ -495,7 +495,21 @@ WRITE8_MEMBER(sms_state::sms_mapper_w)
 
 UINT8 sms_state::read_bus(address_space &space, unsigned int page, UINT16 base_addr, UINT16 offset)
 {
-	if (m_mem_device_enabled != ENABLE_NONE)
+	if (m_is_gamegear)
+	{
+		// Game Gear BIOS behavior, according to Charles MacDonald: "it uses the first
+		// 1K. The rest of the space is mapped to the cartridge, regardless of the slot
+		// that's selected. This allows the BIOS to check for the 'TMR SEGA' string at
+		// 1FF0/3FF0/7FF0, but it can't do a checksum since the first 1K of ROM is
+		// unavailable. Anyway, once the BIOS decides to run the game, it disables
+		// itself, and the first 1K is assigned to the cartridge ROM like normal."
+
+		if ((m_mem_device_enabled & ENABLE_BIOS) && page == 3)
+			return m_BIOS[(m_bios_page[page] * 0x4000) + (offset & 0x3fff)];
+		if (m_mem_device_enabled & ENABLE_CART)
+			return m_cartslot->read_cart(space, base_addr + offset);
+	}
+	else if (m_mem_device_enabled != ENABLE_NONE)
 	{
 		UINT8 data = 0xff;
 
@@ -514,10 +528,7 @@ UINT8 sms_state::read_bus(address_space &space, unsigned int page, UINT16 base_a
 
 		return data;
 	}
-	else
-	{
 	return m_region_maincpu->base()[offset];
-	}
 }
 
 
@@ -583,6 +594,9 @@ WRITE8_MEMBER(sms_state::sms_mem_control_w)
 
 WRITE8_MEMBER(sms_state::gg_sio_w)
 {
+	if (m_cartslot->exists() && m_cartslot->m_cart->get_sms_mode())
+		return;
+
 	logerror("*** write %02X to SIO register #%d\n", data, offset);
 
 	m_gg_sio[offset & 0x07] = data;
@@ -608,6 +622,9 @@ WRITE8_MEMBER(sms_state::gg_sio_w)
 
 READ8_MEMBER(sms_state::gg_sio_r)
 {
+	if (m_cartslot->exists() && m_cartslot->m_cart->get_sms_mode())
+		return 0xff;
+
 	logerror("*** read SIO register #%d\n", offset);
 
 	switch (offset & 7)
@@ -667,7 +684,7 @@ void sms_state::setup_enabled_slots()
 		logerror("Card ROM port enabled.\n");
 	}
 
-	if (!(m_mem_ctrl_reg & IO_CARTRIDGE) && m_cartslot && m_cartslot->exists())
+	if ((m_is_gamegear || !(m_mem_ctrl_reg & IO_CARTRIDGE)) && m_cartslot && m_cartslot->exists())
 	{
 		m_mem_device_enabled |= ENABLE_CART;
 		logerror("Cartridge ROM/RAM enabled.\n");