(MESS) sms/gamegear: misc improvements [Enik Land]

- Renamed the gear2gear port to EXT port, after reading the references
  in the official GG documents
- Invert Y1 pin signal bits: now high is 1 and low is 0;
- More complete Y1 behavior: goes low only for transparent pixels;
- Fix color of column 0 when it doesn't completely entered in the active display;
- Improve behavior of sprite overflow, to not be flagged when VINT is active.

out of whatsnew: the new Y1 pin behavior of the SMS VDP is based on Charles' findings and TMS9918 manual.

src/emu/bus/bus.mak

@@ -1291,12 +1291,12 @@ endif
 
 #-------------------------------------------------
 #
-#@src/emu/bus/gamegear/gear2gear.h,BUSES += GAMEGEAR
+#@src/emu/bus/gamegear/ggext.h,BUSES += GAMEGEAR
 #-------------------------------------------------
 
 ifneq ($(filter GAMEGEAR,$(BUSES)),)
 OBJDIRS += $(BUSOBJ)/gamegear
-BUSOBJS += $(BUSOBJ)/gamegear/gear2gear.o
+BUSOBJS += $(BUSOBJ)/gamegear/ggext.o
 BUSOBJS += $(BUSOBJ)/gamegear/smsctrladp.o
 endif
 

src/emu/bus/gamegear/ggext.c

@@ -1,13 +1,13 @@
 /**********************************************************************
 
-    Sega Game Gear "Gear to Gear Port" emulation
+    Sega Game Gear EXT port emulation
 
     Copyright MESS Team.
     Visit http://mamedev.org for licensing and usage restrictions.
 
 **********************************************************************/
 
-#include "gear2gear.h"
+#include "ggext.h"
 // slot devices
 #include "smsctrladp.h"
 
@@ -17,7 +17,7 @@
 //  GLOBAL VARIABLES
 //**************************************************************************
 
-const device_type GG_GEAR2GEAR_PORT = &device_creator<gg_gear2gear_port_device>;
+const device_type GG_EXT_PORT = &device_creator<gg_ext_port_device>;
 
 
 
@@ -26,21 +26,21 @@ const device_type GG_GEAR2GEAR_PORT = &device_creator<gg_gear2gear_port_device>;
 //**************************************************************************
 
 //-------------------------------------------------
-//  device_gg_gear2gear_port_interface - constructor
+//  device_gg_ext_port_interface - constructor
 //-------------------------------------------------
 
-device_gg_gear2gear_port_interface::device_gg_gear2gear_port_interface(const machine_config &mconfig, device_t &device)
+device_gg_ext_port_interface::device_gg_ext_port_interface(const machine_config &mconfig, device_t &device)
 	: device_slot_card_interface(mconfig,device)
 {
-	m_port = dynamic_cast<gg_gear2gear_port_device *>(device.owner());
+	m_port = dynamic_cast<gg_ext_port_device *>(device.owner());
 }
 
 
 //-------------------------------------------------
-//  ~device_gg_gear2gear_port_interface - destructor
+//  ~device_gg_ext_port_interface - destructor
 //-------------------------------------------------
 
-device_gg_gear2gear_port_interface::~device_gg_gear2gear_port_interface()
+device_gg_ext_port_interface::~device_gg_ext_port_interface()
 {
 }
 
@@ -51,11 +51,11 @@ device_gg_gear2gear_port_interface::~device_gg_gear2gear_port_interface()
 //**************************************************************************
 
 //-------------------------------------------------
-//  gg_gear2gear_port_device - constructor
+//  gg_ext_port_device - constructor
 //-------------------------------------------------
 
-gg_gear2gear_port_device::gg_gear2gear_port_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
+gg_ext_port_device::gg_ext_port_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
-						device_t(mconfig, GG_GEAR2GEAR_PORT, "Gear to Gear Port", tag, owner, clock, "gg_gear2gear_port", __FILE__),
+						device_t(mconfig, GG_EXT_PORT, "EXT Port", tag, owner, clock, "gg_ext_port", __FILE__),
 						device_slot_interface(mconfig, *this),
 						m_th_pin_handler(*this),
 						m_pixel_handler(*this)
@@ -64,10 +64,10 @@ gg_gear2gear_port_device::gg_gear2gear_port_device(const machine_config &mconfig
 
 
 //-------------------------------------------------
-//  gg_gear2gear_port_device - destructor
+//  gg_ext_port_device - destructor
 //-------------------------------------------------
 
-gg_gear2gear_port_device::~gg_gear2gear_port_device()
+gg_ext_port_device::~gg_ext_port_device()
 {
 }
 
@@ -76,16 +76,16 @@ gg_gear2gear_port_device::~gg_gear2gear_port_device()
 //  device_start - device-specific startup
 //-------------------------------------------------
 
-void gg_gear2gear_port_device::device_start()
+void gg_ext_port_device::device_start()
 {
-	m_device = dynamic_cast<device_gg_gear2gear_port_interface *>(get_card_device());
+	m_device = dynamic_cast<device_gg_ext_port_interface *>(get_card_device());
 
 	m_th_pin_handler.resolve_safe();
 	m_pixel_handler.resolve_safe(0);
 }
 
 
-UINT8 gg_gear2gear_port_device::port_r()
+UINT8 gg_ext_port_device::port_r()
 {
 	UINT8 data = 0xff;
 	if (m_device)
@@ -93,28 +93,28 @@ UINT8 gg_gear2gear_port_device::port_r()
 	return data;
 }
 
-void gg_gear2gear_port_device::port_w( UINT8 data )
+void gg_ext_port_device::port_w( UINT8 data )
 {
 	if (m_device)
 		m_device->peripheral_w(data);
 }
 
 
-void gg_gear2gear_port_device::th_pin_w(int state)
+void gg_ext_port_device::th_pin_w(int state)
 {
 	m_th_pin_handler(state);
 }
 
-UINT32 gg_gear2gear_port_device::pixel_r()
+UINT32 gg_ext_port_device::pixel_r()
 {
 	return m_pixel_handler();
 }
 
 
 //-------------------------------------------------
-//  SLOT_INTERFACE( gg_gear2gear_port_devices )
+//  SLOT_INTERFACE( gg_ext_port_devices )
 //-------------------------------------------------
 
-SLOT_INTERFACE_START( gg_gear2gear_port_devices )
+SLOT_INTERFACE_START( gg_ext_port_devices )
 	SLOT_INTERFACE("smsctrladp", SMS_CTRL_ADAPTOR)
 SLOT_INTERFACE_END

src/emu/bus/gamegear/ggext.h

@@ -1,6 +1,6 @@
 /**********************************************************************
 
-    Sega Game Gear "Gear to Gear Port" emulation
+    Sega Game Gear EXT port emulation
 
     Copyright MESS Team.
     Visit http://mamedev.org for licensing and usage restrictions.
@@ -12,8 +12,8 @@
 
 #pragma once
 
-#ifndef __GG_GEAR2GEAR_PORT__
+#ifndef __GG_EXT_PORT__
-#define __GG_GEAR2GEAR_PORT__
+#define __GG_EXT_PORT__
 
 #include "emu.h"
 
@@ -23,19 +23,19 @@
 //  INTERFACE CONFIGURATION MACROS
 //**************************************************************************
 
-#define MCFG_GG_GEAR2GEAR_PORT_ADD(_tag, _slot_intf, _def_slot) \
+#define MCFG_GG_EXT_PORT_ADD(_tag, _slot_intf, _def_slot) \
-	MCFG_DEVICE_ADD(_tag, GG_GEAR2GEAR_PORT, 0) \
+	MCFG_DEVICE_ADD(_tag, GG_EXT_PORT, 0) \
 	MCFG_DEVICE_SLOT_INTERFACE(_slot_intf, _def_slot, false)
-#define MCFG_GG_GEAR2GEAR_PORT_MODIFY(_tag) \
+#define MCFG_GG_EXT_PORT_MODIFY(_tag) \
 	MCFG_DEVICE_MODIFY(_tag)
 
 
-#define MCFG_GG_GEAR2GEAR_PORT_TH_INPUT_HANDLER(_devcb) \
+#define MCFG_GG_EXT_PORT_TH_INPUT_HANDLER(_devcb) \
-	devcb = &gg_gear2gear_port_device::set_th_input_handler(*device, DEVCB_##_devcb);
+	devcb = &gg_ext_port_device::set_th_input_handler(*device, DEVCB_##_devcb);
 
 
-#define MCFG_GG_GEAR2GEAR_PORT_PIXEL_HANDLER(_devcb) \
+#define MCFG_GG_EXT_PORT_PIXEL_HANDLER(_devcb) \
-	devcb = &gg_gear2gear_port_device::set_pixel_handler(*device, DEVCB_##_devcb);
+	devcb = &gg_ext_port_device::set_pixel_handler(*device, DEVCB_##_devcb);
 
 
 
@@ -43,27 +43,26 @@
 //  TYPE DEFINITIONS
 //**************************************************************************
 
-// ======================> gg_gear2gear_port_device
+// ======================> gg_ext_port_device
 
-class device_gg_gear2gear_port_interface;
+class device_gg_ext_port_interface;
 
-class gg_gear2gear_port_device : public device_t,
+class gg_ext_port_device : public device_t,
 								public device_slot_interface
 {
 public:
 	// construction/destruction
-	gg_gear2gear_port_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
+	gg_ext_port_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock);
-	virtual ~gg_gear2gear_port_device();
+	virtual ~gg_ext_port_device();
 
 	// static configuration helpers
-	template<class _Object> static devcb_base &set_th_input_handler(device_t &device, _Object object) { return downcast<gg_gear2gear_port_device &>(device).m_th_pin_handler.set_callback(object); }
+	template<class _Object> static devcb_base &set_th_input_handler(device_t &device, _Object object) { return downcast<gg_ext_port_device &>(device).m_th_pin_handler.set_callback(object); }
 
-	template<class _Object> static devcb_base &set_pixel_handler(device_t &device, _Object object) { return downcast<gg_gear2gear_port_device &>(device).m_pixel_handler.set_callback(object); }
+	template<class _Object> static devcb_base &set_pixel_handler(device_t &device, _Object object) { return downcast<gg_ext_port_device &>(device).m_pixel_handler.set_callback(object); }
 
 	// Currently, only the support for SMS Controller Adaptor is emulated,
-	// for when SMS Compatibility mode is enabled. In that mode, the 10
+	// for when SMS Compatibility mode is enabled. In that mode, the 10 pins
-	// pins of the Gear to Gear Port follows the same numbering of a SMS
+	// of the EXT port follows the same numbering of a SMS Control port.
-	// Control port.
 
 	// Data returned by the port_r methods:
 	// bit 0 - pin 1 - Up
@@ -87,7 +86,7 @@ public:
 	// device-level overrides
 	virtual void device_start();
 
-	device_gg_gear2gear_port_interface *m_device;
+	device_gg_ext_port_interface *m_device;
 
 private:
 	devcb_write_line m_th_pin_handler;
@@ -95,29 +94,29 @@ private:
 };
 
 
-// ======================> device_gg_gear2gear_port_interface
+// ======================> device_gg_ext_port_interface
 
 // class representing interface-specific live sms_expansion card
-class device_gg_gear2gear_port_interface : public device_slot_card_interface
+class device_gg_ext_port_interface : public device_slot_card_interface
 {
 public:
 	// construction/destruction
-	device_gg_gear2gear_port_interface(const machine_config &mconfig, device_t &device);
+	device_gg_ext_port_interface(const machine_config &mconfig, device_t &device);
-	virtual ~device_gg_gear2gear_port_interface();
+	virtual ~device_gg_ext_port_interface();
 
 	virtual UINT8 peripheral_r() { return 0xff; };
 	virtual void peripheral_w(UINT8 data) { };
 
 protected:
-	gg_gear2gear_port_device *m_port;
+	gg_ext_port_device *m_port;
 };
 
 
 // device type definition
-extern const device_type GG_GEAR2GEAR_PORT;
+extern const device_type GG_EXT_PORT;
 
 
-SLOT_INTERFACE_EXTERN( gg_gear2gear_port_devices );
+SLOT_INTERFACE_EXTERN( gg_ext_port_devices );
 
 
 #endif

src/emu/bus/gamegear/smsctrladp.c

@@ -1,6 +1,6 @@
 /**********************************************************************
 
-    Sega Game Gear "Gear to Gear Port SMS Controller Adaptor" emulation
+    Sega Game Gear "SMS Controller Adaptor" emulation
     Also known as "Master Link" cable.
 
     Copyright MESS Team.
@@ -29,7 +29,7 @@ const device_type SMS_CTRL_ADAPTOR = &device_creator<sms_ctrl_adaptor_device>;
 
 sms_ctrl_adaptor_device::sms_ctrl_adaptor_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
 	device_t(mconfig, SMS_CTRL_ADAPTOR, "SMS Controller Adaptor", tag, owner, clock, "sms_ctrl_adaptor", __FILE__),
-	device_gg_gear2gear_port_interface(mconfig, *this),
+	device_gg_ext_port_interface(mconfig, *this),
 	m_subctrl_port(*this, "ctrl")
 {
 }

src/emu/bus/gamegear/smsctrladp.h

@@ -1,6 +1,6 @@
 /**********************************************************************
 
-    Sega Game Gear "Gear to Gear Port SMS Controller Adaptor" emulation
+    Sega Game Gear "SMS Controller Adaptor" emulation
     Also known as "Master Link" cable.
 
     Copyright MESS Team.
@@ -15,7 +15,7 @@
 
 
 #include "emu.h"
-#include "gear2gear.h"
+#include "ggext.h"
 #include "../sms_ctrl/smsctrl.h"
 
 
@@ -27,7 +27,7 @@
 // ======================> sms_ctrl_adaptor_device
 
 class sms_ctrl_adaptor_device : public device_t,
-							public device_gg_gear2gear_port_interface
+							public device_gg_ext_port_interface
 {
 public:
 	// construction/destruction
@@ -41,7 +41,7 @@ protected:
 	virtual void device_start();
 	virtual machine_config_constructor device_mconfig_additions() const;
 
-	// device_gg_gear2gear_port_interface overrides
+	// device_gg_ext_port_interface overrides
 	virtual UINT8 peripheral_r();
 	virtual void peripheral_w(UINT8 data);
 

src/emu/video/315_5124.c

@@ -14,6 +14,7 @@ To do:
   - Display mode 1 (text)
   - Display mode 3 (multicolor)
   - Sprite doubling bug of the 315-5124 chip
+  - Verify timing on the Game Gear (315-5378 chip)
 
 
 SMS Display Timing
@@ -343,7 +344,7 @@ void sega315_5124_device::device_timer(emu_timer &timer, device_timer_id id, int
 			rec.min_x = SEGA315_5124_LBORDER_START;
 			rec.max_x = SEGA315_5124_LBORDER_START + SEGA315_5124_LBORDER_WIDTH - 1;
 			m_tmpbitmap.fill(m_palette->pen(m_current_palette[BACKDROP_COLOR]), rec);
-			m_y1_bitmap.fill(1, rec);
+			m_y1_bitmap.fill(( m_reg[0x07] & 0x0f ) ? 1 : 0, rec);
 		}
 		break;
 
@@ -358,7 +359,7 @@ void sega315_5124_device::device_timer(emu_timer &timer, device_timer_id id, int
 			rec.min_x = SEGA315_5124_LBORDER_START + SEGA315_5124_LBORDER_WIDTH + 256;
 			rec.max_x = rec.min_x + SEGA315_5124_RBORDER_WIDTH - 1;
 			m_tmpbitmap.fill(m_palette->pen(m_current_palette[BACKDROP_COLOR]), rec);
-			m_y1_bitmap.fill(1, rec);
+			m_y1_bitmap.fill(( m_reg[0x07] & 0x0f ) ? 1 : 0, rec);
 		}
 		break;
 
@@ -847,18 +848,19 @@ void sega315_5124_device::draw_scanline_mode4( int *line_buffer, int *priority_s
 				//logerror("%x %x\n", pixel_plot_x, line);
 				if (tile_column == 0 && (x_scroll & 0x07))
 				{
-					/* the VDP only draws the first column when it has completely entered
+					/* when the first column hasn't completely entered in the screen, its
-					   in the screen, else it is filled with the sprite pattern #0 */
+					   background is filled only with color #0 of the selected palette */
-					line_buffer[pixel_plot_x] = m_current_palette[0x10];
+					line_buffer[pixel_plot_x] = m_current_palette[palette_selected ? 0x10 : 0x00];
+					priority_selected[pixel_plot_x] = priority_select;
 				}
 				else
 				{
 					line_buffer[pixel_plot_x] = m_current_palette[pen_selected];
-				}
 					priority_selected[pixel_plot_x] = priority_select | (pen_selected & 0x0f);
 				}
 			}
 		}
+	}
 }
 
 
@@ -1012,7 +1014,8 @@ void sega315_5124_device::select_sprites( int line )
 
 		m_sprite_count = max_sprites;
 
-		if (line >= 0 && line < m_frame_timing[ACTIVE_DISPLAY_V])
+		/* Overflow is flagged only on active display and when VINT isn't active */
+		if (!(m_status & STATUS_VINT) && line >= 0 && line < m_frame_timing[ACTIVE_DISPLAY_V])
 		{
 			m_pending_status |= STATUS_SPROVR;
 		}
@@ -1030,7 +1033,8 @@ void sega315_5124_device::draw_sprites_mode4( int *line_buffer, int *priority_se
 	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 */
+	/* Sprites aren't drawn and collisions don't occur on column 0 if it is disabled.
+	   Note: On Megadrive/Genesis VDP, collisions occur on the disabled column 0. */
 	if (m_reg[0x00] & 0x20)
 		plot_min_x = 8;
 
@@ -1084,6 +1088,8 @@ void sega315_5124_device::draw_sprites_mode4( int *line_buffer, int *priority_se
 					continue;
 				}
 
+				/* Draw sprite pixel */
+				/* Check if the background has lower priority */
 				if (!(priority_selected[pixel_plot_x] & PRIORITY_BIT))
 				{
 					line_buffer[pixel_plot_x] = m_current_palette[pen_selected];
@@ -1296,10 +1302,11 @@ void sega315_5124_device::draw_scanline( int pixel_offset_x, int pixel_plot_y, i
 
 	if ( line < m_frame_timing[ACTIVE_DISPLAY_V] )
 	{
+		memset(priority_selected, 1, sizeof(priority_selected));
+
 		switch( m_vdp_mode )
 		{
 		case 0:
-			memset(priority_selected, 1, sizeof(priority_selected));
 			if ( line >= 0 )
 			{
 				draw_scanline_mode0( blitline_buffer, line );
@@ -1311,7 +1318,6 @@ void sega315_5124_device::draw_scanline( int pixel_offset_x, int pixel_plot_y, i
 			break;
 
 		case 2:
-			memset(priority_selected, 1, sizeof(priority_selected));
 			if ( line >= 0 )
 			{
 				draw_scanline_mode2( blitline_buffer, line );
@@ -1324,7 +1330,6 @@ void sega315_5124_device::draw_scanline( int pixel_offset_x, int pixel_plot_y, i
 
 		case 4:
 		default:
-			memset(priority_selected, 0, sizeof(priority_selected));
 			if ( line >= 0 )
 			{
 				draw_scanline_mode4( blitline_buffer, priority_selected, line );
@@ -1346,7 +1351,7 @@ void sega315_5124_device::draw_scanline( int pixel_offset_x, int pixel_plot_y, i
 		rec.min_x = pixel_offset_x;
 		rec.max_x = pixel_offset_x + 255;
 		m_tmpbitmap.fill(m_palette->pen(m_current_palette[BACKDROP_COLOR]), rec);
-		m_y1_bitmap.fill(1, rec);
+		m_y1_bitmap.fill(( m_reg[0x07] & 0x0f ) ? 1 : 0, rec);
 	}
 	else
 	{
@@ -1361,13 +1366,13 @@ void sega315_5124_device::blit_scanline( int *line_buffer, int *priority_selecte
 	UINT8  *p_y1 = &m_y1_bitmap.pix8(pixel_plot_y + line, pixel_offset_x);
 	int x = 0;
 
-	if (m_vdp_mode == 4 && m_reg[0x00] & 0x20)
+	if (m_vdp_mode == 4 && (m_reg[0x00] & 0x20))
 	{
 		/* Fill column 0 with overscan color from m_reg[0x07] */
 		do
 		{
 			p_bitmap[x] = m_palette->pen(m_current_palette[BACKDROP_COLOR]);
-			p_y1[x] = 1;
+			p_y1[x] = ( m_reg[0x07] & 0x0f ) ? 1 : 0;
 		}
 		while(++x < 8);
 	}
@@ -1375,7 +1380,7 @@ void sega315_5124_device::blit_scanline( int *line_buffer, int *priority_selecte
 	do
 	{
 		p_bitmap[x] = m_palette->pen(line_buffer[x]);
-		p_y1[x] = ( priority_selected[x] & 0x0f ) ? 0 : 1;
+		p_y1[x] = ( priority_selected[x] & 0x0f ) ? 1 : 0;
 	}
 	while(++x < 256);
 }
@@ -1397,7 +1402,7 @@ void sega315_5378_device::blit_scanline( int *line_buffer, int *priority_selecte
 		do
 		{
 			p_bitmap[x] = m_palette->pen(m_current_palette[BACKDROP_COLOR]);
-			p_y1[x] = 1; // not verified
+			p_y1[x] = ( m_reg[0x07] & 0x0f ) ? 1 : 0;
 		}
 		while (++x < 48);
 
@@ -1406,7 +1411,7 @@ void sega315_5378_device::blit_scanline( int *line_buffer, int *priority_selecte
 			do
 			{
 				p_bitmap[x] = m_palette->pen(line_buffer[x]);
-				p_y1[x] = ( priority_selected[x] & 0x0f ) ? 0 : 1;
+				p_y1[x] = ( priority_selected[x] & 0x0f ) ? 1 : 0;
 			}
 			while (++x < 208);
 		}
@@ -1416,7 +1421,7 @@ void sega315_5378_device::blit_scanline( int *line_buffer, int *priority_selecte
 			do
 			{
 				p_bitmap[x] = m_palette->pen(m_current_palette[BACKDROP_COLOR]);
-				p_y1[x] = 1; // not verified
+				p_y1[x] = ( m_reg[0x07] & 0x0f ) ? 1 : 0;
 			}
 			while (++x < 208);
 		}
@@ -1425,7 +1430,7 @@ void sega315_5378_device::blit_scanline( int *line_buffer, int *priority_selecte
 		do
 		{
 			p_bitmap[x] = m_palette->pen(m_current_palette[BACKDROP_COLOR]);
-			p_y1[x] = 1; // not verified
+			p_y1[x] = ( m_reg[0x07] & 0x0f ) ? 1 : 0;
 		}
 		while (++x < 256);
 	}

src/mame/drivers/segae.c

@@ -956,8 +956,8 @@ UINT32 systeme_state::screen_update_systeme(screen_device &screen, bitmap_rgb32
 
 		for ( int x = cliprect.min_x; x <= cliprect.max_x; x++ )
 		{
-			dest_ptr[x] = ( y1_ptr[x] ) ? vdp1_ptr[x] : vdp2_ptr[x];
+			dest_ptr[x] = ( y1_ptr[x] ) ? vdp2_ptr[x] : vdp1_ptr[x];
-//dest_ptr[x] = y1_ptr[x] ? 0xFF0000 : 0x00FF00;
+			//dest_ptr[x] = y1_ptr[x] ? 0x00FF00 : 0xFF0000;
 		}
 	}
 

src/mess/drivers/sms.c

@@ -14,6 +14,7 @@
 
  - SIO interface for Game Gear (needs netplay, I guess)
  - Sega Demo Unit II (kiosk expansion device)
+ - SMS 8 slot game changer (kiosk expansion device)
  - SMS Disk System (floppy disk drive expansion device) - unreleased
  - Rapid button of Japanese Master System
  - Keyboard support for Sega Mark III (sg1000m3 driver)
@@ -57,15 +58,15 @@ General compatibility issues on real hardware (not emulation bugs):
 - Few games of the ones with FM support need to detect the system region as
   Japanese to play FM sound;
 - The Light Phaser gun doesn't work with the Japanese SMS;
-- There are reports about Light Phaser working on the second Korean console
+- There are reports about Light Phaser working on the second Korean SMS
   version, and a Korean advert shows support on the first version (Gam*Boy I,
   although based on Japanese SMS);
 - The Korean SMS versions have Japanese-format cartridge slot, but only on the
   first (Gam*Boy I) the region is detected as Japanese;
 - Some SMS ROMs don't run when are plugged-in to SMS expansion slot, through
   the gender adapter;
-- Some SMS ROMs don't run when are plugged-in to a Game Gear, through the
+- Some SMS ROMs don't run or have issues when are plugged-in to a Game Gear,
-  Master Gear adapter;
+  through the Master Gear adapter;
 
 --------------------------------------------------------------------------------
 
@@ -405,6 +406,13 @@ static INPUT_PORTS_START( smsj )
 INPUT_PORTS_END
 
 static INPUT_PORTS_START( smssdisp )
+	// For each peripheral port (for controllers or 3-D glasses), there are sets
+	// of two connectors wired in parallel on the real hardware. This allows to
+	// have different controllers, like a pad and a Light Phaser, plugged together
+	// for a player input, what avoids having to re-plug them every time a game is
+	// changed to another that requires a different controller. Also, this allows
+	// 3-D games to be properly watched by two persons at same time.
+	// For now the driver just uses single input ports.
 	PORT_INCLUDE( sms1 )
 
 	PORT_START("DSW")
@@ -805,9 +813,9 @@ static MACHINE_CONFIG_START( gamegear, sms_state )
 
 	MCFG_SOFTWARE_LIST_ADD("cart_list", "gamegear")
 
-	MCFG_GG_GEAR2GEAR_PORT_ADD("gear2gear", gg_gear2gear_port_devices, NULL)
+	MCFG_GG_EXT_PORT_ADD("ext", gg_ext_port_devices, NULL)
-	MCFG_GG_GEAR2GEAR_PORT_TH_INPUT_HANDLER(WRITELINE(sms_state, sms_ctrl2_th_input)) // not verified
+	MCFG_GG_EXT_PORT_TH_INPUT_HANDLER(WRITELINE(sms_state, sms_ctrl2_th_input)) // not verified
-	//MCFG_GG_GEAR2GEAR_PORT_PIXEL_HANDLER(READ32(sms_state, sms_pixel_color)) // only for GG-TV mod
+	//MCFG_GG_EXT_PORT_PIXEL_HANDLER(READ32(sms_state, sms_pixel_color)) // only for GG-TV mod
 MACHINE_CONFIG_END
 
 

src/mess/includes/sms.h

@@ -19,7 +19,7 @@
 #define CONTROL1_TAG   "ctrl1"
 #define CONTROL2_TAG   "ctrl2"
 
-#include "bus/gamegear/gear2gear.h"
+#include "bus/gamegear/ggext.h"
 #include "bus/sms_ctrl/smsctrl.h"
 #include "bus/sms_exp/smsexp.h"
 #include "bus/sega8/sega8_slot.h"
@@ -37,7 +37,7 @@ public:
 		m_region_maincpu(*this, "maincpu"),
 		m_port_ctrl1(*this, CONTROL1_TAG),
 		m_port_ctrl2(*this, CONTROL2_TAG),
-		m_port_gear2gear(*this, "gear2gear"),
+		m_port_gg_ext(*this, "ext"),
 		m_port_gg_dc(*this, "GG_PORT_DC"),
 		m_port_pause(*this, "PAUSE"),
 		m_port_reset(*this, "RESET"),
@@ -66,7 +66,7 @@ public:
 	required_memory_region m_region_maincpu;
 	optional_device<sms_control_port_device> m_port_ctrl1;
 	optional_device<sms_control_port_device> m_port_ctrl2;
-	optional_device<gg_gear2gear_port_device> m_port_gear2gear;
+	optional_device<gg_ext_port_device> m_port_gg_ext;
 	optional_ioport m_port_gg_dc;
 	optional_ioport m_port_pause;
 	optional_ioport m_port_reset;
@@ -75,25 +75,15 @@ public:
 	optional_ioport m_port_scope_binocular;
 	optional_ioport m_port_persist;
 
-	device_t *m_left_lcd;
-	device_t *m_right_lcd;
 	address_space *m_space;
-
-	UINT8 m_bios_page_count;
-	UINT8 m_fm_detect;
-	UINT8 m_io_ctrl_reg;
-	int m_paused;
-	UINT8 m_mem_ctrl_reg;
-	UINT8 m_mem_device_enabled;
 	UINT8 *m_mainram;
 	UINT8 *m_BIOS;
-	UINT8 m_mapper[4];
-	UINT8 m_port_dc_reg;
-	UINT8 m_port_dd_reg;
-	UINT8 m_gg_sio[5];
 
-	// [0] for 0x400-0x3fff, [1] for 0x4000-0x7fff, [2] for 0x8000-0xffff, [3] for 0x0000-0x0400
+	// for 3D glass binocular hack
-	UINT8 m_bios_page[4];
+	device_t *m_left_lcd;
+	device_t *m_right_lcd;
+	bitmap_rgb32 m_prevleft_bitmap;
+	bitmap_rgb32 m_prevright_bitmap;
 
 	// for gamegear LCD persistence hack
 	bitmap_rgb32 m_prev_bitmap;
@@ -105,10 +95,6 @@ public:
 	// vertical scaling in the gamegear sms compatibility mode.
 	int *m_line_buffer;
 
-	// for 3D glass binocular hack
-	bitmap_rgb32 m_prevleft_bitmap;
-	bitmap_rgb32 m_prevright_bitmap;
-
 	// model identifiers
 	UINT8 m_is_gamegear;
 	UINT8 m_is_gg_region_japan;
@@ -121,6 +107,20 @@ public:
 	UINT8 m_has_fm;
 	UINT8 m_has_jpn_sms_cart_slot;
 
+	// [0] for 0x400-0x3fff, [1] for 0x4000-0x7fff, [2] for 0x8000-0xffff, [3] for 0x0000-0x0400
+	UINT8 m_bios_page[4];
+
+	UINT8 m_bios_page_count;
+	UINT8 m_mapper[4];
+	UINT8 m_io_ctrl_reg;
+	UINT8 m_mem_ctrl_reg;
+	UINT8 m_mem_device_enabled;
+	UINT8 m_fm_detect;
+	UINT8 m_port_dc_reg;
+	UINT8 m_port_dd_reg;
+	UINT8 m_gg_sio[5];
+	int m_paused;
+
 	// Data needed for Light Phaser
 	UINT8 m_ctrl1_th_state;
 	UINT8 m_ctrl2_th_state;
@@ -132,32 +132,19 @@ public:
 	UINT8 m_sscope_state;
 	UINT8 m_frame_sscope_state;
 
+	// slot devices
 	sega8_cart_slot_device *m_cartslot;
 	sega8_card_slot_device *m_cardslot;
 	sms_expansion_slot_device *m_expslot;
 
 	// these are only used by the Store Display unit, but we keep them here temporarily to avoid the need of separate start/reset
-	UINT8 m_store_control;
-	UINT8 m_store_cart_selection_data;
 	sega8_cart_slot_device *m_slots[16];
 	sega8_card_slot_device *m_cards[16];
+	UINT8 m_store_control;
+	UINT8 m_store_cart_selection_data;
 	void store_post_load();
 	void store_select_cart(UINT8 data);
 
-	/* Cartridge slot info */
-	DECLARE_WRITE8_MEMBER(sms_fm_detect_w);
-	DECLARE_READ8_MEMBER(sms_fm_detect_r);
-	DECLARE_WRITE8_MEMBER(sms_io_control_w);
-	DECLARE_READ8_MEMBER(sms_count_r);
-	DECLARE_READ8_MEMBER(sms_input_port_dc_r);
-	DECLARE_READ8_MEMBER(sms_input_port_dd_r);
-	DECLARE_READ8_MEMBER(gg_input_port_00_r);
-	DECLARE_WRITE8_MEMBER(sms_ym2413_register_port_w);
-	DECLARE_WRITE8_MEMBER(sms_ym2413_data_port_w);
-	DECLARE_READ8_MEMBER(sms_sscope_r);
-	DECLARE_WRITE8_MEMBER(sms_sscope_w);
-	DECLARE_READ8_MEMBER(sms_mapper_r);
-
 	DECLARE_READ8_MEMBER(read_0000);
 	DECLARE_READ8_MEMBER(read_4000);
 	DECLARE_READ8_MEMBER(read_8000);
@@ -165,10 +152,29 @@ public:
 	DECLARE_WRITE8_MEMBER(write_ram);
 	DECLARE_WRITE8_MEMBER(write_cart);
 
+	DECLARE_READ8_MEMBER(sms_mapper_r);
 	DECLARE_WRITE8_MEMBER(sms_mapper_w);
 	DECLARE_WRITE8_MEMBER(sms_mem_control_w);
+	DECLARE_WRITE8_MEMBER(sms_io_control_w);
+	DECLARE_READ8_MEMBER(sms_count_r);
+	DECLARE_READ8_MEMBER(sms_input_port_dc_r);
+	DECLARE_READ8_MEMBER(sms_input_port_dd_r);
+	DECLARE_READ8_MEMBER(gg_input_port_00_r);
 	DECLARE_WRITE8_MEMBER(gg_sio_w);
 	DECLARE_READ8_MEMBER(gg_sio_r);
+	DECLARE_WRITE8_MEMBER(sms_fm_detect_w);
+	DECLARE_READ8_MEMBER(sms_fm_detect_r);
+	DECLARE_WRITE8_MEMBER(sms_ym2413_register_port_w);
+	DECLARE_WRITE8_MEMBER(sms_ym2413_data_port_w);
+	DECLARE_READ8_MEMBER(sms_sscope_r);
+	DECLARE_WRITE8_MEMBER(sms_sscope_w);
+
+	DECLARE_WRITE_LINE_MEMBER(sms_int_callback);
+	DECLARE_WRITE_LINE_MEMBER(sms_pause_callback);
+	DECLARE_WRITE_LINE_MEMBER(sms_ctrl1_th_input);
+	DECLARE_WRITE_LINE_MEMBER(sms_ctrl2_th_input);
+	DECLARE_READ32_MEMBER(sms_pixel_color);
+
 	DECLARE_DRIVER_INIT(sg1000m3);
 	DECLARE_DRIVER_INIT(gamegear);
 	DECLARE_DRIVER_INIT(gamegeaj);
@@ -183,16 +189,12 @@ public:
 	DECLARE_VIDEO_RESET(gamegear);
 	DECLARE_VIDEO_START(sms1);
 	DECLARE_VIDEO_RESET(sms1);
-	void screen_gg_sms_mode_scaling(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
+
-	UINT32 screen_update_gamegear(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 	UINT32 screen_update_sms(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 	UINT32 screen_update_sms1(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
+	UINT32 screen_update_gamegear(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
+	void screen_gg_sms_mode_scaling(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 	void screen_vblank_sms1(screen_device &screen, bool state);
-	DECLARE_WRITE_LINE_MEMBER(sms_int_callback);
-	DECLARE_WRITE_LINE_MEMBER(sms_pause_callback);
-	DECLARE_READ32_MEMBER(sms_pixel_color);
-	DECLARE_WRITE_LINE_MEMBER(sms_ctrl1_th_input);
-	DECLARE_WRITE_LINE_MEMBER(sms_ctrl2_th_input);
 
 protected:
 	UINT8 read_bus(address_space &space, unsigned int bank, UINT16 base_addr, UINT16 offset);

src/mess/machine/sms.c

@@ -94,7 +94,7 @@ void sms_state::sms_get_inputs()
 		data1 = m_port_gg_dc->read();
 		m_port_dc_reg &= ~0x03f | data1;
 
-		data2 = m_port_gear2gear->port_r();
+		data2 = m_port_gg_ext->port_r();
 	}
 	else
 	{
@@ -207,7 +207,7 @@ WRITE8_MEMBER(sms_state::sms_io_control_w)
 		if (!m_is_gamegear)
 			m_port_ctrl2->port_w(ctrl2_port_data);
 		else
-			m_port_gear2gear->port_w(ctrl2_port_data); // not verified
+			m_port_gg_ext->port_w(ctrl2_port_data); // not verified
 	}
 	// check if TH is set to input (1).
 	if (data & 0x08)
@@ -215,7 +215,7 @@ WRITE8_MEMBER(sms_state::sms_io_control_w)
 		if (!m_is_gamegear)
 			ctrl2_port_data &= ~0x40 | m_port_ctrl2->port_r();
 		else
-			ctrl2_port_data &= ~0x40 | m_port_gear2gear->port_r(); // not verified
+			ctrl2_port_data &= ~0x40 | m_port_gg_ext->port_r(); // not verified
 
 		// check if TH input level is high (1) and was output/low (0)
 		if ((ctrl2_port_data & 0x40) && !(m_io_ctrl_reg & 0x88))