sms.c: few corrections to the driver [Enik Land]

- define the default offset setting for Light Phaser at only one place;
 - add to the smsj the TH input handling that latches the HCounter,
   because the /HL line is connected to the VDP;
 - minor code/comments maintenance.

out of whatsnew: also fixed the release year of the gamegear parent driver...

src/emu/bus/sega8/sega8_slot.c

@@ -56,7 +56,7 @@ device_sega8_cart_interface::device_sega8_cart_interface(const machine_config &m
 		m_rom_page_count(0),
 		has_battery(FALSE),
 		m_late_battery_enable(FALSE),
-		m_lphaser_xoffs(0),
+		m_lphaser_xoffs(-1),
 		m_sms_mode(0)
 {
 }
@@ -247,7 +247,7 @@ void sega8_cart_slot_device::set_lphaser_xoffset( UINT8 *rom, int size )
 		{ 0x54, 0x4d, 0x52, 0x20, 0x53, 0x45, 0x47, 0x41, 0x41, 0x4c, 0x15, 0x4a, 0x01, 0x80, 0x00, 0x4f }
 	};
 
-	int xoff = 36;
+	int xoff = -1;
 
 	if (size >= 0x8000)
 	{

src/mess/drivers/sms.c

@@ -18,6 +18,7 @@
  - Support for other DE-9 compatible controllers, like the Mega Drive 6-Button
    that has homebrew software support
  - Rapid button of Japanese Master System
+ - Verify if disabling of the SN76489 PSG chip is possible on sms1krfm console
  - Keyboard support for Sega Mark III (sg1000m3 driver)
  - Link between two Mark III's through keyboard, supported by F-16 Fighting Falcon
  - Mark III expansion slot, used by keyboard and FM module
@@ -52,7 +53,7 @@ General compatibility issues on real hardware (not emulation bugs):
 
 - Some ROMs have issues or don't work when running on a console of different
   region;
-- Many Japanese/Korean or homebrew ROMs don't have the signature required by
+- Many Japanese, Korean and homebrew ROMs don't have the signature required by
   BIOSes of consoles sold overseas;
 - Paddle games need to detect the system region as Japanese to work with the
   Paddle controller;
@@ -229,10 +230,10 @@ SMS Store Unit memory map for the second CPU:
 8000      - System Control Register (R/W)
             Reading:
             bit7      - ready (0 = ready, 1 = not ready)
-            bit6      - active timer bit switch (0 = selection 2, 1 = selection 1)
+            bit6      - active timer bit switch (0 = timer 2, 1 = timer 1)
             bit5      - unknown
-            bit4-bit3 - timer selection 2 bit switches (10s-25s)
+            bit4-bit3 - timer 2 length bit switches (10s-25s)
-            bit2-bit0 - timer selection 1 bit switches (30s-135s)
+            bit2-bit0 - timer 1 length bit switches (30s-135s)
             Writing:
             bit7-bit4 - led of selected game to set
             bit3      - unknown, 1 seems to be written all the time
@@ -322,7 +323,8 @@ ADDRESS_MAP_END
 // It seems the Korean versions do some more strict decoding on the I/O
 // addresses.
 // At least the mirrors for I/O ports $3E/$3F don't seem to exist there.
-// Enri's doc about the Japanese SMS also doesn't mention them.
+// Enri's doc ( http://www43.tok2.com/home/cmpslv/Sms/EnrSms.htm ) about
+// the Japanese SMS also doesn't mention them.
 // Leaving the mirrors breaks the Korean cartridge bublboky.
 static ADDRESS_MAP_START( smsj_io, AS_IO, 8, sms_state )
 	AM_IMPORT_FROM(sg1000m3_io)
@@ -331,13 +333,13 @@ static ADDRESS_MAP_START( smsj_io, AS_IO, 8, sms_state )
 ADDRESS_MAP_END
 
 
-// The first Korean SMS version also seems to lack I/O port $3F.
+// The first Korean SMS version also seems to lack I/O port $3F. Games execute
-// Games detect the first version as Japanese region (opposite to the second
+// a region detection procedure that, through that port, sets the mode used by
-// version). The region detection tests the behavior of the TH bits of port
+// the TH bits of port $DD and tests their behavior. The region of the first SMS
-// $DD. Port $3F sets the mode used by those bits. If the first version would
+// version is detected as Japanese (opposite to the second version). However,
-// use the same mode used by Japanese SMS, it would't support the Light Phaser,
+// as it supports Light Phaser games, it doesn't have the same behavior of the
-// as it does. If it would use the standard mode of other SMS versions, the
+// Japanese SMS. If it had the behavior of other SMS versions, the system
-// system would be detected as Export region.
+// region would be detected as Export, so it probably lacks the port.
 static ADDRESS_MAP_START( sms1kr_io, AS_IO, 8, sms_state )
 	AM_IMPORT_FROM(sg1000m3_io)
 	AM_RANGE(0x3e, 0x3e)                 AM_WRITE(sms_mem_control_w)
@@ -748,19 +750,17 @@ MACHINE_CONFIG_END
 static MACHINE_CONFIG_DERIVED( smsj, sms1_krfm )
 	MCFG_CPU_MODIFY("maincpu")
 	MCFG_CPU_IO_MAP(smsj_io)
-
-	// Mark III does not have TH connected. Also, according with Enri's docs
-	// (http://www43.tok2.com/home/cmpslv/Sms/EnrSms.htm), the Japanese SMS
-	// only allows read of TH direction, through port $dd, not its input state.
-	MCFG_SMS_CONTROL_PORT_MODIFY(CONTROL1_TAG)
-	MCFG_SMS_CONTROL_PORT_TH_INPUT_HANDLER(NULL)
-	MCFG_SMS_CONTROL_PORT_MODIFY(CONTROL2_TAG)
-	MCFG_SMS_CONTROL_PORT_TH_INPUT_HANDLER(NULL)
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( sg1000m3, smsj )
 	MCFG_CPU_MODIFY("maincpu")
 	MCFG_CPU_IO_MAP(sg1000m3_io)
+
+	// Mark III does not have TH connected.
+	MCFG_SMS_CONTROL_PORT_MODIFY(CONTROL1_TAG)
+	MCFG_SMS_CONTROL_PORT_TH_INPUT_HANDLER(NULL)
+	MCFG_SMS_CONTROL_PORT_MODIFY(CONTROL2_TAG)
+	MCFG_SMS_CONTROL_PORT_TH_INPUT_HANDLER(NULL)
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( sms2_kr, sms2_ntsc )
@@ -812,7 +812,7 @@ static MACHINE_CONFIG_START( gamegear, sms_state )
 	MCFG_SOFTWARE_LIST_ADD("cart_list", "gamegear")
 
 	MCFG_GG_EXT_PORT_ADD("ext", gg_ext_port_devices, NULL)
-	MCFG_GG_EXT_PORT_TH_INPUT_HANDLER(WRITELINE(sms_state, sms_ctrl2_th_input)) // not verified
+	MCFG_GG_EXT_PORT_TH_INPUT_HANDLER(WRITELINE(sms_state, gg_ext_th_input))
 	//MCFG_GG_EXT_PORT_PIXEL_HANDLER(READ32(sms_state, sms_pixel_color)) // only for GG-TV mod
 MACHINE_CONFIG_END
 
@@ -1012,5 +1012,5 @@ CONS( 1989, sms1krfm,   sms,        0,      sms1_krfm,   smsj,     sms_state,
 CONS( 19??, sms1kr,     sms,        0,      sms1_kr,     smsj,     sms_state,      sms1kr,   "Samsung",  "Gam*Boy I (Korea)",                GAME_SUPPORTS_SAVE )
 CONS( 1991, smskr,      sms,        0,      sms2_kr,     sms,      sms_state,      smskr,    "Samsung",  "Gam*Boy II (Korea)",               GAME_SUPPORTS_SAVE )
 
-CONS( 1990, gamegear,   0,          sms,    gamegear,    gg,       sms_state,      gamegear, "Sega",     "Game Gear (Europe/America)",       GAME_SUPPORTS_SAVE )
+CONS( 1991, gamegear,   0,          sms,    gamegear,    gg,       sms_state,      gamegear, "Sega",     "Game Gear (Europe/America)",       GAME_SUPPORTS_SAVE )
 CONS( 1990, gamegeaj,   gamegear,   0,      gamegear,    gg,       sms_state,      gamegeaj, "Sega",     "Game Gear (Japan)",                GAME_SUPPORTS_SAVE )

src/mess/includes/sms.h

@@ -184,6 +184,7 @@ public:
 	DECLARE_WRITE_LINE_MEMBER(sms_pause_callback);
 	DECLARE_WRITE_LINE_MEMBER(sms_ctrl1_th_input);
 	DECLARE_WRITE_LINE_MEMBER(sms_ctrl2_th_input);
+	DECLARE_WRITE_LINE_MEMBER(gg_ext_th_input);
 	DECLARE_READ32_MEMBER(sms_pixel_color);
 
 	DECLARE_DRIVER_INIT(sg1000m3);

src/mess/machine/sms.c

@@ -48,9 +48,6 @@ WRITE_LINE_MEMBER(sms_state::sms_ctrl1_th_input)
 
 WRITE_LINE_MEMBER(sms_state::sms_ctrl2_th_input)
 {
-	if (m_is_gamegear && !(m_cartslot->exists() && m_cartslot->m_cart->get_sms_mode()))
-		return;
-
 	// Check if TH of controller port 2 is set to input (1)
 	if (m_io_ctrl_reg & 0x08)
 	{
@@ -69,6 +66,16 @@ WRITE_LINE_MEMBER(sms_state::sms_ctrl2_th_input)
 }
 
 
+WRITE_LINE_MEMBER(sms_state::gg_ext_th_input)
+{
+	if (!(m_cartslot->exists() && m_cartslot->m_cart->get_sms_mode()))
+		return;
+
+	// The EXT port act as the controller port 2 on SMS compatibility mode.
+	sms_ctrl2_th_input(state);
+}
+
+
 void sms_state::sms_get_inputs()
 {
 	bool port_dd_has_th_input = true;
@@ -182,7 +189,7 @@ WRITE8_MEMBER(sms_state::sms_io_control_w)
 		if (!m_is_gamegear)
 			m_port_ctrl2->port_w(ctrl2_port_data);
 		else
-			m_port_gg_ext->port_w(ctrl2_port_data); // not verified
+			m_port_gg_ext->port_w(ctrl2_port_data);
 	}
 	// check if TH is set to input (1).
 	if (data & 0x08)
@@ -190,7 +197,7 @@ 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_gg_ext->port_r(); // not verified
+			ctrl2_port_data &= ~0x40 | m_port_gg_ext->port_r();
 
 		// check if TH input level is high (1) and was output/low (0)
 		if ((ctrl2_port_data & 0x40) && !(m_io_ctrl_reg & 0x88))
@@ -325,7 +332,7 @@ READ8_MEMBER(sms_state::sms_input_port_dd_r)
 	{
 		// For Japanese Master System, set upper 4 bits with TH/TR
 		// direction bits of IO control register, according to Enri's
-		// docs (http://www43.tok2.com/home/cmpslv/Sms/EnrSms.htm).
+		// docs ( http://www43.tok2.com/home/cmpslv/Sms/EnrSms.htm ).
 		// This makes the console incapable of using the Light Phaser.
 		// Assume the same for a Japanese Game Gear.
 		m_port_dd_reg &= ~0x10 | ((m_io_ctrl_reg & 0x01) << 4);
@@ -390,7 +397,9 @@ WRITE8_MEMBER(sms_state::sms_audio_control_w)
 READ8_MEMBER(sms_state::sms_audio_control_r)
 {
 	if (m_has_fm)
-		return m_audio_control & 0x01; // just one bit even for smsj.
+		// The register reference on SMSPower states that just the
+		// first bit written is returned on reads (even for smsj?).
+		return m_audio_control & 0x01;
 	else
 		return sms_input_port_dc_r(space, offset);
 }
@@ -825,7 +834,7 @@ void sms_state::setup_media_slots()
 	// Set offset for Light Phaser
 	if (!m_is_mark_iii)
 	{
-		m_lphaser_x_offs = 36;
+		m_lphaser_x_offs = -1; // same value returned for ROMs without custom offset.
 
 		if (m_mem_device_enabled & ENABLE_CART)
 			m_lphaser_x_offs = m_cartslot->m_cart->get_lphaser_xoffs();
@@ -833,6 +842,9 @@ void sms_state::setup_media_slots()
 			m_lphaser_x_offs = m_cardslot->m_cart->get_lphaser_xoffs();
 		else if (m_mem_device_enabled & ENABLE_EXPANSION)
 			m_lphaser_x_offs = m_expslot->m_device->get_lphaser_xoffs();
+
+		if (m_lphaser_x_offs == -1)
+			m_lphaser_x_offs = 36;
 	}
 }