seta2: improve screen size / visible area / offset handling, preliminary raster effects (#4369)

* seta2: document raster effect findings so far, it's about as illogical as the rest (nw)

* improvements, some stuff still broken by yofset change tho (nw)

* fixup problem in previous (nw)

* preliminary raster type stuff (nw)

* refactor and fix silly mistake (nw)

* not really happy with this, but not much evidence to go on at the moment (nw)

3 files changed, 290 insertions, 168 deletions

diff --git a/src/mame/drivers/seta2.cpp b/src/mame/drivers/seta2.cpp
index cf1194459fe..56326c2bf64 100644
--- a/src/mame/drivers/seta2.cpp
+++ b/src/mame/drivers/seta2.cpp
@@ -82,7 +82,7 @@ grdians:
   has the shadow bit set, and has become invisible after implementing it.
 
 penbros/ablast:
-- Zooming is used briefly.
+- Zooming is used briefly (between scenes, stage exit, stage introduction)
 
 deerhunt,wschamp:
 - offset tilemap sprite during demo. In deerhunt intro, the hunter should zoom
@@ -94,18 +94,12 @@ wschampb:
   original release? Is that why the next bug fix release is v1.01? IE: such a
   a minor increase in the version number.
 
-trophyh:
-- mame hangs for around 15 seconds every now and then, at scene changes.
-  This is probably due to a couple of frames with an odd or corrupt sprites list,
-  taking a long time to render.
-
 funcube series:
 - Hacked to run, as they use a ColdFire CPU.
 - Pay-out key causes "unknown error" after coin count reaches 0.
 
 reelquak:
 - Needs an x offset for tilemap sprites.
-- There are one frame glitches in the reels scroll.
 
 ***************************************************************************/
 
@@ -200,7 +194,7 @@ void seta2_state::grdians_map(address_map &map)
 	map(0x70000c, 0x70000d).r("watchdog", FUNC(watchdog_timer_device::reset16_r));
 	map(0x800000, 0x800001).w(FUNC(seta2_state::grdians_lockout_w));
 	map(0xb00000, 0xb03fff).rw("x1snd", FUNC(x1_010_device::word_r), FUNC(x1_010_device::word_w));   // Sound
-	map(0xc00000, 0xc3ffff).ram().share("spriteram");       // Sprites
+	map(0xc00000, 0xc3ffff).ram().w(FUNC(seta2_state::spriteram_w)).share("spriteram");    // Sprites
 	map(0xc40000, 0xc4ffff).ram().w(m_palette, FUNC(palette_device::write16)).share("palette");    // Palette
 	map(0xc50000, 0xc5ffff).ram();                             // cleared
 	map(0xc60000, 0xc6003f).w(FUNC(seta2_state::vregs_w)).share("vregs");  // Video Registers
@@ -2394,12 +2388,13 @@ MACHINE_CONFIG_START(seta2_state::seta2)
 	// video hardware
 	MCFG_SCREEN_ADD("screen", RASTER)
 	MCFG_SCREEN_REFRESH_RATE(60)
-	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(0))
-	MCFG_SCREEN_SIZE(0x200, 0x200)
-	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x1c0-1, 0x80, 0x170-1)
+	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500))
+	MCFG_SCREEN_SIZE(0x200, 0x100)
+	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x1c0-1, 0x00, 0xf0-1)
 	MCFG_SCREEN_UPDATE_DRIVER(seta2_state, screen_update)
 	MCFG_SCREEN_VBLANK_CALLBACK(WRITELINE(*this, seta2_state, screen_vblank))
 	MCFG_SCREEN_PALETTE("palette")
+	//MCFG_SCREEN_VIDEO_ATTRIBUTES(VIDEO_UPDATE_SCANLINE)
 
 	MCFG_DEVICE_ADD("gfxdecode", GFXDECODE, "palette", gfx_seta2)
 	MCFG_PALETTE_ADD("palette", 0x8000+0xf0)    // extra 0xf0 because we might draw 256-color object with 16-color granularity
@@ -2426,7 +2421,7 @@ MACHINE_CONFIG_START(seta2_state::gundamex)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x00, 0x180-1, 0x100, 0x1e0-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x00, 0x180-1, 0x000, 0x0e0-1)
 MACHINE_CONFIG_END
 
 
@@ -2437,7 +2432,7 @@ MACHINE_CONFIG_START(seta2_state::grdians)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x80, 0x80 + 0x130 -1, 0x80, 0x80 + 0xe8 -1)
+	MCFG_SCREEN_VISIBLE_AREA(0x80, 0x80 + 0x130 -1, 0x00, 0x00 + 0xe8 -1)
 MACHINE_CONFIG_END
 
 
@@ -2448,7 +2443,7 @@ MACHINE_CONFIG_START(seta2_state::myangel)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0, 0x178-1, 0x10, 0x100-1)
+	MCFG_SCREEN_VISIBLE_AREA(0, 0x178-1, 0x00, 0xf0-1)
 MACHINE_CONFIG_END
 
 
@@ -2459,7 +2454,7 @@ MACHINE_CONFIG_START(seta2_state::myangel2)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0, 0x178-1, 0x10, 0x100-1)
+	MCFG_SCREEN_VISIBLE_AREA(0, 0x178-1, 0x00, 0xf0-1)
 MACHINE_CONFIG_END
 
 
@@ -2470,7 +2465,7 @@ MACHINE_CONFIG_START(seta2_state::pzlbowl)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x10, 0x190-1, 0x100, 0x1f0-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x10, 0x190-1, 0x00, 0xf0-1)
 MACHINE_CONFIG_END
 
 
@@ -2481,7 +2476,7 @@ MACHINE_CONFIG_START(seta2_state::penbros)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0, 0x140-1, 0x80, 0x160-1)
+	MCFG_SCREEN_VISIBLE_AREA(0, 0x140-1, 0x00, 0xe0-1)
 MACHINE_CONFIG_END
 
 MACHINE_CONFIG_START(seta2_state::ablastb)
@@ -2505,7 +2500,7 @@ MACHINE_CONFIG_START(seta2_state::reelquak)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x180-1, 0x80, 0x170-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x180-1, 0x00, 0xf0-1)
 
 	MCFG_VIDEO_START_OVERRIDE(seta2_state,xoffset)
 MACHINE_CONFIG_END
@@ -2523,7 +2518,7 @@ MACHINE_CONFIG_START(seta2_state::samshoot)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x180-1, 0x40, 0x130-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x180-1, 0x00, 0xf0-1)
 MACHINE_CONFIG_END
 
 
@@ -2538,7 +2533,7 @@ MACHINE_CONFIG_START(staraudi_state::staraudi)
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
 	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500))  // not accurate
-	MCFG_SCREEN_VISIBLE_AREA(0x10, 0x150-1, 0x100, 0x1f0-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x10, 0x150-1, 0x00, 0x0f0-1)
 
 	MCFG_GFXDECODE_MODIFY("gfxdecode", gfx_seta2)
 MACHINE_CONFIG_END
@@ -2558,7 +2553,7 @@ MACHINE_CONFIG_START(seta2_state::telpacfl)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x0, 0x180-1, 0xff, 0x1ef-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x0, 0x180-1, 0x00, 0xf0-1)
 	MCFG_VIDEO_START_OVERRIDE(seta2_state,xoffset1)
 MACHINE_CONFIG_END
 
@@ -2614,7 +2609,7 @@ MACHINE_CONFIG_START(funcube_state::funcube)
 	MCFG_SCREEN_REFRESH_RATE(60)
 	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500))  // not accurate
 	MCFG_SCREEN_SIZE(0x200, 0x200)
-	MCFG_SCREEN_VISIBLE_AREA(0x0+1, 0x140-1+1, 0x80, 0x170-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x0+1, 0x140-1+1, 0x00, 0xf0-1)
 	MCFG_SCREEN_UPDATE_DRIVER(seta2_state, screen_update)
 	MCFG_SCREEN_VBLANK_CALLBACK(WRITELINE(*this, seta2_state, screen_vblank))
 	MCFG_SCREEN_PALETTE("palette")
@@ -2643,7 +2638,7 @@ MACHINE_CONFIG_START(funcube_state::funcube2)
 
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x0, 0x140-1, 0x80, 0x170-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x0, 0x140-1, 0x00, 0xf0-1)
 MACHINE_CONFIG_END
 
 
@@ -2651,7 +2646,7 @@ MACHINE_CONFIG_START(funcube_state::funcube3)
 	funcube2(config);
 	// video hardware
 	MCFG_SCREEN_MODIFY("screen")
-	MCFG_SCREEN_VISIBLE_AREA(0x0, 0x140-1, 0x80-0x40, 0x170-1-0x40)
+	MCFG_SCREEN_VISIBLE_AREA(0x0, 0x140-1, 0x00, 0xf0-1)
 MACHINE_CONFIG_END
 
 
@@ -2669,7 +2664,7 @@ MACHINE_CONFIG_START(seta2_state::namcostr)
 	MCFG_SCREEN_REFRESH_RATE(60)
 	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(0))
 	MCFG_SCREEN_SIZE(0x200, 0x200)
-	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x1c0-1, 0x80, 0x170-1)
+	MCFG_SCREEN_VISIBLE_AREA(0x40, 0x1c0-1, 0x00, 0xf0-1)
 	MCFG_SCREEN_UPDATE_DRIVER(seta2_state, screen_update)
 	MCFG_SCREEN_VBLANK_CALLBACK(WRITELINE(*this, seta2_state, screen_vblank))
 	MCFG_SCREEN_PALETTE("palette")
diff --git a/src/mame/includes/seta2.h b/src/mame/includes/seta2.h
index c90ee1c4b0c..82a69b5f274 100644
--- a/src/mame/includes/seta2.h
+++ b/src/mame/includes/seta2.h
@@ -22,8 +22,8 @@ class seta2_state : public driver_device
 public:
 	seta2_state(const machine_config &mconfig, device_type type, const char *tag) :
 		driver_device(mconfig, type, tag),
-		m_maincpu(*this,"maincpu"),
-		m_sub(*this,"sub"),
+		m_maincpu(*this, "maincpu"),
+		m_sub(*this, "sub"),
 		m_gfxdecode(*this, "gfxdecode"),
 		m_screen(*this, "screen"),
 		m_palette(*this, "palette"),
@@ -34,7 +34,7 @@ public:
 		m_flash(*this, "flash"),
 		m_dispenser(*this, "dispenser"),
 
-		m_x1_bank(*this,"x1_bank_%u", 1U),
+		m_x1_bank(*this, "x1_bank_%u", 1U),
 		m_nvram(*this, "nvram"),
 		m_spriteram(*this, "spriteram", 0),
 		m_tileram(*this, "tileram", 0),
@@ -93,10 +93,12 @@ protected:
 	DECLARE_READ16_MEMBER(gundamex_eeprom_r);
 	DECLARE_WRITE16_MEMBER(gundamex_eeprom_w);
 
+	DECLARE_WRITE16_MEMBER(spriteram_w);
+
 	DECLARE_VIDEO_START(xoffset);
 	DECLARE_VIDEO_START(xoffset1);
 
-	void draw_sprites(bitmap_ind16 &bitmap,const rectangle &cliprect);
+	void draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect);
 
 	INTERRUPT_GEN_MEMBER(seta2_interrupt);
 	INTERRUPT_GEN_MEMBER(samshoot_interrupt);
@@ -130,7 +132,7 @@ protected:
 	optional_device<eeprom_serial_93cxx_device> m_eeprom;
 	optional_device<intelfsh16_device> m_flash;
 	optional_device<ticket_dispenser_device> m_dispenser;
-
+	
 	optional_memory_bank_array<8> m_x1_bank;
 	optional_shared_ptr<uint16_t> m_nvram;
 	optional_shared_ptr<uint16_t> m_spriteram;
@@ -143,6 +145,9 @@ protected:
 	int m_keyboard_row;
 	std::unique_ptr<uint16_t[]> m_buffered_spriteram;
 
+	uint16_t m_private_spriteram[0x1000 / 2];
+
+
 private:
 	void drawgfx_line(bitmap_ind16 &bitmap, const rectangle &cliprect, int gfx, const uint8_t* const addr, const uint32_t realcolor, int flipx, int flipy, int base_sx, int shadow, int realline, int line, int opaque);
 	inline void get_tile(uint16_t* spriteram, int is_16x16, int x, int y, int page, int& code, int& attr, int& flipx, int& flipy, int& color);
@@ -154,7 +159,6 @@ private:
 	uint16_t m_rasterenabled;
 	TIMER_CALLBACK_MEMBER(raster_timer_done);
 	emu_timer *m_raster_timer;
-
 };
 
 
diff --git a/src/mame/video/seta2.cpp b/src/mame/video/seta2.cpp
index 28e098a9226..be5f59e7009 100644
--- a/src/mame/video/seta2.cpp
+++ b/src/mame/video/seta2.cpp
@@ -17,7 +17,7 @@
     Offset:     Bits:                   Value:
 
         0.w     f--- ---- ---- ----     Last sprite
-                -e-- ---- ---- ----     ?
+                -e-- ---- ---- ----     ? (ignore global offsets, zooming etc. used on frame of map in grdians)
                 --d- ---- ---- ----     Opaque
                 ---c ---- ---- ----     0 = Each sprite specifies its size, 1 = Use the global size (following words)
                 ---- b--- ---- ----     Shadow
@@ -99,7 +99,9 @@
     1c                                  Zoom Y? low bits
     1e                                  Zoom Y? high bits *
 
+	24                                  1->0 in funcube3 and staraudi
     26                                  1->0 during INT0, before writing sprites
+	                                    (probably creates a custom format sprite list at 0x0000 by processing the list at 0x3000)
 
     30          fedc ba98 7654 321-
                 ---- ---- ---- ---0     Disable video
@@ -111,51 +113,131 @@
 
 ***************************************************************************/
 
+/***************************************************************************
+  
+  NON-BUGS
+
+  grdians : After the fire rowscroll effect in the intro there is a small artifact
+            left scrolling at the top of the screen when the next image is displayed
+			See 4:24 in https://www.youtube.com/watch?v=cvHGFEsB_cM
+   
+***************************************************************************/
+
 WRITE16_MEMBER(seta2_state::vregs_w)
 {
 	/* 02/04 = horizontal display start/end
-	           mj4simai = 0065/01E5 (0180 visible area)
-	           myangel =  005D/01D5 (0178 visible area)
-	           pzlbowl =  0058/01D8 (0180 visible area)
-	           penbros =  0065/01A5 (0140 visible area)
-	           grdians =  0059/0188 (012f visible area)
+			   mj4simai = 0065/01E5 (0180 visible area)
+			   myangel =  005D/01D5 (0178 visible area)
+			   pzlbowl =  0058/01D8 (0180 visible area)
+			   penbros =  0065/01A5 (0140 visible area)
+			   grdians =  0059/0188 (012f visible area)
 	   06    = horizontal total?
-	           mj4simai = 0204
-	           myangel =  0200
-	           pzlbowl =  0204
-	           penbros =  01c0
-	           grdians =  019a
+			   mj4simai = 0204
+			   myangel =  0200
+			   pzlbowl =  0204
+			   penbros =  01c0
+			   grdians =  019a
 	*/
 
 	uint16_t olddata = m_vregs[offset];
 
 	COMBINE_DATA(&m_vregs[offset]);
-	if ( m_vregs[offset] != olddata )
-		logerror("CPU #0 PC %06X: Video Reg %02X <- %04X\n",m_maincpu->pc(),offset*2,data);
+	if (m_vregs[offset] != olddata)
+		logerror("CPU #0 PC %06X: Video Reg %02X <- %04X\n", m_maincpu->pc(), offset * 2, data);
 
-	switch( offset*2 )
+	switch (offset * 2)
 	{
+	case 0x1a:
+		logerror("%s: Register 1a write (vertical offset?) %04X (%04x)\n", machine().describe_context(), data, mem_mask);
+		break;
+
 	case 0x1c:  // FLIP SCREEN (myangel)    <- this is actually zoom
-		flip_screen_set(data & 1 );
-		if (data & ~1)  logerror("CPU #0 PC %06X: flip screen unknown bits %04X\n",m_maincpu->pc(),data);
+		flip_screen_set(data & 1);
+		if (data & ~1)  logerror("CPU #0 PC %06X: flip screen unknown bits %04X\n", m_maincpu->pc(), data);
 		break;
 	case 0x2a:  // FLIP X (pzlbowl)
-		flip_screen_x_set(data & 1 );
-		if (data & ~1)  logerror("CPU #0 PC %06X: flipx unknown bits %04X\n",m_maincpu->pc(),data);
+		flip_screen_x_set(data & 1);
+		if (data & ~1)  logerror("CPU #0 PC %06X: flipx unknown bits %04X\n", m_maincpu->pc(), data);
 		break;
 	case 0x2c:  // FLIP Y (pzlbowl)
-		flip_screen_y_set(data & 1 );
-		if (data & ~1)  logerror("CPU #0 PC %06X: flipy unknown bits %04X\n",m_maincpu->pc(),data);
+		flip_screen_y_set(data & 1);
+		if (data & ~1)  logerror("CPU #0 PC %06X: flipy unknown bits %04X\n", m_maincpu->pc(), data);
 		break;
 
 	case 0x30:  // BLANK SCREEN (pzlbowl, myangel)
-		if (data & ~1)  logerror("CPU #0 PC %06X: blank unknown bits %04X\n",m_maincpu->pc(),data);
+		if (data & ~1)  logerror("CPU #0 PC %06X: blank unknown bits %04X\n", m_maincpu->pc(), data);
+		break;
+
+	case 0x24: // funcube3 and staraudi write here instead, why? mirror or different meaning?
+	case 0x26: // something display list related? buffering control?
+		if (data)
+		{
+			// Buffer sprites by 1 frame
+			//memcpy(m_buffered_spriteram.get(), m_spriteram, m_spriteram.bytes());
+
+			/* copy the base spritelist to a private (non-CPU visible buffer)
+			   copy the indexed sprites to 0 in spriteram, adjusting pointers in base sprite list as appropriate
+			   this at least gets the sprite data in the right place for the grdians raster effect to write the
+			   changed scroll values to the correct sprites, but is still nothing more than a guess
+			*/
+			int current_sprite_entry = 0;
+
+			for (int i = 0; i < 0x1000 / 2; i += 4)
+			{
+				uint16_t num = m_private_spriteram[i + 0] = m_spriteram[(0x3000 / 2) + i + 0];
+				m_private_spriteram[i + 1] = m_spriteram[(0x3000 / 2) + i + 1];
+				m_private_spriteram[i + 2] = m_spriteram[(0x3000 / 2) + i + 2];
+
+				int sprite = m_spriteram[(0x3000 / 2) + i + 3];
+				m_private_spriteram[i + 3] = ((current_sprite_entry / 4) & 0x7fff) | (sprite & 0x8000);
+
+				int list2addr = (sprite & 0x7fff) * 4;
+
+				num &=0xff;
+
+				for (int j = 0; j <= num; j++)
+				{
+					if (current_sprite_entry < 0x3000 / 2)
+					{
+						m_spriteram[current_sprite_entry + 0] = m_spriteram[(list2addr + (j * 4) + 0) & 0x1ffff];
+						m_spriteram[current_sprite_entry + 1] = m_spriteram[(list2addr + (j * 4) + 1) & 0x1ffff];
+						m_spriteram[current_sprite_entry + 2] = m_spriteram[(list2addr + (j * 4) + 2) & 0x1ffff];
+						m_spriteram[current_sprite_entry + 3] = m_spriteram[(list2addr + (j * 4) + 3) & 0x1ffff];
+						current_sprite_entry += 4;
+					}
+				}
+
+				if (m_private_spriteram[i + 0] & 0x8000) // end of list marker, mj4simai must draw the sprite this covers for the company logo, title screen etc.
+				{
+					// HACK: however penbros has a dummy sprite entry there which points to 0x0000 as the tile source, and causes garbage with the rearranged format,
+					// so change it to something that's invalid where we can filter it later.  This strongly indicates that the current approach is incorrect however.
+					if (sprite == 0x00)
+					{
+						m_private_spriteram[i + 3] |= 0x4000;
+					}
+
+					break;  
+				}
+			}
+
+		}
 		break;
 
 	case 0x3c: // Raster IRQ related
-		//logerror("%s: Register 3c write (raster enable?) %04X (%04x)\n",machine().describe_context(),data, mem_mask);
+		//logerror("%s: Register 3c write (raster enable?) current vpos is %d  :   %04X (%04x)\n",machine().describe_context(),m_screen->vpos(), data, mem_mask);
 		COMBINE_DATA(&m_rasterenabled);
-		if (m_rasterenabled & 1) m_raster_timer->adjust(m_screen->time_until_pos((m_rasterposition&0x1ff)+0x80, 0), 0);
+
+		//if (m_rasterenabled & 1)
+		{
+			int hpos = 0;
+			int vpos = m_rasterposition;
+
+			// in the vblank it specifies line 0, the first raster interrupt then specifies line 0 again before the subsequent ones use the real line numbers?
+			// It seems more likely the the raster IRQ stays asserted for the entire line, thus triggering a second interrupt unless the line number is changed?
+			if (m_rasterposition == m_screen->vpos()) hpos = m_screen->hpos() + 0x100;
+			//logerror("setting raster to %d %d\n", vpos, hpos);
+			m_raster_timer->adjust(m_screen->time_until_pos(vpos, hpos), 0);
+		}
 		break;
 
 	case 0x3e: // Raster IRQ related
@@ -165,6 +247,11 @@ WRITE16_MEMBER(seta2_state::vregs_w)
 	}
 }
 
+WRITE16_MEMBER(seta2_state::spriteram_w)
+{
+	COMBINE_DATA(&m_spriteram[offset]);
+}
+
 /***************************************************************************
 
 
@@ -249,23 +336,28 @@ inline void seta2_state::get_tile(uint16_t* spriteram, int is_16x16, int x, int
 void seta2_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
 {
 	// Sprites list
+	uint16_t *spriteram = m_spriteram;
+	int global_yoffset = (m_vregs[0x1a/2] & 0x7ff);
+	if (global_yoffset & 0x400)
+		global_yoffset -= 0x800;
+
+	global_yoffset += 1;
+
+	uint16_t *s1 = m_private_spriteram;
 
-	// When debugging, use m_spriteram here, and run mame -update_in_pause, i.e.:
-//  uint16_t *buffered_spriteram16 = m_spriteram;
-	uint16_t *buffered_spriteram16 = m_buffered_spriteram.get();
-	uint16_t *s1 = buffered_spriteram16 + 0x3000 / 2;
-	uint16_t *end = &buffered_spriteram16[m_spriteram.bytes() / 2];
 
 	//  for ( ; s1 < end; s1+=4 )
-	for (; s1 < buffered_spriteram16 + 0x4000 / 2; s1 += 4)   // more reasonable (and it cures MAME lockup in e.g. funcube3 boot)
+	for (; s1 < m_private_spriteram + 0x1000 / 2; s1 += 4)   // more reasonable (and it cures MAME lockup in e.g. funcube3 boot)
 	{
 		int num = s1[0];
+
 		int xoffs = s1[1];
 		int yoffs = s1[2];
 		int sprite = s1[3];
 
 		// Single-sprite address
-		uint16_t *s2 = &buffered_spriteram16[(sprite & 0x7fff) * 4];
+		uint16_t *s2 = &spriteram[(sprite & 0x7fff) * 4];
+		uint16_t *end = &spriteram[m_spriteram.bytes() / 2];
 
 		// Single-sprite size
 		int global_sizex = xoffs & 0xfc00;
@@ -281,136 +373,155 @@ void seta2_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
 		// Number of single-sprites
 		num = (num & 0x00ff) + 1;
 
-		for (; num > 0; num--, s2 += 4)
+		// all sprites, except invalid ones should have a pointer <0x3000 in the reformatted list
+		if ((sprite&0x7fff) < 0x3000 / 2 / 4)
 		{
-			if (s2 >= end)  break;
-
-			if (sprite & 0x8000)
+			for (; num > 0; num--, s2 += 4)
 			{
-				// "floating tilemap" sprite
-				// the 'floating tilemap sprites' are just a window into the tilemap, the position of the sprite does not change the scroll values
-
-				int sx = s2[0];
-				int sy = s2[1];
-				int scrollx = s2[2];
-				int scrolly = s2[3];
-				int is_16x16 = (scrollx & 0x8000) >> 15;
-				int page = (scrollx & 0x7c00) >> 10;
-				int local_sizex = sx & 0xfc00;
-				int local_sizey = sy & 0xfc00;
-				sx &= 0x3ff;
-				sy &= 0x1ff;
-
-				int width = use_global_size ? global_sizex : local_sizex;
-				int height = use_global_size ? global_sizey : local_sizey;
-
-				height = ((height & 0xfc00) >> 10) + 1;
-				width = ((width & 0xfc00) >> 10)/* + 1*/; // reelquak reels
-				if (!width)
-					continue;
-
-				scrollx += m_xoffset;
-				scrollx &= 0x3ff;
-				scrolly &= 0x1ff;
-
-				rectangle clip;
-				// sprite clipping region (x)
-				clip.min_x = (sx + xoffs) & 0x3ff;
-				clip.min_x = (clip.min_x & 0x1ff) - (clip.min_x & 0x200);
-				clip.max_x = clip.min_x + width * 0x10 - 1;
-
-				if (clip.min_x > cliprect.max_x)    continue;
-				if (clip.max_x < cliprect.min_x)    continue;
-				if (clip.min_x < cliprect.min_x)    clip.min_x = cliprect.min_x;
-				if (clip.max_x > cliprect.max_x)    clip.max_x = cliprect.max_x;
-
-				// sprite clipping region (y)
-				clip.min_y = ((sy + yoffs) & 0x1ff);
-				clip.max_y = clip.min_y + height * 0x10 - 1;
-
-				if (clip.min_y > cliprect.max_y)    continue;
-				if (clip.max_y < cliprect.min_y)    continue;
-				if (clip.min_y < cliprect.min_y)    clip.min_y = cliprect.min_y;
-				if (clip.max_y > cliprect.max_y)    clip.max_y = cliprect.max_y;
-
-				for (int realline = clip.min_y; realline <= clip.max_y; realline++)
-				{
-					int sourceline = (realline - scrolly) & 0x1ff;
-
-					int y = sourceline >> (is_16x16 ? 4 : 3);
+				if (s2 >= end)  break;
 
-					for (int x = 0; x < 0x40; x++)
+				if (sprite & 0x8000)
+				{
+					// "floating tilemap" sprite
+					// the 'floating tilemap sprites' are just a window into the tilemap, the position of the sprite does not change the scroll values
+
+					int sx = s2[0];
+					int sy = s2[1];
+					int scrollx = s2[2];
+					int scrolly = s2[3];
+					int is_16x16 = (scrollx & 0x8000) >> 15;
+					int page = (scrollx & 0x7c00) >> 10;
+					int local_sizex = sx & 0xfc00;
+					int local_sizey = sy & 0xfc00;
+					sx &= 0x3ff;
+					sy += global_yoffset;
+					sy &= 0x1ff;
+
+					if (sy & 0x100)
+						sy -= 0x200;
+
+					int width = use_global_size ? global_sizex : local_sizex;
+					int height = use_global_size ? global_sizey : local_sizey;
+
+					height = ((height & 0xfc00) >> 10) + 1;
+					width = ((width & 0xfc00) >> 10)/* + 1*/; // reelquak reels
+					if (!width)
+						continue;
+
+					scrollx += m_xoffset;
+					scrollx &= 0x3ff;
+					scrolly &= 0x1ff;
+
+					scrolly += global_yoffset;
+
+					rectangle clip;
+					// sprite clipping region (x)
+					clip.min_x = (sx + xoffs) & 0x3ff;
+					clip.min_x = (clip.min_x & 0x1ff) - (clip.min_x & 0x200);
+					clip.max_x = clip.min_x + width * 0x10 - 1;
+
+					if (clip.min_x > cliprect.max_x)    continue;
+					if (clip.max_x < cliprect.min_x)    continue;
+					if (clip.min_x < cliprect.min_x)    clip.min_x = cliprect.min_x;
+					if (clip.max_x > cliprect.max_x)    clip.max_x = cliprect.max_x;
+
+					// sprite clipping region (y)
+
+					int basey = (sy + yoffs) & 0x1ff;
+					if (basey & 0x100) basey -= 0x200;
+
+					clip.min_y = basey;
+					clip.max_y = clip.min_y + height * 0x10 - 1;
+
+					if (clip.min_y > cliprect.max_y)    continue;
+					if (clip.max_y < cliprect.min_y)    continue;
+					if (clip.min_y < cliprect.min_y)    clip.min_y = cliprect.min_y;
+					if (clip.max_y > cliprect.max_y)    clip.max_y = cliprect.max_y;
+
+					for (int realline = clip.min_y; realline <= clip.max_y; realline++)
 					{
-						int code, attr, flipx, flipy, color;
-						get_tile(buffered_spriteram16, is_16x16, x, y ^ 0x1f, page, code, attr, flipx, flipy, color); // yes the tilemap in RAM is flipped?!
+						int sourceline = (realline - scrolly) & 0x1ff;
 
-						int line = is_16x16 ? (sourceline & 0x0f) : (sourceline & 0x07);
+						int y = sourceline >> (is_16x16 ? 4 : 3);
 
-						int ty = (line >> 3) & 1;
-						line &= 0x7;
-						for (int tx = 0; tx <= is_16x16; tx++)
+						for (int x = 0; x < 0x40; x++)
 						{
-							int dx = sx + (scrollx & 0x3ff) + xoffs + 0x10;
-							int px = ((dx + x * (8 << is_16x16) + 0x10) & 0x3ff) - 0x10;
-							int dst_x = (px + (flipx ? is_16x16 - tx : tx) * 8) & 0x3ff;
-							dst_x = (dst_x & 0x1ff) - (dst_x & 0x200);
+							int code, attr, flipx, flipy, color;
+							// tilemap data is NOT buffered? (and yes the tilemap in RAM is flipped?!)
+							get_tile(spriteram, is_16x16, x, y ^ 0x1f, page, code, attr, flipx, flipy, color);
 
-							if ((dst_x >= clip.min_x - 8) && (dst_x <= clip.max_x))
+							int line = is_16x16 ? (sourceline & 0x0f) : (sourceline & 0x07);
+
+							int ty = (line >> 3) & 1;
+							line &= 0x7;
+							for (int tx = 0; tx <= is_16x16; tx++)
 							{
-								int realcode = code ^ tx ^ ((flipy ? is_16x16 - ty : ty) << 1);
-								drawgfx_line(bitmap, clip, which_gfx, m_spritegfx->get_data(m_realtilenumber[realcode]), color << 4, flipx, flipy, dst_x, use_shadow, realline, line, opaque);
+								int dx = sx + (scrollx & 0x3ff) + xoffs + 0x10;
+								int px = ((dx + x * (8 << is_16x16) + 0x10) & 0x3ff) - 0x10;
+								int dst_x = (px + (flipx ? is_16x16 - tx : tx) * 8) & 0x3ff;
+								dst_x = (dst_x & 0x1ff) - (dst_x & 0x200);
+
+								if ((dst_x >= clip.min_x - 8) && (dst_x <= clip.max_x))
+								{
+									int realcode = code ^ tx ^ ((flipy ? is_16x16 - ty : ty) << 1);
+									drawgfx_line(bitmap, clip, which_gfx, m_spritegfx->get_data(m_realtilenumber[realcode]), color << 4, flipx, flipy, dst_x, use_shadow, realline, line, opaque);
+								}
 							}
 						}
 					}
 				}
-			}
-			else
-			{
-				// "normal" sprite
-				int sx = s2[0];
-				int sy = s2[1];
-				int attr = s2[2];
-				int code = s2[3] + ((attr & 0x0007) << 16);
-				int flipx = (attr & 0x0010);
-				int flipy = (attr & 0x0008);
-				int color = (attr & 0xffe0) >> 5;
+				else
+				{
+					// "normal" sprite
+					int sx = s2[0];
+					int sy = s2[1];
+					int attr = s2[2];
+					int code = s2[3] + ((attr & 0x0007) << 16);
+					int flipx = (attr & 0x0010);
+					int flipy = (attr & 0x0008);
+					int color = (attr & 0xffe0) >> 5;
 
-				int sizex = use_global_size ? global_sizex : sx;
-				int sizey = use_global_size ? global_sizey : sy;
-				sizex = (1 << ((sizex & 0x0c00) >> 10)) - 1;
-				sizey = (1 << ((sizey & 0x0c00) >> 10)) - 1;
+					int sizex = use_global_size ? global_sizex : sx;
+					int sizey = use_global_size ? global_sizey : sy;
+					sizex = (1 << ((sizex & 0x0c00) >> 10)) - 1;
+					sizey = (1 << ((sizey & 0x0c00) >> 10)) - 1;
 
-				sx += xoffs;
-				sy += yoffs;
+					sx += xoffs;
+					sy += yoffs;
 
-				sx = (sx & 0x1ff) - (sx & 0x200);
+					sx = (sx & 0x1ff) - (sx & 0x200);
 
-				sy &= 0x1ff;
+					sy += global_yoffset;
 
-				int basecode = code &= ~((sizex + 1) * (sizey + 1) - 1);   // see myangel, myangel2 and grdians
+					sy &= 0x1ff;
 
-				int firstline = sy;
-				int endline = (sy + (sizey + 1) * 8) - 1;
+					if (sy & 0x100)
+						sy -= 0x200;
 
-				int realfirstline = firstline;
 
-				if (firstline < cliprect.min_y)	realfirstline = cliprect.min_y;
-				if (endline > cliprect.max_y) endline = cliprect.max_y;
+					int basecode = code &= ~((sizex + 1) * (sizey + 1) - 1);   // see myangel, myangel2 and grdians
 
-				for (int realline = realfirstline; realline <= endline; realline++)
-				{
-					int line = realline - firstline;
-					int y = (line >> 3);
-					line &= 0x7;
+					int firstline = sy;
+					int endline = (sy + (sizey + 1) * 8) - 1;
 
-					for (int x = 0; x <= sizex; x++)
+					int realfirstline = firstline;
+
+					if (firstline < cliprect.min_y)	realfirstline = cliprect.min_y;
+					if (endline > cliprect.max_y) endline = cliprect.max_y;
+
+					for (int realline = realfirstline; realline <= endline; realline++)
 					{
-						int realcode = (basecode + (flipy ? sizey - y : y)*(sizex + 1)) + (flipx ? sizex - x : x);
-						drawgfx_line(bitmap, cliprect, which_gfx, m_spritegfx->get_data(m_realtilenumber[realcode]), color << 4, flipx, flipy, sx + x * 8, use_shadow, realline, line, opaque);
+						int line = realline - firstline;
+						int y = (line >> 3);
+						line &= 0x7;
+
+						for (int x = 0; x <= sizex; x++)
+						{
+							int realcode = (basecode + (flipy ? sizey - y : y)*(sizex + 1)) + (flipx ? sizex - x : x);
+							drawgfx_line(bitmap, cliprect, which_gfx, m_spritegfx->get_data(m_realtilenumber[realcode]), color << 4, flipx, flipy, sx + x * 8, use_shadow, realline, line, opaque);
+						}
 					}
 				}
-
-
 			}
 		}
 		if (s1[0] & 0x8000) break;  // end of list marker
@@ -420,9 +531,19 @@ void seta2_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect)
 
 TIMER_CALLBACK_MEMBER(seta2_state::raster_timer_done)
 {
-
+	if (m_tmp68301)
+	{
+		if (m_rasterenabled & 1)
+		{
+			m_tmp68301->external_interrupt_1();
+			logerror("external int (vpos is %d)\n", m_screen->vpos());
+		    m_screen->update_partial(m_screen->vpos() - 1);
+		}
+	}
 }
 
+
+
 /***************************************************************************
 
 
@@ -449,6 +570,8 @@ void seta2_state::video_start()
 	}
 
 	m_raster_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(seta2_state::raster_timer_done), this));
+
+	save_item(NAME(m_private_spriteram));
 }
 
 VIDEO_START_MEMBER(seta2_state,xoffset)
@@ -488,8 +611,8 @@ WRITE_LINE_MEMBER(seta2_state::screen_vblank)
 	// rising edge
 	if (state)
 	{
-		// Buffer sprites by 1 frame
-		memcpy(m_buffered_spriteram.get(), m_spriteram, m_spriteram.bytes());
+		// Buffer sprites by 1 frame, moved to video register 0x26, improves grdians intro there
+		//memcpy(m_buffered_spriteram.get(), m_spriteram, m_spriteram.bytes());
 	}
 }