megadriv.c: small steps to keep a few 32x operations inside 32x. nw.

src/mame/includes/megadriv.h

@@ -97,7 +97,7 @@ public:
 		m_segacd(*this,"segacd"),
 		m_megadrive_ram(*this,"megadrive_ram")
 	{ }
-	optional_device<cpu_device> m_maincpu;
+	required_device<cpu_device> m_maincpu;
 	optional_device<cpu_device> m_z80snd;
 	required_device<sega_genesis_vdp_device> m_vdp;
 	optional_device<sega_32x_device> m_32x;

src/mame/machine/mega32x.c

@@ -1602,7 +1602,7 @@ int _32x_fifo_available_callback(device_t *device, UINT32 src, UINT32 dst, UINT3
 
 
 
-UINT32* sega_32x_device::_32x_render_videobuffer_to_screenbuffer_helper(int scanline)
+void sega_32x_device::_32x_render_videobuffer_to_screenbuffer_helper(int scanline)
 {
 	int x;
 
@@ -1707,8 +1707,50 @@ UINT32* sega_32x_device::_32x_render_videobuffer_to_screenbuffer_helper(int scan
 			}
 		}
 	}
+}
 
-	return m_32x_linerender;
+int sega_32x_device::_32x_render_videobuffer_to_screenbuffer_lopri(int x, UINT16 &lineptr)
+{
+	int drawn = 0;
+
+	if (m_32x_displaymode != 0)
+	{
+		if (!m_32x_videopriority)
+		{
+			if (!(m_32x_linerender[x] & 0x8000))
+			{
+				lineptr = m_32x_linerender[x] & 0x7fff;
+				drawn = 1;
+			}
+		}
+		else
+		{
+			if (m_32x_linerender[x] & 0x8000)
+			{
+				lineptr = m_32x_linerender[x] & 0x7fff;
+				drawn = 1;
+			}
+		}
+	}
+
+	return drawn;
+}
+
+void sega_32x_device::_32x_render_videobuffer_to_screenbuffer_hipri(int x, UINT16 &lineptr)
+{
+	if (m_32x_displaymode != 0)
+	{
+		if (!m_32x_videopriority)
+		{
+			if (m_32x_linerender[x] & 0x8000)
+				lineptr = m_32x_linerender[x] & 0x7fff;
+		}
+		else
+		{
+			if (!(m_32x_linerender[x] & 0x8000))
+				lineptr = m_32x_linerender[x] & 0x7fff;
+		}
+	}
 }
 
 static const sh2_cpu_core sh2_conf_master = { 0, NULL, _32x_fifo_available_callback };

src/mame/machine/mega32x.h

@@ -104,7 +104,9 @@ public:
 	DECLARE_WRITE16_MEMBER( _32x_sh2_master_401e_w );
 	DECLARE_WRITE16_MEMBER( _32x_sh2_slave_401e_w );
 
-	UINT32* _32x_render_videobuffer_to_screenbuffer_helper(int scanline);
+	void _32x_render_videobuffer_to_screenbuffer_helper(int scanline);
+	int _32x_render_videobuffer_to_screenbuffer_lopri(int x, UINT16 &lineptr);
+	void _32x_render_videobuffer_to_screenbuffer_hipri(int x, UINT16 &lineptr);
 	int sh2_master_pwmint_enable, sh2_slave_pwmint_enable;
 
 	void _32x_check_framebuffer_swap(bool enabled);
@@ -112,19 +114,12 @@ public:
 	void _32x_scanline_cb0();
 	void _32x_scanline_cb1(int scanline);
 
-	/* our current main rendering code needs to know this for mixing in */
-	int m_32x_displaymode;
-	int m_32x_videopriority;
 	/* our main vblank handler resets this */
 	int m_32x_hcount_compare_val;
 	int m_sh2_are_running;
 	int m_32x_240mode;
 	UINT16 m_32x_a1518a_reg;
 
-
-	UINT32 m_32x_linerender[320+258]; // tmp buffer (bigger than it needs to be to simplify RLE decode)
-
-
 	void handle_pwm_callback();
 	void calculate_pwm_timer();
 	UINT16 m_pwm_ctrl, m_pwm_cycle, m_pwm_tm_reg;
@@ -138,6 +133,7 @@ public:
 	UINT16 get_hposition(void);
 
 	emu_timer *m_32x_pwm_timer;
+
 protected:
 	virtual void device_start();
 	virtual void device_reset();
@@ -145,7 +141,13 @@ protected:
 	// optional information overrides
 //  virtual const rom_entry *device_rom_region() const;
 	virtual machine_config_constructor device_mconfig_additions() const;
+
 private:
+
+	int m_32x_displaymode;
+	int m_32x_videopriority;
+	UINT32 m_32x_linerender[320+258]; // tmp buffer (bigger than it needs to be to simplify RLE decode)
+
 //  virtual void device_config_complete();
 	int m_32x_adapter_enabled;
 	int m_32x_access_auth;

src/mame/machine/megavdp.c

@@ -2498,124 +2498,50 @@ void sega_genesis_vdp_device::genesis_render_videoline_to_videobuffer(int scanli
 void sega_genesis_vdp_device::genesis_render_videobuffer_to_screenbuffer(running_machine &machine, int scanline)
 {
 	sega_32x_device *_32xdev = machine.device<sega_32x_device>("sega32x"); // take this out of the VDP eventually
-
+	UINT16 *lineptr;
-
-	UINT16*lineptr;
-	int x;
 
 	if (!m_use_alt_timing)
-	{
 		lineptr = &m_render_bitmap->pix16(scanline);
-	}
 	else
-	{
 		lineptr = m_render_line;
-	}
-
 
 	if (_32xdev) _32xdev->_32x_render_videobuffer_to_screenbuffer_helper(scanline);
 
-
+	for (int x = 0; x < 320; x++)
-
-	if (!MEGADRIVE_REG0C_SHADOW_HIGLIGHT)
 	{
-		for (x=0;x<320;x++)
+		UINT32 dat = m_video_renderline[x];
+		int drawn = 0;
+
+		// low priority 32x - if it's the bg pen, we have a 32x, and its display is enabled...
+		if (_32xdev && dat & 0x20000)
+			drawn = _32xdev->_32x_render_videobuffer_to_screenbuffer_lopri(x, lineptr[x]);
+
+		if (!(dat & 0x20000))
+			m_render_line_raw[x] = 0x100;
+		else
+			m_render_line_raw[x] = 0x000;
+
+
+		if (!drawn)
 		{
-			UINT32 dat;
+			if (!MEGADRIVE_REG0C_SHADOW_HIGLIGHT)
-			dat = m_video_renderline[x];
-			int drawn = 0;
-
-			// low priority 32x - if it's the bg pen, we have a 32x, and it's display is enabled...
-			if (_32xdev)
 			{
-				if ((dat&0x20000) && (_32xdev->m_32x_displaymode != 0))
+				if (dat & 0x10000)
 				{
-					if (!_32xdev->m_32x_videopriority)
+					lineptr[x] = megadrive_vdp_palette_lookup_sprite[(dat & 0x3f)];
-					{
-						if (!(_32xdev->m_32x_linerender[x]&0x8000))
-						{
-							lineptr[x] = _32xdev->m_32x_linerender[x]&0x7fff;
-							drawn = 1;
-						}
-					}
-					else
-					{
-						if ((_32xdev->m_32x_linerender[x]&0x8000))
-						{
-							lineptr[x] = _32xdev->m_32x_linerender[x]&0x7fff;
-							drawn = 1;
-						}
-					}
-				}
-			}
-
-			if (!(dat&0x20000))
-				m_render_line_raw[x] = 0x100;
-			else
-				m_render_line_raw[x] = 0x000;
-
-
-			if (drawn==0)
-			{
-				if (dat&0x10000)
-				{
-					lineptr[x] = megadrive_vdp_palette_lookup_sprite[(dat&0x3f)];
 					m_render_line_raw[x] |= (dat & 0x3f) | 0x080;
 				}
 				else
 				{
-					lineptr[x] = megadrive_vdp_palette_lookup[(dat&0x3f)];
+					lineptr[x] = megadrive_vdp_palette_lookup[(dat & 0x3f)];
 					m_render_line_raw[x] |= (dat & 0x3f) | 0x040;
 				}
+
 			}
-
-
-
-		}
-	}
-	else
-	{
-		for (x=0;x<320;x++)
-		{
-			UINT32 dat;
-			dat = m_video_renderline[x];
-
-			int drawn = 0;
-
-			// low priority 32x - if it's the bg pen, we have a 32x, and it's display is enabled...
-			if (_32xdev)
-			{
-				if ((dat&0x20000) && (_32xdev->m_32x_displaymode != 0))
-				{
-					if (!_32xdev->m_32x_videopriority)
-					{
-						if (!(_32xdev->m_32x_linerender[x]&0x8000))
-						{
-							lineptr[x] = _32xdev->m_32x_linerender[x]&0x7fff;
-							drawn = 1;
-						}
-					}
-					else
-					{
-						if ((_32xdev->m_32x_linerender[x]&0x8000))
-						{
-							lineptr[x] = _32xdev->m_32x_linerender[x]&0x7fff;
-							drawn = 1;
-						}
-					}
-				}
-			}
-
-			if (!(dat&0x20000))
-				m_render_line_raw[x] = 0x100;
 			else
-				m_render_line_raw[x] = 0x000;
-
-
-			if (drawn==0)
 			{
 				/* Verify my handling.. I'm not sure all cases are correct */
-				switch (dat&0x1e000)
+				switch (dat & 0x1e000)
 				{
 					case 0x00000: // low priority, no shadow sprite, no highlight = shadow
 					case 0x02000: // low priority, shadow sprite, no highlight = shadow
@@ -2623,26 +2549,26 @@ void sega_genesis_vdp_device::genesis_render_videobuffer_to_screenbuffer(running
 					case 0x10000: // (sprite) low priority, no shadow sprite, no highlight = shadow
 					case 0x12000: // (sprite) low priority, shadow sprite, no highlight = shadow
 					case 0x16000: // (sprite) normal pri,   shadow sprite, no highlight = shadow?
-						lineptr[x] = megadrive_vdp_palette_lookup_shadow[(dat&0x3f)];
+						lineptr[x] = megadrive_vdp_palette_lookup_shadow[(dat & 0x3f)];
 						m_render_line_raw[x] |= (dat & 0x3f) | 0x000;
 						break;
 
 					case 0x4000: // normal pri, no shadow sprite, no highlight = normal;
 					case 0x8000: // low pri, highlight sprite = normal;
-						lineptr[x] = megadrive_vdp_palette_lookup[(dat&0x3f)];
+						lineptr[x] = megadrive_vdp_palette_lookup[(dat & 0x3f)];
 						m_render_line_raw[x] |= (dat & 0x3f) | 0x040;
 						break;
 
 					case 0x14000: // (sprite) normal pri, no shadow sprite, no highlight = normal;
 					case 0x18000: // (sprite) low pri, highlight sprite = normal;
-						lineptr[x] = megadrive_vdp_palette_lookup_sprite[(dat&0x3f)];
+						lineptr[x] = megadrive_vdp_palette_lookup_sprite[(dat & 0x3f)];
 						m_render_line_raw[x] |= (dat & 0x3f) | 0x080;
 						break;
 
 
 					case 0x0c000: // normal pri, highlight set = highlight?
 					case 0x1c000: // (sprite) normal pri, highlight set = highlight?
-						lineptr[x] = megadrive_vdp_palette_lookup_highlight[(dat&0x3f)];
+						lineptr[x] = megadrive_vdp_palette_lookup_highlight[(dat & 0x3f)];
 						m_render_line_raw[x] |= (dat & 0x3f) | 0x0c0;
 						break;
 
@@ -2651,44 +2577,22 @@ void sega_genesis_vdp_device::genesis_render_videobuffer_to_screenbuffer(running
 					case 0x1a000: // (sprite)shadow set, highlight set - not possible
 					case 0x1e000: // (sprite)shadow set, highlight set, normal set, not possible
 					default:
-						lineptr[x] = m_render_line_raw[x] |= (machine.rand()&0x3f);
+						lineptr[x] = m_render_line_raw[x] |= (machine.rand() & 0x3f);
-					break;
+						break;
-				}
-
-			}
-
-
-
-		}
-
-	}
-
-
-	// high priority 32x
-	if (_32xdev)
-	{
-		if (_32xdev->m_32x_displaymode != 0)
-		{
-			for (x=0;x<320;x++)
-			{
-				if (!_32xdev->m_32x_videopriority)
-				{
-					if ((_32xdev->m_32x_linerender[x]&0x8000))
-						lineptr[x] = _32xdev->m_32x_linerender[x]&0x7fff;
-				}
-				else
-				{
-					if (!(_32xdev->m_32x_linerender[x]&0x8000))
-						lineptr[x] = _32xdev->m_32x_linerender[x]&0x7fff;
 				}
 			}
 		}
+
+		// high priority 32x
+		if (_32xdev)
+			_32xdev->_32x_render_videobuffer_to_screenbuffer_hipri(x, lineptr[x]);
 	}
 }
 
 void sega_genesis_vdp_device::genesis_render_scanline(running_machine &machine)
 {
 	int scanline = genesis_get_scanline_counter(machine);
+
 	if (scanline >= 0 && scanline < m_visible_scanlines)
 	{
 		//if (MEGADRIVE_REG01_DMA_ENABLE==0) mame_printf_debug("off\n");

src/mess/machine/md_slot.c

@@ -886,6 +886,8 @@ int base_md_cart_slot_device::get_cart_type(UINT8 *ROM, UINT32 len)
 		}
 		else
 		{
+			logerror("No SRAM detected from header, using fallback SRAM in case this is a broken header\n");
+
 			// Unfortunately, there are ROMs without correct info in the header,
 			// Hence, when loading from fullpath we do the SRAM mapping anyway...
 			// but treat it in a custom way