Experimental scanline code, to be improved on a later date

src/mame/drivers/naomi.c

@@ -2486,6 +2486,7 @@ static MACHINE_CONFIG_START( naomi_aw_base, naomi_state )
 	MCFG_CPU_CONFIG(sh4cpu_config)
 	MCFG_CPU_PROGRAM_MAP(naomi_map)
 	MCFG_CPU_IO_MAP(naomi_port)
+	MCFG_TIMER_DRIVER_ADD_SCANLINE("scantimer", dc_state, dc_scanline, "screen", 0, 1)
 
 	MCFG_CPU_ADD("soundcpu", ARM7, ((XTAL_33_8688MHz*2)/3)/8)   // AICA bus clock is 2/3rds * 33.8688.  ARM7 gets 1 bus cycle out of each 8.
 	MCFG_CPU_PROGRAM_MAP(dc_audio_map)

src/mame/includes/dc.h

@@ -85,6 +85,7 @@ class dc_state : public driver_device
 	optional_device<naomi_g1_device> m_naomig1;
 
 	void generic_dma(UINT32 main_adr, void *dma_ptr, UINT32 length, UINT32 size, bool to_mainram);
+	TIMER_DEVICE_CALLBACK_MEMBER(dc_scanline);
 };
 
 /*--------- Ch2-DMA Control Registers ----------*/

src/mame/machine/dc.c

@@ -807,3 +807,8 @@ WRITE32_MEMBER(dc_state::dc_arm_aica_w)
 {
 	aica_w(machine().device("aica"), space, offset*2, data, mem_mask&0xffff);
 }
+
+TIMER_DEVICE_CALLBACK_MEMBER(dc_state::dc_scanline)
+{
+	m_powervr2->pvr_scanline_timer(param);
+}

src/mame/video/powervr2.c

@@ -1129,11 +1129,11 @@ WRITE32_MEMBER( powervr2_device::spg_vblank_int_w )
 	COMBINE_DATA(&spg_vblank_int);
 
 	/* clear pending irqs and modify them with the updated ones */
-	vbin_timer->adjust(attotime::never);
+//	vbin_timer->adjust(attotime::never);
-	vbout_timer->adjust(attotime::never);
+//	vbout_timer->adjust(attotime::never);
 
-	vbin_timer->adjust(m_screen->time_until_pos(spg_vblank_int & 0x3ff));
+//	vbin_timer->adjust(m_screen->time_until_pos(spg_vblank_int & 0x3ff));
-	vbout_timer->adjust(m_screen->time_until_pos((spg_vblank_int >> 16) & 0x3ff));
+//	vbout_timer->adjust(m_screen->time_until_pos((spg_vblank_int >> 16) & 0x3ff));
 }
 
 READ32_MEMBER( powervr2_device::spg_hblank_r )
@@ -2763,14 +2763,14 @@ TIMER_CALLBACK_MEMBER(powervr2_device::vbin)
 	irq_cb(VBL_IN_IRQ);
 
 	//popmessage("VII %d VOI %d VI %d VO %d VS %d",spg_vblank_int & 0x3ff,(spg_vblank_int >> 16) & 0x3ff,spg_vblank & 0x3ff,(spg_vblank >> 16) & 0x3ff,(spg_load >> 16) & 0x3ff);
-	vbin_timer->adjust(m_screen->time_until_pos(spg_vblank_int & 0x3ff));
+//	vbin_timer->adjust(m_screen->time_until_pos(spg_vblank_int & 0x3ff));
 }
 
 TIMER_CALLBACK_MEMBER(powervr2_device::vbout)
 {
 	irq_cb(VBL_OUT_IRQ);
 
-	vbout_timer->adjust(m_screen->time_until_pos((spg_vblank_int >> 16) & 0x3ff));
+//	vbout_timer->adjust(m_screen->time_until_pos((spg_vblank_int >> 16) & 0x3ff));
 }
 
 TIMER_CALLBACK_MEMBER(powervr2_device::hbin)
@@ -3006,8 +3006,8 @@ void powervr2_device::device_start()
 
 	computedilated();
 
-	vbout_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(powervr2_device::vbout),this));
+//	vbout_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(powervr2_device::vbout),this));
-	vbin_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(powervr2_device::vbin),this));
+//	vbin_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(powervr2_device::vbin),this));
 	hbin_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(powervr2_device::hbin),this));
 
 	endofrender_timer_isp = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(powervr2_device::endofrender_isp),this));
@@ -3149,8 +3149,8 @@ void powervr2_device::device_reset()
 	renderselect= -1;
 	grabsel=0;
 
-	vbout_timer->adjust(m_screen->time_until_pos((spg_vblank_int >> 16) & 0x3ff));
+//	vbout_timer->adjust(m_screen->time_until_pos((spg_vblank_int >> 16) & 0x3ff));
-	vbin_timer->adjust(m_screen->time_until_pos(spg_vblank_int & 0x3ff));
+//	vbin_timer->adjust(m_screen->time_until_pos(spg_vblank_int & 0x3ff));
 	hbin_timer->adjust(m_screen->time_until_pos(0, ((spg_hblank_int >> 16) & 0x3ff)-1));
 
 	scanline = 0;
@@ -3164,3 +3164,18 @@ void powervr2_device::device_reset()
 	dc_texture_ram = state->dc_texture_ram.target();
 	dc_framebuffer_ram = state->dc_framebuffer_ram.target();
 }
+
+/* called by TIMER_ADD_PERIODIC, in driver sections */
+void powervr2_device::pvr_scanline_timer(int vpos)
+{
+	int vbin_line = spg_vblank_int & 0x3ff;
+	int vbout_line = (spg_vblank_int >> 16) & 0x3ff;
+
+	if(vbin_line == vpos)
+		irq_cb(VBL_IN_IRQ);
+
+	if(vbout_line == vpos)
+		irq_cb(VBL_OUT_IRQ);
+
+}
+

src/mame/video/powervr2.h

@@ -264,6 +264,7 @@ public:
 	TIMER_CALLBACK_MEMBER(pvr_dma_irq);
 
 	void pvr_dma_execute(address_space &space);
+	void pvr_scanline_timer(int vpos);
 	UINT32 screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 
 protected:

src/mess/drivers/dccons.c

@@ -26,7 +26,7 @@
     - F355 Challenge: asserts after Sega logo;
 	- Idol Janshi wo Tsukucchaou: pixel aspect is way wrong (stretched and offsetted horizontally)
 	- Power Stone: hangs at Capcom logo;
-	- Sega GT: hangs at "produced by Sega" screen;
+	- Sega GT: hangs with a white screen after pressing start on attract mode (executes SCSI command 0x20 -> CD-Play);
 	- Tetris 4D: has color bugs, hangs at FMV anyway
 
 	Note:
@@ -369,6 +369,7 @@ static MACHINE_CONFIG_START( dc, dc_cons_state )
 	MCFG_CPU_CONFIG(sh4cpu_config)
 	MCFG_CPU_PROGRAM_MAP(dc_map)
 	MCFG_CPU_IO_MAP(dc_port)
+	MCFG_TIMER_DRIVER_ADD_SCANLINE("scantimer", dc_state, dc_scanline, "screen", 0, 1)
 
 	MCFG_CPU_ADD("soundcpu", ARM7, ((XTAL_33_8688MHz*2)/3)/8)   // AICA bus clock is 2/3rds * 33.8688.  ARM7 gets 1 bus cycle out of each 8.
 	MCFG_CPU_PROGRAM_MAP(dc_audio_map)