Corrected refresh rate

src/mame/drivers/naomi.c

@@ -2499,7 +2499,7 @@ static MACHINE_CONFIG_START( naomi_aw_base, naomi_state )
 
 	/* video hardware */
 	MCFG_SCREEN_ADD("screen", RASTER)
-	MCFG_SCREEN_RAW_PARAMS(CPU_CLOCK/2/4, 820, 0, 640, 532, 0, 480) /* TODO: PVR is clocked at 100 MHz, pixel clock is guessed to be /4 so ~57 fps. */
+	MCFG_SCREEN_RAW_PARAMS(13458568*2, 820, 0, 640, 532, 0, 480) /* TODO: where pclk actually comes? */
 	MCFG_SCREEN_UPDATE_DEVICE("powervr2", powervr2_device, screen_update)
 	MCFG_PALETTE_LENGTH(0x1000)
 	MCFG_POWERVR2_ADD("powervr2", WRITE8(dc_state, pvr_irq))

src/mame/video/powervr2.c

@@ -1450,6 +1450,8 @@ WRITE32_MEMBER( powervr2_device::palette_w )
 
 void powervr2_device::update_screen_format()
 {
+	INT32 spg_hsize = spg_load & 0x3ff;
+	INT32 spg_vsize = (spg_load >> 16) & 0x3ff;
 	INT32 spg_hbstart = spg_hblank & 0x3ff;
 	INT32 spg_hbend = (spg_hblank >> 16) & 0x3ff;
 	INT32 spg_vbstart = spg_vblank & 0x3ff;
@@ -1457,6 +1459,8 @@ void powervr2_device::update_screen_format()
 	INT32 vo_horz_start_pos = vo_startx & 0x3ff;
 	INT32 vo_vert_start_pos_f1 = vo_starty & 0x3ff;
 
+	attoseconds_t refresh = HZ_TO_ATTOSECONDS(13458568*2) * spg_hsize * spg_vsize;
+
 	rectangle visarea = m_screen->visible_area();
 	/* FIXME: right visible area calculations aren't known yet*/
 	visarea.min_x = 0;
@@ -1464,7 +1468,7 @@ void powervr2_device::update_screen_format()
 	visarea.min_y = 0;
 	visarea.max_y = ((spg_vbstart - spg_vbend - vo_vert_start_pos_f1) <= 0x100 ? 240 : 480) - 1;
 
-	m_screen->configure(spg_hbstart, spg_vbstart, visarea, m_screen->frame_period().attoseconds );
+	m_screen->configure(spg_hsize, spg_vsize, visarea, refresh );
 }
 
 
@@ -2572,6 +2576,7 @@ void powervr2_device::pvr_drawframebuffer(bitmap_rgb32 &bitmap,const rectangle &
 			break;
 
 		case 0x02: ; // 888 RGB 24-bit - suchie3 - HACKED, see pvr_accumulationbuffer_to_framebuffer!
+			popmessage("888RGB 24-bit mode used, contact MAME/MESSdev");
 			for (y=0;y <= dy;y++)
 			{
 				addrp = fb_r_sof1+y*xi*2;

src/mess/drivers/dccons.c

@@ -1,7 +1,7 @@
 /*
 
     dc.c - Sega Dreamcast driver
-    by R. Belmont
+    by R. Belmont & Angelo Salese
 
     SH-4 @ 200 MHz
     ARM7DI @ 2.8223 MHz (no T or M extensions)
@@ -17,6 +17,18 @@
     PCLKs = 26917135 (NTSC 480 @ 59.94), 26944080 (VGA 480 @ 60.0), 13458568 (NTSC 240 @ 59.94),
             25925600 (PAL 480 @ 50.00), 13462800 (PAL 240 @ 50.00)
 
+    TODO:
+    - DC splash logo: video and audio are off-sync
+    - RTC error always pops up at start-up, tied to the aforementioned?
+    - Only JP games boots so far;
+    - Inputs doesn't work most of the time;
+    - Capcom vs. SNK Pro: asserts after VMU message
+    - 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;
+	- Tetris 4D: has color bugs, hangs at FMV anyway
+
 */
 
 #include "emu.h"
@@ -95,7 +107,7 @@ READ64_MEMBER(dc_cons_state::dc_pdtra_r )
 	cable setting, (0-1) VGA, (2) TV RGB (3) TV VBS/Y + S/C.
 	Note: several games doesn't like VGA setting (i.e. Idol Janshi wo Tsukucchaou, Airforce Delta), so hard-wire it to most common setting for now.
 	*/
-	out |= 0x02 << 8;
+	out |= ioport("SCREEN_TYPE")->read() << 8;
 
 	return out;
 }
@@ -221,7 +233,7 @@ static MACHINE_CONFIG_START( dc, dc_cons_state )
 
 	/* video hardware */
 	MCFG_SCREEN_ADD("screen", RASTER)
-	MCFG_SCREEN_RAW_PARAMS(CPU_CLOCK/2/4, 820, 0, 640, 532, 0, 480) /* TODO: PVR is clocked at 100 MHz, pixel clock is guessed to be /4 so ~57 fps. */
+	MCFG_SCREEN_RAW_PARAMS(13458568*2, 857, 0, 640, 524, 0, 480) /* TODO: where pclk actually comes? */
 	MCFG_SCREEN_UPDATE_DEVICE("powervr2", powervr2_device, screen_update)
 	MCFG_PALETTE_LENGTH(0x1000)
 	MCFG_POWERVR2_ADD("powervr2", WRITE8(dc_state, pvr_irq))
@@ -420,6 +432,13 @@ static INPUT_PORTS_START( dc )
 	PORT_DIPNAME( 0x01, 0x00, "Bilinear Filtering" )
 	PORT_DIPSETTING(    0x00, DEF_STR( Off ) )
 	PORT_DIPSETTING(    0x01, DEF_STR( On ) )
+
+	PORT_START("SCREEN_TYPE")
+	PORT_CONFNAME( 0x03, 0x00, "Connection Type" )
+	PORT_CONFSETTING(    0x00, "NTSC" )
+	PORT_CONFSETTING(    0x01, "PAL" )
+	PORT_CONFSETTING(    0x02, "VGA (0)" )
+	PORT_CONFSETTING(    0x03, "VGA (1)" )
 INPUT_PORTS_END