simpsons: Correct video clocks [P. Bennett]

src/mame/drivers/simpsons.cpp

@@ -173,9 +173,12 @@ void simpsons_state::device_timer(emu_timer &timer, device_timer_id id, int para
 	case TIMER_NMI:
 		m_audiocpu->set_input_line(INPUT_LINE_NMI, ASSERT_LINE);
 		break;
-	case TIMER_DMAEND:
+	case TIMER_DMASTART:
 		if (m_firq_enabled)
-			m_maincpu->set_input_line(KONAMI_FIRQ_LINE, HOLD_LINE);
+			m_maincpu->set_input_line(KONAMI_FIRQ_LINE, ASSERT_LINE);
+		break;
+	case TIMER_DMAEND:
+		m_maincpu->set_input_line(KONAMI_FIRQ_LINE, CLEAR_LINE);
 		break;
 	default:
 		throw emu_fatalerror("Unknown id in simpsons_state::device_timer");
@@ -313,8 +316,8 @@ INTERRUPT_GEN_MEMBER(simpsons_state::simpsons_irq)
 	if (m_k053246->k053246_is_irq_enabled())
 	{
 		simpsons_objdma();
-		// 32+256us delay at 8MHz dotclock; artificially shortened since actual V-blank length is unknown
+		timer_set(attotime::from_ticks(256, XTAL(24'000'000)/4), TIMER_DMASTART);
-		timer_set(attotime::from_usec(30), TIMER_DMAEND);
+		timer_set(attotime::from_ticks(256+2048, XTAL(24'000'000)/4), TIMER_DMAEND);
 	}
 }
 
@@ -335,12 +338,19 @@ void simpsons_state::simpsons(machine_config &config)
 	EEPROM_ER5911_8BIT(config, "eeprom");
 
 	WATCHDOG_TIMER(config, "watchdog");
+	//So, the horizontal timing of simpsons is 16/32/16/320
+	//6MHz dot clock
+	//Vertical is 16/8/16/224
 
 	/* video hardware */
 	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_RASTER));
-	screen.set_raw(XTAL(24'000'000)/3, 528, 112, 400, 256, 16, 240);
+
-//  6MHz dotclock is more realistic, however needs drawing updates. replace when ready
+	// Screen timings generated by the 051962, probably not programmable (except maybe between 6 amd 8MHz)
-//  screen.set_raw(XTAL(24'000'000)/4, 396, hbend, hbstart, 256, 16, 240);
+	// 6MHz dot clock
+	// horizontal: 16 cycles front porch, 32 cycles sync, 16 cycles back porch
+	// vertical: 16 lines front porch, 8 lines sync, 16 lines back porch
+
+	screen.set_raw(XTAL(24'000'000)/4, 384, 0, 320, 256, 0, 224);
 	screen.set_video_attributes(VIDEO_UPDATE_AFTER_VBLANK);
 	screen.set_screen_update(FUNC(simpsons_state::screen_update_simpsons));
 	screen.set_palette("palette");
@@ -348,6 +358,7 @@ void simpsons_state::simpsons(machine_config &config)
 	PALETTE(config, "palette").set_format(palette_device::xBGR_555, 2048).enable_shadows().enable_hilights();
 
 	K052109(config, m_k052109, 0);
+	m_k052109->set_xy_offset(-96, -16);
 	m_k052109->set_palette("palette");
 	m_k052109->set_screen("screen");
 	m_k052109->set_tile_callback(FUNC(simpsons_state::tile_callback));
@@ -355,7 +366,7 @@ void simpsons_state::simpsons(machine_config &config)
 
 	K053246(config, m_k053246, 0);
 	m_k053246->set_sprite_callback(FUNC(simpsons_state::sprite_callback));
-	m_k053246->set_config(NORMAL_PLANE_ORDER, 53, 23);
+	m_k053246->set_config(NORMAL_PLANE_ORDER, -43, 39);
 	m_k053246->set_palette("palette");
 
 	K053251(config, m_k053251, 0);

src/mame/includes/simpsons.h

@@ -32,6 +32,7 @@ private:
 	enum
 	{
 		TIMER_NMI,
+		TIMER_DMASTART,
 		TIMER_DMAEND
 	};
 

src/mame/machine/simpsons.cpp

@@ -22,6 +22,8 @@ WRITE8_MEMBER(simpsons_state::simpsons_eeprom_w)
 	simpsons_video_banking(data & 0x03);
 
 	m_firq_enabled = data & 0x04;
+	if (!m_firq_enabled)
+		m_maincpu->set_input_line(KONAMI_FIRQ_LINE, CLEAR_LINE);
 }
 
 /***************************************************************************

src/mame/video/k052109.cpp

@@ -184,6 +184,8 @@ k052109_device::k052109_device(const machine_config &mconfig, const char *tag, d
 	m_irq_enabled(0),
 	m_romsubbank(0),
 	m_scrollctrl(0),
+	m_dx(0),
+	m_dy(0),
 	m_char_rom(*this, DEVICE_SELF),
 	m_k052109_cb(*this),
 	m_irq_handler(*this),
@@ -248,8 +250,12 @@ void k052109_device::device_start()
 	m_tilemap[1]->set_transparent_pen(0);
 	m_tilemap[2]->set_transparent_pen(0);
 
-	m_tilemap[1]->set_scrolldx(6, 6);
+	m_tilemap[0]->set_scrolldx(m_dx, m_dx);
-	m_tilemap[2]->set_scrolldx(6, 6);
+	m_tilemap[1]->set_scrolldx(m_dx+6, m_dx+6);
+	m_tilemap[2]->set_scrolldx(m_dx+6, m_dx+6);
+	m_tilemap[0]->set_scrolldy(m_dy, m_dy);
+	m_tilemap[1]->set_scrolldy(m_dy, m_dy);
+	m_tilemap[2]->set_scrolldy(m_dy, m_dy);
 
 	save_pointer(NAME(m_ram), 0x6000);
 	save_item(NAME(m_rmrd_line));
@@ -294,6 +300,12 @@ void k052109_device::device_post_load()
     DEVICE HANDLERS
 *****************************************************************************/
 
+void k052109_device::set_xy_offset(int dx, int dy)
+{
+	m_dx = dx;
+	m_dy = dy;
+}
+
 void k052109_device::vblank_callback(screen_device &screen, bool state)
 {
 	if (state && m_irq_enabled)

src/mame/video/k052109.h

@@ -58,6 +58,8 @@ public:
 
 	void vblank_callback(screen_device &screen, bool state);
 
+	void set_xy_offset(int dx, int dy);
+
 protected:
 	// device-level overrides
 	virtual void device_start() override;
@@ -86,6 +88,8 @@ private:
 	uint8_t    m_irq_enabled;
 	uint8_t    m_romsubbank, m_scrollctrl;
 
+	int        m_dx, m_dy;
+
 	optional_region_ptr<uint8_t> m_char_rom;
 
 	tile_delegate m_k052109_cb;