alpha/splendor.cpp: denote same irq meanings as per equites.cpp bullfgtr

src/mame/alpha/equites.cpp

@@ -557,10 +557,10 @@ TIMER_DEVICE_CALLBACK_MEMBER(equites_state::scanline_cb)
 
     // all games but bullfgtr have both valid
     // bullfgtr definitely expects to vblank from 2, reversing will make it to run at half speed.
-	if(scanline == 232) // vblank-out irq
+	if(scanline == 232) // vblank-in irq
 		m_maincpu->set_input_line(2, HOLD_LINE);
 
-	if(scanline == 24) // vblank-in irq or sprite DMA done
+	if(scanline == 24) // vblank-out irq or sprite DMA done
 		m_maincpu->set_input_line(1, HOLD_LINE);
 }
 

src/mame/alpha/splendor.cpp

@@ -20,9 +20,9 @@ Stephh's notes (based on the games M68000 code and some tests) :
 
 hvoltage:
 - There is sort of "debug mode" that you can access if 0x000038.w returns 0x0000
-  instead of 0xffff. To enable it, use the MAME debugger or cheats.
-- When you are in "debug mode", the Inputs and Dip Switches have special features.
-  Here is IMO the full list :
+  instead of 0xffff under irq 1. To enable it, use the MAME debugger or cheats.
+  This also applies to all non-parent splndrbt sets, at least for the freeze part.
+- When you are in "debug mode", the Inputs and Dip Switches have special features:
 
   * pressing IPT_JOYSTICK_DOWN of player 2 freezes the game
   * pressing IPT_JOYSTICK_UP of player 2 unfreezes the game
@@ -130,7 +130,7 @@ class splendor_state : public driver_device
 	TILE_GET_INFO_MEMBER(bg_info);
 	void palette(palette_device &palette) const;
 	uint32_t screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
-	TIMER_DEVICE_CALLBACK_MEMBER(scanline);
+	TIMER_DEVICE_CALLBACK_MEMBER(scanline_cb);
 	void draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect);
 	void copy_bg(bitmap_ind16 &dst_bitmap, const rectangle &cliprect);
 
@@ -395,15 +395,19 @@ uint32_t splendor_state::screen_update(screen_device &screen, bitmap_ind16 &bitm
 /******************************************************************************/
 // Interrupt Handlers
 
-TIMER_DEVICE_CALLBACK_MEMBER(splendor_state::scanline)
+// Same as alpha/equites.cpp, including the almost empty irq 1 service observed with bullfgtr
+TIMER_DEVICE_CALLBACK_MEMBER(splendor_state::scanline_cb)
 {
 	int scanline = param;
 
-	if(scanline == 224) // vblank-out irq
-		m_maincpu->set_input_line(1, HOLD_LINE);
-
-	if(scanline == 32) // vblank-in irq
+    // vblank-in irq
+	if(scanline == 224)
 		m_maincpu->set_input_line(2, HOLD_LINE);
+
+    // vblank-out irq or sprite DMA end, applies bg scroll writes
+    // and checks debug flag (if available) for screen freeze.
+	if(scanline == 32)
+		m_maincpu->set_input_line(1, HOLD_LINE);
 }
 
 
@@ -635,7 +639,7 @@ void splendor_state::splndrbt(machine_config &config)
 	// basic machine hardware
 	M68000(config, m_maincpu, 24_MHz_XTAL/4); // 68000P8 running at 6mhz, verified on pcb
 	m_maincpu->set_addrmap(AS_PROGRAM, &splendor_state::splndrbt_map);
-	TIMER(config, "scantimer").configure_scanline(FUNC(splendor_state::scanline), "screen", 0, 1);
+	TIMER(config, "scantimer").configure_scanline(FUNC(splendor_state::scanline_cb), "screen", 0, 1);
 
 	LS259(config, m_mainlatch);
 	m_mainlatch->q_out_cb<0>().set(FUNC(splendor_state::flip_screen_set));