x68k: if raster irq is on same line, trigger it immediately

mamedev · May 14, 2021 · c89891e · c89891e
1 parent 57feb3f
commit c89891e
Showing 1 changed file with 8 additions and 7 deletions.
diff --git a/src/mame/video/x68k_crtc.cpp b/src/mame/video/x68k_crtc.cpp
@@ -5,7 +5,7 @@
 #include "video/x68k_crtc.h"
 #include "screen.h"
 
-//#define VERBOSE 0
+//#define VERBOSE 1
 #include "logmacro.h"
 
 // device type definitions
@@ -397,14 +397,15 @@ void x68k_crtc_device::crtc_w(offs_t offset, u16 data, u16 mem_mask)
 	case 9:  // CRTC raster IRQ (GPIP6)
 		{
 			data = m_reg[9];
-			attotime irq_time = screen().time_until_pos((data) / m_vmultiple,2);
-
-			if (data != screen().vpos())
+			attotime irq_time = attotime::zero;
+			if ((data / m_vmultiple) != screen().vpos())
+			{
+				irq_time = screen().time_until_pos((data) / m_vmultiple,2);
 				m_rint_callback(1);
-			if (irq_time.as_double() > 0)
-				m_raster_irq_timer->adjust(irq_time, (data) / m_vmultiple);
+			}
+			m_raster_irq_timer->adjust(irq_time, (data) / m_vmultiple);
+			LOG("CRTC: Write to raster IRQ register - %i %i %f\n",data, screen().vpos(), irq_time.as_double());
 		}
-		LOG("CRTC: Write to raster IRQ register - %i\n",data);
 		break;
 	case 20:
 		if (ACCESSING_BITS_0_7)