For the Blitter, use a common function to propagate the state of the IRQ line to the MFP

src/blitter.c

@@ -210,6 +210,8 @@ typedef struct
 	uint16_t	CountBusBlitter;			/* To count bus accesses made by the blitter */
 	uint16_t	CountBusCpu;				/* To count bus accesses made by the CPU */
 	uint8_t		ContinueLater;				/* 0=false / 1=true */
+
+	uint8_t		IRQ_Line;				/* 0=IRQ set  1=IRQ cleared */
 } BLITTERSTATE;
 
 
@@ -308,6 +310,43 @@ void Blitter_Reset ( void )
 
 
 
+/*-----------------------------------------------------------------------*/
+/**
+ * Set or reset the Blitter's IRQ line
+ * IRQ signal is inverted (0/low irq set, 1/high irq cleared)
+ *
+ * The IRQ signal is connected to GPIP5 on the MFP on ST/STE
+ */
+static void	Blitter_Set_Line_IRQ_MFP ( uint8_t bit )
+{
+	uint8_t		Line_State;
+
+	LOG_TRACE ( TRACE_BLITTER, "blitter set irq line val=%d (%s) VBL=%d HBL=%d\n" , bit , bit==BLITTER_IRQ_ON ? "on" : "off" , nVBLs , nHBL );
+
+	if ( bit == BLITTER_IRQ_ON )
+		Line_State = MFP_GPIP_STATE_LOW;
+	else
+		Line_State = MFP_GPIP_STATE_HIGH;
+
+	BlitterState.IRQ_Line = Line_State;
+
+	MFP_GPIP_Set_Line_Input ( pMFP_Main , MFP_GPIP_LINE_GPU_DONE , Line_State );
+}
+
+
+
+/*-----------------------------------------------------------------------*/
+/**
+ * Return the value of the Blitter's IRQ line
+ * IRQ signal is inverted (0/low irq set, 1/high irq cleared)
+ */
+uint8_t	Blitter_Get_Line_IRQ_MFP ( void )
+{
+	return BlitterState.IRQ_Line;
+}
+
+
+
 /*-----------------------------------------------------------------------*/
 /**
  * Compute some stats for the blitter's usage during a period (eg one VBL)
@@ -892,7 +931,7 @@ Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
 	BlitterPhase = BLITTER_PHASE_RUN_TRANSFER;
 
 	/* Busy=1, set line to high/1 and clear interrupt */
-	MFP_GPIP_Set_Line_Input ( pMFP_Main , MFP_GPIP_LINE_GPU_DONE , MFP_GPIP_STATE_HIGH );
+	Blitter_Set_Line_IRQ_MFP ( BLITTER_IRQ_OFF );
 
 	/* Now we enter the main blitting loop */
 	do
@@ -913,8 +952,7 @@ Video_GetPosition ( &FrameCycles , &HblCounterVideo , &LineCycles );
 		BlitterRegs.ctrl &= ~(0x80|0x40);
 
 		/* Busy=0, set line to low/0 and request interrupt */
-		MFP_GPIP_Set_Line_Input ( pMFP_Main , MFP_GPIP_LINE_GPU_DONE , MFP_GPIP_STATE_LOW );
-
+		Blitter_Set_Line_IRQ_MFP ( BLITTER_IRQ_ON );
 		BlitterPhase = BLITTER_PHASE_STOP;
 
 		if ( BLITTER_RUN_CE )

src/includes/blitter.h

@@ -11,9 +11,17 @@
 #define BLITTER_H
 
 
+#define BLITTER_IRQ_ON				0	/* O/low sets IRQ line */
+#define BLITTER_IRQ_OFF				1	/* 1/high clears IRQ line */
+
+
 extern uint16_t	BlitterPhase;
 
-extern void Blitter_Reset ( void );
+
+
+extern void	Blitter_Reset ( void );
+extern uint8_t	Blitter_Get_Line_IRQ_MFP ( void );
+
 
 extern void	Blitter_StatsUpdateRate ( int period_cycles );
 extern int	Blitter_StatsGetRate ( void );

src/mfp.c

@@ -327,7 +327,7 @@ Input -----/             |         ------------------------              |
       0 : parallel port, busy signal (0=not busy, 1=busy)
       1 : rs232 port, data carrier detect (DCD) signal
       2 : rs232 port, clear to send (CTS) signal
-      3 : STF/STE/TT : blitter, active low (0=IRQ set, 1=IRQ not set)
+      3 : STF/STE : blitter, active low (0=IRQ set, 1=IRQ not set)
           Falcon : DSP, active low (0=HREQ set, 1=HREQ not set)
       4 : ACIAs 6850 (ikbd and midi), active low (0=IRQ set for ACIA 1 and/or 2, 1=IRQ not set for neither ACIA 1 nor 2)
       5 : FDC/HD, active low (0=IRQ set, 1=IRQ not set)