diff --git a/cpuexec.cpp b/cpuexec.cpp
index 1b9d892b..1537aeaf 100644
--- a/cpuexec.cpp
+++ b/cpuexec.cpp
@@ -400,7 +400,7 @@ void S9xDoHEventProcessing (void)
 			if (PPU.HDMA && CPU.V_Counter <= PPU.ScreenHeight)
 			{
 			#ifdef DEBUGGER
-				S9xTraceFormattedMessage("*** HDMA  HC:%04d, Channel:%02x", CPU.Cycles, PPU.HDMA);
+				S9xTraceFormattedMessage("*** HDMA Transfer HC:%04d, Channel:%02x", CPU.Cycles, PPU.HDMA);
 			#endif
 				PPU.HDMA = S9xDoHDMA(PPU.HDMA);
 			}
@@ -544,7 +544,7 @@ void S9xDoHEventProcessing (void)
 			if (CPU.V_Counter == 0)
 			{
 			#ifdef DEBUGGER
-				S9xTraceFormattedMessage("*** HDMA Init  HC:%04d, Channel:%02x", CPU.Cycles, PPU.HDMA);
+				S9xTraceFormattedMessage("*** HDMA Init     HC:%04d, Channel:%02x", CPU.Cycles, PPU.HDMA);
 			#endif
 				S9xStartHDMA();
 			}
diff --git a/cpuops.cpp b/cpuops.cpp
index ea8d8653..5cabf9e2 100644
--- a/cpuops.cpp
+++ b/cpuops.cpp
@@ -2857,7 +2857,11 @@ void S9xOpcode_IRQ (void)
 {
 #ifdef DEBUGGER
 	if (CPU.Flags & TRACE_FLAG)
+	#ifdef SA1_OPCODES
+		S9xTraceMessage("*** SA1 IRQ");
+	#else
 		S9xTraceMessage("*** IRQ");
+	#endif
 #endif
 
 	// IRQ and NMI do an opcode fetch as their first "IO" cycle.
@@ -2928,7 +2932,11 @@ void S9xOpcode_NMI (void)
 {
 #ifdef DEBUGGER
 	if (CPU.Flags & TRACE_FLAG)
+	#ifdef SA1_OPCODES
+		S9xTraceMessage("*** SA1 NMI");
+	#else
 		S9xTraceMessage("*** NMI");
+	#endif
 #endif
 
 	// IRQ and NMI do an opcode fetch as their first "IO" cycle.
@@ -2949,7 +2957,7 @@ void S9xOpcode_NMI (void)
 		AddCycles(2 * SLOW_ONE_CYCLE);
 		S9xSA1SetPCBase(Memory.FillRAM[0x2205] | (Memory.FillRAM[0x2206] << 8));
 	#else
-		if (Settings.SA1 && (Memory.FillRAM[0x2209] & 0x20))
+		if (Settings.SA1 && (Memory.FillRAM[0x2209] & 0x10))
 		{
 			OpenBus = Memory.FillRAM[0x220d];
 			AddCycles(2 * SLOW_ONE_CYCLE);
diff --git a/sa1.cpp b/sa1.cpp
index f8d8892c..813051dc 100644
--- a/sa1.cpp
+++ b/sa1.cpp
@@ -361,7 +361,7 @@ uint8 S9xGetSA1 (uint32 address)
 		}
 
 		default:
-			printf("R: %04x\n", address);
+			//printf("R: %04x\n", address);
 			break;
 	}
 
@@ -393,12 +393,10 @@ void S9xSetSA1 (uint8 byte, uint32 address)
 			if (byte & 0x10)
 			{
 				Memory.FillRAM[0x2301] |= 0x10;
-			#ifdef DEBUGGER
-				printf("###SA1 NMI\n");
-			#endif
 				if (Memory.FillRAM[0x220a] & 0x10)
 				{
-					//
+					SA1.Flags |= NMI_FLAG;
+					SA1.Executing = !SA1.Waiting && SA1.S9xOpcodes;
 				}
 			}
 
@@ -487,9 +485,8 @@ void S9xSetSA1 (uint8 byte, uint32 address)
 
 			if (((byte ^ Memory.FillRAM[0x220a]) & 0x10) && (Memory.FillRAM[0x2301] & byte & 0x10))
 			{
-			#ifdef DEBUGGER
-				printf("###SA1 NMI\n");
-			#endif
+				SA1.Flags |= NMI_FLAG;
+				//SA1.Executing = !SA1.Waiting;
 			}
 
 			break;
@@ -513,7 +510,7 @@ void S9xSetSA1 (uint8 byte, uint32 address)
 				Memory.FillRAM[0x2301] &= ~0x20;
 			}
 
-			if (byte & 0x10) // Clear NMI
+			if (byte & 0x10)
 				Memory.FillRAM[0x2301] &= ~0x10;
 
 			if (!SA1.IRQActive)
diff --git a/sa1cpu.cpp b/sa1cpu.cpp
index dd79509e..b90092fb 100644
--- a/sa1cpu.cpp
+++ b/sa1cpu.cpp
@@ -229,19 +229,22 @@
 
 void S9xSA1MainLoop (void)
 {
-#if 0
 	if (SA1.Flags & NMI_FLAG)
 	{
-		SA1.Flags &= ~NMI_FLAG;
-		if (SA1.WaitingForInterrupt)
+		if (Memory.FillRAM[0x2200] & 0x10)
 		{
-			SA1.WaitingForInterrupt = FALSE;
-			SA1Registers.PCw++;
-		}
+			SA1.Flags &= ~NMI_FLAG;
+			Memory.FillRAM[0x2301] |= 0x10;
 
-		S9xSA1Opcode_NMI();
+			if (SA1.WaitingForInterrupt)
+			{
+				SA1.WaitingForInterrupt = FALSE;
+				SA1Registers.PCw++;
+			}
+
+			S9xSA1Opcode_NMI();
+		}
 	}
-#endif
 
 	if (SA1.Flags & IRQ_FLAG)
 	{