diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
index eded123433..2a677d44fd 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
@@ -39,6 +39,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			byte[] ROM { get; set; }
 			byte[] VROM { get; set; }
 			void SyncState(Serializer ser);
+			bool IRQSignal { get; }
 
 			//mixes the board's custom audio into the supplied sample buffer
 			void ApplyCustomAudio(short[] samples);
@@ -74,13 +75,17 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				ser.Sync("vram", ref vram, true);
 				ser.Sync("wram", ref wram, true);
 				for (int i = 0; i < 4; i++) ser.Sync("mirroring" + i, ref mirroring[i]);
+				ser.Sync("irq_signal", ref irq_signal);
 			}
 
 			public virtual void SyncIRQ(bool flag)
 			{
-				NES.irq_cart = flag;
+				IRQSignal = flag;
 			}
 
+			private bool irq_signal;
+			public bool IRQSignal { get { return irq_signal; } set { irq_signal = value; } }
+
 			public virtual void Dispose() { }
 
 			int[] mirroring = new int[4];
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/BANDAI-FCG-1.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/BANDAI-FCG-1.cs
index 592e680517..63021262d4 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/BANDAI-FCG-1.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/BANDAI-FCG-1.cs
@@ -53,11 +53,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_asserted", ref irq_asserted);
 			ser.Sync("clock_counter", ref clock_counter);
 
-			if (ser.IsReader)
-			{
-				SyncPRG();
-				SyncIrq();
-			}
+			SyncPRG();
+			SyncIrq();
 		}
 
 		public override void Dispose()
@@ -169,7 +166,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIrq()
 		{
-			NES.irq_cart = irq_asserted;
+			IRQSignal = irq_asserted;
 		}
 
 		void ClockCPU()
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs
index be5b5d0704..a2331e4244 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/ExROM.cs
@@ -66,12 +66,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("last_nt_read", ref last_nt_read);
 			ser.Sync("EXRAM", ref EXRAM, false);
 
-			if (ser.IsReader)
-			{
-				SyncPRGBanks();
-				SyncCHRBanks();
-				SyncMultiplier();
-			}
+			SyncPRGBanks();
+			SyncCHRBanks();
+			SyncMultiplier();
+			SyncIRQ();
 		}
 
 		public override void Dispose()
@@ -451,7 +449,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = (irq_pending && irq_enabled);
+			IRQSignal = (irq_pending && irq_enabled);
 		}
 
 		public override void ClockPPU()
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Irem_H3001.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Irem_H3001.cs
index 7448e7ac76..0ae3c841a8 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Irem_H3001.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Irem_H3001.cs
@@ -40,6 +40,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_counter", ref irq_counter);
 			ser.Sync("irq_reload", ref irq_reload);
 			ser.Sync("clock_counter", ref clock_counter);
+			SyncIRQ();
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
@@ -89,7 +90,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = irq_asserted;
+			IRQSignal = irq_asserted;
 		}
 
 		public override byte ReadPRG(int addr)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs
index 02a6f33776..ba71583264 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs
@@ -74,6 +74,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		public void Sync()
 		{
+			SyncIRQ();
 			if (prg_mode)
 			{
 				prg_regs_8k[0] = 0xFE;
@@ -138,7 +139,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			Sync();
 		}
 
-		protected virtual void SyncIRQ()
+		//some MMC3 variants pass along the irq signal differently (primarily different delay)
+		//this is overrideable so that those boards can get signals whenever this mmc3 base class code manipulates the irq line
+		public virtual void SyncIRQ()
 		{
 			board.SyncIRQ(irq_pending);
 		}
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs
index 14588480d9..ad919b9fe2 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper069.cs
@@ -63,6 +63,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_enabled", ref irq_enabled);
 			ser.Sync("irq_asserted", ref irq_asserted);
 			ser.Sync("clock_counter", ref clock_counter);
+			SyncIrq();
 		}
 
 		public override void Dispose()
@@ -171,7 +172,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIrq()
 		{
-			NES.irq_cart = irq_asserted;
+			IRQSignal = irq_asserted;
 		}
 
 		void ClockCPU()
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/NAMCOT_m19_m210.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/NAMCOT_m19_m210.cs
index b47e719946..6e40ace7db 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/NAMCOT_m19_m210.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/NAMCOT_m19_m210.cs
@@ -45,6 +45,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_enabled", ref irq_enabled);
 			ser.Sync("irq_cycles", ref irq_cycles);
 			ser.Sync("irq_pending", ref irq_pending);
+			SyncIRQ();
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
@@ -256,7 +257,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = (irq_pending && irq_enabled);
+			IRQSignal = (irq_pending && irq_enabled);
 		}
 
 		void TriggerIRQ()
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Sunsoft3.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Sunsoft3.cs
index 70391e078a..9063457f35 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Sunsoft3.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Sunsoft3.cs
@@ -30,6 +30,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_enable", ref irq_enable);
 			ser.Sync("irq_asserted", ref irq_asserted);
 			ser.Sync("clock_counter", ref clock_counter);
+			SyncIRQ();
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
@@ -63,7 +64,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = irq_asserted;
+			IRQSignal = irq_asserted;
 		}
 
 		public override void WritePRG(int addr, byte value)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/TENGEN-800032.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/TENGEN-800032.cs
index 100d75070c..b41d991a57 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/TENGEN-800032.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/TENGEN-800032.cs
@@ -54,8 +54,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_reload_pending", ref irq_reload_pending);
 			ser.Sync("separator_counter", ref separator_counter);
 
-			if (ser.IsReader)
-				Sync();
+			Sync();
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
@@ -83,6 +82,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void Sync()
 		{
+			SyncIRQ();
+	
 			if (prg_mode)
 			{
 				prg_banks_8k[0] = regs[0xF] & prg_bank_mask_8k;
@@ -189,7 +190,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 		}
 
-
 		public override byte ReadPRG(int addr)
 		{
 			int bank_8k = addr >> 13;
@@ -216,7 +216,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = irq_pending;
+			IRQSignal = irq_pending;
 		}
 
 		void ClockIRQ()
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_TC0190FMC.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_TC0190FMC.cs
index 6179f2a6d3..11ef124a79 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_TC0190FMC.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_TC0190FMC.cs
@@ -38,14 +38,14 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				ser.EndSection();
 			}
 
-			protected override void SyncIRQ()
+			public override void SyncIRQ()
 			{
 				if (irq_pending && !pending)
 					delay = 12; //supposed to be 4 cpu clocks
 				if (!irq_pending)
 				{
 					delay = 0;
-					board.NES.irq_cart = false;
+					board.IRQSignal = false;
 				}
 				pending = irq_pending;
 			}
@@ -58,7 +58,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				{
 					delay--;
 					if(delay==0)
-						board.NES.irq_cart = true;
+						board.IRQSignal = true;
 				}
 			}
 		}
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC2_4.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC2_4.cs
index 07ad67a830..3ba4099b09 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC2_4.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC2_4.cs
@@ -51,11 +51,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_prescaler", ref irq_prescaler);
 			ser.Sync("extra_vrom", ref extra_vrom);
 
-			if (ser.IsReader)
-			{
-				SyncPRG();
-				SyncCHR();
-			}
+			SyncPRG();
+			SyncCHR();
+			SyncIRQ();
 		}
 
 		void SyncPRG()
@@ -93,7 +91,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = (irq_pending && irq_enabled);
+			IRQSignal = (irq_pending && irq_enabled);
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC3.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC3.cs
index 1ab9140b8b..738e3c0f74 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC3.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC3.cs
@@ -36,11 +36,12 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_reload", ref irq_reload);
 			ser.Sync("irq_counter", ref irq_counter);
 			ser.Sync("irq_cycles", ref irq_cycles);
+			SyncIRQ();
 		}
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = (irq_pending && irq_enabled);
+			IRQSignal = (irq_pending && irq_enabled);
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs
index d7ddd9db43..5e86e0d3f0 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC6.cs
@@ -43,10 +43,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_counter", ref irq_counter);
 			ser.Sync("irq_prescaler", ref irq_prescaler);
 
-			if (ser.IsReader)
-			{
-				SyncPRG();
-			}
+			SyncPRG();
+			SyncIRQ();
 		}
 
 		void SyncPRG()
@@ -59,7 +57,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = (irq_pending && irq_enabled);
+			IRQSignal = (irq_pending && irq_enabled);
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC7.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC7.cs
index 82ccc15dc7..6fa75f973e 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC7.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/VRC7.cs
@@ -43,11 +43,12 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("irq_reload", ref irq_reload);
 			ser.Sync("irq_counter", ref irq_counter);
 			ser.Sync("irq_prescaler", ref irq_prescaler);
+			SyncIRQ();
 		}
 
 		void SyncIRQ()
 		{
-			NES.irq_cart = (irq_pending && irq_enabled);
+			IRQSignal = (irq_pending && irq_enabled);
 		}
 
 		public override bool Configure(NES.EDetectionOrigin origin)
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
index aac3bb8b2a..854f3cb68c 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
@@ -24,15 +24,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		INESBoard board; //the board hardware that is currently driving things
 		public bool SoundOn = true;
 		int sprdma_countdown; //used to 
-		bool _irq_apu, _irq_cart; //various irq signals that get merged to the cpu irq pin
+		bool _irq_apu; //various irq signals that get merged to the cpu irq pin
 
 		//irq state management
-		public bool irq_apu { get { return _irq_apu; } set { _irq_apu = value; sync_irq(); } }
-		public bool irq_cart { get { return _irq_cart; } set { _irq_cart = value; sync_irq(); } }
-		void sync_irq()
-		{
-			cpu.IRQ = _irq_apu || _irq_cart;
-		}
+		public bool irq_apu { get { return _irq_apu; } set { _irq_apu = value; } }
 
 		//user configuration 
 		int[,] palette = new int[64,3];
@@ -119,10 +114,13 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					}
 				}
 
-				if(cpu_deadcounter>0)
+				if (cpu_deadcounter > 0)
 					cpu_deadcounter--;
 				else
+				{
+					cpu.IRQ = _irq_apu || board.IRQSignal;
 					cpu.ExecuteOne();
+				}
 
 				if (SoundOn) apu.RunOne(); //THIS ISNT SAFE!!!!!!!!! SOUND MUST ALWAYS RUN!!!!
 				ppu.PostCpuInstructionOne();
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
index d318b18034..155244b2a8 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
@@ -590,12 +590,10 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			ser.Sync("CIRAM", ref CIRAM, false);
 			ser.Sync("cpu_accumulate", ref cpu_accumulate);
 			ser.Sync("_irq_apu", ref _irq_apu);
-			ser.Sync("_irq_cart", ref _irq_cart);
 			ser.Sync("sprdma_countdown", ref sprdma_countdown);
 			ser.Sync("cpu_step", ref cpu_step);
 			ser.Sync("cpu_stepcounter", ref cpu_stepcounter);
 			ser.Sync("cpu_deadcounter", ref cpu_deadcounter);
-			sync_irq();
 			board.SyncState(ser);
 			ppu.SyncState(ser);
 			apu.SyncState(ser);