diff --git a/source/CPU.cpp b/source/CPU.cpp
index bcdff14..2d070d1 100644
--- a/source/CPU.cpp
+++ b/source/CPU.cpp
@@ -133,9 +133,9 @@ static ULONG g_nCyclesExecuted;	// # of cycles executed up to last IO access
 
 //static signed long g_uInternalExecutedCycles;
 // Use IRQ_CHECK_TIMEOUT=128 when running at full-speed; else use IRQ_CHECK_TIMEOUT=1 (GH#651)
-static const int IRQ_CHECK_TIMEOUT_FULL_SPEED = 128;
-static const int IRQ_CHECK_TIMEOUT_NORMAL_SPEED = 1;
-static signed int g_nIrqCheckTimeout = IRQ_CHECK_TIMEOUT_NORMAL_SPEED;
+//static const int IRQ_CHECK_TIMEOUT_FULL_SPEED = 128;
+//static const int IRQ_CHECK_TIMEOUT_NORMAL_SPEED = 1;
+//static signed int g_nIrqCheckTimeout = IRQ_CHECK_TIMEOUT_NORMAL_SPEED;
 
 //
 
@@ -417,21 +417,21 @@ static __forceinline void IRQ(ULONG& uExecutedCycles, BOOL& flagc, BOOL& flagn,
 	}
 }
 
-static __forceinline void CheckInterruptSources(ULONG uExecutedCycles, const bool bVideoUpdate)
+static __forceinline void CheckInterruptSources(ULONG uExecutedCycles/*, const bool bVideoUpdate*/)
 {
-	if (g_nIrqCheckTimeout < 0)
+//	if (g_nIrqCheckTimeout < 0)
 	{
 		MB_UpdateCycles(uExecutedCycles);
 		sg_Mouse.SetVBlank( !VideoGetVblBar(uExecutedCycles) );
-		g_nIrqCheckTimeout = bVideoUpdate ? IRQ_CHECK_TIMEOUT_NORMAL_SPEED : IRQ_CHECK_TIMEOUT_FULL_SPEED;
+//		g_nIrqCheckTimeout = bVideoUpdate ? IRQ_CHECK_TIMEOUT_NORMAL_SPEED : IRQ_CHECK_TIMEOUT_FULL_SPEED;
 	}
 }
 
 // GH#608: IRQ needs to occur within 17 cycles (6 opcodes) of configuring the timer interrupt
 void CpuAdjustIrqCheck(UINT uCyclesUntilInterrupt)
 {
-	if (g_bFullSpeed && uCyclesUntilInterrupt < IRQ_CHECK_TIMEOUT_FULL_SPEED)
-		g_nIrqCheckTimeout = uCyclesUntilInterrupt;
+//	if (g_bFullSpeed && uCyclesUntilInterrupt < IRQ_CHECK_TIMEOUT_FULL_SPEED)
+//		g_nIrqCheckTimeout = uCyclesUntilInterrupt;
 }
 
 //===========================================================================
diff --git a/source/CPU/cpu6502.h b/source/CPU/cpu6502.h
index 29b8452..2b58bf5 100644
--- a/source/CPU/cpu6502.h
+++ b/source/CPU/cpu6502.h
@@ -318,7 +318,7 @@ static DWORD Cpu6502(DWORD uTotalCycles, const bool bVideoUpdate)
 #undef $
 		}
 
-		CheckInterruptSources(uExecutedCycles, bVideoUpdate);
+		CheckInterruptSources(uExecutedCycles/*, bVideoUpdate*/);
 		NMI(uExecutedCycles, flagc, flagn, flagv, flagz);
 		IRQ(uExecutedCycles, flagc, flagn, flagv, flagz);
 
diff --git a/source/CPU/cpu65C02.h b/source/CPU/cpu65C02.h
index 1dc0622..9bf37a6 100644
--- a/source/CPU/cpu65C02.h
+++ b/source/CPU/cpu65C02.h
@@ -321,7 +321,7 @@ static DWORD Cpu65C02(DWORD uTotalCycles, const bool bVideoUpdate)
 #undef $
 		}
 
-		CheckInterruptSources(uExecutedCycles, bVideoUpdate);
+		CheckInterruptSources(uExecutedCycles/*, bVideoUpdate*/);
 		NMI(uExecutedCycles, flagc, flagn, flagv, flagz);
 		IRQ(uExecutedCycles, flagc, flagn, flagv, flagz);
 
diff --git a/source/CPU/cpu65d02.h b/source/CPU/cpu65d02.h
index bdb7863..21bad4d 100644
--- a/source/CPU/cpu65d02.h
+++ b/source/CPU/cpu65d02.h
@@ -406,7 +406,7 @@ static DWORD Cpu65D02(DWORD uTotalCycles, const bool bVideoUpdate)
 		}
 #undef $
 
-		CheckInterruptSources(uExecutedCycles, bVideoUpdate);
+		CheckInterruptSources(uExecutedCycles/*, bVideoUpdate*/);
 		NMI(uExecutedCycles, flagc, flagn, flagv, flagz);
 		IRQ(uExecutedCycles, flagc, flagn, flagv, flagz);
 
diff --git a/source/CPU/cpu_general.inl b/source/CPU/cpu_general.inl
index 4d565ef..9ee2a71 100644
--- a/source/CPU/cpu_general.inl
+++ b/source/CPU/cpu_general.inl
@@ -49,7 +49,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 			      | (flagz ? AF_ZERO     : 0)		    \
 			      | AF_RESERVED | AF_BREAK;
 // CYC(a): This can be optimised, as only certain opcodes will affect uExtraCycles
-#define CYC(a)	 uExecutedCycles += (a)+uExtraCycles; g_nIrqCheckTimeout -= (a)+uExtraCycles;
+#define CYC(a)	 uExecutedCycles += (a)+uExtraCycles; /*g_nIrqCheckTimeout -= (a)+uExtraCycles;*/
 #define POP	 (*(mem+((regs.sp >= 0x1FF) ? (regs.sp = 0x100) : ++regs.sp)))
 #define PUSH(a)	 *(mem+regs.sp--) = (a);				    \
 		 if (regs.sp < 0x100)					    \
diff --git a/test/TestCPU6502/TestCPU6502.cpp b/test/TestCPU6502/TestCPU6502.cpp
index 2e86946..f013edb 100644
--- a/test/TestCPU6502/TestCPU6502.cpp
+++ b/test/TestCPU6502/TestCPU6502.cpp
@@ -54,7 +54,7 @@ static __forceinline void DoIrqProfiling(DWORD uCycles)
 {
 }
 
-static __forceinline void CheckInterruptSources(ULONG uExecutedCycles, const bool bVideoUpdate)
+static __forceinline void CheckInterruptSources(ULONG uExecutedCycles/*, const bool bVideoUpdate*/)
 {
 }