diff --git a/simulator/sim_lib/cray_mainframe.cpp b/simulator/sim_lib/cray_mainframe.cpp
index ae4084b..34a4852 100644
--- a/simulator/sim_lib/cray_mainframe.cpp
+++ b/simulator/sim_lib/cray_mainframe.cpp
@@ -140,13 +140,15 @@ Mainframe_c::Mainframe_c(const Configuration_c &aConfig, CLogger_c &aLogger, boo
 	mLogger(aConfig),
 	mOsType(OsTypes_e::None),
 	mUseHostRealTimeClock(aConfig.get<bool>("UseHostRealTimeClock", true)),
+	mRealTimeClockIncrement(aConfig.get<CInt_t>("RealTimeClockIncrement", 10)),
+	mRealTimeClockChunkLimit(aConfig.get<CInt_t>("RealTimeClockChunkLimit", 5000)),
+	mDeltaClockIncrement(aConfig.get<CInt_t>("DeltaClockIncrement", 1)),
 	mDisableAutoTerminal(aDisableAutoTerminal)
 {
 	mLogger.SetParent(aLogger);
 	mChannels.resize(aConfig.get<size_t>("ChannelCount", 8));
 	mOwnedChannels.resize(mChannels.size());
 	try {
-		mRealTimeClockIncrement = aConfig.get<CInt_t>("RealTimeClockIncrement", 10);
 		std::string MachineType = aConfig.get<std::string>("MachineType", "J90");
 		if (MachineType == "J90") {
 			mMachineType = MachineTypes_e::J90;
@@ -768,11 +770,15 @@ CInt_t Mainframe_c::GetRealTimeClock() const {
 	if (mUseHostRealTimeClock) {
 		boost::timer::nanosecond_type DeltaTime = mRealTimeTimer.elapsed().wall - mRealTimeStart;
 		CInt_t DeltaClocks = CInt_t(double(DeltaTime) / mSystemClockPeriod);
-		if (DeltaClocks == mLastRealTimeReading) {
-			DeltaClocks += 1;
+		CInt_t NewRTC = mRealTimeClock + DeltaClocks;
+		if (NewRTC > mLastRealTimeReading + mRealTimeClockChunkLimit) {
+			mLastRealTimeReading = NewRTC;
+			return NewRTC;
+		} else {
+			NewRTC = mLastRealTimeReading + mRealTimeClockIncrement;
+			mLastRealTimeReading = NewRTC;
+			return NewRTC;
 		}
-		mLastRealTimeReading = DeltaClocks;
-		return mRealTimeClock + DeltaClocks;
 	} else {
 		return mRealTimeClock;
 	}
diff --git a/simulator/sim_lib/cray_mainframe.h b/simulator/sim_lib/cray_mainframe.h
index 10d490e..899833d 100644
--- a/simulator/sim_lib/cray_mainframe.h
+++ b/simulator/sim_lib/cray_mainframe.h
@@ -341,7 +341,7 @@ public:
 	void Dump(size_t aIdent=0) const;
 	void DumpMemories() const;
 	void DumpHistory();
-	CLogger_c &GetLogger() { return mLogger; }
+	CLogger_c &GetLogger() const { return mLogger; }
 
 	virtual uint64_t GetTimeStamp() const override { return mEnableTimeStamp ? mTickCnt : 0ULL; }
 	virtual uint64_t GetResolution() const override { return 105000000ULL; } // TODO: make this configurable
@@ -367,6 +367,7 @@ protected:
 	bool mMultiThreaded;
 	bool mDisableAutoTerminal;
 	mutable CInt_t mLastRealTimeReading;
+	CInt_t mDeltaClockIncrement;
 
 	class MainFrameEventDispatcher_c: public DebugEventDispatcher_c {
 	public:
@@ -409,6 +410,7 @@ protected:
 	double mSystemClockPeriod;
 	CInt_t mRealTimeClock;
 	CInt_t mRealTimeClockIncrement;
+	CInt_t mRealTimeClockChunkLimit;
 	bool mUseHostRealTimeClock;
 
 	struct WatchPoint_c {
diff --git a/simulator/sim_lib/sys_task_req.cpp b/simulator/sim_lib/sys_task_req.cpp
index 1a3c819..8f18145 100644
--- a/simulator/sim_lib/sys_task_req.cpp
+++ b/simulator/sim_lib/sys_task_req.cpp
@@ -206,12 +206,15 @@ void PrintIntArg(std::ostream &aLogger, size_t aArg, const ExchangePacket_c &aEx
 void ParseUnicosExchangePacket(const ExchangePacket_c &aCurrentEP, const ExchangePacket_c &aNewEP, std::ostream &aLogger, const Cpu_c &aCpu) {
 	static size_t LastSysCall = SIZE_MAX;
 	const Mainframe_c &Mainframe = aCpu.GetMainframe();
+
 	if (aCurrentEP.GetMode().IsMonitorMode()) {
 		CInt_t S[8];
 		for (size_t Idx = 0; Idx<sizeof(S) / sizeof(S[0]); ++Idx) S[Idx] = aNewEP.GetS(Idx);
 		CInt_t A[8];
 		for (size_t Idx = 0; Idx<sizeof(A) / sizeof(A[0]); ++Idx) A[Idx] = aNewEP.GetA(Idx);
 
+		//aLogger << "return from monitor mode with XA: " << HexPrinter(aCpu.GetExchangePacketAddress()) << " " << "IBA: " << HexPrinter(aCurrentEP.GetInstBaseAddr());
+
 		// Swapping out from monitor mode - parse it as a reply
 		if (LastSysCall < SysCallTableSize) {
 			try {
@@ -260,6 +263,16 @@ void ParseUnicosExchangePacket(const ExchangePacket_c &aCurrentEP, const Exchang
 							aLogger << " , ";
 							PrintStringArrayArg(aLogger, 2, aCurrentEP, Mainframe);
 						break;
+						case 0x9b: // waitpid
+							PrintIntArg(aLogger, 0, aCurrentEP, Mainframe);
+							aLogger << " , ";
+							PrintPtrArg(aLogger, 1, aCurrentEP, Mainframe);
+							aLogger << " , ";
+							PrintIntArg(aLogger, 2, aCurrentEP, Mainframe);
+						break;
+						case 125: // mtimes
+							PrintPtrArg(aLogger, 0, aCurrentEP, Mainframe);
+						break;
 						default:
 							for (uint32_t ArgIdx = 0; ArgIdx < std::min(Entry.ArgCnt, uint32_t(10)); ++ArgIdx) {
 								if (ArgIdx != 0) aLogger << " , ";
@@ -285,6 +298,8 @@ void ParseUnicosExchangePacket(const ExchangePacket_c &aCurrentEP, const Exchang
 				//aLogger << "XA: " << HexPrinter(aCpu.GetExchangePacketAddress()) << " " << "IBA: " << HexPrinter(aCurrentEP.GetInstBaseAddr()) << " ";
 				//aLogger << "unknown SYSCALL with S0 = " << HexPrinter(S[0]);
 			}
+		} else {
+			//aLogger << "entering monitor mode with XA: " << HexPrinter(aCpu.GetExchangePacketAddress()) << " " << "IBA: " << HexPrinter(aCurrentEP.GetInstBaseAddr()) << " ";
 		}
 	}
 }