diff --git a/BizHawk.Client.Common/RomLoader.cs b/BizHawk.Client.Common/RomLoader.cs
index a93abaefc7..0c1bdf73a3 100644
--- a/BizHawk.Client.Common/RomLoader.cs
+++ b/BizHawk.Client.Common/RomLoader.cs
@@ -415,7 +415,7 @@ namespace BizHawk.Client.Common
 								nextEmulator = new N64(nextComm, game, rom.RomData, GetCoreSyncSettings<N64>());
 								break;
 							case "WSWAN":
-								nextEmulator = new WonderSwan(nextComm, rom.RomData);
+								nextEmulator = new WonderSwan(nextComm, rom.RomData, Deterministic);
 								break;
 							case "DEBUG":
 								if (VersionInfo.INTERIM)
diff --git a/BizHawk.Emulation.Cores/Consoles/WonderSwan/BizSwan.cs b/BizHawk.Emulation.Cores/Consoles/WonderSwan/BizSwan.cs
index 6abb0973ae..fcf0a4662e 100644
--- a/BizHawk.Emulation.Cores/Consoles/WonderSwan/BizSwan.cs
+++ b/BizHawk.Emulation.Cores/Consoles/WonderSwan/BizSwan.cs
@@ -53,7 +53,7 @@ namespace BizHawk.Emulation.Cores.WonderSwan
 		/// <param name="settings"></param>
 		/// <returns></returns>
 		[DllImport(dd, CallingConvention = cc)]
-		public static extern bool bizswan_load(IntPtr core, byte[] data, int length, [In] ref Settings settings);
+		public static extern bool bizswan_load(IntPtr core, byte[] data, int length, [In] ref SyncSettings settings);
 
 		/// <summary>
 		/// get size of saveram
@@ -120,7 +120,7 @@ namespace BizHawk.Emulation.Cores.WonderSwan
 		}
 
 		[StructLayout(LayoutKind.Sequential, Pack = 4)]
-		public struct Settings
+		public struct SyncSettings
 		{
 			public ushort byear;
 			public byte bmonth;
@@ -132,6 +132,11 @@ namespace BizHawk.Emulation.Cores.WonderSwan
 			public Bloodtype blood;
 			[MarshalAs(UnmanagedType.U1)]
 			public bool rotateinput;
+			[MarshalAs(UnmanagedType.U1)]
+			public bool color; // true for color system
+			[MarshalAs(UnmanagedType.U1)]
+			public bool userealtime; // true for use real real RTC instead of emulation pegged time
+			public ulong initialtime; // inital time in unix format; only used when userealtime = false
 
 			public void SetName(string newname)
 			{
diff --git a/BizHawk.Emulation.Cores/Consoles/WonderSwan/WonderSwan.cs b/BizHawk.Emulation.Cores/Consoles/WonderSwan/WonderSwan.cs
index ae09f88f59..ed2fdcccf8 100644
--- a/BizHawk.Emulation.Cores/Consoles/WonderSwan/WonderSwan.cs
+++ b/BizHawk.Emulation.Cores/Consoles/WonderSwan/WonderSwan.cs
@@ -40,15 +40,16 @@ namespace BizHawk.Emulation.Cores.WonderSwan
 
 		#endregion
 
-		public WonderSwan(CoreComm comm, byte[] rom)
+		public WonderSwan(CoreComm comm, byte[] rom, bool deterministicEmulation)
 		{
 			this.CoreComm = comm;
+			DeterministicEmulation = deterministicEmulation; // when true, remember to force the RTC flag!
 			Core = BizSwan.bizswan_new();
 			if (Core == IntPtr.Zero)
 				throw new InvalidOperationException("bizswan_new() returned NULL!");
 			try
 			{
-				var ss = new BizSwan.Settings
+				var ss = new BizSwan.SyncSettings
 				{
 					sex = BizSwan.Gender.Male,
 					blood = BizSwan.Bloodtype.A,
@@ -120,7 +121,7 @@ namespace BizHawk.Emulation.Cores.WonderSwan
 
 
 		public string SystemId { get { return "WSWAN"; } }
-		public bool DeterministicEmulation { get { return true; } }
+		public bool DeterministicEmulation { get; private set; }
 		public string BoardName { get { return null; } }
 
 		#region SaveRam
diff --git a/output/dll/bizswan.dll b/output/dll/bizswan.dll
index 76a33992fc..2203c861ef 100644
Binary files a/output/dll/bizswan.dll and b/output/dll/bizswan.dll differ
diff --git a/wonderswan/gfx.cpp b/wonderswan/gfx.cpp
index f16519b392..a56cb27c45 100644
--- a/wonderswan/gfx.cpp
+++ b/wonderswan/gfx.cpp
@@ -240,7 +240,7 @@ namespace MDFN_IEN_WSWAN
 		return(ret);
 	}
 
-	void GFX::SetLayerEnableMask(uint64 mask)
+	void GFX::SetLayerEnableMask(uint32 mask)
 	{
 		LayerEnabled = mask;
 	}
diff --git a/wonderswan/gfx.h b/wonderswan/gfx.h
index f30709239b..e6a1a9a09a 100644
--- a/wonderswan/gfx.h
+++ b/wonderswan/gfx.h
@@ -27,7 +27,7 @@ public:
 
 	bool ExecuteLine(uint32 *surface, bool skip);
 
-	void SetLayerEnableMask(uint64 mask);
+	void SetLayerEnableMask(uint32 mask);
 
 private:
 	// TCACHE ====================================
diff --git a/wonderswan/mednafen/types.h b/wonderswan/mednafen/types.h
index 320aab5069..4e2b24f631 100644
--- a/wonderswan/mednafen/types.h
+++ b/wonderswan/mednafen/types.h
@@ -76,7 +76,6 @@ typedef uint64_t uint64;
  #undef MDFN_GCC_VERSION
 #elif defined(_MSC_VER)
 
-  #pragma message("Compiling with MSVC, untested")
 
   #define INLINE __forceinline
   #define NO_INLINE __declspec(noinline)
diff --git a/wonderswan/memory.cpp b/wonderswan/memory.cpp
index 8ccef25115..434fa49d5f 100644
--- a/wonderswan/memory.cpp
+++ b/wonderswan/memory.cpp
@@ -289,13 +289,14 @@ namespace MDFN_IEN_WSWAN
 		}
 	}
 	
-	void Memory::Init(const Settings &settings)
+	void Memory::Init(const SyncSettings &settings)
 	{
 		char tmpname[17];
 		std::memcpy(tmpname, settings.name, 16);
 		tmpname[16] = 0;
 
 		language = settings.language;
+		wsc = settings.color;
 
 		// WSwan_EEPROMInit() will also clear wsEEPROM
 		sys->eeprom.Init(tmpname, settings.byear, settings.bmonth, settings.bday, settings.sex, settings.blood);
diff --git a/wonderswan/memory.h b/wonderswan/memory.h
index fc19116774..3dce1ced7b 100644
--- a/wonderswan/memory.h
+++ b/wonderswan/memory.h
@@ -13,7 +13,7 @@ public:
 	uint8 Read20(uint32);
 	void Write20(uint32 address,uint8 data);
 
-	void Init(const Settings &settings);
+	void Init(const SyncSettings &settings);
 
 	void CheckSoundDMA();
 	void Reset();
@@ -50,6 +50,7 @@ private:
 
 	bool language;
 
+	bool wsc; // mono / color
 
 public:
 	System *sys;
diff --git a/wonderswan/rtc.cpp b/wonderswan/rtc.cpp
index 9ee167b0b9..b621ba0a93 100644
--- a/wonderswan/rtc.cpp
+++ b/wonderswan/rtc.cpp
@@ -19,10 +19,20 @@
 */
 
 #include "system.h"
-#include <ctime>
+#include <time.h>
 
 namespace MDFN_IEN_WSWAN
 {
+	static void GMTime(uint64 ticks, tm &time)
+	{
+		time_t t = ticks;
+		#ifdef __GNUC__
+		gmtime_r(&t, &time);
+		#elif defined _MSC_VER
+		gmtime_s(&time, &t);
+		#endif
+	}
+
 	void RTC::Write(uint32 A, uint8 V)
 	{
 		switch(A)
@@ -46,18 +56,19 @@ namespace MDFN_IEN_WSWAN
 		case 0xcb :
 			if(Command == 0x15)
 			{
-				time_t long_time = CurrentTime;
-				struct tm *newtime = gmtime( &long_time );
+				tm newtime;
+				uint64 now = userealtime ? time(0) : CurrentTime;
+				GMTime(CurrentTime, newtime);
 
 				switch(wsCA15)
 				{
-				case 0: wsCA15++;return mBCD(newtime->tm_year-100);
-				case 1: wsCA15++;return mBCD(newtime->tm_mon);
-				case 2: wsCA15++;return mBCD(newtime->tm_mday);
-				case 3: wsCA15++;return mBCD(newtime->tm_wday);
-				case 4: wsCA15++;return mBCD(newtime->tm_hour);
-				case 5: wsCA15++;return mBCD(newtime->tm_min);
-				case 6: wsCA15=0;return mBCD(newtime->tm_sec);
+				case 0: wsCA15++;return mBCD(newtime.tm_year-100);
+				case 1: wsCA15++;return mBCD(newtime.tm_mon);
+				case 2: wsCA15++;return mBCD(newtime.tm_mday);
+				case 3: wsCA15++;return mBCD(newtime.tm_wday);
+				case 4: wsCA15++;return mBCD(newtime.tm_hour);
+				case 5: wsCA15++;return mBCD(newtime.tm_min);
+				case 6: wsCA15=0;return mBCD(newtime.tm_sec);
 				}
 				return 0;
 			}
@@ -68,22 +79,33 @@ namespace MDFN_IEN_WSWAN
 		return(0);
 	}
 
-	void RTC::Reset()
+	void RTC::Init(uint64 initialtime, bool realtime)
 	{
-		time_t happy_time = time(NULL);
+		if (realtime)
+		{
+			userealtime = true;
+			CurrentTime = time(0);
+		}
+		else
+		{
+			userealtime = false;
+			CurrentTime = initialtime;
+		}
 
-		CurrentTime = mktime(localtime(&happy_time));
 		ClockCycleCounter = 0;
-		wsCA15 = 0;
+		wsCA15 = 0; // is this also possibly set to 0 on reset?
 	}
 
 	void RTC::Clock(uint32 cycles)
 	{
-		ClockCycleCounter += cycles;
-		while(ClockCycleCounter >= 3072000)
+		if (!userealtime)
 		{
-			ClockCycleCounter -= 3072000;
-			CurrentTime++;
+			ClockCycleCounter += cycles;
+			while(ClockCycleCounter >= 3072000)
+			{
+				ClockCycleCounter -= 3072000;
+				CurrentTime++;
+			}
 		}
 	}
 
diff --git a/wonderswan/rtc.h b/wonderswan/rtc.h
index d4319e2c43..cdead60466 100644
--- a/wonderswan/rtc.h
+++ b/wonderswan/rtc.h
@@ -10,11 +10,13 @@ class RTC
 public:
 	void Write(uint32 A, uint8 V);
 	uint8 Read(uint32 A);
-	void Reset();
+	void Init(uint64 initialtime, bool realtime);
 	void Clock(uint32 cycles);
 
 private:
 	uint64 CurrentTime;
+	bool userealtime;
+
 	uint32 ClockCycleCounter;
 	uint8 wsCA15;
 	uint8 Command, Data;
diff --git a/wonderswan/system.cpp b/wonderswan/system.cpp
index 62b4ba7ea5..a4baa2cafc 100644
--- a/wonderswan/system.cpp
+++ b/wonderswan/system.cpp
@@ -52,7 +52,7 @@ namespace MDFN_IEN_WSWAN
 		gfx.Reset();
 		sound.Reset();
 		interrupt.Reset();
-		rtc.Reset();
+		//rtc.Reset(); // at the moment, RTC changes no state on hard reset
 		eeprom.Reset();
 
 		for(int u0=0;u0<0xc9;u0++)
@@ -101,7 +101,7 @@ namespace MDFN_IEN_WSWAN
 		return(v);
 	}
 
-	bool System::Load(const uint8 *data, int length, const Settings &settings)
+	bool System::Load(const uint8 *data, int length, const SyncSettings &settings)
 	{
 		uint32 real_rom_size;
 
@@ -201,6 +201,7 @@ namespace MDFN_IEN_WSWAN
 		// TODO: control WSC setting
 
 		memory.Init(settings);
+		rtc.Init(settings.initialtime, settings.userealtime);
 
 		//MDFNGameInfo->fps = (uint32)((uint64)3072000 * 65536 * 256 / (159*256));
 
@@ -219,7 +220,6 @@ namespace MDFN_IEN_WSWAN
 	}
 
 	System::System()
-		:wsc(1)
 	{
 		gfx.sys = this;
 		memory.sys = this;
@@ -294,7 +294,7 @@ namespace MDFN_IEN_WSWAN
 		s->Advance(buttons, novideo, surface, soundbuff, *soundbuffsize);
 	}
 
-	EXPORT int bizswan_load(System *s, const uint8 *data, int length, const Settings *settings)
+	EXPORT int bizswan_load(System *s, const uint8 *data, int length, const SyncSettings *settings)
 	{
 		return s->Load(data, length, *settings);
 	}
diff --git a/wonderswan/system.h b/wonderswan/system.h
index 81c6514f5d..fad4f6cb40 100644
--- a/wonderswan/system.h
+++ b/wonderswan/system.h
@@ -4,6 +4,7 @@
 namespace MDFN_IEN_WSWAN
 {
 class System;
+struct SyncSettings;
 struct Settings;
 }
 
@@ -30,7 +31,7 @@ public:
 
 	void Reset();
 	void Advance(uint16 buttons, bool novideo, uint32 *surface, int16 *soundbuff, int &soundbuffsize);
-	bool Load(const uint8 *data, int length, const Settings &s);
+	bool Load(const uint8 *data, int length, const SyncSettings &s);
 
 	int SaveRamSize();
 	bool SaveRamLoad(const uint8 *data, int size);
@@ -44,12 +45,9 @@ public:
 	Sound sound;
 	V30MZ cpu;
 	Interrupt interrupt;
-public:
-	int 		wsc; // 1 = 1;			/*color/mono*/
-
 };
 
-struct Settings
+struct SyncSettings
 {
 	uint16 byear; // birth year, 0000-9999
 	uint8 bmonth; // birth month, 1-12
@@ -59,6 +57,14 @@ struct Settings
 	uint8 sex; // sex, 1 = male, 2 = female
 	uint8 blood; // 1 = a, 2 = b, 3 = o, 4 = ab
 	bool rotateinput; // true to rotate input and dpads,  sync setting because of this
+	bool color; // true if wonderswan is in color mode
+	bool userealtime; // true to use the system's actual clock; false to use an emulation pegged clock
+	uint64 initialtime; // when userealtime is false, the initial time in unix format
+};
+
+struct Settings
+{
+	uint32 LayerMask; // 1 = enable bg, 2 = enable fg, 4 = enable sprites
 };
 
 namespace Debug