diff --git a/Core/Core.vcxproj b/Core/Core.vcxproj
index e6eeadcc..22dd06e1 100644
--- a/Core/Core.vcxproj
+++ b/Core/Core.vcxproj
@@ -443,6 +443,7 @@
     <ClInclude Include="Kaiser202.h" />
     <ClInclude Include="Kaiser7022.h" />
     <ClInclude Include="Kaiser7058.h" />
+    <ClInclude Include="Mapper103.h" />
     <ClInclude Include="Mapper107.h" />
     <ClInclude Include="Mapper108.h" />
     <ClInclude Include="Mapper112.h" />
diff --git a/Core/Core.vcxproj.filters b/Core/Core.vcxproj.filters
index 7b1e39b2..adaa6f77 100644
--- a/Core/Core.vcxproj.filters
+++ b/Core/Core.vcxproj.filters
@@ -832,6 +832,9 @@
     <ClInclude Include="Mapper221.h">
       <Filter>Nes\Mappers\Unnamed</Filter>
     </ClInclude>
+    <ClInclude Include="Mapper103.h">
+      <Filter>Nes\Mappers\Unnamed</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">
diff --git a/Core/Mapper103.h b/Core/Mapper103.h
new file mode 100644
index 00000000..08616964
--- /dev/null
+++ b/Core/Mapper103.h
@@ -0,0 +1,77 @@
+#pragma once
+#include "stdafx.h"
+#include "BaseMapper.h"
+
+class Mapper103 : public BaseMapper
+{
+private:
+	bool _prgRamDisabled;
+	uint8_t _prgReg;
+
+protected:
+	virtual uint16_t GetPRGPageSize() { return 0x2000; }
+	virtual uint16_t GetCHRPageSize() { return 0x2000; }
+	virtual uint32_t GetWorkRamSize() { return 0x4000; }
+	virtual uint32_t GetWorkRamPageSize() { return 0x2000; }
+	virtual uint16_t RegisterStartAddress() { return 0x6000; }
+	virtual uint16_t EndStartAddress() { return 0xFFFF; }
+
+	void InitMapper()
+	{
+		_prgRamDisabled = false;
+		_prgReg = 0;
+		SelectCHRPage(0, 0);
+		UpdateState();
+	}
+
+	void StreamState(bool saving)
+	{
+		BaseMapper::StreamState(saving);
+		Stream(_prgRamDisabled, _prgReg);
+		if(!saving) {
+			UpdateState();
+		}
+	}
+
+	void UpdateState()
+	{
+		SelectPrgPage4x(0, -4);
+		if(_prgRamDisabled) {
+			SetCpuMemoryMapping(0x6000, 0x7FFF, _prgReg, PrgMemoryType::PrgRom);
+		} else {
+			SetCpuMemoryMapping(0x6000, 0x7FFF, 0, PrgMemoryType::WorkRam);
+			SetCpuMemoryMapping(0xB800, 0xD7FF, 1, PrgMemoryType::WorkRam);
+		}
+	}
+
+	void WriteRegister(uint16_t addr, uint8_t value)
+	{
+		switch(addr & 0xF000) {
+			case 0x6000: case 0x7000:
+				//Workram is always writeable, even when PRG ROM is mapped to $6000
+				_workRam[addr - 0x6000] = value;
+				break;
+
+			case 0x8000:
+				_prgReg = value & 0x0F;
+				UpdateState();
+				break;
+			
+			case 0xB000: case 0xC000: case 0xD000:
+				//Workram is always writeable, even when PRG ROM is mapped to $B800-$D7FF
+				if(addr >= 0xB800 && addr < 0xD800) {
+					_workRam[0x2000 + addr - 0xB800] = value;
+				}
+				break;
+
+			case 0xE000:
+				SetMirroringType(value & 0x08 ? MirroringType::Horizontal : MirroringType::Vertical);
+				break;
+
+			case 0xF000:
+				_prgRamDisabled = (value & 0x10) == 0x10;
+				UpdateState();
+				break;
+		}
+	}
+};
\ No newline at end of file
diff --git a/Core/MapperFactory.cpp b/Core/MapperFactory.cpp
index 456fb152..4c15c803 100644
--- a/Core/MapperFactory.cpp
+++ b/Core/MapperFactory.cpp
@@ -49,6 +49,7 @@
 #include "Mapper61.h"
 #include "Mapper62.h"
 #include "Mapper91.h"
+#include "Mapper103.h"
 #include "Mapper107.h"
 #include "Mapper108.h"
 #include "Mapper112.h"
@@ -163,7 +164,7 @@ Supported mappers:
 | 48| 49| 50| 51| 52| 53|   |   | 56| 57| 58|===| 60| 61| 62| 63|
 | 64| 65| 66| 67| 68| 69| 70| 71| 72| 73| 74| 75| 76| 77| 78| 79|
 | 80|===| 82|   |===| 85| 86| 87| 88| 89| 90| 91| 92| 93| 94| 95|
-| 96| 97|===| 99|...|101|===|   |   |   |   |107|108|===|===|===|
+| 96| 97|===| 99|...|101|===|103|   |   |   |107|108|===|===|===|
 |112|113|   |115|   |   |118|119|   |   |===|   |===|   |   |===|
 |===|===|===|===|132|133|   |===|   |137|138|139|140|141|142|143|
 |144|145|146|147|148|149|150|151|152|153|154|155|156|157|   |159|
@@ -280,6 +281,7 @@ BaseMapper* MapperFactory::GetMapperFromID(RomData &romData)
 		case 97: return new IremTamS1();
 		case 99: return new VsSystem();
 		case 101: return new JalecoJfxx(true);
+		case 103: return new Mapper103();
 		case 105: break; //NES World Champ - has dip switches
 		case 107: return new Mapper107();
 		case 108: return new Mapper108();