diff --git a/BizHawk.Emulation/BizHawk.Emulation.csproj b/BizHawk.Emulation/BizHawk.Emulation.csproj
index efc5488022..8dd4fb7040 100644
--- a/BizHawk.Emulation/BizHawk.Emulation.csproj
+++ b/BizHawk.Emulation/BizHawk.Emulation.csproj
@@ -263,6 +263,7 @@
     <Compile Include="Consoles\PC Engine\MemoryMap.Populous.cs" />
     <Compile Include="Consoles\PC Engine\ScsiCDBus.cs" />
     <Compile Include="Consoles\PC Engine\TurboCD.cs" />
+    <Compile Include="Consoles\Sega\Genesis\Cart\EEPROM.cs" />
     <Compile Include="Consoles\Sega\Genesis\Cart\RomHeader.cs" />
     <Compile Include="Consoles\Sega\Genesis\Cart\SaveRAM.cs" />
     <Compile Include="Consoles\Sega\Genesis\Input.cs" />
diff --git a/BizHawk.Emulation/Consoles/Sega/Genesis/Cart/SaveRAM.cs b/BizHawk.Emulation/Consoles/Sega/Genesis/Cart/SaveRAM.cs
index c4ccbbf387..da84efd0b7 100644
--- a/BizHawk.Emulation/Consoles/Sega/Genesis/Cart/SaveRAM.cs
+++ b/BizHawk.Emulation/Consoles/Sega/Genesis/Cart/SaveRAM.cs
@@ -14,7 +14,8 @@ namespace BizHawk.Emulation.Consoles.Sega
 
         void InitializeSaveRam(GameInfo game)
         {
-            // TODO if eeprom in use, abort saveram check
+            if (EepromEnabled) 
+                return;
 
             if (game["DisableSaveRam"] || RH_SRamPresent == false)
                 return;
@@ -32,11 +33,7 @@ namespace BizHawk.Emulation.Consoles.Sega
             SaveRamLength = (SaveRamEndOffset - SaveRamStartOffset) + 1;
 
             if (SaveRamEveryOtherByte)
-            {
-                SaveRamStartOffset &= 0xFFFFFE;
-                SaveRamEndOffset &= 0xFFFFFE;
                 SaveRamLength = ((SaveRamEndOffset - SaveRamStartOffset) / 2) + 1;
-            }
 
             SaveRAM = new byte[SaveRamLength];
 
diff --git a/BizHawk.Emulation/Consoles/Sega/Genesis/Genesis.cs b/BizHawk.Emulation/Consoles/Sega/Genesis/Genesis.cs
index 400edb7538..4884e71f66 100644
--- a/BizHawk.Emulation/Consoles/Sega/Genesis/Genesis.cs
+++ b/BizHawk.Emulation/Consoles/Sega/Genesis/Genesis.cs
@@ -136,6 +136,7 @@ namespace BizHawk.Emulation.Consoles.Sega
         void InitializeCartHardware(GameInfo game)
         {
             LogCartInfo();
+            InitializeEeprom(game);
             InitializeSaveRam(game);
         }
 
diff --git a/BizHawk.Emulation/Consoles/Sega/Genesis/MemoryMap.68000.cs b/BizHawk.Emulation/Consoles/Sega/Genesis/MemoryMap.68000.cs
index 226ad0733c..fb9e706eb0 100644
--- a/BizHawk.Emulation/Consoles/Sega/Genesis/MemoryMap.68000.cs
+++ b/BizHawk.Emulation/Consoles/Sega/Genesis/MemoryMap.68000.cs
@@ -167,6 +167,13 @@ namespace BizHawk.Emulation.Consoles.Sega
                 return;
             }
 
+            if (EepromEnabled && (address == SclAddr || address == SdaInAddr))
+            {
+                WriteByteEeprom(address, (byte) value);
+                return;
+
+            }
+
             Console.WriteLine("UNHANDLED WRITEB {0:X6}:{1:X2}", address, value);
         }
 
diff --git a/BizHawk.MultiClient/output/gamedb_sega_md.txt b/BizHawk.MultiClient/output/gamedb_sega_md.txt
index 240e360854..4cc52f43f8 100644
--- a/BizHawk.MultiClient/output/gamedb_sega_md.txt
+++ b/BizHawk.MultiClient/output/gamedb_sega_md.txt
@@ -5546,24 +5546,24 @@ D629DC27FF7657295BC6031142183926		Wolverine Adamantium Rage (UE) [h3C]	GEN
 BFFB9630079B61024C67D7D3C9AA09B4		Wonder Boy III - Monster Lair (JE) [b1]	GEN
 17F53791945CE7CCD83A4E812E3705E4		Wonder Boy III - Monster Lair (JE) [c][!]	GEN
 F992B15CC91DD24E3D3B7896D49B95E3		Wonder Boy III - Monster Lair (JE) [f1]	GEN
-EDBA0BDB192D47712EDBE0097F885F40		Wonder Boy in Monster World (UE) [!]	GEN
-69E5E95FA5B2C01EDD28B40B479C7FF0		Wonder Boy in Monster World (UE) [f1+C]	GEN
-70881D8F992E7222C667F815CD25FF8D		Wonder Boy in Monster World (UE) [f1]	GEN
-6366092E18FB4CF310A651307472B531		Wonder Boy in Monster World (UE) [h1C]	GEN
-ED9C03FF6DDB59CC7B8EC6404FFD5C7B		Wonder Boy in Monster World (UE) [h2C]	GEN
-945335637611A0951595FAE0994F4303		Wonder Boy in Monster World (UE) [o1]	GEN
-3524CBE579A50015D4674DB5DAC2E186		Wonder Boy in Monster World (UE) [o1][f1]	GEN
-73017C4267DD87223ABDE89313642396		Wonder Boy in Monster World (UE) [T+Fre]	GEN
-E25AFC5B755555397E4047061050AE05		Wonder Boy V - Monster World III (J) [!]	GEN
-E9AD2A8857B58F300B668619DB377640		Wonder Boy V - Monster World III (J) [b1]	GEN
-CC41CDDA50D55290E959673281FD4D11		Wonder Boy V - Monster World III (J) [b2]	GEN
-7571A54079024B762CFF639D670E6D12		Wonder Boy V - Monster World III (J) [f1+C]	GEN
-1494668708041AAA7B0AC4F5148390DF		Wonder Boy V - Monster World III (J) [f1]	GEN
-11EF7EFC54760660D635567BFE420D93		Wonder Boy V - Monster World III (J) [f1][o1]	GEN
-0B1870D3132068A9A3018C684C275202		Wonder Boy V - Monster World III (J) [h1C]	GEN
-43451679C0EA5CE0DD0B5FA9FC1FDD00		Wonder Boy V - Monster World III (J) [o2+C]	GEN
-A8071EC317B58F98B729A34F2528B340		Wonder Boy V - Monster World III (J) [o2]	GEN
-1FB07182D41FB50800D3C4562DE802EF		Wonder Boy V - Monster World III (J) [p1]	GEN
+EDBA0BDB192D47712EDBE0097F885F40		Wonder Boy in Monster World (UE) [!]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+69E5E95FA5B2C01EDD28B40B479C7FF0		Wonder Boy in Monster World (UE) [f1+C]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+70881D8F992E7222C667F815CD25FF8D		Wonder Boy in Monster World (UE) [f1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+6366092E18FB4CF310A651307472B531		Wonder Boy in Monster World (UE) [h1C]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+ED9C03FF6DDB59CC7B8EC6404FFD5C7B		Wonder Boy in Monster World (UE) [h2C]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+945335637611A0951595FAE0994F4303		Wonder Boy in Monster World (UE) [o1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+3524CBE579A50015D4674DB5DAC2E186		Wonder Boy in Monster World (UE) [o1][f1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+73017C4267DD87223ABDE89313642396		Wonder Boy in Monster World (UE) [T+Fre]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+E25AFC5B755555397E4047061050AE05		Wonder Boy V - Monster World III (J) [!]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+E9AD2A8857B58F300B668619DB377640		Wonder Boy V - Monster World III (J) [b1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+CC41CDDA50D55290E959673281FD4D11		Wonder Boy V - Monster World III (J) [b2]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+7571A54079024B762CFF639D670E6D12		Wonder Boy V - Monster World III (J) [f1+C]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+1494668708041AAA7B0AC4F5148390DF		Wonder Boy V - Monster World III (J) [f1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+11EF7EFC54760660D635567BFE420D93		Wonder Boy V - Monster World III (J) [f1][o1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+0B1870D3132068A9A3018C684C275202		Wonder Boy V - Monster World III (J) [h1C]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+43451679C0EA5CE0DD0B5FA9FC1FDD00		Wonder Boy V - Monster World III (J) [o2+C]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+A8071EC317B58F98B729A34F2528B340		Wonder Boy V - Monster World III (J) [o2]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
+1FB07182D41FB50800D3C4562DE802EF		Wonder Boy V - Monster World III (J) [p1]	GEN		EEPROM;SDA_IN=200001:0;SDA_OUT=200001:0;SCL=200001:1;EEPROM_ADDR_MASK=7F
 B772F18DD3FFF8B61A6DC801AA74ED07		Wonder Library (J) [!]	GEN
 9EF694AB80344A7CCED0D33F9C84A1B5		World Championship Soccer (JU) (REV00) [!]	GEN
 2C490E1AB0153C73990F72E3EAC3298A		World Championship Soccer (JU) (REV02) [p1+1C]	GEN