diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 5efa164f0e..09b371a9f5 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -176,6 +176,7 @@
     <Compile Include="Computers\Commodore64\Tape\VIC1530.cs" />
     <Compile Include="Consoles\Atari\2600\Atari2600.cs" />
     <Compile Include="Consoles\Atari\2600\Atari2600.Core.cs" />
+    <Compile Include="Consoles\Atari\2600\Atari2600.IMemoryDomains.cs" />
     <Compile Include="Consoles\Atari\2600\Atari2600.RomHeuristics.cs" />
     <Compile Include="Consoles\Atari\2600\Atari2600.Settings.cs" />
     <Compile Include="Consoles\Atari\2600\Mappers\m0840.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IMemoryDomains.cs b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IMemoryDomains.cs
new file mode 100644
index 0000000000..a55a85c696
--- /dev/null
+++ b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.IMemoryDomains.cs
@@ -0,0 +1,63 @@
+using System.Collections.Generic;
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Emulation.Cores.Atari.Atari2600
+{
+	public partial class Atari2600 : IMemoryDomains
+	{
+		public MemoryDomainList MemoryDomains { get; private set; }
+
+		private void SetupMemoryDomains()
+		{
+			var domains = new List<MemoryDomain>
+			{
+				new MemoryDomain(
+					"Main RAM",
+					128,
+					MemoryDomain.Endian.Little,
+					addr => Ram[addr],
+					(addr, value) => Ram[addr] = value),
+				new MemoryDomain(
+					"TIA",
+					16,
+					MemoryDomain.Endian.Little,
+					addr => _tia.ReadMemory((ushort)addr, true),
+					(addr, value) => this._tia.WriteMemory((ushort)addr, value)),
+				new MemoryDomain(
+					"PIA",
+					1024,
+					MemoryDomain.Endian.Little,
+					addr => M6532.ReadMemory((ushort)addr, true),
+					(addr, value) => M6532.WriteMemory((ushort)addr, value)),
+				new MemoryDomain(
+					"System Bus",
+					8192,
+					MemoryDomain.Endian.Little,
+					addr => _mapper.PeekMemory((ushort) addr),
+					(addr, value) => _mapper.PokeMemory((ushort) addr, value)) 
+			};
+
+			if (_mapper is mDPC) // TODO: also mDPCPlus
+			{
+				domains.Add(new MemoryDomain(
+					"DPC",
+					2048,
+					MemoryDomain.Endian.Little,
+					addr => (_mapper as mDPC).DspData[addr],
+					(addr, value) => (_mapper as mDPC).DspData[addr] = value));
+			}
+
+			if (_mapper.HasCartRam)
+			{
+				domains.Add(new MemoryDomain(
+					"Cart Ram",
+					_mapper.CartRam.Len,
+					MemoryDomain.Endian.Little,
+					addr => _mapper.CartRam[addr],
+					(addr, value) => _mapper.CartRam[addr] = value));
+			}
+
+			MemoryDomains = new MemoryDomainList(domains);
+		}
+	}
+}
diff --git a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.cs b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.cs
index 48b597e1e1..cadcb4fc3b 100644
--- a/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Atari/2600/Atari2600.cs
@@ -30,34 +30,6 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 			Settings = (A2600Settings)settings ?? new A2600Settings();
 			SyncSettings = (A2600SyncSettings)syncSettings ?? new A2600SyncSettings();
 
-			var domains = new List<MemoryDomain>
-			{
-				new MemoryDomain(
-					"Main RAM",
-					128,
-					MemoryDomain.Endian.Little,
-					addr => Ram[addr],
-					(addr, value) => Ram[addr] = value),
-				new MemoryDomain(
-					"TIA",
-					16,
-					MemoryDomain.Endian.Little,
-					addr => _tia.ReadMemory((ushort)addr, true),
-					(addr, value) => this._tia.WriteMemory((ushort)addr, value)),
-				new MemoryDomain(
-					"PIA",
-					1024,
-					MemoryDomain.Endian.Little,
-					addr => M6532.ReadMemory((ushort)addr, true),
-					(addr, value) => M6532.WriteMemory((ushort)addr, value)),
-				new MemoryDomain(
-					"System Bus",
-					8192,
-					MemoryDomain.Endian.Little,
-					addr => _mapper.PeekMemory((ushort) addr),
-					(addr, value) => _mapper.PokeMemory((ushort) addr, value)) 
-			};
-
 			CoreComm.CpuTraceAvailable = true;
 			Rom = rom;
 			_game = game;
@@ -69,28 +41,7 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 
 			Console.WriteLine("Game uses mapper " + game.GetOptionsDict()["m"]);
 			RebootCore();
-
-			if (_mapper is mDPC) // TODO: also mDPCPlus
-			{
-				domains.Add(new MemoryDomain(
-					"DPC",
-					2048,
-					MemoryDomain.Endian.Little,
-					addr => (_mapper as mDPC).DspData[addr],
-					(addr, value) => (_mapper as mDPC).DspData[addr] = value));
-			}
-
-			if (_mapper.HasCartRam)
-			{
-				domains.Add(new MemoryDomain(
-					"Cart Ram",
-					_mapper.CartRam.Len,
-					MemoryDomain.Endian.Little,
-					addr => _mapper.CartRam[addr],
-					(addr, value) => _mapper.CartRam[addr] = value));
-			}
-
-			MemoryDomains = new MemoryDomainList(domains);
+			SetupMemoryDomains();
 		}
 
 		public string SystemId { get { return "A26"; } }
@@ -132,8 +83,6 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 
 		public A2600SyncSettings SyncSettings { get; private set; }
 
-		public MemoryDomainList MemoryDomains { get; private set; }
-
 		public static readonly ControllerDefinition Atari2600ControllerDefinition = new ControllerDefinition
 		{
 			Name = "Atari 2600 Basic Controller",