diff --git a/BizHawk.Client.Common/tools/Watch.cs b/BizHawk.Client.Common/tools/Watch.cs
index 3428693338..13c16c2684 100644
--- a/BizHawk.Client.Common/tools/Watch.cs
+++ b/BizHawk.Client.Common/tools/Watch.cs
@@ -174,32 +174,44 @@ namespace BizHawk.Client.Common
 
 		protected byte GetByte()
 		{
-			return _domain.PeekByte(_address % _domain.Size);
+			if (_domain.Size == 0)
+				return _domain.PeekByte(_address);
+			else return _domain.PeekByte(_address % _domain.Size);
 		}
 
 		protected ushort GetWord()
 		{
-			return _domain.PeekWord(_address % _domain.Size, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			if (_domain.Size == 0)
+				return _domain.PeekWord(_address, _bigEndian);
+			else return _domain.PeekWord(_address % _domain.Size, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
 		}
 
 		protected uint GetDWord()
 		{
-			return _domain.PeekDWord(_address % _domain.Size, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			if(_domain.Size == 0)
+				return _domain.PeekDWord(_address, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			else return _domain.PeekDWord(_address % _domain.Size, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
 		}
 
 		protected void PokeByte(byte val)
 		{
-			_domain.PokeByte(_address % _domain.Size, val);
+			if(_domain.Size == 0)
+				_domain.PokeByte(_address, val);
+			else _domain.PokeByte(_address % _domain.Size, val);
 		}
 
 		protected void PokeWord(ushort val)
 		{
-			_domain.PokeWord(_address % _domain.Size, val, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			if (_domain.Size == 0)
+				_domain.PokeWord(_address, val, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			else _domain.PokeWord(_address % _domain.Size, val, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
 		}
 
 		protected void PokeDWord(uint val)
 		{
-			_domain.PokeDWord(_address % _domain.Size, val, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			if (_domain.Size == 0)
+				_domain.PokeDWord(_address, val, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
+			else _domain.PokeDWord(_address % _domain.Size, val, _bigEndian); // TODO: % size stil lisn't correct since it could be the last byte of the domain
 		}
 
 		public void ClearChangeCount() { _changecount = 0; }
@@ -208,7 +220,7 @@ namespace BizHawk.Client.Common
 		{
 			get
 			{
-				return !IsSeparator && Address.Value >= Domain.Size;
+				return !IsSeparator && (Domain.Size != 0 && Address.Value >= Domain.Size);
 			}
 		}
 
diff --git a/BizHawk.Client.EmuHawk/tools/HexEditor/HexEditor.cs b/BizHawk.Client.EmuHawk/tools/HexEditor/HexEditor.cs
index 1041d26610..07104cd52e 100644
--- a/BizHawk.Client.EmuHawk/tools/HexEditor/HexEditor.cs
+++ b/BizHawk.Client.EmuHawk/tools/HexEditor/HexEditor.cs
@@ -661,6 +661,9 @@ namespace BizHawk.Client.EmuHawk
 
 			for (var i = 0; i < MemoryDomains.Count; i++)
 			{
+				//zero 09-sep-2014 - what cases would have a MemoryDomain of size 0? 
+				//1. unspecified malfunctions (please specify)
+				//2. full 32bit memorydomains
 				if (MemoryDomains[i].Size > 0)
 				{
 					var str = MemoryDomains[i].ToString();
diff --git a/BizHawk.Common/Extensions/NumberExtensions.cs b/BizHawk.Common/Extensions/NumberExtensions.cs
index 0c7522560b..f8ed99835d 100644
--- a/BizHawk.Common/Extensions/NumberExtensions.cs
+++ b/BizHawk.Common/Extensions/NumberExtensions.cs
@@ -60,6 +60,12 @@ namespace BizHawk.Common.NumberExtensions
 		/// </summary>
 		public static int NumHexDigits(this int i)
 		{
+			//now this is a bit of a trick. if it was less than 0, it mustve been >= 0x80000000 and so takes all 8 digits
+			if (i < 0)
+			{
+				return 8;
+			}
+
 			if (i < 0x100)
 			{
 				return 2;
diff --git a/BizHawk.Emulation.Common/MemoryDomain.cs b/BizHawk.Emulation.Common/MemoryDomain.cs
index 08e4c5943f..ffb978a23d 100644
--- a/BizHawk.Emulation.Common/MemoryDomain.cs
+++ b/BizHawk.Emulation.Common/MemoryDomain.cs
@@ -10,6 +10,11 @@ namespace BizHawk.Emulation.Common
 		public enum Endian { Big, Little, Unknown }
 
 		public readonly string Name;
+
+		/// <summary>
+		/// Special note: if this is 0, the memorydomain is 0x100000000 (full 32bits) in size.
+		/// This was judged to be less of a mess than using a bunch of longs everywhere.
+		/// </summary>
 		public readonly int Size;
 		public readonly Endian EndianType;
 
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/N64/N64.IMemoryDomains.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/N64/N64.IMemoryDomains.cs
index 3f7ae045da..a620c52357 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/N64/N64.IMemoryDomains.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/N64/N64.IMemoryDomains.cs
@@ -129,7 +129,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.N64
 			_memoryDomains.Add(new MemoryDomain
 				(
 					name: "Sytem Bus",
-					size: int.MaxValue,
+					size: 0, //special case for full 32bit memorydomain
 					endian: MemoryDomain.Endian.Big,
 					peekByte: peekByte,
 					pokeByte: pokeByte