diff --git a/source/Cosmos.Build.MSBuild/ReadNAsmMapToDebugInfo.cs b/source/Cosmos.Build.MSBuild/ReadNAsmMapToDebugInfo.cs
index c64c8cf4a..3f97b1d73 100644
--- a/source/Cosmos.Build.MSBuild/ReadNAsmMapToDebugInfo.cs
+++ b/source/Cosmos.Build.MSBuild/ReadNAsmMapToDebugInfo.cs
@@ -79,10 +79,10 @@ namespace Cosmos.Build.MSBuild {
         {
           uint xAddress = UInt32.Parse(xLineParts[0], NumberStyles.HexNumber);
 
-          ulong xId;
+          long xId;
           if (xLineParts[2].StartsWith("GUID_"))
           {
-            xId = ulong.Parse(xLineParts[2].Substring(5));
+              xId = long.Parse(xLineParts[2].Substring(5));
           }
           else
           {
diff --git a/source/Cosmos.Debug.Common/DebugInfo.cs b/source/Cosmos.Debug.Common/DebugInfo.cs
index b8d66767a..e7f6cb2f3 100644
--- a/source/Cosmos.Debug.Common/DebugInfo.cs
+++ b/source/Cosmos.Debug.Common/DebugInfo.cs
@@ -21,27 +21,27 @@ namespace Cosmos.Debug.Common
         /// <summary>
         /// Current id of the generation.
         /// </summary>
-        private static UInt64 mLastGuid = 0;
+        private static long mLastGuid = 0;
 
         /// <summary>
         /// Range for the id generation process.
         /// </summary>
-        private static UInt64 mPrefix = 0;
+        private static long mPrefix = 0;
 
         /// <summary>
         /// Specifies range which is used by the assembler during compilation phase.
         /// </summary>
-        public const ulong AssemblerDebugSymbolsRange = 0xUL;
+        public const long AssemblerDebugSymbolsRange = 0xL;
 
         /// <summary>
         /// Specifies range which is used by the Elf map extraction process.
         /// </summary>
-        public const ulong ElfFileMapExtractionRange = 0x1000000000000000UL;
+        public const long ElfFileMapExtractionRange = 0x1000000000000000L;
 
         /// <summary>
         /// Specifies range which is used by the Nasm map extraction process.
         /// </summary>
-        public const ulong NAsmMapExtractionRange = 0x4000000000000000UL;
+        public const long NAsmMapExtractionRange = 0x4000000000000000L;
 
         // Please beware this field, it may cause issues if used incorrectly.
         public static DebugInfo CurrentInstance { get; private set; }
@@ -316,7 +316,7 @@ namespace Cosmos.Debug.Common
 
         // Quick look up of assemblies so we dont have to go to the database and compare by fullname.
         // This and other GUID lists contain only a few members, and save us from issuing a lot of selects to SQL.
-		public Dictionary<Assembly, UInt64> AssemblyGUIDs = new Dictionary<Assembly, UInt64>();
+        public Dictionary<Assembly, long> AssemblyGUIDs = new Dictionary<Assembly, long>();
         List<Cosmos.Debug.Common.AssemblyFile> xAssemblies = new List<Cosmos.Debug.Common.AssemblyFile>();
         public void AddAssemblies(List<Assembly> aAssemblies, bool aFlush = false)
         {
@@ -338,7 +338,7 @@ namespace Cosmos.Debug.Common
             BulkInsert("AssemblyFiles", xAssemblies, 2500, aFlush);
         }
 
-		public Dictionary<string, UInt64> DocumentGUIDs = new Dictionary<string, UInt64>();
+        public Dictionary<string, long> DocumentGUIDs = new Dictionary<string, long>();
         List<Document> xDocuments = new List<Document>(1);
         public void AddDocument(string aPathname, bool aFlush = false)
         {
@@ -500,7 +500,7 @@ namespace Cosmos.Debug.Common
 
         public Label GetMethodHeaderLabel(UInt32 aAddress)
         {
-            var xAddress = (ulong)aAddress;
+            var xAddress = (long)aAddress;
             var xLabels = mConnection.Query<Label>(new SQLinq<Label>().Where(i => i.Address <= xAddress).OrderByDescending(i => i.Address)).ToArray();
             
             Label methodHeaderLabel = null;
@@ -682,7 +682,7 @@ namespace Cosmos.Debug.Common
         /// Sets the range in which id would be generated.
         /// </summary>
         /// <param name="idRange">Number which specified id range.</param>
-        public static void SetRange(ulong idRange)
+        public static void SetRange(long idRange)
         {
             mPrefix = idRange;
             mLastGuid = idRange;
@@ -692,7 +692,7 @@ namespace Cosmos.Debug.Common
         /// Gets count of ids generated during last session.
         /// </summary>
         /// <returns>Count of generated ids.</returns>
-        public static ulong GeneratedIdsCount()
+        public static long GeneratedIdsCount()
         {
             return mLastGuid - mPrefix;
         }
@@ -701,7 +701,7 @@ namespace Cosmos.Debug.Common
         /// Generates new id for the symbol.
         /// </summary>
         /// <returns>New value for the id.</returns>
-        public static ulong CreateId()
+        public static long CreateId()
         {
             mLastGuid++;
             return mLastGuid;
diff --git a/source/Cosmos.Debug.Common/DebugModel.cs b/source/Cosmos.Debug.Common/DebugModel.cs
index 82b78af49..dd726343b 100644
--- a/source/Cosmos.Debug.Common/DebugModel.cs
+++ b/source/Cosmos.Debug.Common/DebugModel.cs
@@ -20,7 +20,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("ID")]
-        public global::System.UInt64 ID
+        public global::System.Int64 ID
         {
             get;set;
         }
@@ -47,7 +47,7 @@ namespace Cosmos.Debug.Common
         [Key]
         [DataMemberAttribute()]
         [SQLinqColumn("ID")]
-			public global::System.UInt64 ID
+			public global::System.Int64 ID
         {
             get;
             set;
@@ -110,7 +110,7 @@ namespace Cosmos.Debug.Common
         [DataMemberAttribute()]
         [Key]
         [SQLinqColumn("ID")]
-				public global::System.UInt64 ID
+				public global::System.Int64 ID
         {
             get;
             set;
@@ -154,7 +154,7 @@ namespace Cosmos.Debug.Common
         [Key]
         [DataMemberAttribute()]
         [SQLinqColumn("ID")]
-        public global::System.UInt64 ID
+        public global::System.Int64 ID
         {
             get;
             set;
@@ -174,7 +174,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("ID")]
-			public global::System.UInt64 ID
+			public global::System.Int64 ID
         {
             get;
             set;
@@ -196,7 +196,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("ADDRESS")]
-        public global::System.UInt64 Address
+        public global::System.Int64 Address
         {
             get;
             set;
@@ -283,7 +283,7 @@ namespace Cosmos.Debug.Common
         [Key]
         [DataMemberAttribute()]
         [SQLinqColumn("ID")]
-				public global::System.UInt64 ID
+				public global::System.Int64 ID
         {
             get;
             set;
@@ -304,7 +304,7 @@ namespace Cosmos.Debug.Common
         [DataMemberAttribute()]
         [Key]
         [SQLinqColumn("ID")]
-			public global::System.UInt64 ID
+			public global::System.Int64 ID
         {
             get;
             set;
@@ -337,7 +337,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("ASSEMBLYFILEID")]
-				public global::System.UInt64 AssemblyFileID
+				public global::System.Int64 AssemblyFileID
         {
             get;
             set;
@@ -370,7 +370,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("DOCUMENTID")]
-				public global::System.UInt64 DocumentID
+				public global::System.Int64 DocumentID
         {
             get;
             set;
@@ -381,7 +381,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("LABELSTARTID")]
-				public Nullable<global::System.UInt64> LabelStartID
+				public Nullable<global::System.Int64> LabelStartID
         {
             get;
             set;
@@ -392,7 +392,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("LABELENDID")]
-				public Nullable<global::System.UInt64> LabelEndID
+				public Nullable<global::System.Int64> LabelEndID
         {
             get;
             set;
@@ -424,7 +424,7 @@ namespace Cosmos.Debug.Common
         [Key]
         [DataMemberAttribute()]
         [SQLinqColumn("ID")]
-			public global::System.UInt64 ID
+			public global::System.Int64 ID
         {
             get;
             set;
@@ -468,7 +468,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("METHODID")]
-				public Nullable<global::System.UInt64> MethodID
+				public Nullable<global::System.Int64> MethodID
         {
             get;
             set;
@@ -499,7 +499,7 @@ namespace Cosmos.Debug.Common
         /// </summary>
         [DataMemberAttribute()]
         [SQLinqColumn("METHODID")]
-				public global::System.UInt64 MethodID
+				public global::System.Int64 MethodID
         {
             get;
             set;
diff --git a/source/Cosmos.Debug.Common/ObjDump.cs b/source/Cosmos.Debug.Common/ObjDump.cs
index 89b86fa37..8b1b0eee9 100644
--- a/source/Cosmos.Debug.Common/ObjDump.cs
+++ b/source/Cosmos.Debug.Common/ObjDump.cs
@@ -83,11 +83,11 @@ namespace Cosmos.Debug.Common {
                     continue;
                 }
 
-                UInt64 xGuid;
+                long xGuid;
                 // See if label has an embedded GUID. If so, use it.
                 if (xLabel.StartsWith("GUID_"))
                 {
-                    xGuid = ulong.Parse(xLabel.Substring(5));
+                    xGuid = long.Parse(xLabel.Substring(5));
                 }
                 else
                 {
diff --git a/source/Cosmos.Debug.VSDebugEngine/AD7.Impl/AD7PendingBreakpoint.cs b/source/Cosmos.Debug.VSDebugEngine/AD7.Impl/AD7PendingBreakpoint.cs
index 8803b7428..b3b6aff13 100644
--- a/source/Cosmos.Debug.VSDebugEngine/AD7.Impl/AD7PendingBreakpoint.cs
+++ b/source/Cosmos.Debug.VSDebugEngine/AD7.Impl/AD7PendingBreakpoint.cs
@@ -106,7 +106,7 @@ namespace Cosmos.Debug.VSDebugEngine {
           // VS will send us BPs from other Cosmos projects (and possibly non Cosmos ones, didnt look that deep)
           // but we wont have them in our doc list because it contains only ones from the currently project
           // to run.
-		  UInt64 xDocID;
+          long xDocID;
           if (xDebugInfo.DocumentGUIDs.TryGetValue(xDocName, out xDocID)) {
               // Find which Method the Doc, Line, Col are in.
               // Must add +1 for both Line and Col. They are 0 based, while SP ones are 1 based.
diff --git a/source/Cosmos.IL2CPU/AppAssembler.cs b/source/Cosmos.IL2CPU/AppAssembler.cs
index 49e7c835e..df4b79ee2 100644
--- a/source/Cosmos.IL2CPU/AppAssembler.cs
+++ b/source/Cosmos.IL2CPU/AppAssembler.cs
@@ -45,8 +45,8 @@ namespace Cosmos.IL2CPU
         public readonly Cosmos.Assembler.Assembler Assembler;
         //
         protected string mCurrentMethodLabel;
-		protected UInt64 mCurrentMethodLabelEndGuid;
-		protected UInt64 mCurrentMethodGuid;
+        protected long mCurrentMethodLabelEndGuid;
+        protected long mCurrentMethodGuid;
 
         public AppAssembler(int aComPort, string assemblerLogFile)
         {