diff --git a/WoofWare.PawPrint.Domain/MethodInfo.fs b/WoofWare.PawPrint.Domain/MethodInfo.fs
index e5912bb..d17febc 100644
--- a/WoofWare.PawPrint.Domain/MethodInfo.fs
+++ b/WoofWare.PawPrint.Domain/MethodInfo.fs
@@ -52,6 +52,14 @@ module Parameter =
 
         result.ToImmutable ()
 
+type GenericVariance =
+    | Covariant
+    | Contravariant
+
+type GenericConstraint =
+    | Reference
+    | NonNullableValue
+
 /// <summary>
 /// Represents a generic type or method parameter definition.
 /// Corresponds to GenericParameter in System.Reflection.Metadata.
@@ -66,6 +74,10 @@ type GenericParameter =
         /// For example, in Dictionary&lt;TKey, TValue&rt;, TKey has index 0 and TValue has index 1.
         /// </summary>
         SequenceNumber : int
+
+        Variance : GenericVariance option
+        Constraint : GenericConstraint option
+        RequiresParameterlessConstructor : bool
     }
 
 [<RequireQualifiedAccess>]
@@ -79,9 +91,31 @@ module GenericParameter =
         |> Seq.map (fun param ->
             let param = metadata.GetGenericParameter param
 
+            let requiresParamlessCons =
+                param.Attributes.HasFlag GenericParameterAttributes.DefaultConstructorConstraint
+
+            let constr =
+                if param.Attributes.HasFlag GenericParameterAttributes.NotNullableValueTypeConstraint then
+                    Some GenericConstraint.NonNullableValue
+                elif param.Attributes.HasFlag GenericParameterAttributes.ReferenceTypeConstraint then
+                    Some GenericConstraint.Reference
+                else
+                    None
+
+            let variance =
+                if param.Attributes.HasFlag GenericParameterAttributes.Contravariant then
+                    Some GenericVariance.Contravariant
+                elif param.Attributes.HasFlag GenericParameterAttributes.Covariant then
+                    Some GenericVariance.Covariant
+                else
+                    None
+
             {
                 Name = metadata.GetString param.Name
                 SequenceNumber = param.Index
+                Variance = variance
+                Constraint = constr
+                RequiresParameterlessConstructor = requiresParamlessCons
             }
         )
         |> ImmutableArray.CreateRange
diff --git a/WoofWare.PawPrint.Domain/TypeConcretisation.fs b/WoofWare.PawPrint.Domain/TypeConcretisation.fs
index 5c83535..0f9c29c 100644
--- a/WoofWare.PawPrint.Domain/TypeConcretisation.fs
+++ b/WoofWare.PawPrint.Domain/TypeConcretisation.fs
@@ -119,7 +119,13 @@ module ConcreteActivePatterns =
         match handle with
         | ConcreteTypeHandle.Concrete id ->
             match concreteTypes.Mapping |> Map.tryFind id with
-            | Some ct when ct.Namespace = "System" && ct.Name = "Void" && ct.Generics.IsEmpty -> Some ()
+            | Some ct when
+                ct.Assembly.Name = "System.Private.CoreLib"
+                && ct.Namespace = "System"
+                && ct.Name = "Void"
+                && ct.Generics.IsEmpty
+                ->
+                Some ()
             | _ -> None
         | _ -> None
 
@@ -149,6 +155,34 @@ module ConcreteActivePatterns =
             | None -> None
         | _ -> None
 
+    let (|ConcreteRuntimeFieldHandle|_|) (concreteTypes : AllConcreteTypes) (handle : ConcreteTypeHandle) =
+        match handle with
+        | ConcreteTypeHandle.Concrete id ->
+            match concreteTypes.Mapping |> Map.tryFind id with
+            | Some ct when
+                ct.Assembly.Name = "System.Private.CoreLib"
+                && ct.Namespace = "System"
+                && ct.Name = "RuntimeFieldHandle"
+                && ct.Generics.IsEmpty
+                ->
+                Some ()
+            | _ -> None
+        | _ -> None
+
+    let (|ConcreteNonGenericArray|_|) (concreteTypes : AllConcreteTypes) (handle : ConcreteTypeHandle) =
+        match handle with
+        | ConcreteTypeHandle.Concrete id ->
+            match concreteTypes.Mapping |> Map.tryFind id with
+            | Some ct when
+                ct.Assembly.Name = "System.Private.CoreLib"
+                && ct.Namespace = "System"
+                && ct.Name = "Array"
+                && ct.Generics.IsEmpty
+                ->
+                Some ()
+            | _ -> None
+        | _ -> None
+
     let (|ConcreteBool|_|) (concreteTypes : AllConcreteTypes) (handle : ConcreteTypeHandle) : unit option =
         match handle with
         | ConcreteTypeHandle.Concrete id ->
@@ -542,7 +576,7 @@ module TypeConcretization =
     let rec concretizeType
         (ctx : ConcretizationContext<'corelib>)
         (loadAssembly :
-            AssemblyName -> AssemblyReferenceHandle -> (ImmutableDictionary<string, DumpedAssembly> * DumpedAssembly))
+            AssemblyName -> AssemblyReferenceHandle -> ImmutableDictionary<string, DumpedAssembly> * DumpedAssembly)
         (assembly : AssemblyName)
         (typeGenerics : ConcreteTypeHandle ImmutableArray)
         (methodGenerics : ConcreteTypeHandle ImmutableArray)
@@ -890,7 +924,7 @@ module Concretization =
     let concretizeMethod
         (ctx : AllConcreteTypes)
         (loadAssembly :
-            AssemblyName -> AssemblyReferenceHandle -> (ImmutableDictionary<string, DumpedAssembly> * DumpedAssembly))
+            AssemblyName -> AssemblyReferenceHandle -> ImmutableDictionary<string, DumpedAssembly> * DumpedAssembly)
         (assemblies : ImmutableDictionary<string, DumpedAssembly>)
         (baseTypes : BaseClassTypes<DumpedAssembly>)
         (method : WoofWare.PawPrint.MethodInfo<TypeDefn, WoofWare.PawPrint.GenericParameter, TypeDefn>)
diff --git a/WoofWare.PawPrint/IlMachineState.fs b/WoofWare.PawPrint/IlMachineState.fs
index 28f6128..1fc14a2 100644
--- a/WoofWare.PawPrint/IlMachineState.fs
+++ b/WoofWare.PawPrint/IlMachineState.fs
@@ -403,9 +403,9 @@ module IlMachineState =
                 | PrimitiveType.Double -> baseClassTypes.Double
                 | PrimitiveType.String -> baseClassTypes.String
                 | PrimitiveType.TypedReference -> failwith "todo"
-                | PrimitiveType.IntPtr -> failwith "todo"
-                | PrimitiveType.UIntPtr -> failwith "todo"
-                | PrimitiveType.Object -> failwith "todo"
+                | PrimitiveType.IntPtr -> baseClassTypes.IntPtr
+                | PrimitiveType.UIntPtr -> baseClassTypes.UIntPtr
+                | PrimitiveType.Object -> baseClassTypes.Object
                 |> TypeInfo.mapGeneric (fun _ -> failwith "none of these types are generic")
 
             state, baseClassTypes.Corelib, ty
diff --git a/WoofWare.PawPrint/UnaryConstIlOp.fs b/WoofWare.PawPrint/UnaryConstIlOp.fs
index 22b789d..1f4167f 100644
--- a/WoofWare.PawPrint/UnaryConstIlOp.fs
+++ b/WoofWare.PawPrint/UnaryConstIlOp.fs
@@ -403,7 +403,34 @@ module internal UnaryConstIlOp =
                else
                    id
             |> Tuple.withRight WhatWeDid.Executed
-        | Bne_un_s b -> failwith "TODO: Bne_un_s unimplemented"
+        | Bne_un_s b ->
+            // Table III.4
+            let value2, state = IlMachineState.popEvalStack currentThread state
+            let value1, state = IlMachineState.popEvalStack currentThread state
+
+            let isNotEqual =
+                match value1, value2 with
+                | EvalStackValue.Int32 v1, EvalStackValue.Int32 v2 -> v1 <> v2
+                | EvalStackValue.Int32 v1, EvalStackValue.NativeInt v2 -> failwith "TODO"
+                | EvalStackValue.Int32 v1, _ -> failwith $"invalid comparison, {v1} with {value2}"
+                | _, EvalStackValue.Int32 v2 -> failwith $"invalid comparison, {value1} with {v2}"
+                | EvalStackValue.Int64 v1, EvalStackValue.Int64 v2 -> v1 <> v2
+                | EvalStackValue.Int64 v1, _ -> failwith $"invalid comparison, {v1} with {value2}"
+                | _, EvalStackValue.Int64 v2 -> failwith $"invalid comparison, {value1} with {v2}"
+                | EvalStackValue.Float v1, EvalStackValue.Float v2 -> v1 <> v2
+                | _, EvalStackValue.Float v2 -> failwith $"invalid comparison, {value1} with {v2}"
+                | EvalStackValue.Float v1, _ -> failwith $"invalid comparison, {v1} with {value2}"
+                | EvalStackValue.NativeInt v1, EvalStackValue.NativeInt v2 -> v1 <> v2
+                | EvalStackValue.ManagedPointer ptr1, EvalStackValue.ManagedPointer ptr2 -> ptr1 <> ptr2
+                | _, _ -> failwith $"TODO {value1} {value2} (see table III.4)"
+
+            state
+            |> IlMachineState.advanceProgramCounter currentThread
+            |> if isNotEqual then
+                   IlMachineState.jumpProgramCounter currentThread (int b)
+               else
+                   id
+            |> Tuple.withRight WhatWeDid.Executed
         | Bge_un_s b ->
             let value2, state = IlMachineState.popEvalStack currentThread state
             let value1, state = IlMachineState.popEvalStack currentThread state