diff --git a/WoofWare.PawPrint/EvalStackValueComparisons.fs b/WoofWare.PawPrint/EvalStackValueComparisons.fs
index 7a8fdf0..45c3bb4 100644
--- a/WoofWare.PawPrint/EvalStackValueComparisons.fs
+++ b/WoofWare.PawPrint/EvalStackValueComparisons.fs
@@ -164,6 +164,15 @@ module EvalStackValueComparisons =
             failwith $"TODO (CEQ): nativeint vs managed pointer"
         | EvalStackValue.NativeInt _, _ -> failwith $"bad ceq: NativeInt vs {var2}"
         | EvalStackValue.ObjectRef var1, EvalStackValue.ObjectRef var2 -> var1 = var2
+        | EvalStackValue.ManagedPointer src, EvalStackValue.ObjectRef var1
+        | EvalStackValue.ObjectRef var1, EvalStackValue.ManagedPointer src ->
+            match src with
+            | ManagedPointerSource.Heap src -> src = var1
+            | ManagedPointerSource.Null -> false
+            | ManagedPointerSource.Field _
+            | ManagedPointerSource.LocalVariable _
+            | ManagedPointerSource.Argument _ -> false
+            | ManagedPointerSource.ArrayIndex (arr, index) -> failwith "todo"
         | EvalStackValue.ObjectRef _, _ -> failwith $"bad ceq: ObjectRef vs {var2}"
         | EvalStackValue.ManagedPointer var1, EvalStackValue.ManagedPointer var2 -> var1 = var2
         | EvalStackValue.ManagedPointer var1, EvalStackValue.NativeInt var2 ->
diff --git a/WoofWare.PawPrint/Intrinsics.fs b/WoofWare.PawPrint/Intrinsics.fs
index ac5a78b..ce5a349 100644
--- a/WoofWare.PawPrint/Intrinsics.fs
+++ b/WoofWare.PawPrint/Intrinsics.fs
@@ -14,6 +14,10 @@ module Intrinsics =
             "System.Private.CoreLib", "ArgumentNullException", "ThrowIfNull"
             // https://github.com/dotnet/runtime/blob/ec11903827fc28847d775ba17e0cd1ff56cfbc2e/src/coreclr/System.Private.CoreLib/src/System/Type.CoreCLR.cs#L82
             "System.Private.CoreLib", "Type", "GetTypeFromHandle"
+            // https://github.com/dotnet/runtime/blob/108fa7856efcfd39bc991c2d849eabbf7ba5989c/src/libraries/System.Private.CoreLib/src/System/ReadOnlySpan.cs#L161
+            "System.Private.CoreLib", "ReadOnlySpan`1", "get_Length"
+            // https://github.com/dotnet/runtime/blob/9e5e6aa7bc36aeb2a154709a9d1192030c30a2ef/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.cs#L153
+            "System.Private.CoreLib", "RuntimeHelpers", "CreateSpan"
         ]
         |> Set.ofList
 
@@ -324,9 +328,6 @@ module Intrinsics =
         | "System.Private.CoreLib", "RuntimeHelpers", "InitializeArray" ->
             // https://github.com/dotnet/runtime/blob/9e5e6aa7bc36aeb2a154709a9d1192030c30a2ef/src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.CoreCLR.cs#L18
             failwith "TODO: array initialization"
-        | "System.Private.CoreLib", "RuntimeHelpers", "CreateSpan" ->
-            // https://github.com/dotnet/runtime/blob/9e5e6aa7bc36aeb2a154709a9d1192030c30a2ef/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.cs#L153
-            None
         | "System.Private.CoreLib", "Unsafe", "As" ->
             // https://github.com/dotnet/runtime/blob/721fdf6dcb032da1f883d30884e222e35e3d3c99/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/Unsafe.cs#L64
             let inputType, retType =
@@ -339,6 +340,22 @@ module Intrinsics =
                 | [ from ; to_ ] -> from, to_
                 | _ -> failwith "bad generics"
 
+            if ConcreteTypeHandle.Byref to_ <> retType then
+                failwith "bad return type"
+
+            if ConcreteTypeHandle.Byref from <> inputType then
+                failwith "bad input type"
+
+            let from =
+                match AllConcreteTypes.lookup from state.ConcreteTypes with
+                | None -> failwith "somehow have not concretised input type"
+                | Some t -> t
+
+            let to_ =
+                match AllConcreteTypes.lookup to_ state.ConcreteTypes with
+                | None -> failwith "somehow have not concretised ret type"
+                | Some t -> t
+
             failwith "TODO: transmute fields etc"
             let state = state |> IlMachineState.advanceProgramCounter currentThread
 
@@ -362,8 +379,5 @@ module Intrinsics =
             |> IlMachineState.pushToEvalStack (CliType.Numeric (CliNumericType.Int32 size)) currentThread
             |> IlMachineState.advanceProgramCounter currentThread
             |> Some
-        | "System.Private.CoreLib", "ReadOnlySpan`1", "get_Length" ->
-            // https://github.com/dotnet/runtime/blob/108fa7856efcfd39bc991c2d849eabbf7ba5989c/src/libraries/System.Private.CoreLib/src/System/ReadOnlySpan.cs#L161
-            None
         | a, b, c -> failwith $"TODO: implement JIT intrinsic {a}.{b}.{c}"
         |> Option.map (fun s -> s.WithThreadSwitchedToAssembly callerAssy currentThread |> fst)
diff --git a/WoofWare.PawPrint/UnaryMetadataIlOp.fs b/WoofWare.PawPrint/UnaryMetadataIlOp.fs
index 98b6a8d..3d64253 100644
--- a/WoofWare.PawPrint/UnaryMetadataIlOp.fs
+++ b/WoofWare.PawPrint/UnaryMetadataIlOp.fs
@@ -1198,7 +1198,7 @@ module internal UnaryMetadataIlOp =
                                     {
                                         Name = field.Name
                                         Contents = zero
-                                        Offset = failwith "offset"
+                                        Offset = field.Offset
                                     }
 
                                 state, field :: acc