diff --git a/lib/register/register_reference.rb b/lib/register/register_reference.rb
index d6c9ee83..6748cb32 100644
--- a/lib/register/register_reference.rb
+++ b/lib/register/register_reference.rb
@@ -48,33 +48,66 @@ module Register
       RegisterReference.new( sym )
     end
 
-    MESSAGE_REGISTER = :r0
-    SELF_REGISTER = :r1
-    FRAME_REGISTER = :r2
-    NEW_MESSAGE_REGISTER = :r3
-
-    TMP_REGISTER = :r4
-
-    def self.self_reg
-      new SELF_REGISTER
-    end
-    def self.message_reg
-      new MESSAGE_REGISTER
-    end
-    def self.frame_reg
-      new FRAME_REGISTER
-    end
-    def self.new_message_reg
-      new NEW_MESSAGE_REGISTER
-    end
-    def self.tmp_reg
-      new TMP_REGISTER
-    end
-
     def sof_reference_name
       @symbol
     end
 
   end
 
+  MESSAGE_REGISTER = :r0
+  SELF_REGISTER = :r1
+  FRAME_REGISTER = :r2
+  NEW_MESSAGE_REGISTER = :r3
+
+  TMP_REGISTER = :r4
+
+  def self.self_reg
+    RegisterReference.new SELF_REGISTER
+  end
+  def self.message_reg
+    RegisterReference.new MESSAGE_REGISTER
+  end
+  def self.frame_reg
+    RegisterReference.new FRAME_REGISTER
+  end
+  def self.new_message_reg
+    RegisterReference.new NEW_MESSAGE_REGISTER
+  end
+  def self.tmp_reg
+    RegisterReference.new TMP_REGISTER
+  end
+
+  def self.get_slot from , index , to
+    index = resolve_index( from , index)
+    from = resolve_to_register from
+    to = resolve_to_register to
+    GetSlot.new( from , index , to)
+  end
+
+  def self.resolve_index( clazz_name , instance_name )
+    return instance_name unless instance_name.is_a? Symbol
+    real_name = "#{clazz_name}".capitalize.to_sym
+    clazz = Parfait::Space.object_space.get_class_by_name(real_name)
+    raise "Class name not given #{real_name}" unless clazz
+    index = clazz.object_layout.index_of( instance_name )
+    raise "Instance name=#{instance_name} not found on #{real_name}" unless index
+    return index
+  end
+
+  def self.resolve_to_register reference
+    register = reference
+    if reference.is_a? Symbol
+      case reference
+      when :message
+        register = message_reg
+      when :self
+        register = self_reg
+      when :frame
+        register = frame_reg
+      else
+        raise "not recognized register reference #{reference}"
+      end
+    end
+    return register
+  end
 end
diff --git a/lib/virtual/slots/frame_slot.rb b/lib/virtual/slots/frame_slot.rb
index e8ce6076..d237ed17 100644
--- a/lib/virtual/slots/frame_slot.rb
+++ b/lib/virtual/slots/frame_slot.rb
@@ -2,9 +2,9 @@ module Virtual
 
   # Slots in the Frame a re represented by instances of FrameSlot
 
-  # Slots in the Frame are local or temporary varialbes in a message
+  # Slots in the Frame are local or temporary variables in a message
   class FrameSlot < Slot
-    def initialize index , type = Unknown, value = nil
+    def initialize type = Unknown, value = nil
       super
     end
   end
diff --git a/lib/virtual/slots/message_slot.rb b/lib/virtual/slots/message_slot.rb
index 13a001a0..11a23ee0 100644
--- a/lib/virtual/slots/message_slot.rb
+++ b/lib/virtual/slots/message_slot.rb
@@ -1,18 +1,5 @@
 module Virtual
 
-  #TODO : this constant approach is a bit old, from before PArfait adapter
-  #      nowadays these are unneccessary as we can resolve the names by using the
-  #      layout of the class. (get Class from space)
-  TYPE_INDEX = 0
-  LAYOUT_INDEX = 1
-  CALLER_INDEX = 2
-  RETURN_INDEX = 3
-  EXCEPTION_INDEX = 4
-  SELF_INDEX = 5
-  NAME_INDEX = 6
-  FRAME_INDEX = 7
-  ARGUMENT_START = 8
-
   # The current Message is one of four objects the virtual machine knows
   #
   # Slots represent instance variables of objects, so MessageSlots
@@ -20,31 +7,31 @@ module Virtual
   # The Message has a layout as per the constant above
 
   class MessageSlot < Slot
-    def initialize index , type = Unknown , value = nil
-      super(index ,type , value )
+    def initialize type = Unknown , value = nil
+      super(type , value )
     end
   end
 
   # named classes exist for slots that often accessed
 
-  # Return is the MessageSlot(RETURN_INDEX)
+  # Return is the return of MessageSlot
   class Return < MessageSlot
     def initialize type = Unknown, value = nil
-      super( RETURN_INDEX , type , value  )
+      super( type , value  )
     end
   end
 
-  # Self is the MessageSlot(SELF_INDEX)
+  # Self is the self in MessageSlot
   class Self < MessageSlot
     def initialize type = Unknown, value = nil
-      super( SELF_INDEX , type , value  )
+      super( type , value  )
     end
   end
 
   # MessageName of the current message
   class MessageName < MessageSlot
     def initialize type = Unknown, value = nil
-      super( NAME_INDEX , type , value  )
+      super( type , value  )
     end
   end
 end
diff --git a/lib/virtual/slots/next_message_slot.rb b/lib/virtual/slots/next_message_slot.rb
index 3e0aa217..b2471244 100644
--- a/lib/virtual/slots/next_message_slot.rb
+++ b/lib/virtual/slots/next_message_slot.rb
@@ -7,31 +7,31 @@ module Virtual
   # The Message has a layout as per the constant above
 
   class NextMessageSlot < Slot
-    def initialize index , type = Unknown, value = nil
-      super(index , type , value )
+    def initialize type = Unknown, value = nil
+      super( type , value )
     end
   end
 
   # named classes exist for slots that often accessed
 
-  # NextReturn is the NextMessageSlot(RETURN_INDEX)
+  # NextReturn is the return of NextMessageSlot
   class NextReturn < NextMessageSlot
     def initialize type = Unknown, value = nil
-      super( RETURN_INDEX, type , value  )
+      super( type , value  )
     end
   end
 
-  # NextSelf is the NextMessageSlot(SELF_INDEX)
+  # NextSelf is the self of NextMessageSlot
   class NextSelf < NextMessageSlot
     def initialize type = Unknown, value = nil
-      super( SELF_INDEX , type , value  )
+      super( type , value  )
     end
   end
 
   # NextMessageName of the next message
   class NextMessageName < NextMessageSlot
     def initialize type = Unknown, value = nil
-      super( NAME_INDEX, type , value )
+      super( type , value )
     end
   end
 end
diff --git a/lib/virtual/slots/self_slot.rb b/lib/virtual/slots/self_slot.rb
index d0b38987..4133bd12 100644
--- a/lib/virtual/slots/self_slot.rb
+++ b/lib/virtual/slots/self_slot.rb
@@ -14,7 +14,7 @@ module Virtual
   #  that object
   #
   class SelfSlot < Slot
-    def initialize index , type = Unknown, value = nil
+    def initialize type = Unknown, value = nil
       super
     end
   end
diff --git a/lib/virtual/slots/slot.rb b/lib/virtual/slots/slot.rb
index 19bee9e5..2f585394 100644
--- a/lib/virtual/slots/slot.rb
+++ b/lib/virtual/slots/slot.rb
@@ -2,7 +2,8 @@ module Virtual
   # A slot is a slot in an object. It is the storage location for a value.
   #             (Remember, values are typed)
   # From a memory perspective a slot is an index into an array (the object)
-  # We are not modelling the array here, but the index into it.
+  # The mapping into arrays is a straightforward matter, but happens in the
+  # next level down, the register machine.
 
   # Four known objects exist and those correspond to subclasses:
   # - the message that has been received: MessageSlot
@@ -17,12 +18,11 @@ module Virtual
 
   class Slot < Object
 
-    attr_accessor :index , :type , :value
+    attr_accessor :type , :value
 
     private #abstract base class
 
-    def initialize index , type , value
-      @index = index
+    def initialize type , value
       @type = type
       @value = value
     end