Jerry van Dijk writes
: It might be just me again, but I cannot figure out how to convert an access 
: type to an address, as in assigning Address_C in the code below. GNAT (3.03)
: tells me I have an invalid parameter list in the call to To_Address here ?
[source and comments deleted]

You  should have a  close  look   to  the spec of   System.Address_To_
Access_Conversions : (taken from the GNAT sources) 

generic
   type Object (<>) is limited private;
 
package System.Address_To_Access_Conversions is
pragma Preelaborate (Address_To_Access_Conversions);
 
   type Object_Pointer is access all Object;
 
   function To_Pointer (Value : Address)        return Object_Pointer;
   function To_Address (Value : Object_Pointer) return Address;
 
   pragma Convention (Intrinsic, To_Pointer);
   pragma Convention (Intrinsic, To_Address);
 
end System.Address_To_Access_Conversions;

   Once you instanciate it with ab "Object" type,  it provides you the
"access all"  type,  and you should  use this   one to avoid  compiler
complaints about silly type mismatch ;-).

-- 
--  Laurent Guerby, student at Telecom Bretagne (France), Team Ada
--  "Use the Source, Luke. The Source will be with you, always (GPL)"
--  http://www-eleves.enst-bretagne.fr/~guerby/ (GATO Project)
--  Try GNAT, the GNU Ada 95 compiler (ftp://cs.nyu.edu/pub/gnat)