The IADDRESS64 function is essentially identical to the IADDRESS
  function with the exception that IADDRESS64 returns an INTEGER64
  result.  This does not force the parameter  of  IADDRESS64  into
  64-bit  address  space  but  simply  returns  the address of the
  parameter as an INTEGER64 value.

  Syntax:

     IADDRESS64( x )

  The parameter 'x' can be of any type except  a  component  of  a
  packed structured type or a routine name.  The parameter 'x' can
  be a variable, parameter, routine, or constant-expression.  When
  IADDRESS  is  used on constant-expressions, the returned address
  is valid for  the  remainder  of  the  program.   Two  calls  to
  IADDRESS64  with  the  same  constant  may  not  return the same
  address.

  Note that the VSI Pascal compiler automatically assumes that all
  pointers  refer either to dynamic variables allocated by the NEW
  procedure or to variables  that  have  the  VOLATILE  attribute;
  therefore, you should use utmost caution when using the IADDRESS
  function.   This  function  does   not   generate   compile-time
  warnings.