anchor.diff:  %% API functions
   %% ===================================================================
   
  +-spec start_driver( string(), [string()] ) -> { ok, port() } | { error, term() }.
   start_driver( Driver, Parameters ) ->
   	try Port = open_port( { spawn_executable, driver_path( Driver ) },
   						  [ { args, Parameters }
  
positive.code: 	end.
  
  
  driver_path( Driver ) ->
  	case filename:pathtype( Driver ) of
  		relative -> ok;
  
negative.code: 	end.
  
  
  -spec stop_driver( port() ) -> ok.
  stop_driver( Port ) ->
  	{ os_pid, Pid } = erlang:port_info( Port, os_pid ),
  	erlang:port_close( Port ),
  