Barbaros,

You didn't say which version but I guess it dosen't matter since I don't
know of any serial libraries that aren't copyrighted.  There are some
serial functions in the Clipper tools package and several 3rd party
companies sell them.  FWIW, Zac catalog sells them 1-800-clipper (USA).  I
recommend Telepathy (~$154 U.S$)

You might try Compuserv, they have an excellent clipper forum.  Maybe
someone there could help.