Talk is available again on Cal Poly's Central UNIX (formerly AIX)

The Talk capability has been re-enabled on Central UNIX after the
installation of several vendor security patches.  Both talk and ytalk
should be working as of April 28, 1997.  For more information on using
talk, please see the man page by entering:

        % man talk

If the site you are trying to talk to responds with an error, try using
ytalk instead since all talk servers are not compatible.