Many telnet clients also include a third option, the port on which the connection should take place. Normally, port 23 is the default telnet port; the user never has to think about it. But sometimes it's desirable to telnet to a different port on a system, where there may be a service available, or to aid in debugging a problem. Using
telnet somewhere.domain port
will connect the user to the given port on the system somewhere.domain. Many libraries use this port method to offer their facilities to the general Internet community; other services are also available. For instance, one would type
telnet martini.eecs.umich.edu 3000
to connect to the geographic server at the University of Michigan (Geographic Server). Other such port connections follow the same usage.
Publicly Accessible Libraries
Over the last several years, most university libraries have switched from a manual (card) catalog system to computerized library catalogs. The automated systems provide users with easily accessible and up-to-date information about the books available in these libraries. This has been further improved upon with the advent of local area networks, dialup modems, and wide area networks. Now many of us can check on our local library's holdings or that of a library halfway around the world!
Many, many institutions of higher learning have made their library catalogs available for searching by anyone on the Internet. They include Boston University, the Colorado Alliance of Research Libraries (CARL), and London University King's College.
To include a listing of some of the existing sites would not only be far too long for this document, it would soon be out of date. Instead, several lists are being maintained and are available either by mail or via FTP. Also, the Internet Resource Guide (IRG) also describes a few libraries that are accessible—-IRG for further information.
Art St. George and Ron Larsen are maintaining a list of Internet-accessible libraries and databases often referred to as "the St. George directory." It began with only library catalogs but has expanded to include sections on campus-wide information systems, and even bulletin board systems that are not on the Internet. The library catalog sections are divided into those that are free, those that charge, and international (i.e. non-U.S.) catalogs; they are arranged by state, province, or country within each section. There is also a section giving dialup information for some of the library catalogs. It's available for FTP (Anonymous FTP) on nic.cerf.net in the directory cerfnet/cerfnet_info/library_catalog. The file internet-catalogs has a date suffix; check for the most current date. The information is updated periodically.