The Internet, part 2.
How Computers Communicate
A lot of supposedly knowledgeable people forget to tell you the things in this section. Specifically, people often forget to tell you that your microcomputer does not have to act dumb when it is connected to another computer. They also forget to differentiate between how different software programs communicate. This isn't the most fun stuff to discuss, but it's probably the most important.
Terminal-host communication. In the Sixties and early Seventies, "time-sharing" computers were common. Time-sharing was an apt name, since not everyone could use the computer at once. Users had to wait in an electronic line - called a queue - that was maintained by the computer. (In the early Seventies I used to do my computing on a university computer at 2 a.m. - the queue was shorter then.) Users would sit at a terminal and wait their turn to use the computing power of the host computer; thus these systems might be called terminal-host systems. No matter what it looks like, a terminal is nothing more than a monitor and keyboard for a host or remote computer. Everything on the monitor is controlled by the host - a terminal does not contain a processor. Sitting at a terminal in a building far away from a host is deceptive. It seems like the computer is in the workstation on your desk, but it isn't. The host manages the terminals and performs all computing.
Terminal emulation programs (communications software). With the advent of personal computers (PCs) in the late Seventies and early Eighties, terminal emulation programs became common. Examples of common terminal emulation programs are White Knight, Procomm, Smartcom, Mac-Terminal, EZ-term, and the "communications modules" in programs like Microsoft Works and Windows. A terminal emulation program lets a PC serve as a terminal. Essentially, a terminal emulation program lets an intelligent microcomputer become a dumb terminal.
Turning a personal computer into a dumb terminal is tricky, because the keyboards on the two kinds of devices are substantially different. Most terminals have special keys like Attn, Ctrl, EOL, and PF1 to PF12 - some of which are not common on microcomputer keyboards. Extended keyboards for Macs and PCs, which have 12 function keys, help out a lot but do not solve the problem entirely. My advice is always to order computers with extended keyboards. New terminal emulation program users have great difficulty with the keyboard problem.
User-interface software packages. User-interface software packages are a recent (early Nineties) development. Examples include software disks supplied with a subscription to Compuserve, Prodigy, eWorld, and the National Geographic Kids Network online services. Typically these programs provide icons for each service or menu choice. Additionally, user-interface software programs may make the phone call to the remote host, assist in log-on and -off, and facilitate file transfer to and from the PC. User-interface software programs help one use a terminal to communicate with a host, but the local PC is still basically a dumb terminal.
Host-host communication. In the late Sixties the U.S. Defense Department began developing a way for its various computers (hosts) in the U.S. and around the world to talk with one another. If a bomb destroyed the telephone line from one computer to another, the military needed a way to automatically reroute the connection. The military's solution was to enclose messages from one computer to another in small "packets" (or bundles), to give every packet an "address," and to provide special use computers that did nothing but act as giant routers or "switches" for sending packets from place to place. Packet switching and addressing are important, since they allow one computer to communicate with another as a peer, thus breaking down the terminal-host arrangement. Wouldn't you rather have your PC act like a computer instead of a dumb terminal?
Early military and National Science Foundation networks were the genesis of today's Internet. The practical result of this effort for you and me is that, for our computers to act as peers on the Internet (and not terminals), we need to use the same protocol suite (software) developed by the military - it's called TCP/IP (Transmission Control Protocol/Internet Protocol, a set of conventions for computer-to-computer communication). One of the first steps in rigging a microcomputer to be a full-fledged Internet peer is to install TCP/IP software.
Client-server communication. The term client-server sounds like it might be synonymous with terminal-host, but it is not. A client is a software package that runs on a PC, works in conjunction with a similar program running on a host computer or server, and interacts with the host for the user. The desktop PC is not doing terminal emulation. To the user the communication between the PC and the server becomes so transparent that it often seems as if the mailbox, document, file, or program is on the desktop, when in fact it might be halfway around the world. Here is an illustration that will help explain the power of client-server communication.
One of the most powerful Internet tools is Gopher - developed at the University of Minnesota and named after the school's mascot, the Golden Gopher. Gopher software lets you effortlessly explore information resources on hundreds of Gopher servers in the world. In other words, Gopher lets you burrow through piles of information at the thousands of Gopher sites - Gopher holes - around the world making up what is called Gopherspace. Gopher software passes you from one server to another so that you need not worry about where you are or where you are going. If you want to experience Cyberspace, using a Gopher is a surefire way to do it! (More about our furry friend later.)
Types of Local Internet Access
There are three common ways people access (are connected to) the Internet: direct network connection, dial-in access to a SLIP or PPP server, and dial-in access. This section discusses all three access methods, but first an exhortation. K-12 schools need fast direct network access to the Internet, and they need it soon. As the United States High Performance Computing Act of 1991 puts it, "Opening schools to information sources is a grand challenge."(1)
Direct network connection. The best type of Internet access is via a direct network connection between the LAN (local area network) at a school or university and the nearest Internet node. Most universities and a few progressive K-12 schools have this type of Internet access. These connections are called bridges or gateways. (It's possible to connect an AppleTalk, IBM Baseband, IBM Tokenring, or Ethernet LAN directly to the Internet.) This is the best type of Internet access for two reasons: speed and services. Network connection to the Internet is between 100 and 40,000 times faster than a modern connection!
The second reason direct network access to the Internet is preferable is that all Internet features (services) are available. Other access methods, especially dial-in, frequently limit the features of the Internet you can use.
Dial-in access to a SLIP or PPP server. Using a modem to dial a server that provides either the SLIP or PPP Internet protocol is the second-best Internet access method. (Incidentally, SLIP stands for Serial Line Interface Protocol and PPP stands for Point to Point Protocol.) Once you are connected to a server running one of these protocols, you can use a wide variety of Internet software tools to access the full range of Internet services - it's just like a direct network connection, only slower due to modem speeds. By the way, most universities and community colleges have dial-in access to SLIP or PPP servers.
Dial-in access. For a large number of people, this is the only Internet access method available - and it's not as bad as it might seem. This access method is the same method as above - dial a SLIP or PPP server - except that you must stay in terminal emulation mode. You cannot access a server and run "client" software. That means that your computer will remain a dumb terminal.
On the bright side, if you have a reasonably fast modem (I suggest 14.4 thousand bps), terminal emulation software with a friendly user interface, and a high-quality service provider, you will have a very pleasing experience with the Internet.
Regardless of the method you use to access the Internet, any access method is far better than no access! Internet mail, news groups, and discussions are readily available via this dial-in Internet access method.
Internet Software Tools
There are dozens of software tools designed to facilitate use of the Internet. The programs below are mostly "clients," as discussed above; they are readily available; and they are all freeware or shareware.
TCP/IP software lets your computer communicate with others on the Internet.
Gopher software makes navigating from place to place on the Internet a "point-and-click" job. Gopher also lets you retrieve a variety of interesting files (text files, programs, and images) from Gopher sites around the world.
NewsWatcher software makes reading and posting USENET news articles on the Internet a breeze. You can even customize NewsWatcher so that it will track only the news that most interests you or is most appropriate for your class.
Compact Pro and Stuffit Expander are tools that decompress software that you retrieve using Gopher. (Most sites on the Internet compress their archived programs to save disk space and minimize download times.)
Eudora is a full-featured Internet e-mail program.
IRC (Internet Relay Chat) is a client program that lets the user simultaneously chat with other users who are currently on the Net.
Mosaic is a multimedia, hypermedia Internet client that is much like a multimedia Gopher.
In my judgment, Gopher is the best navigation tool for neophyte Internet users. Plus, Gopher is provided free to educational institutions by the Gopher Development Team at the University of Minnesota. With Gopher you can effortlessly connect to hundreds of servers and then quickly find and easily download useful information/documents and programs. The nicest aspect of Gopher is that it transfers you from server to server around the world and you don't have to worry about how to get from place to place. If you aim Gopher at the Internet Information Center, the InterNIC, you can effortlessly acquire a lot of helpful information about the Internet.
I strongly advise that you ask a friend or associate to help you get connected to the Internet and help you learn to use the tools described above. After all, that's what the Internet is all about - people connecting to other people.
Being connected to the Internet takes more than just reading conferences and logging messages to your computer; it takes asking and answering questions, exchanging opinions - getting involved.
If you choose to go forward, to use and contribute, you will become a citizen of Cyberspace. If you're reading these words for the first time, this may seem like an amusing but unlikely notion - that one could "inhabit" a place without physical space. But put a mark beside these words. Join the Net and actively participate for a year. Then reread this passage. It will no longer seem so strange to be a "citizen of Cyberspace." It will seem like the most natural thing in the world.(2)
Sorry, there's no more space here. Next month I'll illustrate both Gopher and Mosaic. Your assignment is to visit your local bookstore - there are lots of books about the Internet.
1. Office of Science and Technology Policy, United States High Performance Computing Act of 1991 (P.L. 102-194), 102nd Congress, 1st Session, 1991, United States Statutes at Large, vol. 105, Part 2, pp. 1594-99.
2. Electronic Frontier Foundation, Big Dummy's Guide to the Internet, 15 July 1993, HyperCard stack. Contact email@example.com (also available on various Gophers).
ROYAL VAN HORN is a professor of education at the University of North Florida, Jacksonville. He is the author of Advanced Technology in Education (Wadsworth, 1991).
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|Author:||Van Horn, Royal|
|Publication:||Phi Delta Kappan|
|Date:||Apr 1, 1995|
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