Home computers have, over the past year or so, become commodity items. Prices of $600 and less (not including monitor) have made it practical to have more than one system at home. With applications like home banking along with the ability to work on office documents at home, parents often need to have access to a home computer. With the vast information resources available on the 'net to help with homework, not to mention games, kids require access as well.
This is why we're starting to see homes with two or more computer systems. The big question now is how to effectively provide network access for these machines. While most systems today come with a built-in 56 Kbps modem, you don't really want to have a telephone line for each system. You also don't want everyone in your household to have their own ISP account, as that can get quite expensive. Let's work out some baseline figures for dial-up access.
BellSouth charges approximately $50 for a regular analog telephone installation. Monthly charges, once the various taxes are included, run about $30. ISPs usually don't have a front-end fee but typically charge about $20/month. Adding this up gives us $50 + 12 * ( $30 + $20 ) = $650 for the first year and $600 for subsequent years. That's quite an investment to make! And remember, that's for each telephone line. There has to be a better way!
The analog telephone model fails for a couple of different reasons. Either you try to share a single line and face resource contention issues (not to mention not being able to receive incoming calls while connected,) or you face the significant expense of multiple lines. What's needed is some mechanism to permit sharing of a connection. Keep in mind that the TCP/IP protocol is designed to be able to support multiple simultaneous connections.
Before we can address the facilities available for resource sharing, we need to touch on how to connect the multiple machines together. We have a number of choices in this regard, ranging from the simple to the exotic. The easiest way to connect just two PC-type machines is with a direct connection through a serial cable. You should keep in mind, however, that you will face speed limitations based on the quality of cable and the distance between machines.
The other reasonably straight-forward solution is to install some form of LAN. This can range from ARCnet or thin-wire ethernet to UTP ethernet or IEEE 802.11 wireless networking. Only the individual can decide what level of expense and complexity is appropriate in a particular situation. In some houses which have been constructed fairly recently, 3 or even 4-pair wiring has been installed to the telephone outlets. As long as two pairs are free, you can use the existing wiring and plumb a UTP ethernet hub in the basement.
The least intrusive mechanism would be to use the new IEEE 802.11 gear just coming to market. With a range of 150' and a nominal speed of 11 Mbps, this technology requires no hard-wiring at the node locations. Used by the Apple AirPort transceiver, interoperable cards for PCs are anticipated "any time now." (Look here, for example.)
So we've somehow interconnected our machines; what next? Now we have to configure the networking on the machine which is going to serve as the internet gateway. The operating system could be Microsoft Windows or NT or one of the many variants of UNIX.