The almost universally accepted standard for local area networks is ethernet. These cards, which plug into an ISA or PCI slot in your computer are widely available and not expensive. Inexpensive cards can be had for under $20. and even top name-brand products are usually under $60. The cabling to connect them is becoming cheap, too. The first question to resolve is what kind of cards to buy.

Ethernet cards have an RJ-45 connector in the back which looks like an oversize phone jack. In addition some also have a coaxial (round) jack that sticks out and occasionally a multi-pin connector for older networking standards. ISA cards only support 10 megabit per second transfer rates, but PCI cards, depending on the card, can support either 10 megabit per second transfer rates, 100 megabit or both. So how do we select the card?

The first question is how many computers are we going to hook up and how much network traffic will be generated. If more than 3 computers will be networked, or they will generate more than occasional traffic, I would recommend AGAINST coaxial cable (10-base 2).

The next question is this -- is there a cable-modem or DSL-modem as part of your system? If so, these devices ALWAYS require a 10-base-T ONLY network card. The card can be either PCI or ISA, but MUST be 10-base-T (using the RJ45 slot) and CANNOT be either coax OR 100-base-TX. Other cards on the network CAN however be 10/100 speed but CANNOT be either 100 only or 10-base-2.

The next question is what kind of slots you have inside your computer. If you still use a 486 or earlier, you'll have only ISA slots. In some modern computers, you'll have only PCI slots, or all the ISA slots may be already filled. If given the choice, I would in most cases opt for the PCI slot, because you can install 10/100 speed cards and preserve the ISA slots for devices that really need them, such as modems and soundcards (PCI modems generally don't work as well as old-fashioned ISA modems and PCI soundcards don't always work with DOS). Some older Pentium motherboards can only set up one slot for bus-mastering, so in these cases, you have to either set up the BIOS for the slot OR find the slot which works by trial and error. In these cases, if you need to install a second network card for any reason, ISA would be the way to go.

CAUTION!! Some cards are 100 speed only. AVOID THEM!! Also, if you hook up 3 or more computers AND you're not using coax, you'll need a hub, which is a central station to which all the PCs on the network connect to. This hub should be 10/100 compatible if you have any 100 speed cards or plan to get them in the future. Otherwise a 10-speed only hub is cheaper. But AVOID the 100-only hubs for compatibility reasons.

The cheapest network, overall, is one based on coaxial cable.  For this, you need RG-58 type 50-ohm cable that you can not only get from computer stores, but also from consumer electronics stores such as Radio Shack®, since it is a type of cable used for years in ham radio. It is known in network terminology as 10-base-2 thinnet. It is limited, however to a 10 Megabit/sec transfer rate.

Most corporate LANs use 10-base-T or 100-base-TX (Category 5) cabling. This cable has 8 conductors and looks like oversize telephone wiring. It terminates on each end with an RJ-45 connector, which looks like an oversize telephone connector. The only difference between 10-base-T and 100-base-TX cable (Category 5) is the rating--how many Megabits/sec can reliably transmit data. 10-base-T can only transmit at 10 Megabits/sec, whereas the 100-base-TX cable can transmit at speeds of at least 100 Megabits/sec.

Aside from speed, there is one other important consideration when buying base-T type cable: Normal vs. crossover cable. Normal cable is designed to be plugged into a hub at one end. and a computer at the other end. It is required if you want three or more computers on the same network segment in a base-T network. Crossover cable can be used only for direct PC-to-PC connections. It is called crossover, because the wires are internally crossed over so that the send ports of computer 'A' hook to the receive ports of computer 'B'. Both types of cabling can be found at computer stores, and at computer fairs.

One final consideration is the operating system you want to use on the network. With Windows-95, 98, NT4, or Novell Netware, virtually all network cards work. Most, but not all will also work with Windows-2000. But Windows 3.1 is another story. If the manufacturer has not written a driver for 3.1 IT WILL NOT WORK, unless it can be recognized as a NE-2000 compatible. (That's an ISA card). For Linux, most cards will work provided they have been out long enough for Linux developers to write a driver for them. AVOID cards with a Linux driver from the manufacturer. This is done usually only if the card has problems with Linux. Linksys cards (tulip-based) have been known to require special drivers that novices are not always capable of installing.