A matter of fax.

Of all the new technological gadgets that have pelted us since the mid-1980s, facsimile machines are among the most popular. Long ago, we mastered the telephone and copy machine. Combine their functions and you have a facsimile, or fax, machine. This handy device transmits images - facsimiles - of documents over telephone lines to another fax machine. It's easy to use, and even the least technical person understands it.

In spite of the benefits fax machines have provided to organizations, they do have drawbacks. Namely, they aren't always available, they aren't cheap, and all but the most expensive models use paper that feels like the skin of something that crawled out of the primordial ooze.

As with so many other things in this era of microchip technology, the PC - the trusty workhorse of the '90s - comes to the rescue. Using a personal computer as a fax machine - although not a panacea - can solve some of these inconveniences. By adding a fax circuit board and modem to your PC, you have your very own personal fax machine.

There are too many brands and models of fax boards to list here. However, if you are in the market for a fax machine, you should consider some important features. The hardware options are pretty simple. The fax board will either fit inside or outside your PC and will come with or without a modem.

The software options allow you to set up and manage dialing directories, keep track of faxes sent and received, and handle multiple transmissions. Since the software is actually more important than the hardware, arrange a demonstration of the fax board just to see how it functions.

The most significant option is how the fax board works in your machine. The most convenient fax boards work in background - that is, they send and receive faxes while you work on your PC. Other fax boards appear to work in background but don't because their programs - known as TSRs - reside in memory. These programs take over your machine when you send or receive a fax. Thus, you can't do anything else with your PC during the process.

Cost is the main advantage of using a fax board instead of a fax machine. Fax machines cost $500-$2,000; fax boards cost $200-$500. Fax boards also eliminate the slime paper that most fax machines use, since you use your own plain paper to produce the hard copy. Here are other advantages of fax boards:

* You can send a fax directly on disk from your PC. Thus, you don't need to print documents to fax them. Not only is this convenient, but it also lowers paper costs.

* You can review documents on your computer screen without printing them.

* With most software, you can easily send documents to multiple locations. With many fax machines, this requires refeeding the original document.

* Documents come directly to and go directly from your computer, providing privacy and security.

* The faxes sent from your PC are sharper, higher-quality images.

* Document transmission is faster than with a traditional fax machine, which requires feeding and scanning.

* Fax boards travel. You can put a fax board in your laptop computer, and your personal fax machine is always available.

The biggest drawback to a fax board is that you must send documents already in your computer or on disk. If you want to send a hard copy, you must add a scanner, an expensive accessory. Here are some other drawbacks.

* You will experience work interruptions if your fax board's software resides in memory. For example, you could be working on a spreadsheet at just the moment the fax comes in and the fax board takes over your computer.

* Fax boards are difficult to install. Unless you like wading through dip switches, jumpers, and other such technical goo, have someone else install the board. This, of course, adds to your expense.

* You need to leave your computer turned on when you want to receive a fax.

* Printing faxes is slower than printing text.

* Some fax boards will send but not receive faxes. These boards - sometimes called broadcast faxes - are a poor investment, since boards that send and receive are available at about the same cost.

On a local area network, or LAN, fax boards allow several people to fax documents from their own work stations. Most network fax boards manage the queues of incoming and outgoing documents so that there is no waiting. Unfortunately, most LAN fax systems require a dedicated PC called a fax server. In other words, to provide fax services to all network servers requires an additional PC used only for that purpose.

Would a fax board serve you as well as a fax machine? If you send a large volume of hard copy, a fax board will not be very useful without the addition of an expensive scanner. On the other hand, if you mainly send documents that originate on your PC, send multiple documents, send more documents than you receive, or are on a limited budget, a fax board may be the right choice.

Steven L. Harrison is director of information management systems at the American Nurses Association, Kansas City, Missouri.