Cut-throat competition has driven modem prices into the cellar. Bargain 56kbps units are available for as little as $150; most are in the $200û$300 range. Higher-end models add extras like voice mail and speakerphone support. (All modems can send and receive faxes these days.)

Initially, 56kbps modems used one of two incompatible specifications: x2 and K56flex. For the moment, many ISPs support only one spec ù and on relatively few dial-up lines. This situation should change rapidly following the creation of a single v.90 international standard, defined in February and expected to be formally adopted in September. Modems supporting the new standard were just beginning to ship as we went to press. Additionally, all modem suppliers have promised that users can upgrade their older 56kbps units to the final standard.

But here the devil, as usual, is in the details. Some companies promise a free upgrade, while others say they'll charge a nominal fee. You can upgrade some modems by downloading and installing new firmware from the Web; other units will have to be returned to the vendor for upgrading. (For updates on these issues, visit www.v90.com.)

It's hard to predict actual data speeds for a 56kbps modem; most users can expect downloads in the 40û50kbps range. The data you send is constrained by technology to 33.6kbps max, but that isn't a big problem in typical Web sessions, since you download most data.

Also, 56kbps modems are extremely fussy about the quality of phone lines. Especially if you live in a rural area far from a central telephone office, lines can get noisy; a phone line that sounds fine to you may be terrible for moving data at high speed. And in metropolitan areas, telephone companies often combine multiple phone sessions on one channel, which can put you back in the slow lane. To pinpoint where traffic really jams up throughout your Web connection, try VitalSigns Software's Net Medic (download a free trial version from www.vitalsigns.com).

Once you get under the hood, installing a 56kbps modem isn't much different from installing any other modem. Here's how to do it.

1. Find an ISP. Your existing ISP may offer support for x2, K56flex, or the new V.90 international standard ù or it may support some combination of the three. Check the provider's Web page, send e-mail, or call its technical support. Also check whether the ISP offers a local telephone number to access 56kbps services.

It's also a good idea to download the latest version of Microsoft's Dial-Up Networking for Windows 95 (www.microsoft.com/Windows95/info/dialup.htm).

2. Buy the modem. The next step is deciding whether you should buy an external or internal 56kbps modem. If you're upgrading from an existing modem, it's best to replace it with the same type you have now. If you opt for an external unit, make sure that your computer's serial port has a high-speed UART chip ù at least a 16550 (most PCs made in the last few years do). For a review of current offerings in the 56kbps modem market, see 56K modems: how they stack up, May 1998, p100).

3. Swap modems. If you're installing a new internal modem, unplug the telephone line (and the phone too, if you have one connected through the modem) from the old modem card, remove the cover from your PC, take out the old modem card, and replace it with the new one. Reconnect the telephone line (and phone if necessary). Don't put the PC's cover back on yet.

If your new modem is an external unit, disconnect the serial cable and phone line (and a phone if one's connected), remove the old modem, and reconnect everything to the new one. Don't forget to connect the modem's power cord, and turn on the new unit if there is a switch.

4. Configure the modem. Restart your PC. If you installed an internal modem and use Windows 95, it should detect the new device at start-up and ask for the driver. Insert the driver floppy or CD-ROM and follow the on-screen directions. It's a good idea to read the modem manual, too.

If you installed an external modem or are running NT 4.0 (with an external or internal unit), select StartûSettingsûControl Panel and double-click Modems. In the Modems Properties dialogue box, make sure the old modem's name is highlighted. Click Remove.

Then click the Add button. On the next screen, check the Don't detect my modem box and click Next. Click the Have Disk button on the following screen, insert the floppy or CD-ROM that came with your new modem, and follow the directions. You'll eventually see a screen showing that everything's correctly installed.

5. Update your ISP information. If you're using the same ISP as before, select StartûProgramsûAccessoriesûDial-Up Networking, right-click the icon for your current connection, and select Properties. Make sure your new modem shows in the Connect using box. If your ISP requires a different telephone number for 56kbps access, fill it in.

If you're using a new ISP, select StartûProgramsûAccessoriesûDial-Up Networking, double-click Make New Connection, and follow the steps on screen, typing the required information. Select StartûSettingsûControl Panel, click Internet and then the Connection tab, and make sure that this connection is selected as the default for dial-up.

You also need to set up network parameters for your new ISP. Select StartûSettingsûControl Panel, double-click Network, click the Configuration tab, highlight TCP/IP Dial-Up Networking in the scroll list at the top of the dialogue box, and click Properties. Type all required information, which your ISP should have supplied when you signed up.

Now you can finally try your new connection. Keep your ISP's tech support number handy in case you have problems connecting.