2,001 Tips
Hardware
Modems

Manual Modem Installation

If you have trouble getting a new modem to work under Windows 95, try manually installing the modem as though it were a generic unit. Use the Add New Hardware Wizard under Control Panel, but select No when it asks if it should search for the new device. Select Modem/Next/Don't detect my modem/Next/Standard Mode Types or Voice View Types (depending on your modem's capabilities), then select the appropriate modem speed. You can add any special string the manufacturer recommends for the modem's proper initialization in the modem's Properties dialog box.

The Art of UART

If you're working in Windows 95 and you have a 16550 UART chip governing your serial ports, make sure you're getting your modem's worth. Click Control Panel and select Modems/Properties, then look under the Connection tab for Port Settings. Check the "Use FIFObuffers" option and drag both sliders all the way to the right. If that causes problems down the road, drag the sliders back a little and initiate a new session. Repeat this procedure until everything stabilizes.

Hearing Is Believing

Sometimes listening to your modem attempt a connection can help you track a problem (like if there's a PBX on the other end waiting for an extension to be entered). You can turn on your modem's speaker by setting options or sending ATL3 when initializing the modem from most communications programs.

AT Your Command

If you need to pass AT commands to your modem in addition to what Windows already sends, click on Modems in the Control Panel, select the modem, click on Properties, select the Connection tab, click on Advanced, and enter the string in the "Extra settings" box. Be sure to use AT at the beginning of the command string. Windows won't add that command prefix for you.

Chronicle Comm Sessions

If your modem consistently fails to connect to a service, a log of its progress could be revealing. You can turn on modem logging under Control Panel/Modems. Select the modem, click on Properties, select the Connection tab, click on Advanced and check the "Record a log file" box.

Put Call Waiting on Hold

If Call Waiting service bounces you out of a modem connection, use the prefix *70 (or 1170 in some locations) to turn off Call Waiting. This command only lasts for the duration of the current phone call, so Call Waiting will automatically resume once you've finished your online work.

The Need for Speed

Your 28.8 modem should be able to handle 115.2Kbps from your computer, but Windows 95 typically communicates with these modems at 57.6Kbps. To correct that, use Control Panel/Modems/Properties and select 115200 as the Maximum speed. If that causes problems, (perhaps due to a slow serial port), set the Maximum speed back to 57600.

Response Review

If you're not sure your modem is responding to your commands, go to Control Panel/Modems/Diagnostics, select your modem (if it's internal) or its COM port (if it's external), and choose More Info. After a pause, you should get a list of responses from the modem. If you get an empty list, or an error, check your physical connections and the port and IRQ settings for the modem.

Shedding Light on Data Woes

One fact that many do not realize: If a modem is placed near a fluorescent light, the modem could experience a loss of data. So if you have a desk lamp with a fluorescent bulb and have data-error woes, move the lamp well away from your modem.

Go with the Flow

For high-speed modem connections under Windows 3.x, set the serial port to use hardware handshaking (CTS\RTS) by going into Control Panel/Choose Ports, clicking on the proper port, then selecting Hardware under Flow Control.

Flash! New BIOS Arrives

Modems with a flash BIOS can be readily upgraded with software from the manufacturer. However, you should follow each step of the recommended upgrade procedure carefully, and be sure to complete all the steps. The most important step is typically the last one, which on some modems creates a new default profile for the modem to load the next time power is turned on. If that default profile is not saved, you will never be able to communicate with the modem again.

BIOS Compatibility

Before using recently downloaded info files or drivers for your modem, you should make sure you have the latest BIOS version if your modem has flash. Sometimes new modem drivers are only tested on modems with the latest BIOS in the manufacturer's labs, which can cause them to overlook compatibility issues with prior BIOS versions.

See Through the Hayes

People are sometimes confused by the phrase "Hayes compatible," thinking it's a guarantee of compatibility or maximum throughput when used with other Hayes-compatible modems, but that's not true. What it really means is the modem understands a set of basic commands originated by Hayes that allow the computer to set up and control some of the modem's characteristics. To determine the interoperability of a modem, check the company's user groups for complaints about the modem's inability to connect.

Red Light District

If you have an internal or PCMCIA modem, but you want status lights, try using one of the many shareware software modem light programs. These are tiny applets that sit on your desktop and simulate the lights on the front of an external modem.

ASCII, and You Shall Receive

Sometimes, you need to log in to an online service or BBS using a plain ASCII interface. Here are the proper settings for some of the more popular services and networks: CompuServe: VT100, 7E1, full duplex; GEnie: VT100, 8N1, half duplex; TymNet: VT100, 8N1, full duplex; SprintNet: VT100, 8N1, full duplex; most BBSes: VT100, 8N1 or 7E1, full duplex; almost all Internet sites: VT100, 8N1, full duplex.

Zapped by a PBX

One of the more insidious causes of modem damage among traveling computer users is the hotel PBX phone system. Hotel phone jacks often carry high-voltage signals that can fry your modem's innards when you plug it in. An acoustic coupler or PBX adapter, which goes between your modem and hotel phone, or modem and room wall plate, can shield it from harm.

Wake-Up Call

Sometimes a go/no-go test for peripherals comes in handy. For a modem, you can go to the DOS command line in Windows 3.x or Windows 95 and type ECHO ATDT > COMx, where COMx represents the port you're testing. If you hear a dial tone, it's working (at least from DOS). To hang up, type ECHO ATH > COMx.

Alphabet Soup

When wrestling with communications hardware and software, folks often get confused between the acronyms DCE and DTE. Data communications equipment (DCE) are devices that simply communicate; they can't display information, they can only send and receive it. Data terminal equipment (DTE) displays information like a PC can. You can remember that by recalling that terminals are used to display information.

Troubleshooting MNP5

If your modem uses MNP5 and you're having trouble connecting to a particular site, try deactivating that protocol. When an MNP5-capable modem talks to a modem without MNP5 capability, it often causes problems.

Zee Protocol of Choice

Some file-transfer protocols are quicker and more convenient than others. Zmodem is a popular protocol you should try because of its speed and features. It compresses files well (making it fast), handles multiple files per download and can resume a download after you restore a connection gone south.

Make a Connection

When you're buying an external modem, order a new serial cable, too. Most modems don't come with a cable.

When You Don't Get More from V.34

If you've added a V.34 modem to an old system but you're not happy with the results, it could be because the serial port on the old PC can't handle the throughput. Check its documentation to see if the PC's ports have 16550 UART chips. If they do, you might need to enable them. If they don't, you'll have to add a high-speed serial port to replace the PC's older ports.

Restart Software, Too

When modem problems arise, it's quite natural for people to flip their modem on and off to reset it. That's okay, but you should also re-initialize the modem using your communications software. If you don't, the modem will institute its default profile of commands, but that may not include commands needed by your software.

Flashier V.34 Reached 33.6 Speed

Are you unhappy because your V.34 operates at 28.8-not 33.6 like some of its close relatives? For some modems, a simple flash upgrade is all that's needed to boost their speed. Check with the manufacturer to see if that's true for yours.

Read the Right Speed

People often find it confusing when communications software reports a speed significantly lower than the modem's rated maximum. That's often because the software has set the modem to tell it the speed of the telephone connection without compression, or the speed of connection between the modem and your own PC. To rectify this, check your modem's documentation for an AT command that'll make it generate the right response, and add that command to the modem's initialization string located in your communications software.

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