Inside Windows 98

Previous chapterNext chapterContents


- 19 -

Modems and Telephony


Windows 98, like Windows 95 before it, improves the way you and your applications configure and use modems. Many of the data communications features in Windows 98 require 32-bit communication programs, but even your existing 16-bit programs can take advantage of some of the improvements in Windows 98. This chapter explains the features in Windows 98 that support data communications, including the following topics:

The first step in using your modem is naturally to install and configure the modem.

Installing and Configuring Modems and COM Ports

Your modem and communications (COM) port work hand-in-hand. Therefore, you must set both properly for your modem to work at its best. Your COM ports probably were configured properly when you installed Windows 98. But you might want to modify some of the COM port settings, such as changing IRQ or other values. The following section explains how to use the Device Manager to configure the COM ports.

Configuring COM Ports

To configure your system's COM ports, open the Control Panel and choose the System object. Then open the Device Manager property page and expand the Ports branch. Select the port you want to configure and choose Properties to display the Communications Port Properties sheet shown in Figure 19.1.

FIGURE 19.1 A typical COM Port Properties sheet.

The General property page, shown in Figure 19.1, provides information about the port and enables you to specify with which hardware profiles the port will be used (refer to Chapter 5, "Adding and Configuring Hardware," for more information on hardware profiles). To specify settings for the port, click on the Port Settings tab to display the Port Settings page, shown in Figure 19.2.

FIGURE 19.2 The Port Settings property page.

The settings on the Port Settings page control parameters such as bits per second, stop bits, parity method, and number of data bits, explained earlier. You also can specify the flow control method for the port, explained later in the section "Setting Advanced Options." In the case of a modem, you really don't have to configure the port settings to match the modem's requirements because the modem settings override the port settings. If you occasionally use other devices on the same COM port, however, you need to configure the port according to those other devices' requirements.

To change the IRQ or input/output (I/O) base address of the port, click on the Resources tab to display the Resources page; then specify the new I/O address and IRQ values. If you are unsure how to accomplish the change, refer to Chapter 5, which explains how to use the Device Manager to set resources. Table 19.1 provides a list of common IRQ assignments for your reference in configuring your computer's COM ports.


NOTE: Although some of the IRQ lines listed in Table 19.1 indicate that they are available, these interrupts might not be available on your system. If your PC contains a network adapter, sound card, or other devices, these IRQs might already be assigned to these devices. For an explanation of how to scan the system for IRQ assignments, refer to Chapter 5.

TABLE 19.1 Common IRQ Assignments

IRQ Number Typical Assignment
NMI Nonmaskable interrupt, reports parity errors
0 System timer
1 Keyboard
2 EGA/VGA and cascaded interrupt for second IRQ controller (IRQ9-15)
3 COM2, COM4
4 COM1, COM3
5 LPT2 (printer port 2)
6 Floppy disk
7 LPT1 (printer port 1)
8 Real-time clock
9 Software redirected to IRQ2
10 Available
11 Available
12 Available
13 Math coprocessor
14 Hard disk controller or host adapter
15 Available, or hard disk controller

Installing a Modem

If you have a modem connected to or installed in your PC, when you install Windows 98 with the modem on, Setup will probably automatically recognize and install support for the modem. If you change modems or add a new modem, you can use the Modems object in the Control Panel to install support for the modem yourself. To install a new modem, open the Control Panel and choose the Modems object. From the General page of the Modem Properties sheet, choose the Add button. Windows 98 starts a modem installation wizard. You have two options for installing the modem. By default, the wizard automatically scans your PC's COM ports for a new modem. Or you can place a check in the check box labeled Don't detect my modem, which enables you to choose a modem from a device list.

If your modem is installed and turned on (if, for example, you have an external modem), leave the check box cleared, which enables the wizard to search for the modem. If you have not yet installed the modem, place a check in the check box, which bypasses the detection phase and enables you to select your modem from a list (see Figure 19.3). If you direct the wizard to detect the modem and the wizard doesn't find a new modem, the wizard will tell you it can't find a new modem and displays this same dialog box, enabling you to select the modem manually.

FIGURE 19.3 A modem selection dialog box.

Search through the Manufacturers list to select your modem's manufacturer; then select the model from the Models list. If the list doesn't include your modem, select Standard Modem Types from the Manufacturers list and select the model from the Models list that matches the maximum speed of your modem. If yours is a 28.8 Kbps modem, for example, choose the 28,8000 model from the Models list.


TIP: If your modem isn't listed, it might be compatible with a model from another manufacturer or with a different model from the same manufacturer because the command sets for the modems might be the same. Choosing a compatible modem rather than one of the standard types could make additional features available that the standard models don't support. If you can't find a compatible model, however, the standard types should provide adequate support in most situations. Or you can check with the your modem's manufacturer to determine whether the manufacturer has a Windows 98 driver available for your model or can suggest a compatible selection. Check the modem's manual to determine whether it is compatible with a specific type of modem.

After you specify the modem model and click on Next, the wizard prompts you to specify the port to which the modem is connected. Choose the appropriate port; then click on Next. The wizard then copies any required files and installs support for the modem.


NOTE: You can install multiple modems for a single COM port. When you configure a Win32 application that uses the Windows 98 communications Application Program Interfaces (APIs) and Telephony Application Interface (TAPI), you select which modem to associate with the application. Installing two or more instances of the same modem driver enables you to use different sets of settings for various applications. You might configure one set of settings to use compression, for example, but configure another to disable compression.

Configuring a Modem

When you install a new modem, the modem installation wizard uses an appropriate set of default parameters for that modem. You might need to change those settings to optimize the modem's performance or tailor it for specific applications.

To configure a modem, open the Control Panel and choose the Modems object. From the General modem property page, select the modem you want to configure; then choose Properties. Windows 98 displays a property sheet for the modem, as shown in Figure 19.4.

FIGURE 19.4 A typical modem property sheet.

The General property page enables you to specify the port to which the modem is connected, the volume level for the modem's speaker, and the connection speed you want to use for the modem. To specify the port, just select the appropriate port from the Port drop-down list. To set the modem's volume, move the Speaker volume slider control. Most modems support four volume levels: off, low, medium, and high. Set yours according to your preference.

When you set the Maximum speed for the modem on the General property page, you need to take your modem's capabilities into account. If you set the speed too high, you could experience problems with the modem. To determine the optimum setting, run the diagnostics on the modem as explained in the section "Testing a Modem," later in this chapter. One value the diagnostics reports is the maximum speed for the modem. In general you shouldn't go any higher than the diagnostics-specified maximum.


TIP: If you want the modem to connect only at the highest possible speed and not renegotiate the connection to a lower speed, enable the check box labeled Only connect at this speed. If you want to connect to your pay-per-use online service only at the highest possible speed, for example, enabling this option will prevent a connection from taking place at a lower speed.

Specifying Connection Settings

The Connection property page (see Figure 19.5) enables you to specify a variety of settings that control the port and other connection options. Some of these settings--Data bits, Parity, and Stop bits--override similar settings in the Port Settings property page for the selected COM port.

FIGURE 19.5 The Connection property page.

The following list details the other settings on the Connection property, located in the Call preferences group:


NOTE: Some online services and remote dial-up connections disconnect you automatically after no activity occurs on the connection for a specified amount of time.

Setting Advanced Options

In addition to the standard settings in the Connection property page, you can use a few advanced settings to control other parameters for the modem. To set these advanced settings, choose the Advanced button from the Connection property page to display the Advanced Connection Settings dialog box.

The following list explains the settings in the Advanced Connection Settings dialog box:

After you specify the necessary advanced settings, choose OK to exit the Advanced Connection Settings dialog box.

Testing a Modem

In addition to providing controls that enable you to configure the modem and its COM port, Windows 98 enables you to perform troubleshooting on the modem. If you click on the Diagnostics tab on the Modems Properties sheet, the Diagnostics page appears, as shown in Figure 19.6.

To test a modem, select the modem from the list by clicking on its assigned port; then choose More Info. Windows 98 attempts to communicate with the modem, and if successful, displays a More Info dialog box similar to the one shown in Figure 19.7. The More Info dialog box contains information about the COM port and modem, including the interrupt, I/O base address, UART type, and recommended maximum speed, as well as modem commands the diagnostic utility sends to the modem and the responses it receives.

FIGURE 19.6 The Diagnostics property page for modems.

FIGURE 19.7 The More Info dialog box.


NOTE: Some responses in the More Info dialog box might read ERROR, which does not necessarily indicate a modem error. The modem might not support the related command. If the diagnostic utility reports more than a few ERROR states, however, you probably have a problem with the modem or are using the wrong driver for the modem.

If Windows 98 can't communicate with the modem, an error message appears, followed by a More Info dialog box that reports the COM port information (interrupt, base address, and UART) but no other information.


TIP: The modem diagnostic utility is a 16-bit application, which means that it can't test the port if you're using the port. If Microsoft Fax is monitoring the port for incoming calls, for example, you must set the answer mode to Don't Answer, making the port available to the diagnostic utility. And because the diagnostic utility is a 16-bit application, it can't test for parallel-port modems.

At this point, you should have your COM ports and modem(s) configured and working properly. In addition, you might need to configure a few telephony options, which includes specifying the location from which you dial. The following section explains how to configure telephony services and also discusses one of Windows 98's telephony-aware accessories, the Phone Dialer.

Configuring and Using Telephony Services

In addition to providing support for features such as call routing, call waiting, conference calls, and other call functions, the telephony services in Windows 98 simplify dialing in various ways. You no longer have to use cryptic setup strings to program your modem to dial your calling card number for credit calls, for example. You now can provide Windows 98 with the calling card number and let TAPI do the rest. TAPI also simplifies using a modem from a variety of different locations, such as hotels and businesses, that require you to dial a special prefix to get an outside line. The following section explains these and other dialing parameters you can set for a connection.

Specifying Dialing Properties

Each modem definition in Windows 98 has associated with it various dialing properties. These dialing properties control the way the modem dials the number you specify for the connection. Dialing properties are associated by dialing location, which enables you to create different sets of dialing properties for each location from which you use the modem. You might have one configuration for your office, another for your home, and a third for dialing from hotels. The office location might require you to dial a 9 for an outside line, whereas the home location would not. The hotel location might require you to dial an 8 for an outside line, and you also might want to use a credit card to charge all calls that you make from a hotel. Dialing properties enable you to configure as many unique dialing locations as you need.


NOTE: Dialing properties affect only Win32 applications that use TAPI to access the modem. Dialing properties do not affect Win16 or DOS applications. These applications control the modem themselves, and the application must handle any special dialing functions separately.

You usually can specify dialing properties from within the Windows 98 application that uses the modem. In the Phone Dialer application, for example (choose Start | Programs | Accessories | Phone Dialer), you can choose Tools | Dialing Properties to specify dialing properties. You also can use the Modems object in the Control Panel to set dialing properties. To do so, choose the Modems object from the Control Panel, select the modem you want to change, and then choose Dialing Properties. Windows 98 displays the Dialing Properties sheet shown in Figure 19.8. (If this is the first time you are setting dialing properties, Windows 98 will prompt you for your current area code before displaying this property sheet.)

FIGURE 19.8 The Dialing Properties sheet.

Windows 98 creates a set of default dialing properties stored with the Default Location. You can modify this group of settings or create a new dialing location. To create a new location, type a new location name in the I am dialing from box; then choose the New button. Windows 98 creates a new set of dialer settings with the specified name.

Next, set any special properties required for the dialing location. The following list describes the settings on the Dialing Properties sheet:

Configuring Calling Card Options

If you are making a connection from a pay-per-use phone, such as from a hotel or airport, you probably want to charge toll calls to your phone calling card. DOS and Win16 applications typically complicate using a calling card in a dialing string, and making connections often is difficult to accomplish. On the other hand, it's relatively simple with Win32 applications and TAPI.

Each dialing location can use a different calling card setup. To define the calling card parameters for a dialing location, first enable the For long distance calls use this calling card check box. After you click on the check box to enable it, click the Calling_ Card button to display the dialog box shown in Figure 19.9.

FIGURE 19.9 Use the Calling Card page to define the options for credit card calling.

To use a credit card, select from drop-down list the carrier and dialing method you want to use. Unless the option you select is a direct-dial option that does not require a credit card, Windows 98 enables the Personal ID Number text box. Enter your calling card number in the text box. After you specify the calling card and card number, choose OK. Then close the Dialing Properties and Modems Properties pages. The next time your Win32 application (such as HyperTerminal or Phone Dialer) uses the calling location with which you have associated your calling card options, the call will be directed to the carrier you have specified and will use your calling card number to make the call. The following section describes how this process works.

Creating a New Calling Card

The Calling Card dialog box contains many predefined calling cards and methods used in different parts of the world. You also can create your own calling card, which enables you to customize the way the calling card connection is made.

To create a new calling card, open the Modems object in the Control Panel, select the modem, and choose Dialing Properties. Enable the check box labeled For long distance calls use this calling card, or if it is already enabled, choose the Calling_ Card button to activate the Calling Card dialog box. Next, choose New. Windows 98 displays a simple dialog box that prompts you to enter a name for the new calling card. Enter a unique name and choose OK.

Next, specify the dialing rules to be used for your new calling card entry. Enter the personal ID (usually the calling card number) access numbers as appropriate. Choose Long Distance Calls to activate the Calling Card Sequence dialog box). Use the drop-down lists provided to specify the sequence of events to dial with this card.

Editing the Toll Prefix List

Although some of the prefixes in your area code probably are local numbers, most aren't. In many areas of the country, you must also dial your area code even when you call within your own area code. Windows 98 keeps track of which numbers in your area code must be treated as long-distance numbers (requiring the area code) and which can be treated as local calls (no area code) through a toll prefix list.

Unfortunately, the capability to edit toll prefixes directly has not been added to Windows 98. Nevertheless, a couple of methods remain that enable you to edit the toll prefix list relatively easily. The Dialing property sheet includes a Dial as a long distance call check box (located at the bottom of the page). Enable this check box to tell Windows 98 to treat the call as a long-distance call and add the prefix to the toll list.

You also can use the Phone Dialer to edit the toll prefix list. Open the Phone Dialer and enter a seven-digit phone number in the Number to dial combo box. Then choose Tools | Dialing Properties to open the Dialing Properties page. Enable the Dial as a long distance call check box to add the prefix to the toll list or disable it to remove the prefix from the toll list.

Using the Phone Dialer

Windows 98 includes a TAPI accessory program you might find useful. The Phone Dialer (see Figure 19.10) enables you to store often-used phone numbers and have your modem automatically dial for you. It stores only eight numbers in its speed dial list, but you still might find it useful.

FIGURE 19.10 The Phone Dialer dialog box.

The Phone Dialer is nearly self explanatory. To enter a number in the speed dial list, click on an empty button. Phone Dialer displays a simple dialog box in which you can enter the name for the speed dial entry and the phone number. Enter the name and number, then choose Save. Phone Dialer adds the name to the button. Repeat the process for any other blank speed dial buttons you want to program. When you're ready to dial the number, just click on its button.

To edit an existing speed dial button, choose Edit | Speed Dial. Click on the entry you want to change. Then enter the new name and number in the appropriate text boxes.

Besides the speed dial buttons, you can use the keyboard or the key buttons on the Phone Dialer to enter a number. The Phone Dialer keeps track of the numbers it dials, and you can select previously dialed numbers from the Number to dial combo box.

Tips for Optimizing Communications

This section provides tips on using special modem settings. They will help you configure your modem properly and make the most of your time online.

Using Special Settings

Sometimes you might want to include special initialization settings for the modem. You might want to include the command ATS11=50, for example, to speed up the rate at which the modem dials. To make the modem use special initialization commands, choose the Modems object from the Control Panel, select the modem, and choose the Properties button. From the Connection property page for the modem, choose the Advanced button. Enter the special modem string in the Extra settings text box; then choose OK.


TIP: Windows 98 stores your special initialization string in the Registry in the UserInit subkey for the modem.

Changing Modem Registry Keys

The Modems object in the Control Panel enables you to select which modem to use, but it doesn't enable you to directly modify the initialization string or many other settings for the modem. Instead, Windows 98 uses a group of settings defined by your modem type.

You can, however, use the Registry Editor to modify modem configuration settings directly. The modem settings are stored in \Hkey_Local_Machine\ System\CurrentControlSet\Services\Class\Modem\modemID, where modemID is the identifier for your modem (such as 0001). By modifying modem settings, you can tailor the way Windows 98 uses the modem. If Windows 98 doesn't include a driver specifically for your modem, modifying the Registry settings enables you to customize the settings of a partially compatible driver to be fully compatible with your modem.

The following list describes the main subkeys for the modem:

TABLE 19.2 Modem Configuration Keys

Subkey Description Example
Blind_Off Detect dial tone before dialing X4
Blind_On Do not detect dial tone before dialing X3
CallSetupFailTimer Specify call setup time-out S7=<#>
Compression_Off Compression disabled S46=136
Compression_On Compression enabled S46=138
DialPrefix Dial command prefix D
DialSuffix Dial command suffix ;
ErrorControl_Cellular Cellular protocol enabled \N3-K1)M1-Q1*H1
ErrorControl_Forced Error control required to connect (reliable) +Q5S36=4S48=7
ErrorControl_Off Error control disabled (normal mode, not direct) +Q6S36=3S48=120
ErrorControl_On Error control enabled (auto reliable) +Q5S36=7S48=7
FlowControl_Hard Hardware flow control &K1
FlowControl_Off No flow control &K0
FlowControl_Soft Software flow control &K2
InactivityTimeout Specify inactivity time-out S30=<#>
Modulation_Bell Use Bell modulations for 300 and 1,200bps B1
Modulation_CCITT Use CCITT modulations for 300 and 1,200bps B0
Pulse Use pulse dialing P
SpeakerMode_Dial Speaker on during dial and negotiation M1
SpeakerMode_Off Speaker always off M0
SpeakerMode_On Speaker always on M2
SpeakerMode_Setup Speaker on only during negotiation M3
SpeakerVolume_High High speaker volume L3
SpeakerVolume_Low Low speaker volume L1
SpeakerVolume_Med Medium speaker volume L2
SpeedNegotiation_Off Connect only at default modem speed; do not fall back N0
SpeedNegotiation_On Use lower DCE speed to connect, if necessary N1
Terminator Configuration command suffix
Tone Use tone dialing T


NOTE: The settings for your modem might be different from those shown in Table 19.2.


Previous chapterNext chapterContents

© Copyright, Macmillan Computer Publishing. All rights reserved.