Apple Macintosh PowerBook Internal Modem User Manual

Setting up your modem’s connections

Label showing icon for card

Connector for
Ethernet/modem
or Ethernet card

The PowerBook G3 Internal Modem is already installed in your PowerBook.
To use the modem you need

m the single-line telephone cord supplied with your PowerBook, which has a

two-wire RJ-11 connector at each end

m an analog telephone line with a modular jack
m (optional) the PowerBook G3 Internal Modem/Ethernet Adapter

(a Y-adapter that is supplied with your PowerBook) to use the modem
while connected to an Ethernet network

Connecting the telephone line to the modem

Follow these steps to connect the telephone line to the modem.

1 Open the cover on the computer’s back panel and check the label on the inside of the

cover to verify that your computer has the Ethernet/modem card.

1

The label for the combination Ethernet/internal modem card shows the two

Modular
connector
on card

Telephone connector

2 visible wires

Single-line telephone cord

Ethernet/modem card label

G W

/

icons illustrated below. (Some models of the PowerBook have an Ethernet­only card, which does not provide a modem connection.)

2 Locate the telephone cord that came with your computer.

Be sure that the phone cord is a single-line, two-wire type.

IMPORTANT

equivalent single-line telephone cord. Any other type of telephone cord may
not work correctly with the modem.

3Plug one end of the telephone cord that came with your computer into the internal

modem port on your PowerBook.

2

Use the telephone cord that came with your computer or an

If you are using the adapter cable, plug it into the modem port. Then plug the

Y-adapter

W

Telephone connector

G

Ethernet connector

telephone line into the adapter, in the connector labeled with the telephone
icon.

4Plug the other end of the telephone cord into your telephone wall socket.

IMPORTANT

The telephone line must be an analog line—the type used in
residences. Do not connect a digital telephone line to the modem, because the
wrong type of line could damage the modem.

Once the telephone line is connected, you are ready to begin using
the modem.

IMPORTANT

When you have established a modem connection with another
computer or an online service, do not put the computer to sleep. Doing so
will disconnect the modem.

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Using your modem

It’s a good idea to become familiar with a modem’s general operations. This
section explains what modems do and shows how to designate the PowerBook
G3 Internal Modem in the software you plan to use with the modem.

What modems do

Modems allow computers to communicate over telephone lines. While
computers manipulate information in digital format, most telephone systems
carry information as analog (wave) signals. Therefore, in order for computers
to communicate over the PSTN (Public Switched Telephone Network),
information must be converted to and from digital and analog formats. A
modem (modulator/demodulator) handles these format conversions. The
modem of the sending computer converts information from digital format to
an analog signal by a process called modulation. The modem of the receiving
computer converts the analog signal back to digital format by a process called

demodulation.

Modems also dial, establish connections, and control the flow of data across
the telephone line so that transmission takes place with optimal speed
and accuracy.

Preparing for a modem connection

Before two computers can exchange data over telephone lines, their modems
must establish a connection and agree on how data will be transmitted.

Your modem is already set to make the best possible connection
automatically. See “Technical Specifications,” later in this manual, for a list
of specifications.

Note: In general, it is best to use your modem’s automatic settings. If you
want to control the speed, error control, and data compression settings
yourself, see the Modem AT Command Set (a file on your hard disk) or the
user’s guide that came with your data communications software.

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Determining the speed

A modem communicates with the computer to which it is connected (by
means of a cable), and with another modem (by means of a telephone line).
The computer-to-modem communication speed is generally faster than the
modem-to-modem speed, often considerably faster. The “advertised” modem
speed, such as 33,600 bits per second (bps), is the maximum speed for
modem-to-modem connections.

Initially, your modem tries to connect to another modem at its fastest speed,
which is 33,600 bps. If the remote modem cannot connect at this speed or if
the telephone line does not provide a completely clear connection, your
modem falls back to the next highest speed. Fallback continues until the two
modems agree on the highest speed supported by both using the particular
telephone line connection.

IMPORTANT

The actual connection speed of your modem may vary, depending
on the specific telephone line in use, the quality of the connection, and other
factors that affect communications.

Error control

Error control is used by modems to ensure data accuracy. Your modem and
the remote modem must agree on an error control method. Your modem will
try to use one of two types of error control, V.42 or MNP class 2–4. If the
remote modem does not support either of these types of error control, no
error control is used.

Data compression

Data compression increases the speed of your modem by eliminating gaps
and redundancies in the data. With data compression enabled, the speed can
increase up to 4 times the normal speed.

Your modem can use two different types of data compression, V.42 bis or
MNP class 5. If the remote modem does not support either of these types of
data compression, no data compression is used.

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Software for your modem

Your Macintosh PowerBook has modem software installed, including
programs to connect to the Internet and to send and receive faxes. For
instructions on using these programs, see their electronic manuals on your
computer’s hard disk.

Choosing the port setting

You must specify the modem port to each communications program before
you can connect to another computer by modem.

The example that follows shows how to specify the modem port in America
Online (AOL), one of the programs installed on your computer’s hard disk.

Follow these steps to specify the modem port in the AOL software.

1 Open AOL (on your hard disk).

2If you are new to America Online, click Continue in the dialog box that appears. If you

have an AOL account already, click Upgrade.

3 Follow the instructions on the screen to set up an AOL account or to upgrade your

current AOL account.

When you finish setting up your AOL account, the AOL Welcome window is
on your screen.

4 Click Setup in the Welcome window.

6

The Location window opens, like the one below.

5 In the Port pop-up menu, choose Internal Modem.

6 In the Type pop-up menu, choose PowerBook G3 Internal 33.6.

7 In the Speed pop-up menu, choose 57600.

Always choose the highest speed available. This is the speed at which the
computer communicates with the modem.

8Click Save.

Now the AOL software is ready to use with your modem.

IMPORTANT

You must repeat this procedure—specifying the modem port—
for each communications program you plan to use with the modem.

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