Compaq Armada 7400 Reference Manual page 96

To connect the modem to a standard telephone wall jack:
!
1. Connect one end of the modem cable into the RJ-11 jack on
the right side of the computer.
(Direct AccessArrangement) that supports multiple countries.
However, some countries may require an adapter to connect
the modem to the telephone wall jack.
The modem cable includes EMI suppression circuitry near the
end of the computer. For continued EMI emissions
compliance, plug that end of the cable into the computer.
2. Plug the opposite end of the cable into a standard telephone
wall jack.
standard telephone jacks but are not compatible with analog
devices such as modems. Be sure the modem cable is
connected to a regular analog phone line. Plugging the modem
into a digital line is not recommended. The modem includes
protective circuitry against the digital lines which may
produce a beep or a series of beeps if it detects excess current.
The modem serves two major functions:
The data communications function allows your computer to
send information to and receive information from an online
service, a host mainframe computer that provides electronic
mail, and even other personal computers.
The facsimile function allows your computer to both send and
receive text and images from facsimile (fax) machines or other
computers.
The internal modem uses a universal DAA
Wall jacks for digital PBX systems may resemble