Page 17 - Viva ICSE Computer Studies 7 : E-book

MODEM

The term MODEM is formed by combining the words MO-dulation and DEM-odulation.
MODEM is a data communication equipment that translates the digital signals used by a
computer into analog signals of the kind that travel by conventional telephone lines. The
process of translating digital signals into analog signals is called modulation. A MODEM also
converts the analog signals into digital signals at the receiving end of a computing device.

The process which translates analog signals into digital signals is called demodulation.

The basic function of a MODEM is to enable communication between various computers on a
network (mainly Internet).

MODEM MODEM

Telephone link

There are mainly two types of MODEM: internal and external.

An internal MODEM is a card that is installed into a slot within the CPU case of a computer.
Internal modem is powered by the power supply of a computer.

An external MODEM is a box-shaped device that is connected to the serial port of a computer.
It is so called as it is placed outside the computer. The external modem is powered by an
external power adapter, connected to an electrical outlet.

Heat Sink

A heat sink is an electronic device designed to disperse the heat
generated by the CPU and cools it for improving performance and
reliability. It also avoids the premature failure of the components.

Port

A computer port is a connection between a computer and an external or internal device.
Internal ports may connect devices such as hard drives and CD ROM or DVD drives. External
ports may connect modems, printers, mouse and other devices.

Characteristics of Ports
A port has the following characteristics.

• External devices are connected to a computer using cables and ports.
• Ports are slots on the motherboard into which the cable of an external device is plugged
in.

Computer ports have numerous functions and connectors of varying designs.

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