Connecting Different Devices

This section explains how to connect different input and output devices such as Keyboard, Monitor, Printers etc. to the main computer system.

Remember that connecting or disconnecting any device to the computer must be done in the computer and device power off condition. If the power supply to the device or the computer is on then this could damage the computer, the device being connected, or both.

Power Cable

To provide power to the computer, a power conditioning device such as stabilizer, CVT (Constant Voltage Transformer) or UPS (Un-interruptible Power Supply) is first connected to the AC mains supply.

The UPS is the best power conditioning device, as it takes care of almost all power problems such as spike (very high over-voltage that lasts for less than a millisecond to a second), surges (over-voltage that lasts for few milliseconds to a second), under-voltage, brown-out, black-out, over-voltage etc. The UPS also provides back up power to the computer in case of any power failure.

The output from this power conditioning device is given to an extension box, to which different devices are connected.

Based on the type of power connector provided on the monitor, a monitor can be connected to the output on the power supply of the computer or it can be connected to the extension box.

Monitor

After connecting power cable to the monitor into the computer’s power supply or into the power extension box, another cable known as data cable from the monitor needs to be connected to the computer system.

9-Pin female or 15-Pin female D-Shell socket at the back of system unit is used to connect monitor to the computer system.

•  The 9-Pin socket is used to connect Monochrome, HGA (Hercules Graphic Adapter), CGA, EGA or Dual display (which supports both HGA & CGA) monitors to the computer system.

• The 15-Pin socket is used to connect currently available VGA or SVGA monitor to the computer system

Keyboard

The keyboard is connected to the small round opening provided at the back of the main system unit.

When connecting the keyboard to this socket make sure that a small notch on the socket and on the keyboard connector are properly aligned, otherwise the pins of the keyboard connector will not aligned with the holes provided on the socket.

Once the connector and socket are properly aligned, insert the keyboard connector fully into the socket.

Currently many Keyboards come with USB, PS/2 Mini-DIN or wireless connector. Check the connector provided with the keyboard and attach to proper socket on the main system unit.

Mouse

A mouse is connected to serial port socket provided at the back of the main system unit. Generally, the computer ha two serial ports COM1 and COM2 (Com stands for Communication Port).

Most of the software provided with Mouse can automatically detect the serial port at which the mouse is connected.

Currently many mouse come with USB, PS/2 or Wireless connectors. Check the connector provided with the Mouse and attach to proper socket on the main system unit.

Printer

Printer is connected to the 25-Pin female D-shell socket provided at back of the main system unit. Socket for serial device is a 25-Pin male D-shell socket.

Cable for connecting printer to the computer has a 25-Pin male D-shell connecter at one end and has a special type of connector known as Centronics Connector at the other end.

The 25-Pin male D-type connector on printer cable is connected to the 25-pin female D-type socket on the main system unit and the other end of the cable with Centronics Connection is connected to the Centronics socket on the printer.

Currently many printers come with USB, and Wireless connection. Check the socket provided on the printer and connect to the proper socket on the main system unit.

Speaker/Microphone

Speaker and Microphone are connected to the output provided at the back of the sound board. Back of the sound board contain jacks for connecting the microphone and a set of speakers.

Using proper cable, speaker output can be connected to an audio amplifier, or home stereo system to produce high volume sound output.

Modem

If you are using an external modem, then connect the modem to the serial port on the computer unit.

If you are using an internal modem comes as an expansion card and is directly connected inside the computer to one of the expansion slots.

If you want to see the same telephone line for normal voice communication as well as for the data communication then connect the modem to the telephone line and a telephone instrument can be connected to the line out provided on the modem.

Connect a RJ-11 cable to the phone socket provided on the wall , connect other end of this cable to the line socket provided on the modem.

One end of another RJ-11 cable should be connected to the phone socket provided on the modem and the other end of this cable can be connected to a telephone instrument.

This allows same line to be used for voice as well as data communication.

If you are using external modem, then connect the power supply provided with the modem to the power socket.

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Posted in: Computer Hardware