14-01-2014, 03:26 PM
Computer Hardware
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Introduction
The term computer hardware refers to the physical components of a computer,
namely Keyboard, Monitor, Mouse, and Printer, including the digital circuitry.
Computer hardware is an integral part embedded in all modern day automobiles,
microwave ovens, electrocardiograph machines, compact disc players, and other
devices. The hardware of a computer is not changed frequently, in contrast with
software and data. The present computers are much advanced in terms of
processing speed and have an efficient memory structure. The present lesson
aims at providing an insight into the hardware concepts of a Computer System.
Personal Computers
A personal computer, very commonly known as the PC or the home computer,
refers to a microcomputer whose price, size, and capabilities make it suitable for
personal usage. They are normally single-microprocessors, single user systems
designed for general-purpose applications. They have sufficiently large amount
of internal memory to store programs and documents. A computer, indeed, is a
machine that can perform a number of tasks for us. It can accept and store data,
process it and produces the output. For performing these functions, computer
systems consist of Input devices, a Central Processing Unit (CPU) and Output
Devices.
Input Devices
The foremost task of a computer is to accept data. An input device is used to
accomplish this task. An input device is used to enter the data and instructions
into the computer. Advancement in the computer technology has resulted in a
variety of input devices being available in the market. Keyboard and mouse are
the most commonly used input devices.
Dot Matrix Printer
Printers in this category print the characters / images using dots through inked
ribbon. These printers are very economic and
require very less maintenance cost. The print
quality of the dot matrix printer is decided by the
quantity of pins it has. The number of the pins can
vary from nine to twenty four, depending on the
kind of dot matrix printer. When compared to the
other kind of printers, like the laser printers or the
ink jet printer, the dot matrix printer is much more
expensive. The dot matrix printer has a tendency
to make a lot of noise when compared to the other
kinds of printers.
Inkjet/Deskjet/Bubblejet Printer
Printers in this category are most popular. These printers are very low priced with
high running/maintenance cost. These printers work on liquid ink technology and
print the image using circuit-controlled jet of ink. An inkjet sprays the ink onto the
paper in tiny droplets to form text and graphics. Printing speed of these printers is
not very high compared to Laser Printers. These printers are
suitable for people having less printing jobs with a desirable
print quality. These printers are available in 'Coloured' and
'Black & White' options.
Different companies have branded their products using the
same technology with different names e.g.
Hewlett Packard (hp) manufactures DeskJet Printers
Epson manufactures Inkjet Printers
Canon manufactures Bubble Jet Printers
Laser Printer
These printers use a technique, which is a combination of
laser and Xerox technology. The technology involves dry
powder based ink, which is adhered to a drum through
magnetic force, and when a paper is passed through the
drum it releases ink on that paper. These are the fastest
available printers in the category and are most suitable for
uses involving high-speed quality prints.
Storage devices
Storing data is an important part of a computer system. The main concern of all
computer designers is to create fast and efficient storage devices. As is commonly
known, the primary memory inside the computer (Random Access Memory or RAM) is
volatile i.e. whatever is stored in RAM is lost as soon as the computer is switched off.
So if there is a need to save data from getting lost, it can be put on a storage device
like floppy disk, hard disks and CD-ROMS before switching off the Computer.