Fundamentals of Computers

Introduction

It is only about three decades since man  started taking a serious note of the possibilities offered by computers. and,within a short span of time,computers have carved out a niche in the history of mankind and changed the entire gamut of human life at an overwhelming pace. the computer is a fascinating machine.it is a gateway to a wonderful world of information and myriad applications for the good humans.be it business, academics , defence strategy, budgeting , research , medicine or space exploration, computers have established themselves as an indispensable part.

The growing popularity of computers of computers has been turned into account by the business world. Today's business involves the active participation of computers. computer science is now being offered as an integral core subject to the students in almost every school and college. In fact, the subject of computers is a mandatory part of many regular courses. In the employment arena also, computers have exercised their influence. The ability to work with computers is a necessary pre-requisite for most of the present job profiles.

The term computer is drived from the word computer. A computer is an electronic equipment which is capable of creating solutions by performing complex processing of information without manual intervention and that too at a tremendous speed. the computer commonly used in homes or offices is popularly referred to as a "PC" which denotes 'personal computer'. Through out this book, we will use the words "PC",'system' and 'computer' interchangeably.

Why do we need computers

Computers play a very important role in human lives.the primary purpose of using a computer is to make life easier. To appreciate the importance of computers in today's world, let us consider a simple instance,say , the accounting system of a company. if we follow the conventional system, preparing a balance sheet would require about a month: whereas with a computer, the could be a matter of just a few hours. A balance sheet,prepared manually, is highly prone to errors and the scope for making corrections is very limited. however, if a computer is used in preparing a balance sheet, the likelihood of committing errors is very remote and corrections can be carried out even at the last moment. all the tasks performed by a computer may also be performed by human beings but at the expense of a lot of time and labour.

Consider the role played by computers in the field of medicine.with the information on case history of each patient stored in the computer's memory , the doctor is freed from the burden of having to grope through bundles of papers for referring to a particular patient. all the information he/she needs can be had for the click of a mouse o the push of a button. similarly, an engineer needs not now brother about hair-splitting design parameters or interminable trials and errors, with  the computer being t his command.

At home,computers are useful for everyone. parents can use a computer to keep a record of their daily expenditure as well as document important dates like birthdays,marriage anniversaries etc.

Computers can be immense utility to students. A student can use a PC to prepare notes, projects etc. or access information on the Internet, take online lessons and tests

Graphics and animation can be used to make even the dullest of subjects lively an interesting. Apart from routine work, students can apply themselves to develop their creative skills by virtue of the myriad features a computer offers.

In a developing country like India, one of the reason for people to go for a PC is the E-mail facility, since this is one of the most convenient, fastest and cheapest ways to communicate with friends, family and acquaintances within and outside the country.Internet chatting is also on interesting activity that attracts the young and the old alike. Computers provide us ready access to the latest news from all over the world.

A PC is not all about serious work. It also offers scope for games,movies,music and even comics that add to our entertainment. children as well as adults have developed a fascination for this little machine. MP3, the compressed format for music file, allows us to store songs in a PC without taking up too much of hard disk space. and again, to watch movies one need not be connected to the internet. They can very well be watched on VCDs played on the PC.

A computer (PC) can also make for domestic bliss by bringing together the members of a family, thereby making the family a closely knit unit. The  family can plan the budget, watch a movie, play video games or work on other innovative things like drawing and designing of a picture, writing an article or sketching a cartoon. The housewife can take-up one of the many lucrative online jobs that are being offered to people these days.

Parts of a Computer

To learn more about the components of a computer,let us examine the various parts that are isible from outside. basically, a computer consists of a CPU, a monitor, a mouse and a keyboard. some computers may also contain additional  accessories like speakers, a microphone, a headphone etc. The additional accessories simply facilitate us to use the computer for doing something extra. A discussion on the essential and optional components of the computer will be taken up later on in this chapter. For the moment, let us discuss the components of a simple computer.

Central Processing Unit:- 

The Central Processing Unit (CPU of computer is usually located in a tower-shaped cabinet. The CPU consists of different smaller components like the motherboard,hard disk, RAM, floppy disk drive, sound card etc. These components are discussed in the next-section.

Monitor:-

Monitor is a television-like equipment  which displays the output of a computer. monitors can be monochrome (black and white),LCD (liquid crystal display), VGA or SVGA. Further, monitors can be analogue or digital.

Mouse:-

Mouse is a small component that fits inside our palm.It contains Buttons(two or three) which help us work on a computer conveniently.

Keyboard:-

Keyboard is a typewriter like device which contains keys to feed information into the computer. Generally, keyboards are available in two models:

• The standard model with 82-84 keys; and
• The enhanced model. This model is more popular nowadays and contains 104 keys or more.

 Components of a PC

Before we actually work on a PC, it is essential to understand the function of the components that form the core of a computer.

The components in a PC work together as a team. As mentioned earlier, some if the components are essential, while others are optional. The additional parts enhance the range of tasks that can be performed on a computer or a PC, thus making one's work on the computer more efficient and easier. The essential and the option components of a computer are listed in the following table.

Basic  Components	Optional
Processor          Hard disk          RAM          Display/video card           Keyboard          Drives : Hard Disk, Floppy Disk           and  CD-ROM          Mouse           Monitor	Printer Scanner Modem DVD drive Speakers Zip Drive

 The System Unit

The system unit is the most important part of a PC. It may be called the brain behind every action of a PC since it controls and executes all the operations performed by the PC. The system Unit holds the windows Operating System. The keyboard, monitor, mouse, printer, etc. ate all linked to the system Unit through cables which are plugged into the back of the system unit. the hard disk, the floppy disk drive and the CD-ROM drive are placed inside this unit. you may also find the DVD drive and the removable  storage device attached to the system unit.

Everything in the system unit is essential for the effective functioning of the computer. In this section, we will discuss the viral components of the system Unit so s to enable you understand the working process of the system.

 a) Hard Disk :- The hard disk is a device which stores all programs and data in the computer. hence, the hard disk is referred to as the memory bank of a computer. The hard disk memory is permanent so that the programs and data are not lost when the computer is turned off. Nowadays, the capacity of the hard disk is measured in Giga Bytes (GB). Earlier, the memory capacity of computers war limited to mega bytes (MB). But, today PCs having hard disks of capacities like 10 GB, 20 GB or 30 GB are popular.Larger the hard disk capacity, more the amount of software programs and information that can store in it. 

                              

b) Motherboard : The motherboard is a flat platform of fiber glass on which the electronic components in PC are mounted. Thin lines of mental connecting pins are etched on the surface of the fiberglass. these pins connect the components to one another, and form the electronic circuit of the computer. The motherboard is also called a printed Circuit Board (PCB)

c) Central Processing Unit (CPU) : The Central Processing Unit (CPU) is the most important component of a computer. It contains the microprocessor chip which undertakes all the thinking for the PC and runs the progarms (series of instructions) according to the user's commands and requests. Following the various types of CPU chips:

• Pentium
• Pentium Pro
• Pentium III
• Pentium IV 
• AMD Athlon
• Intel Celeron 
• AMD Duron
• Cyrix

d) CD-ROM Drive :- CD-ROM drive is a device that reads the information stored on CD-ROM disks. CD-ROM is an abbreviated term for 'Compact Disk- Read Only Memory'. A CD-ROM gives us the opportunity to only read its information. The information stored in a CD-ROM can neither be changed nor can new information be added to it. That is Why, it is called Read Only Memory (ROM). The speed of a CD-ROM drive is indicated by a number followed by the alphabet 'X'. This number is an indication of how fast the disk spins. Faster the spin, faster is the transfer of information from the disk to the computer. The 56X CD-ROM is currently the most popular drive specification. for recording information on a CD, a special CD drive known as 'CD-RW' is used . The CD-Rom disk is flat and circular in shape and can store a lot more information as compared to a floppy disk. Today, the CD Drive Has been replaced by the DVD Drive.

e) Floppy Disk Drive :- Floppy disk drive is a component that enables us to read/store information on floppy disks. The floppy disk drive consists of a slot to accept a floppy disk, a motor to spin the disk, and a recording/reading device that moves across the disk to read or write data. A floppy (also called a diskette) is used to store information just as a hard disk. It stores data magnetically. It is a removable device. However,its capacity (1.44 MB) is far less than that of a hard disk(20 GB or more). A PC can either have the 51/4" floppy disk drive or the 31/2" floppy disk drive, or both.

f) Math Co-Processor Slot :- Some PCs contain a slot where a Math Co-Processor can be inserted. The Processor assists the CPU in performing its mathematical operations(if the programs have been designed to use it). However, computers above the 486 grade do not contain a seperate  Math Co-Processor as it is already in-built in the CPU chip.

g) RAM Chips :- RAM stands for Random Access Memory. RAM chips are components that help the computer to hold the program and its data temporarily while the computer is working. when the PC is switched off, anything held in the RAM is lost. Information of any kind can be stored permanently only when it is stored in the hard disk. RAM chips come in memory sizes of 16 MB, 32 MB, 64 MB, 128 MB and so on.

h) RAM Chip Slots :-These slots are meant to expand the computer's random access memory by incorporating additional RAM chips.

i) Over-Drive Chip :- The Over-Drive chip increases the processing speed so that the performance of the computers improved. This is generally not necessary for ordinary PCs and is used by corporate companies.

j) SCSI :- SCSI stands for 'small Computer System Interface' (pronounced skuzzy). An SCSI provides an internal connector which in turn allows you to connect the computer to an external storage device (like DVD drive, Hard disk drive, CD drive, Zip drive etc.)

k) Power Supply Unit :- The components in a PC can work only they get electric supply. Most components require a 5 Volt supply while the floppy and the hard disk require about 12 Volts. Connecting the components to a normal household electric supply would below these up. The power supply unit safeguards the PC components by converting high-voltage current a low voltage.

l) Disk Drive Control Card :- This card controls the disk drive motors of the PC and transfer data to the control circuitry and directs the read/write heads to access data on computers do not contain a separate slot for the disk drive control card. Instead, it is permanently inserted in the motherboard.

m) Display/Video/Graphic Card :- Display card is used to display the data to the user. It is directly linked with the computer memory. Nowadays, it is inbuilt in the motherboard. Two types of display cards are available. These are PCI graphics card and the AGP card.

n) Printer Adaptor Card :- The information in the computer is stored in its memory. To make use this information, you need to either see it on the monitor or print it. The display/printer adaptor card is the link between the PC's memory, the monitor and the printer. It displays the information on the monitor as well as allows it to be printed.

o) Expansion Slots :- Expansion slots are long and narrow connectors which allow you to plug in expansion cards (also called adaptor cards), like the sound card, network card etc. These expansion cards offer some extra options which are generally not available on a PC.

p) ROM Chips :- Read Only Memory (ROM) chips have data written on them during manufacturing, that tells the CPU the tasks that it needs to carry out when the PC is switched on. The data remains in the PC even when it has been switched off.

q) Sound Card :- This card allows you to play sound and music. 

The sound card converts the digital information into electrical signals that speakers use. When the speaker is connected to the sound card, the sound can be heard on the speaker.   

Written by Mr. krishan kumar saini 

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