Saturday, November 20, 2010

Why Is A Computer So Powerful?

Why Is A Computer So Powerful?
A computer derives its power from its capability of performing the information
processing cycle operations (input, process, output, and storage) with amazing
speed, reliability, and accuracy; storing huge amounts of data and information; and
communicating with other computers.
In the system unit, operations occur through electronic circuits. When data,
instructions, and information flow along these circuits, they travel at clo se to the
speed of light. This allows billions of operations to be carried out in a single second.
The electronic components in modern computers are dependable because they have
a low failure rate. The high reliability of the components enables the computer to pro
duce consistent results.

Computers can process large amounts of data and generate error- free results,
provided the data is entered correctly and the program works properly. If data is
inaccurate, the resulting output will be incorrect. A computing phrase — known as
garbage in, garbage out (GIGO) points out that the accuracy of a computer’s output
depends on the accuracy of the input.
Many computers can store enormous amounts of data and make this data available
for pro cessing anytime it is needed. Using current storage devices, the computer can
transfer data quickly from storage to memory, process it, and then store it again for
future use.
Most computers today have the capability of communicating with other computers.
Computers with this capability can share any of the four information processing cycle
operations — input, process, output, and storage — with another computer. For
example, two computers connected by a communications device such as a modem
can share stored data, instructions, and information.
When two or more computers are connected together via communications media and
devices, they form a network. The most widely known net work is the Internet.

System Unit & Storage Devices

System Unit
The system unit, sometimes called a chassis, is a box-like case made from metal or
plastic that protects the internal electronic components of the computer from damage
(see Figure 1-3). The circuitry in the system unit usually is part of or is connected to a
circuit board called the motherboard.
Two main components on the motherboard are the central processing unit and
memory. The central processing unit (CPU), also called a processor, is the electronic
device that interprets and carries out the basic instructions that operate the
During processing, the processor places instructions to be executed and data
needed by those instructions into memory. Memory is a temporary holding place for
data and instructions.
Both the processor and memory consist of chips. A chip is an electronic device that
contains many microscopic pathways that carry electrical current. Chips, which
usually are no bigger than one-half inch square, are packaged so they can be
attached to a motherboard or other circuit board.
Some computer components, such as the processor, memory, and most storage
devices, are internal and reside inside the system unit. Other components, such as
the key board, mouse, microphone, monitor, p rinter, scanner, digital camera, and PC
camera, usually are located outside the system unit. These devices are considered
external. A peripheral is any external device that attaches to the system unit.
Storage Devices
Storage holds data, instructions, and information for future use. Storage differs from
memory, in that it can hold these items permanently. Memory, by contrast, holds
items only temporarily while the processor interprets and executes instructions.
A storage medium (media is the plural) is the physical material on which a computer
keeps data, instructions, and information. A storage device records and retrieves
items to and from a storage medium. Storage devices often function as a source of
input because they transfer items from storage into memory.
Common storage devices are a floppy disk drive, a Zip® drive, a hard disk drive, a
CD-ROM drive, a CD-RW drive, a DVD -ROM drive, and a DVD+RW drive. A drive is
a device that reads from and may write on a storage medium. This media includes
floppy disks, Zip® disks, hard disks, and compact discs.
A floppy disk consists of a thin, circular, flexible disk enclosed in rigid plastic. A floppy
disk stores data, instructions, and information using magnetic patterns. You insert
and remove a floppy disk into and from a floppy disk drive (Figure 1-5). A Zip® disk is
a higher capacity disk that can store the equivalent of up to 170 standard floppy
A hard disk provides much greater storage capacity than a floppy disk. A hard disk
usually consists of several circular platters that store items electronically. These disks
are enclosed in an airtight, sealed case, which often is housed inside the system unit
.Some hard disks are removable, which enables you to insert and remove the hard
disk from a hard disk drive, much like a floppy disk . Removable disks are enclosed
in plastic or metal cartridges so you can remove them from the drive. The advantage
of removable media such as a floppy disk and removable hard disk is you can take
the media out of the computer and transport or secure it.
A compact disc is a flat, round, portable medium that stores data using microscopic
pits, which are created by a laser light. One type of compact disc is a CD-ROM,
which you can access using a CD -ROM drive. A Picture CD is a special type of CDROM
that stores digital versions of photographs for consumers.
A variation of the standard CD-ROM is the rewriteable CD, or CD-RW. In addition to
accessing data, you also can erase and store data on a CD-RW. To use a CD-RW,
you need a CD-RW drive. Another type of compact disc is a DVD-ROM, which has
tremendous storage capacities — enough for a full-length movie. To use a DVDROM,
you need a DVD drive (Figure 1 -8). A variation of the standard DYD-ROM is
the rewriteable DYD, or DVD+RW.
Some devices, such as digital cameras, use miniature storage media (Figure 1 -9).
PC Cards and memory cards are popular types of miniature storage media. You then
can transfer the items, such as the digital photographs, from the media to your
computer using a device called a card reader.

The Components Of A Computer

A computer consists of a variety of hardware components that work together with
software to perform calculations, organize data, and communicate with other
These hardware components include input devices, output devices, a system unit,
storage devices, and communications devices. Figure 1 -3 shows some common
computer hardware components.
Input Devices
An input device is any hardware component that allows a user to enter data and
instructions into a computer. Six commonly used input devices are the keyboard,
mouse, microphone, scanner, digital camera, and PC camera.
A computer keyboard contains keys that allow you to type letters of the alphabet,
numbers, spaces, punctuation marks, and other symbols. A computer keyboard also
contains other keys that allow you to enter data and instructions into the computer.
A mouse is a small handheld device that contains at least one button. The mouse
controls the movement of a symbol on the screen called a pointer. For example, as
you move the mouse across a flat surface, the pointer on the screen also moves.
With the mouse, you can make choices, initiate a process, and select objects.

A microphone allows a user to speak to the computer to enter data and instructions
into the computer. A scanner reads printed text and pictures and then translates the
results into a form the computer can use. For example, you can scan a picture, and
then include the picture when creating a brochure.
With a digital camera, you can take pictures and transfer the photo graphed image to
the computer, in stead of storing the images on traditional film. A PC camera is a
digital video camera attached to a computer. A PC camera allows home users to
create a movie and take digital still photographs on their computer. With a PC
camera, you also can have a video telephone call — where someone can see you
while communicating with you.

Output Devices
An output device is any hardware component that can convey information to a user.
Three commonly used output devices are a printer, a monitor, and speakers (see
Figure 1-3 on the previous page).
A printer produces text and graphics on a physical medium such as paper or
transparency film. A monitor, which looks like a television screen, displays text,
graphics, and video information. Speakers allow you to hear music, voice, and other
sounds generated by the computer.

Information Processing Cycle

Importance of Computer
Computer is the key of IT world. First we’ll get an overall knowledge about the
What Is A Computer?
A computer is an electronic machine, operating under the control of instructions
stored in its own memory that can accept data, manipulate the data according to
specified rules, produce results, and store the results for future use.
Information Processing Cycle
Input is any data or instructions you enter into a computer. Output is data that has
been p rocessed into information. Computers process input (data) into output
Storage is an area in a computer that can hold data and information for future use.
This series of input, process, output, and storage activities sometimes is called the
information processing cycle.
Most computers today have the capability of communicating with other computers.
Thus, communications also has become an important element of the information
processing cycle.

Why IT is being used?

Why IT is being used?
You can’t think about a world with out IT today. IT has become part and participle
with everybody’s life today. There are thousands of reasons about why people use
computers to fulfill their requirements in many life aspects.
Basically we can have Information Systems which is a major part in IT.
Types Of Information Systems
An information system is a set of hardware, software, data, people, and procedures
that work together to pro duce information. A procedure is an instruction, or set of
instructions, a user follows to accomplish an activity. An information system supports
daily, short- term, and long -range activities of users in a company. Information
systems generally fall into one of five categories: office information systems,
transaction processing systems, management information systems, decision support
systems, and expert systems. The following sections present each type of
information system.

Office Information Systems
An office information system (OIS pronounced oh-eye -ess) increases employee
productivity and assists with communications among employees. In an OIS,
employees perform tasks using computers and other electronic devices, instead of
manually. Some people describe an OIS as office automation.
Just about every type of business or organization uses some form of OIS. For
example, a school might post its class schedules on the Internet. When the school
updates the schedule, students receive an e-mail notification. In a manual system,
the school would photocopy the schedule and mail it to each student’s house.
An OTS supports many office activities. With an OIS, you can create and distribute
graphics and documents, send messages, schedule appointments, browse the Web,
and publish Web pages. All levels of users utilize and benefit from the features of an

An OIS uses many common soft ware products to support its activities. Typical
software in an OIS includes word processing, spread sheet, database, presentation
graphics, e -mail, Web browser, Web page authoring, personal information
management, and groupware. To send text, graphics, audio, and video to others, an
OIS uses communications technology such as voice mail, fax, videoconferencing,
and electronic data interchange (EDI).
In an OIS, computers have modems, video cameras, speakers, and microphones.
Scanners, fax machines, digital cameras, and Web - enabled devices such as cellular
telephones are other types of hardware often found in an OIS.
Transaction Processing Systems
A transaction processin g system (TPS) captures and processes data from day-to-day
business activities. When you use an automated teller machine to withdraw cash,
you are using a TPS. Examples of transactions are deposits, payments, orders, and
reservations. In a company, clerical staff typically perform the activities associated
with a TPS, which include the following:
1. Recording a business activity such as a student’s registration, a customer’s order,
an employee’s time card, or a car owner’s payment
2. Confirming an action or causing a response, such as printing a student’s schedule,
sending a thank-you note to a customer, printing an employee’s paycheck, or issuing
a receipt to a car owner.
3. Maintaining data, which involves adding new data, changing exist ing data, or
removing unwanted data
Transaction processing systems were among the first computerized systems that
processed business data. Many people initially referred to the functions of a TPS as
data processing. The first TPSs computerized an existing manual system. The intent
of these TPSs was to process faster, reduce clerical costs, and improve customer
The first TPSs mostly used batch processing. With batch processing, the computer
collects data over time and processes all transactions later, as a group. As
computers became more powerful, system developers created online transaction
processing systems. With online transaction processing (OLTP), the computer
processes each transaction as it is entered.
When you register for classes, your school probably uses OLTP. The registration
clerk enters your desired schedule. The computer immediately prints your statement
of classes. The invoices often are printed using batch processing. That is, the
computer prints and mails all student invoices at a later date.
Today, most transaction processing systems use OLTP. For some routine processing
tasks, they also use batch processing. Many organizations use batch processing to
calculate paychecks and print invoices.

Management Information Systems
A management information system (MIS pronounced em-eye ess) generates
accurate, timely, and organized information, so managers and other users can make
decisions, solve problems, supervise activities, and track progress. Management
information systems evolved from transaction processing systems. Managers
realized the computer had more potential than just supporting a TPS. Its capability of
quick computing and data comparisons could pro duce meaningful information for
MISs often are integrated with transaction processing systems. To process a sales
order, the TPS records the sale, updates the customer’s account balance, and
reduces the inventory count. Using this information, the related MIS can produce
reports that recap daily sales activities; summarize weekly and monthly sales
activities; list customers with past due account balances; graph slow- or fast-selling
products; and highlight inventory items that need reordering. An MIS focuses on
creating information that managers and other users need to perform their jobs.
An MIS creates three basic types of information: detailed, summary, and exception. A
detailed report usually lists just transactions. For example, a Detailed Order Reportlists 
orders taken during a given period. A summary report consolidates data, so you
can review it quickly and easily. A summary report usually has totals, tables, or
An exception report identifies data outside of a normal condition. These conditions,
called the exception criteria, define the1 activity or status range. For example, an
Inventory Exception report notifies the purchasing department of items it needs to
Exception reports save managers time. Instead of searching through a detailed
report, managers simply review the exception report. These reports help managers
focu s on situations that require immediate decisions or actions.
Decision Support Systems
A decision support system (DSS) helps you analyze data and make decisions. Often,
a TPS or MIS does not generate the type of report a manager needs to make a
decision. Different managers need various types of information. A marketing
manager might need to know how much he or she has spent on Internet advertising
in the past three months. Whereas an office manager might need to know how many
pads of paper were used.
A variety of DSSs exist. Some are company specific and used by managers. Others
are available to everyone on the Web. Programs that analyze data, such as those in
a DSS, sometimes are called online analytical processing (OLAP) applications.
Because they summarize information, these applications process many records at a
time. This is different from OLTP applications, which process individual records at
one time and typically use relational databases.
Some OLAP applications are called MOLAP because they use multidimensional
databases. Those that use relational databases are known as ROLAP. Others blend
two database types. These hybrid OLAPs may use a ROLAP as the back end and a
MOLAP as the front end.
A DSS uses data from internal and external sources. Internal sources of data might
include sales, manufacturing, inventory, or financial data from a company’s database.
Data from external sources could include interest rates, population trends, costs of
new housing construction, or raw material pricing.
Some DSSs have their own query languages, statistical analysis, spreadsheets, and
graphics that help you retrieve data and analyze the results. Some also allow you to
create a model of the factors affecting a decision. A product manager might need to
decide on a price for a new product. A simple model for finding the best price would
include factors for the expected sales volume at various price levels. The model
allows you to ask what-if questions and view the expected results.
Instead of buying a DSS, many people use their application software to perform DSS
functions. With Microsoft Excel, for example, you can model data and create what-if
Expert Systems
An expert system captures and stores the knowledge of human experts and then
imitates human reasoning and decision making.
Expert systems consist of two main components: a knowledge base and inference
rules. A knowledge base is the combined subject knowledge and experiences of the
human experts. The inference rules are a set of logical judgments that are applied to
the knowledge base each time a user describes a situation to the expert system.
Expert systems help all levels of users make decisions. Non management employees
use them to help with job-related decisions. Expert systems also successfully have
resolved such diverse problems as diagnosing illnesses, searching for oil, and
making soup.
These are only few examples but with the time the importance of IT will grow. No
matter in which field you are but IT will be a compulsory for everybody.

What is Information Technology?

IT (information technology) is a term that encompasses all forms of technology used
to create, store, exchange, and use information in its various forms (business data,
voice conversations, still image s, motion pictures, multimedia presentations, and
other forms, including those not yet conceived). It's a convenient term for including
both telephony and computer technology in the same word. It is the technology that
is driving what has often been called "the information revolution."

Data and Information

Data and Information
Data is a collection of raw unprocessed facts, figures, and symbols. Computers
process data to create information. Information is data that is organized, meaningful,
and useful. Computer processes several data items to produce a paycheck. Another
example of information is a grade report, which is generated from data items such as
a student name, course names, and course grades.
A user is someone who communicates with a computer or uses the information it
generate s.
Hardware is the electric, electronic, and mechanical equipment that makes up a
computer. Software is the series of instructions that tells the hardware how to per
form tasks. Without software, most hardware is useless. The hardware needs
instructions from software to process data into information.

(1) In computing, data is information that has been translated into a form that is more
convenient to move or process. Relative to today's computers and transmission
media, data is information converted into binary digital form.
2) In computer component interconnection and network communication, data is often
distinguished from "control information," "control bits," and similar terms to identify
the main content of a transmission unit.
3) In telecommunications, data sometimes means digital-encoded information to
distinguish it from analog-encoded information such as conventional telephone voice
calls. In general, "analog" or voice transmission requires a dedicated continual
connection for the duration of a related series of transmissions. Data transmission
can often be sent with intermittent connections in packets that arrive in piecemeal
4) Generally and in science, data is a gathered body of facts.
Some authorities and publishers, cognizant of the word's Latin origin and as the
plural form of "datum," use plural verb forms with "data". Others take the view that
since "datum" is rarely used, it is more natural to treat "data" as a singular form.

Information is stimuli that has meaning in some context for its receiver. When
information is entered into and stored in a computer, it is generally referred to as
data. After processing (such as formatting and printing), output data can again be
perceived as information. Data will be converted in to Information after processing.
When information is packaged or used for understanding or doing something, it is
known as knowledge.

"සිංහලයා මෝඩයා, කැවුම් කන්න යෝදයා"

"සිංහලයා මෝඩයා, කැවුම් කන්න යෝදයා"

මේ පද පේලිය ඔයාලටත් නිතර ඇහිල තියෙනවාට කිසිම සැකයක් නැහැ...
මේ ඒ ගැන ඔයාලගෙ දැනුමට යමක් එකතු කරන්න ගත්තු පුංචි උත්සාහයක්..

" දෙවන රාජසිංහ රජතුමාගෙ කාලෙ ලන්දේසි එක්ක යුද්ද කරනකොට.... ලන්දේසින් අතින් මැරිල වැටිච්චි අපේ සිංහල සොල්දාදුවො හැම කෙනෙකුගෙම වගේ කරේ කැවුම් මල්ලක් තිබිල තියෙනව.."

සටනින් මැරී වැටිච්චි ඒ වීර සිංහල සොල්දදුවන්ගෙ මිනී දිහා බලං උන්නු ලන්දේසිකාරයො අවඥාවෙන් හිනාවෙලා "සිංහලයා මෝඩයා කැවුම් කන්න යෝදයා.." කියල කිව්වලු..

ඒ වගේ "සිංහලයා මෝඩයා කැවුම් කන්න යෝදයා.." කියන කියමන අපේ ම සිංහල බැලයන් ලවාම සමාජගත කරන්නට පරදේසක්කාරයො එදා ඉඳලම කටයුතු කලා.. ඒක කලේ ශ්‍රේෂ්ඨ ජාතියක් වෙච්චි සිංහල මිනිස්සුන්ට අවමන් කරන්න කියන එක තේරුම් අරන් ඉන්නෙත් අද ඉන්න කීයෙන් කී දෙනා ද?

"සිංහලයා යනු මෝඩයෙකි" කියන මානසිකත්වය සිංහලයන් අතරෙ ව්‍යාප්ත කරන්නට එදා උන්නු පරදේසක්කාරය යොදාගත් උප්පරඇට්ටියට අහු වෙච්චි අද ඉන්න අපේ ඈයොත් "බූරුවො" වගේ කරන්නෙ ශ්‍රේෂ්ඨ ජාතියක් වෙච්චි සිංහල ජාතියට දැන හෝ නොදැන අපහාස කිරීමක්..

තව ප්‍රශ්ණයක්..
දැන් ඔයාල අහයි අපේ මිනිස්සු කැවුම් මල්ලක් අරන් යුද පිටියට ගියෙ අහවල් එහෙකට ද කියාල.. ??

හේතුව මේකයි.. කැවුම් කියන්නෙ, තෙල් සහිත ටිකක් බර ආහාරයක්.... දින ගණනක් උණත් නරක් නොවී කල් තියා ගන්න පුළුවන් විදිහෙ ආහාරයක්.. ඉතිං අපේ මිනිස්සුන්ට බත් ගෙඩියක් ගෙනියනවට වඩා කැවුම් මල්ලක් ගෙනිච්චෙ බත් මුලක් දවසකට වඩා නරක් නොවී තියා ගන්න බැරි හේතුව නිසා..

අළුතින් හිතන්න.. පිට මිනිස්සුන්ට අපේ දේශීය චින්තනයට, අභිමානයට හානි කරන්න ඉඩ දෙන්න එපා.. ඒ වගේමයි, අපේකමට හානියක් සිද්ද වෙන විදිහෙ වචනෙකටවත් "සපෝට් එකක්" දෙන්න එපා අද ඉඳලවත්.. බුද්ධිමත් වෙන්න... මෙවන් පරගැති ගතිසිරිත් තවත් පරම්පරාවකට යන්න දෙන්න එපා...

ආයිත් සැරයක් කවදහරි
"සිංහලයා මෝඩයා කැවුම් කන්න යෝදයා.." කියන දේ තව කෙනෙකුට කියනවද නැද්ද කියාල තම තමංගෙන් ම ප්‍රශ්ණ කරගන්නව නං හොඳා..

"ඔන්න ගෝනි බිල්ලො එනව..."

ඔයාල අහල තියෙනව නේද පුංචි කාලෙ අපේ වැඩිහිටියො අපිව බය කරන්න නිතරම කියන,
"ඔන්න බිල්ලො එනව..."
"ඔන්න ගෝනි බිල්ලො එනව..."
    වාගෙ යෙදුම්....

ඉතිං මේ පුංචි "සපෝර්ට්" එක බිල්ලො කියන්නෙ කව්ද? කොහොමද මේ වචනෙ අපේ භාෂාවට එකතු උනේ කියල ඔයාලට හරියටම දැන ගන්ඩත් එක්කල..

ගජබාහු හෙවත් ගජබා රජ්ජුරුවො ගැන අහල ඇතිනේ..? අර යගදාව මිරිකල වතුර ගත්තේ?? අන්න එ' උත්තමයගෙ තාත්ත, එ' කියන්නෙ පිය රජතුමා වෙච්චි වංකනාසිකතිස්ස රජතුමාගෙ කාලෙ දැවැන්ත සොළී හමුදාවක් මේ රට ආක්‍රමණය කරල 12000ක් වු අපේ ශක්තිමත් සිංහල කොල්ලො වහල් සේවය සඳහා සොළී රටට බලහත්කාරයෙන් ගෙන ගිය කතාව දන්නව ඇතිනෙ නේද?

ඉතිං එ' කාලෙ ලක්දිව කරක් ගහපු සොළී කණ්ඩායම් ගමක් නගරයක් ගානෙ ගිහින්,
අළු භාජනයකුත් අරගෙන ගිහින්,
ශක්තිමත්, කඩවසම් සිංහල ගැටයෙක් දැක්කම,
අළු අහුරක් අරන් අර හාදයගෙ ඇස් අරින්නවත් බැරි වෙන විදිහට මූනට ගහනවලු...
පස්සෙ "ගෝනියක දාගෙන ගැට ගහල" කුදලන් යනවලු..

ඉතිං මේ කාලෙ අපෙ රටේ දුප්පත් ගැමි මිනිස්සු අතර
"බිල්ලො එනව..."
"ගෝනි බිල්ලො අරන් යාවි..." වගේ යෙදුම් භාවිත උනේ ලු...

ඉතිං ගත වෙච්චි මේ අවුරුදු දහස් ගණනක් තිස්සේ ම අපේ ජනවහරෙ විකාශණය වෙච්චි එ' යෙදුම් තමයි අදටත් අපේ අම්මල තාත්තලගෙ කටවල් වලින් පිට වෙන්නේ...

පුදුමයි නේද මෙච්චර කාලයක් මේව එ' විදිහටම පැවතගෙන ආපු එක හා?
බලන්න,, නවීන සුපිරි තාක්ෂණයන්ටත් වඩා රටක, ජාතියක ජනවහර, ජනශ්‍රැතිය, සංස්කෘතිය, සම්ප්‍රදායයන් කොච්චර නම් ප්‍රබ