48 years ago, the Indian Army crossed Wagah border at 4 a.m. on 6th September and unleashed an undeclared war against Pakistan. It was an all out war both in territorial expanse and the mass of resources. Everything was committed to annihilate Pakistan once and for all but Pakistan armed forces frustrated their designs. Courage and valor demonstrated by the brave hearts for the defence of motherland against extremely heavy odds are unparalleled. In memory of their supreme sacrifices, Defence Day of Pakistan is celebrated with great fervor on every 6th September. Special functions are held and wreaths are laid on the graves of Shaheeds who were awarded highest gallantry awards. Chivalries of Ghazis are recalled and prayers are offered for all those who sacrificed their lives for our prosperous tomorrow.

It will be worthwhile to recount the circumstances which led to 1965 Indo-Pakistan war. Conflict between India and Pakistan is rooted in the events and episodes preceding the creation of Pakistan in 1947. Viewing it on narrow communal grounds is indeed communal in itself. For sure, it has been a contest between two contending ideologies and opposing socio-religious creeds.

Indian elite cannot reconcile to the historical fact that united India remained under the effective rule of Muslims for well over 1000 years starting from 712 AD when Muhammad bin Qasim annexed Sindh and made it an integral province of Omayyad’s kingdom. While the low caste Hindus, Buddhists and Jains suffering under the oppressive yoke of Hindu Brahmans welcomed the new rulers who were just and benign, the high caste Hindus hated the Muslims and dubbed them as aliens and impure.

When the British after establishing strong foothold in Bengal in 1757 gradually overpowered India, Brahmans hastened to get aligned with the new masters and both worked hand-in-glove to bring down the fortunes of the Muslims.  In a matter of fifty years, Muslims were reduced from lords to serfs and the Hindus emerged as the new elite class.

Sir Sayad Ahmad Khan came to the rescue of the utterly disillusioned Muslims wandering in apathy and not only raised the slogan of two-nation theory but also motivated the Muslims to get educated. Establishment of Aligarh University helped the Muslims in acquiring higher education. Allama Iqbal who stirred the Muslims through his inspiring poetry and instilled in them greater confidence revealed his dream of a separate homeland for the Muslims in his famous Allahabad address in 1930.

Muhammad Ali Jinnah after assessing that inflexible ruling Congress was unprepared to grant basic constitutional rights to the Muslims, the single largest community in India, and were treating them as second rated citizens, he united the Muslims under the banner of All India Muslim League in 1937. Lahore resolution on March 23, 1940 set the stage for making of Pakistan and from that time onwards there was no looking back. The whole country resounded with the slogans of ‘Pakistan ka matlab kia, la-illaha-illallah’.

Hindu leaders in connivance with the then Viceroy Lord Mountbatten tried their best to dissuade Quaid-e-Azam from his goal of making Pakistan but failed because of his unwavering will and steadfastness.  Pakistan came on the map of the world on August 14, 1947 after rendering huge sacrifices. Partition of the Subcontinent and consequent creation of Pakistan was yet another event that widened the gulf between the two nations and properly put India on the path to unending animosity and antagonism apropos Pakistan.

Not reconciling to the existence of Pakistan, breakup of Pakistan both through kinetic and non-kinetic means became an inalienable part of India’s national pursuits and purpose. Pakistan, thus, emerged as a major preoccupation for India’s foreign and defence policy. This had brought both nations to the battlefield of Kashmir immediately after partition, when Pakistan virtually had no armed forces worth the name and was not even an established polity.

Yet, people of Pakistan stood to their feet and were able to liberate significant chunks of occupied land in form of Azad Jammu & Kashmir, and Gilgit-Baltistan. This was the first section in the string of the struggle after the creation of Pakistan against the Indian ideology, which had transformed into a sort of expansionism.

Ever since, Kashmir has become the bone of contention between India and Pakistan. India claims that Kashmir is its Atoot Ang, Pakistan maintains that Kashmir is its jugular vein. Despite so many UNSC resolutions and so many proposals made by UN appointed mediators, India refused to honor its pledge of giving the right of self-determination to Kashmiris and holding a plebiscite under UN supervision.

It was owing to India’s uncompromising and stubborn attitude that Pakistan was forced to launch operation Gibraltar in August 1965, using Azad Kashmir Mujahideen with a view to creating conditions for a guerrilla war followed by mass uprising and thus forcing India to settle the dispute in accordance with UN resolutions. Humiliating defeat suffered by Indian military against Chinese in 1962 conflict and Pakistan Army’s success in Khem Karan in April 1965 were at the back of the minds of our policy makers.

Although the 7000 strong force managed to infiltrate on a wide front undetected, it ran into grave difficulties since the operation had been launched in haste without adequate preparations and without preparing Kashmiris in occupied Kashmir to wage an armed struggle against occupation forces. Once Indian Army started attacking positions across the ceasefire line in retaliation, Operation Grand Slam was launched on 0I September through Chamb Valley.

After establishing bridgehead across River Tawi, Chamb was captured on 2 September. The force was well-geared to launch a deeper manoeuvre to capture Akhnur which in that point of time was defenseless, but at that critical stage when victory lay within grasping reach, the change of command brought operational pause and gave time to Indian forces to regain balance for the defence of Akhnur. Maj Gen Akhtar Malik who had conceived the whole plan was replaced by Maj Gen Yahya Khan. The new commander preferred to capture Jaurian first, which was captured on 5 September. Although lot of time had been wasted, still, had Yahya pursued the retreating enemy faster, Akhnur could have fallen by the evening of 5 September, giving us options to exploit towards Rajauri, or Jammu and cut off main supply line from India! In that case, India may not have ventured to attack Pakistan the next morning. Outbreak of war on 6 September grounded Operation Grand Slam, since security of Pakistan took precedence over Kashmir.

Even while forces of the two countries were at brawl with each other in Kashmir, it was implicitly understood that the war would remain limited to Kashmir, the disputed territory, and would not transcend to established international border as had happened in 1948. Finding itself in a precarious situation in Kashmir, Indian military launched an all out offensive on 6 September without declaring war. Their first target was Lahore which was attacked with a Corps plus size force from three directions. Indian Army chief Gen JN Chowdhri was so sure of victory that he bragged that he will have his breakfast in Lahore Gymkhana Club next morning.

Although taken by complete surprise, Pak armed forces sprang into action. Soul stirring address to the nation by Field Marshal Ayub Khan acted as a tonic and the whole nation stood behind Pak military like a rock. Civil citizenry, at a number of places, tried to force its way to the borders to wrestle with the advancing Indian forces. Most of them were either bare-handed or at best equipped with their hunting shot-guns. The nation stood to the occasion to defend the state, which bound various ethnicities like beads of a cord together. Bengali officers and men fought as bravely as others and many laid down their lives for the defence of motherland. People of East Pakistan raised anti-India slogans and collected funds for war effort. Nonetheless, it was the weapon of spirit and character that they were equipped with, something that indeed overwhelmed the numerical superiority enjoyed by India due to its size and thus resources.

For next 17 days, the two sides remained locked in mortal combat; India wanting to decimate Pak forces and the latter determined to throw out three-time superior aggressor. The offensive against Lahore was blunted by the extraordinary grit and determination displayed by all ranks particularly young officers, including the heroism of Maj Aziz Bhatti Shaheed whose Company repulsed repeated attacks. He was awarded Nishan-e-Haider.

Once the offensive was stalled, Pak Army launched a counter offensive with 1 Armoured Division and 7 Division and captured Khem Karan. When our forces were poised to advance towards Amritsar and Indian forces including their Army chief were in panic, at that stage Indian military sprung another surprise by launching its main offensive opposite Sialkot sector. Offensive in Khem Karan sector had to be called off and 1 Armoured Division rushed towards Sialkot to regain strategic balance.

Biggest tank battle after 2nd world war took place in the triangle formed by Badiana-Chawinda-Pasrur. Despite being heavily outnumbered and outgunned, the attack was halted inflicting astronomical casualties upon Indian tanks, soldiers and jets. 180 tanks were knocked down in that do-or-die battle of Chawinda. Their losses were so huge that it took the steam out of Indian offensive and on 20 September, India started pleading for ceasefire.

Pak Army had held its ground and repulsed multi-pronged offensives while the PAF crippled Indian air force. Indian air force had 5:1 air superiority over PAF but at the outset all forward Indian airbases were successfully struck by PAF.  Pakistani pilots were matchless in air-to-air combat. Squadron Leader MM Alam single-handed shot down six Indian intruding jets. Pak Navy didn’t lag behind and added a feather in her cap by launching Operation Somnath and destroying Indian naval important surveillance centre at Dwarka. Lone Ghazi submarine kept the Indian Navy terrified and bottled up.

Pakistan had a definite edge when the UN arranged a ceasefire on 22rd September. Its strategic reserves were in a position to destroy the enemy forces stranded in Ravi-Chenab corridor and take the battle inside Indian Territory. PAF had achieved air superiority and so had Pak Navy maintained her unchallenged supremacy at sea. The test was over in about seventeen days. The nation stood victorious. It was Pakistan’s ‘finest hour’.

The entire world was stunned over the success attained by Pakistan as a nation. Pakistan’s military victory over India in the war of 1965 was acknowledged from all pertinent quarters including independent international observers. India, said the London Daily Times, “India is being soundly beaten by a nation which is outnumbered by four and a half to one in population and three to one in size of armed forces”. Louis Karrar wrote in Times,”Who can defeat a nation which knows how to play hide and seek with death”?

Newsweek Pakistan noted in its 16 September 2010 issue that ‘a hard-nerve nation alone can win such a struggle, and Pakistani is undoubtedly hard in nerves and spirit’. It added, ‘despite crises Pakistan is the bravest nation in the world’. In the words of Anatol Lieven, the author of ‘Pakistan: A Hard Country’, Pakistan is “in many ways surprisingly tough and resilient as a state and a society” and that “Pakistan is quite simply far more important to the region, the West and the world than is Afghanistan: a statement which is a matter not of sentiment but of mathematics.”

R.D Pradhan who was an insider in the war writes in his book ‘1965 War: The inside Story’ described the cowardice of Maj Gen Niranjan Prasad, the Indian General who attacked Lahore. ‘When Pakistan defence forces counter attacked the intruding Indian military and the General fired upon on 6 September, he ran away. He was found by Lt Gen Harbakhsh Singh hiding in a sugar cane field.’

Lt Gen Harbakhsh Singh, Commander Western Command  notes in his book War Despatches  that not only “did Indian COAS Gen Chowdhri play a small role in the entire campaign, he was so nervous as to be on the verge of losing half of Punjab to Pakistan, including the city of Amritsar.” He added, “Chowdhri panicked so badly he ordered him to withdraw to a new defensive line behind the Beas, thereby conceding half of Punjab to Pakistan.” Harbakhsh saved the day for India by refusing to withdraw.

R.D. Pradhan also confirms that “Gen Chowdhri feared that a major battle west of Beas would have ended in destruction of Indian Army and thereafter allowing the enemy (Pakistani) forces to push to the gates of Delhi without much resistance. In panic he ordered all forces to withdraw across River Beas.”

The London Daily Mirror reported in 1965: “There is smell of death in the burning Pakistan sun. For it was here that India’s attacking forces came to a dead stop. During the night they threw in every reinforcement they could find. But wave after wave of attacks were repulsed by the Pakistanis.”

USA Aviation Week December 1968 Issue commented: “For the PAF, the 1965 war was as climatic as the Israeli victory over the Arabs in 1967. A further similarity was that India air power had 5:1 numerical superiority at the start of the conflict. Unlike the Middle East conflict, the Pakistani air victory was achieved to a large degree by air-to-air combat rather than on ground. But it was as absolute as that attained by Israel.”

Our armed forces which are among the best in the world are up against internal insurgencies and external threats. Despite their heavy involvement in war on terror, they continue to hone their weapons and remain ever vigilant to take on the external challenges squarely. We as a nation beset with myriad of problems must shun our differences and get united to make Pakistan strong and face the conspiracies of our adversaries scheming to undo Pakistan conjointly. We must never forget the age-old adage that ‘united we stand, divided we fall’. Unity and consolidated home front is the best defence. We just need to bring back the spirit of 1965, a déjà vu that the Pakistan of 21st century earnestly needs and constantly looks for.

Electronic Mail:
With an e-mail anyone can send messages to other users of the internet and to many network connected to the internet through gateways. Most email programs also per miles users to attach data files and program files to messages. An internet electronic mail address has two parts, the user name and the domain name. The user name identifies the person who originates or receiver the mail; the domain name identifies the computer system on which the users had an account.

Advantage of Email: 
 Compared to the postal services, electric mail has many advantages.

  1. It's fact-Most systems can deliver your message to the recipient in a matter seconds almost instantaneous. Many systems let you check to see whether the recipient has accessed you message. 
  2. Its easy when you contact the service, you see a list of the messages you have received. You read the first message and then decide how to respond. You can reply to the message if you like, or just delete it if it requires no reply. You can save it or print it, you can even forward the message to others. 
  3. It's available the email services is available round the clock and round the globe. 
  4. It's fun International electronic mail systems enable you to find friends all over the world. 
  5. It's cheap Worldwide electronic mail access is available through services such as gmail, outlook, hotmail, these services are free to certain level of service and  charge less than you expect to pay for monthly telephone service for some advance services. 
  6. It's flexible you  can send a message to more than one person if you like. 


Disadvantages of Email:
Following are some disadvantages of email.

  1. It is still not generally available to all. 
  2. It has created an information overload, people are swapped by junk mails and finding what is relevant and need to read from the handled of mails. 
  3. It is possible that any of the email contains virus, which may affect your computer system. 
  4. Any email sent to wrong address can not be recalled back after 28seconds only in gmail. 
  5. It is not completely private or confidential due to hacking. 
  6. As email is free, so some one may send email for trouble so that you may feel uneasy to deal with. 

In a disk drive a floppy diskette rotates at speeds of 300-400 RPM(revolutions per minute). Typically, hard disks rotate 7200 RMP. In a disk pack, all disks rotate at the same time, although only one disk is being read or written on at any one time. In the same way,  the high-density 3 1/2 inch floppy disk can  store 1.44 MB of data. Today, hard disks with the capacity range of giga-bytes (GB) are very common. With a hard disk, most people can store all their programs and files in one location. Still hard disk do not eliminate the need for a floppy disk drive. It serves as a transfer device to get software, purchased on floppies, in to hard disk. Some hard disk mechanisms for large system use moving head. in this design, all the read/write heads in a stack of disks are attached to a single access mechanism that moves directly to a specific address. This method is relatively slow, because all the access arms must move together.

A faster technology is that of fixed-head disks. These devices have fixed access arms with separate disk, read/write mechanisms for each track of the disks. The disk, rather than the head, whirls to bring the correct sector to the arm; the read/write mechanism for the depending on the application. Other disk devices combine the technologies of both moving  and fixed head access to produce a high capacity, rapid access device. With a brand new hard disk, the computer will try to place the data in clusters that are contiguous-that, is that are adjacent(next to one another). Thus, data world be stored on track 1 in sectors 1,2,3,4 and so on However as data files are updated and the disk fills up, the operating system stores data in whatever free space is available. Thus files become fragmented. Fragmentation means that a data file becomes spread out across the hard disk in many non-contiguous clusters. 

Secondary Memory:

Secondary memory or storage can store a ruler of information permanently and lies outside the CPU. It provides computer the means of storing and processing large quantities of data for longer periods of time and that is not currently being passed. Secondary storage is also call Auxiliary storage or external memory. It is non volutile.

Purpose of Secondary storage:

Auxiliary storage is used to store.
Input data and programs.
Output results of processing.
Auxiliary storage is where us put last years results of ur school, addresses for old students, programs you may or may not each use, data you entered yesterday everything that is not being used right now.
Secondary memory(or Secondary Storage) is the slowest and cheapest form of memory.
It can not be processed directly by the CPU. It must first be copied in to primary storage (RAM).
Types of Secondary Storage Devices:
Secondary memory devices includes magnetic storage devices like floppy disks, hard disks and magnetic tapes(the first forms of secondary memory) and optical disks such as CDs and CD-ROMS.
Magnetic Storage Devices: 
Magnetic storage devices are designed in such a way that their surfaces are coted with millions of thing from particles. So that data can be stored on them each of these particles can act as a magnet in magnetic field when subjected to an electromagnet. A read/write head is use to access data from these devices.
Storing Data in Magnetic Storage Devices:
The read write head of a hard disk device, floppy disk device and tap device contain electromagnets. Which generate magnetic field in the from on the storage medium as the head posses owr the disk or tape. The read write head record strings of is and of by alterneting the direction of current in the electro-magnets.
    There are following magnetic storage devices.
(1)Floppy Disk   (2)Hard Disk    (3)Magnetic Tape
Optical Storage Devices:
Optical storage techniques make use of the user beams to write and read data which can consist of the graphics, audio clips, or video image at magnetic disk. a single optical disk of the type called CD-ROM can hold up to about too megabytes of data. This works out to about 269,000 pages of test, or more than 7500 photos or graphics or 20 hours of speech or 77 minutes of video. Although some disks are used strictly for data storage many combine, visuals and sound. In the principal type of optical disk technology a high power loser beam is used to represent data by burning tiny pits into the surface of a hard plastic disk. To read the data, a now powers loser light scans the disk surface: pillet area are not reflected and are interpreted as 0 bits: Smooth areas, called land are reflected and are interpreted as 1 bits. Because the pits are very tiny much more data can be represented than is possible in the same amount of space on a magnetic disk whether flexible or hard.
Many types of optical disks are available for computer users. Among them the commonly available optical disks are:

  1. CD-ROM DISKS
  2. CD-R DISKS
  3. CD-RW DISKS 
  4. DVD-ROM DISKS


Star Network: 

In a star network topology each device is connected to a central unit. Any communication between one device and another goes through the central unit. The image shows a typical configuration using central server and peripherals. Each device is directly connected to the central server, which is a computer containing the interface cards and software ;to manage all data communication in this network. If a user at workstation 2 wants to print out a page, workstation 2 sends that request to the central server. This central server notifies workstation 2 when that task is complete.


HArD COpy:

  1. Paper output is known as hard copy. 
  2. Hard copy is tangible and permanent. 
  3. Hard copy produced by a printed on paper. 
  4. The principal hard copy output devices are printers plotters, and microfilm output devices. 
  5. Soft copy is best for information that needs to be viewed only occasionally or a few moments. 
  6. Example of hard copy output is news papers, books magazines etc. 

SOft Copy:
  1. Screen output is known as soft copy. 
  2. Soft copy is intangible and temporary. 
  3. Soft copy produced by a monitor on screen. 
  4. The principal soft copy output devices are monitors and sound of voice output devices. 
  5. Hard copy output is bets for information that may be used later or that may have greater value over time. 
  6. Examples of soft copy output's are ATM Machine, air lines departure and arrivals display. 

                                                                                Information Technology:
We can define the term information technology as information technology is the merger of of computer and technology means the use of hardware. Or Information technology means the use of hardware, software, services and supporting infrastructure to manage and deliver information using voice data and video.
.
Fields of Information Technology: 
Art:
Artists are using personal computers to generate and manipulate experimental images, sculptures for example can use personal computers to create models and experiment with variations before committing to an actual physical piece.
Energy:
Energy companies use computers to locate oil, coal, natural gas and uranium.
Agriculture: 
Computers have penetrated to farms. Farmers now use small computers purchased for less than the price of a tractor to help with billing, crop information, cost per acre feed combination and market price checks.

There are three types of modems.

DIRECT CONNECT: 
Which are linked to the computer by cable and the Rs.232 point and plus in to a standard telephone socket.
INTERNAL: 
Which are built in to the computer and have backup capabilities.
Sales of micro-computers which contain internal, board-mounted modems are increasing rapidly. Alternatively, there are add-on modem cards that can be fitted inside the computer.
ACOUSTIC COUPLER: 
A cheap, low-speed modem where the user places the telephone handset in to the cradle of the coupler.


Compiler:
  1. It translates the whole program at once and give an errors list to be removed.
  2. Computer is not  necessary for repeated execution of a program.
  3. Compiler is a complex program.
  4. Compiler analyses each statement, it uncovers certain types of errors referred to as diagnostic errors .
  5. A computed machine language programs runs much faster than an interpreted program .
Interpreter:

  1. In interpreter is a program that translates a high level programming language in to machine language during the actual step by step execution of program.
  2. In case of the interpreter when cover an instructions are used, it must once again be interpreted and translated into machines language.
  3. Interpreter are easy to write and they do not require large memory space in the  computer.
  4. An interpreter provides a fast response to engages in the source program.
  5. The interpreter is a time consuming translation method.

The OSI Model:
One communication standard created by ISO is called the open system inter connections (OSI) model that simulates the communications processing using seven layers, each with its own set of protocols. The purpose of the OSI model is to enable any vendor’s computer system to share data with any other vendor’s computer system in an open networking environment.

List of Layers of the OSI Model:
The OSI model consists of seven layer.

  1. Physical layer
  2. Data link layer
  3. Network layer transport layer
  4. Session layer
  5. Fresentation layer
  6. Application layer

Uses of computer:
computers are tools, they help people perform many different kinds of tasks. One way to gain an appreciation for computers is to see have some people use them in their daily lives.

Information management:
Computers are excellent tools for managing large quantities of information. This includes all use of computers that support the administrative aspects of  an organization, such as airline reservation systems, student registration system, hospital patient billing system and countless others.
Communication:
The telephone and the computer are two of your most useful tools. Combine them and you end up with a powerful communication system.
Science, Research and Engineering:
For decades scientific research has benefits from the high speed, massive compilation capabilities of computers Engineers and scientists routinely use the computer as a tool experimentation design, and development.
Education and Reference:
Computers can interact with students to enhance the learning process. Relatively inexpensive hardware capable of multidimensional communication, (sound, print, graphics and animation) has resulted in the phenomenal growth of the computer as an educational tool in the home in the classroom and in business.
Entertainment and Education:  
Personal computers have reinvented the concept of entertainment, improvement in personal computer graphics and speed have allowed and sophisticated games to be created.
Artists:
Artists are using personal computer to generate an d manipulate experimental images.
Energy:

Energy companies use computers to locate oil, coal, natural gas and uranium.

Word Processing
A word processor is just a computerized type writer. You use it to enter, edit, arrange, and print next you can use one to create memos, letters , reports, brochures any printed material. All word processors are designed for producing different kinds of written documents. Some are simple they have features for typing, editing and printing. Some word processing programs are complex they have features for formatting characters and pages, and or incorporating drawings, tables and charts into documents.

You would benefit from using a word processor if you:

  1. Spend a lot of time typing and revising documents.
  2. Send out mailings.
  3. Write documents of any kind. Some features to consider in a word processing package include.
  4. Word wrap features that automatically wrap text from the end of one line to the beginning of the next time. If a word processing program has no word wrap, it means you don’t need to press enter at the end of each line unlike a type writer, where you hit return  wherever you get to the end of line. This makes it easy to insert of delete text. The word processing program automatically adjusts the time breaks.
  5. Features that enable you to copy and move text from one place in a document to another, or to text easy. Drag and drop editing enables you to accomplish these taks using a mouse you just selected the text and drag it to its new place in the document.

Web Search Engine:


A search engine like Alta vista or Hot Bot offers a much more complete database of what is on the web because the database of what is on the web because the database is complied automatically. A search engine uses software agents, sometimes called spiders or software robots, to explore the web retrieve information and send it to the data base. To find information with search engine, you type a query using keyword just you might locate construct complex queries using Boolean logic. A search engine can easily produce a list of hundreds of hits pages that contain requested keywords or match a query. Most search engines attempt to list pages in order from best to worst, but their rankings are not nearly as reliable as those done by the human researchers. Who create directories like yahoo. Still search engines are invaluable research tools especially when, you need to find something that has not been cataloged in your favorite directory.

Modem:


The simplest form s of data transmission involve the connection of terminals to a computer via a telephone line. But the problem here is that the computer generates data in the form of digital signals where as the telephone lines used for data communication in computer networks are usually meant for carrying analogue signals when digital data are to be sent over an analogue facility. The digital signals must be converted to analogue form the technique by which a digital signal is converted to its analogue form is known as modulation . The reverse process, that is the conversion of analogue signal to its digital form, at a destination device is called demodulation. The process of modulation and demodulation, that is the conversion of digital data to analogue form and vice versa is carried out by a special device called a modem short for modulator demodulator.

Also see:
Types of modem

An international computer network connecting other networks and computers from companies universities and other institution in order to quick exchange of information is called “Internet”.

Internet has its own merits and demerits. The use and abuse of internet depends upon the users. Some important merits or use of internet are being described as following.
  1. It gives information about every field of life.
  2. You may get information according to your need through internet.
  3. You may take advantages from encyclopedias and dictionaries with the help of internet.
  4. It gives a coordination with whole world and its interests.
  5. It helps to exchange views with person of some mental attitude.
  6. Internet  bring the world closer.
  7. Current happening incidents can be discovered  by the use of internet.
  8. Every kind of related with politics, fashion, science etc can be discovered by the use of internet.
Internet has to many advantages, if it is used positively. Internet is producing false trends especially among the students which easily become a victim of its colorful and charming aspects. Some disadvantages of internet may be described as following.
  1. The students waste their precious hours on sitting internet without taking any positive and constructive benefit.
  2. Most of the people are using internet to satisfy their sexual desires.
  3. Nude pictures and sexual material is easily available through internet which destroy the moral values of young boys  and girls.
  4. Computer hacking is very common by the use of internet, some extreme minded people can digest the money through the use of credit card of others.
  5. The students waste their time in useless talking with each others.
  6. Several hours on internet without any purpose produce wrong effects on a persons health.

The government is trying to take such steps in which the only positive use of internet could make possible however it is totally depended upon the trends and education of the people, if they are aware of their profit and loss they will use internet with their justification.

User Interface: 
A user interface is combination of hardware and software that you use to communicate with and control the computer. Through the user interface, you are able to make selections the computer, request information from the computer and respond to message displayed the computer. Thus, a user interface provides the means for dialog between you and the computer.

The two broad categories of user interface supported by various operating systems are:

  1. Command Line Interface
  2. Graphical user interface(GUI)
Command Line Interface
  1. In command line interface, the user give instruction to the computer by typing commands. 
  2. They use less RAM and secondary storage capacity. 
  3. They do not require graphics display. 
  4. It execute the command very fast. 
  5. Simple task can be performed easily. 

Graphical User Interface
  1. Instead of typing command, selection is achieved by moving a pointer with a mouse and clicking a mouse button. 
  2. They use more RAM and secondary storage capacity. 
  3. They require a more powerful processor and a better graphical display. 
  4. They are slower when executing a command because a much more interpretation takes place. 
  5. They can be irritating to use for simple task because a greater number of operations is required. 



Copyright: 

Copyright law is used to cover computer software. It is illegal to make or distribute copies of computer programs without authorization. No other copies may be made without specific authorization from the copyright owner. 
Advantage of Copyright Law: 
  1. Focus on creating a fair and competitive environment.
  2. Give networks operators the freedom to built their own back bone and local access. 
  3. Facilitate rapid deployment of infrastructure for promotion of IT services. 
  4. To enable a free society to function, minimum amount of instruction will be permitted in terms of monitoring and filtering on all kinds of communication. 


What is server software? 
The server software is used to manage and  administrate the server side applications. The software is installed on main server system which assigned to handle multiple clients.
What does GUI stands for? 
GUI stands for graphical user interface.
What is password? 
A word or phrase known only to the user when entered, it permits the user to gain access to the system.
What does TGP stands for?
Thumb Nail Graphic Post.
What does URL stands for? 
URL stands for Uniform Resource Locator.

The main functions of spread sheet program are to manipulate data in tabular form.


  1. It organize data clearly  into rows and columns. 
  2. To sort the data easily. 
  3. To make use of predefined, built in functions as formulas. 
  4. To format the data easily in the form of graphs and charts.


Switch:


  1. The switch can not send data out out to internet, or across a WAN. 
  2. Switch can handle only similar type of network or toplogy. 
  3. Switch has simple software to handle network activities. 
  4. The switch learns the MAC address of each computer. 
  5. Switch just used in LANs. 


Router:

  1. The router is a device which is smart enough to route data from the LAN to the internet, or to your ISP, or to your WAN or even to another LAN. 
  2. Router can manage several network or topologies. 
  3. A router has additional smart software with security features. 
  4. Router concerned with IP address instead of MAC address. 
  5. High speed routers can serve as a part of internet of back bon.

Bus: 
A bus is a communication path way connecting two or more devices. A key characteristics of a bus is that it is a shared transmission medium. Thus a bus is a wire through which electrical signals can be transmitted. 
There are three types of buses called:
Address bus
Data bus
Control bus

Address Bus: 
The address bus is used by micro processor to transmit the address of the memory location which it wants to access for reading or writing purposes. An address bus is undirectional i.e.electric signals are transmitted in one direction only from micro processor to other devices by this bus. 
Data Bus: 
The data bus is used to transmit data from the memory to micro processor and vice versa. It may be used to transmit data to other devices such as output units. The data bus is bi-directional because data has to pass from microprocessor to memory as well as from memory to the micro processor.
Control Bus: 
The control bus supervises the reading or writing of data. It transmits signals to all the devices at the proper time. In fact, it informs the micro processor that p particular unit has completed its job. 
                  The picture above shows the bus system of a micro computer. 


Instruction Format: 
An instruction format defines the layout of bits of an instruction in terms of constituent parts. There are various instruction format's depending upon the architecture of the computer. The types of commonly used instructions are: 

  • Three-Address Instruction. 
  • Two-Address Instruction. 
  • One-Address Instruction. 
  • Zero-Address Instruction. 


Three-Address Instruction: 
A three address instruction consists of the following parts: 
  • Operation code. 
  • Addresses of two operands, called address 1 and address 2. 
  • Address of the memory location where the result of the operation is to be stored i.e., address of the destination. 

The number of bits (field length) allocated to each of the three parts depend upon the computer. A typical three address instruction is shown below. 

OP code                        Address 1                   Address 2              Address of Destination

A register called program counter (PC) is used to computer the address of the next instruction and the process of the execution of instruction continues. 
Two Address Instruction: 
In this type of instruction one operand is placed in a specified register such as an accumulator and the address of the next instruction is obtained from another register called program counter (PC). This implies that such an instruction should have the following parts. 
  • Operation code. 
  • Address of one of the operands, say address 1. 
  • Address of the storage location where the result is to be stored. This address is denoted by address 2.

       The general form of a two address instruction is 
                                           OP code           Address 1            Address 2

One Address Instruction: 
As the name suggests, this instruction has address of one operand only, the other operand is stored in accumulator. The result of operation are left in the accumulator it self, from where these can be moved to main memory by another instruction. The address of the next instruction is obtained from the program counter. The general form of a one-address instruction is 
                                          OP code         Address 1

No doubt with one address instruction more bits of the instruction word could be allocated to OP code and the address of the operand. 

Zero Address Instruction: 
The zero address instructions are also called stack instructions and consist of OP code only. The address of operand and destination are implied. The general form of zero address instruction is. 
                                                     OP code

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