THE COMPUTER

COMPUTER 

INTRODUCTION:

Calculations and other numerical operation are very difficult to humans. Computer was invested as a computer machine at its first appearance in the late 19th century but became popular in 20th century. Nowadays, computer has become a part and parcel of every life due to its versatility in operation, computer became popular in every locations. Computers create rooms for many kinds of programs to operate and function as programmed. We are going to see how relevant these programs are to our society. Internet technology is a little older in technology. In general, it has been in existence since `60’s when the United State Department of Defense (DOD) which has global nature of activities wanted a wide area network (WAN) that would allow their computers in different ways to inter-connect and inter-operate as it maintain operations through peace keeping in foreign countries.
Therefore, computer is referred to as a machine that requires all electrical power to drive it.

WHAT IS A COMPUTER?

There are many definitions of a computer. Everyone has his/her own definition of a computer from his/her own perspective. But to my own opinion, computer is an electronic device which accepts data through input devices; processes data based on the defined instruction given to the processing unit, stores data in the storage device(s) and produces result of the processed data as information through output devices. Some input devices are mouse, keyboard, scanner, joystick, etc and some output devices are monitor, printer, speaker, etc. A computer can also be summarized as an electronic device which manipulates data and executes software programs according to a given list of instructions. A computer consists of 2 parts – hardware and software. The size of a computer varies considerably from very small to very big. The speed of computers also has a very large range. Computers have become indispensable in today’s world. Millions of people use computers all over the world. Although mechanical examples of computers have existed through much of recorded human history, the first electronic computers were developed in the mid-20th century (1940–1945). These were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space. Simple computers are small enough to fit into a wristwatch, and can be powered by a watch battery. Personal computers in their various forms are icons of the Information Age and are what most people think of as "computers". The embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are however the most numerous. The ability to store and execute lists of instructions called programs makes computers extremely versatile, distinguishing them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore computers ranging from a mobile phone to a supercomputer are all able to perform the same computational tasks, given enough time and storage capacity.

HISTORY OF THE COMPUTER:

The Jacquard loom, on display at the Museum of Science and Industry in Manchester, England, was one of the first programmable devices. The first use of the word "computer" was recorded in 1613, referring to a person who carried out calculations, or computations, and the word continued to be used in that sense until the middle of the 20th century. From the end of the 19th century onwards though, the word began to take on its more familiar meaning, describing a machine that carries out computations. The history of the modern computer begins with two separate technologies—automated calculation and programmability-but no single device can be identified as the earliest computer, partly because of the inconsistent application of that term. Examples of early mechanical calculating devices include the abacus, the slide rule and arguably the astrolabe and the Antikythera mechanism (which dates from about 150–100 BC). Hero of Alexandria (c. 10–70 AD) built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums that might be considered to be a means of deciding which parts of the mechanism performed which actions and when. This is the essence of programmability. The "castle clock", an astronomical clock invented by Al-Jazari in 1206, is considered to be the earliest programmable analog computer. It displayed the zodiac, the solar and lunar orbits, a crescent moon-shaped pointer travelling across a gateway causing automatic doors to open every hour, and five robotic musicians who played music when struck by levers operated by a camshaft attached to a water wheel. The length of day and night could be re-programmed to compensate for the changing lengths of day and night throughout the year. The Renaissance saw a re-invigoration of European mathematics and engineering. Wilhelm Schickard's 1623 device was the first of a number of mechanical calculators constructed by European engineers, but none fit the modern definition of a computer, because they could not be programmed. In 1801, Joseph Marie Jacquard made an improvement to the textile loom by introducing a series of punched paper cards as a template which allowed his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the development of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability. It was the fusion of automatic calculation with programmability that produced the first recognizable computers. In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer, his analytical engine. Limited finances and Babbage's inability to resist tinkering with the design meant that the device was never completed. In the late 1880s, Herman Hollerith invented the recording of data on a machine readable medium. Prior uses of machine readable media, above, had been for control, not data. "After some initial trials with paper tape, he settled on punched cards ..." To process these punched cards he invented the tabulator, and the keypunch machines. These three inventions were the foundation of the modern information processing industry. Large-scale automated data processing of punched cards was performed for the 1890 United States Census by Hollerith's company, which later became the core of IBM. By the end of the 19th century a number of technologies that would later prove useful in the realization of practical computers had begun to appear: the punched card, Boolean algebra, the vacuum tube (thermionic valve) and the teleprinter. During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital computers. Alan Turing is widely regarded to be the father of modern computer science. In 1936 Turing provided an influential formalization of the concept of the algorithm and computation with the Turing machine. Of his role in the modern computer, Time Magazine in naming Turing one of the 100 most influential people of the 20th century, states: "The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine." 

MEMORY – COMPUTER TEMPORARY DATA STORAGE:

Magnetic core memory was the computer memory of choice throughout the 1960s, until it was replaced by semiconductor memory. A computer's memory can be viewed as a list of cells into which numbers can be placed or read. Each cell has a numbered "address" and can store a single number. The computer can be instructed to "put the number 123 into the cell numbered 1357" or to "add the number that is in cell 1357 to the number that is in cell 2468 and put the answer into cell 1595". The information stored in memory may represent practically anything. Letters, numbers, even computer instructions can be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is the software's responsibility to give significance to what the memory sees as nothing but a series of numbers. In almost all modern computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers (2^8 = 256); either from 0 to 255 or -128 to +127. To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. Other arrangements are possible, but are usually not seen outside of specialized applications or historical contexts. A computer can store any kind of information in memory if it can be represented numerically. Modern computers have billions or even trillions of bytes of memory. The CPU contains a special set of memory cells called registers that can be read and written too much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU. Registers are used for the most frequently needed data items to avoid having to access main memory every time data is needed. As data is constantly being worked on, reducing the need to access main memory (which is often slow compared to the ALU and control units) greatly increases the computer's speed. Computer main memory comes in two principal varieties: random-access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM are erased when the power to the computer is turned off, but ROM retains its data indefinitely. In a PC, the ROM contains a specialized program called the BIOS that orchestrates loading the computer's operating system from the hard disk drive into RAM whenever the computer is turned on or reset. In embedded computers, which frequently do not have disk drives, all of the required software may be stored in ROM. Software stored in ROM is often called firmware, because it is notionally more like hardware than software. Flash memory blurs the distinction between ROM and RAM, as it retains its data when turned off but is also rewritable. It is typically much slower than conventional ROM and RAM however, so its use is restricted to applications where high speed is unnecessary. In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part. 

HARD DISK DRIVES – INPUT/OUTPUT (I/O):

Hard disk drives are common I/O devices used with computers. I/O is the means by which a computer exchanges information with the outside world. Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include input devices like the keyboard and mouse, and output devices such as the display and printer. Hard disk drives, floppy disk drives and optical disc drives serve as both input and output devices. Computer networking is another form of I/O. Often, I/O devices are complex computers in their own right with their own CPU and memory. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. Modern desktop computers contain many smaller computers that assist the main CPU in performing I/O.

MULTITASKING:

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by multitasking i.e. having the computer switch rapidly between running each program in turn. One means by which this is done is with a special signal called an interrupt which can periodically cause the computer to stop executing instructions where it was and do something else instead. By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time", then the interrupt generator might be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn. Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer. Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly - in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. If a program is waiting for the user to click on the mouse or press a key on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss.

MULTIPROCESSING:

Cray designed many supercomputers that used multiprocessing heavily. Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employed only in large and powerful machines such as supercomputers, mainframe computers and servers. Multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers are now widely available, and are being increasingly used in lower-end markets as a result. Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers. They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks.

NETWORKING AND THE INTERNET:

Computers have been used to coordinate information between multiple locations since the 1950s. The U.S. military's SAGE system was the first large-scale example of such a system, which led to a number of special-purpose commercial systems like Sabre. In the 1970s, computer engineers at research institutions throughout the United States began to link their computers together using telecommunications technology. This effort was funded by ARPA (now DARPA), and the computer network that it produced was called the ARPANET. The technologies that made the Arpanet possible spread and evolved. In time, the network spread beyond academic and military institutions and became known as the Internet. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer. Initially these facilities were available primarily to people working in high-tech environments, but in the 1990s the spread of applications like e-mail and the World Wide Web, combined with the development of cheap, fast networking technologies like Ethernet and ADSL saw computer networking become almost ubiquitous. In fact, the number of computers that are networked is growing phenomenally. A very large proportion of personal computers regularly connect to the Internet to communicate and receive information. "Wireless" networking, often utilizing mobile phone networks, has meant networking is becoming increasingly ubiquitous even in mobile computing environments. 

HARDWARE: 

The term hardware covers all of those parts of a computer that are tangible objects. Circuits, displays, power supplies, cables, keyboards, printers and mice are all hardware.

SOFTWARE:

Software refers to parts of the computer which do not have a material form, such as programs, data, protocols, etc. When software is stored in hardware that cannot easily be modified (such as BIOS ROM in an IBM PC compatible), it is sometimes called "firmware" to indicate that it falls into an uncertain area somewhere between hardware and software.

PROGRAMMING LANGUAGES:

Programming languages provide various ways of specifying programs for computers to run. Unlike natural languages, programming languages are designed to permit no ambiguity and to be concise. They are purely written languages and are often difficult to read aloud. They are generally either translated into machine code by a compiler or an assembler before being run, or translated directly at run time by an interpreter. Sometimes programs are executed by a hybrid method of the two techniques. There are thousands of different programming languages—some intended to be general purpose, others useful only for highly specialized applications.

PROFESSIONS AND ORGANIZATIONS:

As the use of computers has spread throughout society, there are an increasing number of careers involving computers.

USES OF COMPUTER IN A SOCIETY:

Computer is very useful to our society and helps in our day to day running activities. Information technology has been tremendously improved with the proffic research of American experts in communication technology. Computer helps our society with information to know what is happening around them and some other countries. There are several uses of a computer and there are still more to come in the future. However, computer is used for positive and negative purposes as the saying says, ‘everything that has an advantage, also has a disadvantage. Let’s see: 

POSITIVE USES OF A COMPUTER:

1. Electronic Mail (E-Mail): With an Internet email account, users can communicate with anyone else on-line, any place in the world, with no long distance fees. Email can also be used to join mailing lists, bulletin boards, or discussion groups that cover a huge variety of subjects. According to a 1999 study (the 1999 Consumer Technology Survey), email has replaced research as the leading reason given by people in the US for using the Internet. Approximately 48 percent of U.S. consumers said email was the primarily reason to go on-line, followed by research (28 percent). 

2. World Wide Web (WWW): The World Wide Web is not a physical place, not a set of files, nor even a network of computers. The heart of the WEB lies in the protocols (common communication rules and languages) that define its use. The WWW uses hypertext transfer protocols (http) to transport files from one place to another. What makes the WWW unique is the striking appearance of the information when it gets to your computer. In addition to text, the web presents color, images, sounds and video. This, combined with its ease of use, makes the web the most popular aspect of the Internet for a large majority of users. One 1995 estimate said that there were 27,000 web sites and that the number were doubling daily. This growth rate would be difficult to maintain, but it is true that the web is the single fastest growing neighborhood on the Internet. Media scholar Richard Campbell writes: "By the early 1990s, the world wide web had become the most frequently visited region of the Internet. Developed in the 1980s by software engineer Tim Berners-Lee, the Web was initially a text-only data-linking system that allowed computer-accessed information to associate with, or link to, other information no matter where it was on the Internet. Known as hypertext, this data-linking feature of the Web was a breakthrough for those attempting to use the Internet. Hypertext is a non-linear way of organizing information, allowing a user to click on a highlighted word, phrase, picture or icon and skip directly to other files related to that subject in other computer systems. "By using standardized software, today users can navigate through most features of the Internet, including text data such as email, photo-image files, and video and audio clips. HTML (Hypertext Markup Language), the written code that creates Web pages and links, is a language that all computers can read, so computers with varying operating systems (such as Windows and Macintosh) can communicate easily. JAVA, a HTML compatible language developed by Sun Microsystems in the mid 1990s, is also universally readable by computers and allows small interactive programs to run on Web pages, creating moving graphic elements such as three-dimensional animations and menus....” Some uses of the World Wide Web include: 

* Research, 

* Personal Websites, 

* On-line Shopping, 

* Software

i. For Research: For many of us as students, having Internet access is indispensable in our daily lives. I search the Internet using different search engines such as www.google.com, www.ask.com, etc for private study and research such as this. The internet has stored information posted by people to help others in their search. 

ii. To Promote Oneself: In conferences, there has been a steady increase in the number of writers who finish off their talk by referring the audience to their home page where they can preview some of his book topics/content and have a though of purchasing his/her book, which, more often than not, has the domain name of "presenter's name.com.

iii. To Advertise & Sell Products: Most company Web sites start up as a big advertisement for their products and services. Details of their products are being giving on-line for the perusal of buyers and determine whether or not he/she wishes to buy the product. Internet shopping (e-commerce) is still in its infancy - it takes a very good marketing strategy to actually make money out of selling items over the Web, but that doesn't stop lots of people from trying. They place the prices of their products on net and sell when an order is being made. 

iv. Software: The Internet contains a wealth of useful downloadable freeware and shareware software. Some pieces of shareware are limited versions of the full piece of the software, other are time limited trials. The publisher of the software gives it out (limited versions) for the perusal of those interested in it and should purchase once the limit is up (i.e. if they are interested in it). Other shareware is free for educational institutes, or for non-commercial purposes. 

3. For Threaded Conference: Systems (USENET) or network news. Users enter messages and within a day or so, the messages are delivered to nearly every other USENET host for everyone to read. (Not synchronous). With this, a board can decide to hold a meeting when they are even faraway for each other. 

4. News: There are many websites through which you can read national and international news about sports, weather forecast, business, etc. using your computer that is connected to the internet. 

5. E-Banking: Banking transaction can be carried out from the comfort of ones home through the internet that is making use of computer, these days no need. Also, all financial transactions are done by computer software. They provide security, speed and convenience. The ATMs used in banks today are computerized in the sense that software is installed to authenticate the user and dispense cash. Also, banking system has been made easy for us through means of electronic banking. 

6. E-Commerce: Importers and exporters make judicious use of a computer in the sense that, they send quotations and make order on-line and also track their goods fro its source to its destination. 

7. E-Learning: With the internet-enable computer, students can now register for a course, receive lectures and write exams online without any stress. Many find it difficult to read and assimilate the information a book is trying to pass to them when reading it. They find it easier to understand when it is placed in form of a movie where they can watch and the scenes, wordings or the pictures will help them understand and retain the information the book is trying to pass. To this reason, one can learn using E-learning software which would be installed on the computer. 

8. On-line Employment: Job applicants can easily submit their curriculum vitae to the database of the organization/company on-line, saving them the stress, expenses and time of having to submit the curriculum vitae at their office. And also, they can be contact though their e-mail address if they are short-listed. 

9. For Graphics Designing: This is one of the most uses of a Computer. We are all aware of computer graphics in, say, designing of Invitation Cards, Wedding Cards, Certificates, Identity Cards, Complementary Cards, etc. Images can be used for more than just the enhancement of existing material, the addition of pretty pictures to documents and so much more of graphics designing using a computer. 

10. Word Processing: When typing with a computer, it automatically corrects grammatical errors and when it notices an error in your spelling, it informs you using “spelling check” command. You can format your document to your taste i.e. you change the default font, font style & size to your choice). The word processing applications of a computer serve as an effective means of documentation. 

11. To make a database: Our computer can serve as database that serves us for various purposes. Our databases allow us to manage large amounts of information in a well arranged manner and to help us remember where we have stored our things. 

12. Presentation: The computer can also be used for advert placements of T.V & Radio using an installed application. It is also used for presentations of charts, histograms, drawing of building plans using installed software. 

13. For statistical Presentation With the help of a computer, we can perform statistical jobs like mathematical calculations and formulae, graphical presentation etc easier and neater. 

14. Defense: Countries have some measures that they take in course of defending their territory against attacks or intrusions by their enemies and the use of already-programmed computers controlled by experience and well trained operators to act as tactics and strategies of defense is one of their measures in defending their country. 

15. Security: With the help of a computer, you can monitor inner and outer part of your building/company using cams. Using installed software, you can also monitor the activities/operation of other computers in your company whenever you are far away if your computers are networked. 

16. Traffic Control: The growing use of traffic lights attests to their effectiveness in directing traffic flow, reducing the incidence of accidents, and most recently, to their utility in controlling the flow of traffic through large metropolitan areas when used in conjunction with computer driven systems. 

17. Traveling: The stress of going to the embassy to book a flight ticket has been evicted. One can book air tickets or railway tickets and make hotel reservations on-line. 

18. Meeting People: There are many alumni websites, through which you can meet people you know, make new friends, have an on-line relationship, chat (conversation) on-line and even regain contact with your classmates. 

19. Planning and Scheduling: The computer helps to store contact information of family, friends, etc. It can also be used to generate plans, scheduling appointment, reminders and deadlines. 

20. Appliances: Machines used in washing our cloths, shoes, plates etc, operate using computer based software. The software has been used to program the functionality of the machine. Now it helps us to wash voluminous cloths in no time. Also, Our Microwave Ovens are operated by software that makes them function as programmed. 

21. To Share Your Knowledge: Many individuals write Web pages to share information about their interests or hobbies. They don't expect to make any money out of it - they just feel that the Web has given them so much information that the least they can do is put something into it that may be useful for others. Other rewards come from the prestige of having their site recognized as something good and the contact inspired by their pages with others sharing the same interest.

22. To Participate in On-line Discussions: Mailing lists are an excellent ways to share ideas and keep up to date with fellow professionals. Two of the most popular are LINGUIST and TESL-L. LINGUIST is a mailing list maintained by East Michigan University and Wayne State University to serve as a research and discussion facility for the linguistic academic community. TESL-L was founded in May 1991, with the goal of providing educators with a fast, convenient, and topical electronic discussion forum that focuses on issues related to teaching English as a foreign or second language. As of October 27, 2000, TESL-L had 27,749 members in 159 countries, with an average of ten postings per day. If you join TESL-L you are also eligible to participate in any of their six special interest branches.  

23. Entertainment: You can play CDs/DVDs from a computer that has a DVD player. It gives you the opportunity to create backups (i.e. converting to a convenient file format) of the movies/music you are watching or listening to, so as to enable you watch/listen to them directly from your PC without the need of slotting in the CD/DVD again. You can also listen or watch radio or T.V stations respectively on your computer. 

24. To Have Fun: There's no doubt that the Internet is a fun place to be. You can participate in on-line quiz, play games, read song lyrics, poems, stories, text messages, send picture messages to friends and family and so much more. You can also watch/listen/send streamed audio and video music whenever you feel bored or even seat back and watch streamed trilling movies on-line. 

25. To Make Internet Calls: You can make local and international calls through the internet.

SOME NEGATIVE USES OF A COMPUTER:

1. Espionage: This is a negative use of a computer. It involves individuals obtaining information that is considered secret or confidential without the permission of the holder of the information.

2. Cyber-terrorism: Terrorism's younger relative, cyber-terrorism, came out in the 20th century, with the mass popularization of computers and especially Internet. Cyber-terrorism could be any kind of terrorism activity that is created or assisted with the usage of computer; it could also be any malicious attempt against a computer or a computer network. Computer terrorism is the act of destabilize or destroy a country or to apply pressure on a government by using methods classified in the category of computer crimes It is possible to carry out three types of actions against an information system, a physical, syntactic or semantic attack: The physical attack consists of damaging equipment in a "traditional way", bomb, fire, etc. The syntactic attack consists of modifying the logic of the system in order to introduce delays or to make the system unpredictable. An attack by means of a virus or of a Trojan horse is included in this category. The semantic attack is more perfidious. It exploits the confidence that the users have in their system. It consists of modifying information that is entering or exiting the system, without the users' knowledge, in order to induce errors.

3. Fraud: Fraudsters have their schemes, using their desktop computers/ laptops to connect to one or more online services - such as chat rooms, e-mail, message boards, or Web sites - to present fraudulent solicitations to prospective victims, to conduct fraudulent transactions, or to transmit the proceeds of fraud to financial institutions or to others connected with the scheme.

CONCLUSION:

With this information given above, one can tell how useful a computer is to human in the world today and also we have been able understand the role a computer plays in the day-to-day activities of life. Computer has made things easier and faster for us. We have also learnt the positive and negative usage of a computer