Wednesday, December 31, 2008

History of Internet

The internet has gone through three major evolutions and is currently witnessing its fourth. The internet started as the ARPANET and connected mainframe computers on dedicated connections. The second stage involved adding desktop PCs which connected through the telephone wires. The third stage was adding wireless connections to laptop computers. And currently the internet is evolving to allow mobile phone internet connectivity ubiquitously using cellular networks. Prior to the widespread internetworking that led to the Internet, most communication networks were limited by their nature to only allow communications between the stations on the network, and the prevalent computer networking method was based on the central mainframe computer model. Several research programs began to explore and articulate principles of networking between separate physical networks. This led to the development of the packet switching model of digital networking. These research efforts included those of the laboratories of Donald Davies (NPL), Paul Baran (RAND Corporation), and Leonard Kleinrock's MIT and UCLA.
The research led to the development of several packet-switched networking solutions in the late 1960s and 1970s, including ARPANET and the X.25 protocols. Additionally, public access and hobbyist networking systems grew in popularity, including unix-to-unix copy (UUCP) and FidoNet. They were however still disjointed separate networks, served only by limited gateways between networks. This led to the application of packet switching to develop a protocol for inter-networking, where multiple different networks could be joined together into a super-framework of networks. By defining a simple common network system, the Internet protocol suite, the concept of the network could be separated from its physical implementation. This spread of inter-network began to form into the idea of a global inter-network that would be called 'The Internet', and this began to quickly spread as existing networks were converted to become compatible with this. This spread quickly across the advanced telecommunication networks of the western world, and then began to penetrate into the rest of the world as it became the de-facto international standard and global network. However, the disparity of growth led to a digital divide that is still a concern today.

How should you backup?

Exactly how and where you backup to will depend on the size and nature of your business and the volume of data to be saved.
  • Small amounts of data can be backed up manually just copy the documents onto your chosen backup medium: memory stick, CD, DVD, external harddrive.
  • Larger amounts of data will be much easier to handle and back ups will be more effective if you use specialist backup software. This software will allow you to perform incremental backups backing up the data you have created or changed since the last backup. With specialist software you will be able to choose which data to back up, how often to back it up and be reminded to perform backups if your computer is turned off when the backup is due.
  • For larger businesses, backup software can perform running backups, ensuring that your data is being constantly backed up to another location on your network, to an external storage device or remotely to an online backup service.

The Role of memory in a Computer

People in the computer industry commonly use the term "memory" to refer to RAM (Random Access Memory). A computer uses RAM to hold temporary instructions and data needed to complete tasks. This enables the computer's CPU (Central Processing Unit) to access instructions and data stored in memory very quickly.
A good example of this is when the CPU loads an application program - such as a word processing or page layout program - into memory, thereby allowing the application program to work as quickly and efficiently as possible. In practical terms, having the program loaded into memory means that you can get work done more quickly with less time spent waiting for the computer to perform tasks.
The process begins when you enter a command from your keyboard. The CPU interprets the command and instructs the hard drive to load the command or program into memory. Once the data is loaded into memory, the CPU is able to access it much more quickly than if it had to retrieve it from the hard drive.
This process is similar to placing various electronic files and documents you're using on the computer into a single file folder or directory. By doing so, you keep all the files you need handy and avoid searching in several places every time you need them.

How to protect your computer against viruses

To protect your computer against viruses, follow these steps:

  • On the computer, turn on the firewall.
  • Keep the computer operating system up-to-date.
  • Use updated antivirus software on the computer.
  • Use updated antispyware software on the computer.

How to remove a computer virus

Even for an expert, removing a computer virus can be a difficult task without the help of computer virus removal tools. Some computer viruses and other unwanted software, such as spyware, even reinstall themselves after the viruses have been detected and removed. Fortunately, by updating the computer and by using antivirus tools, you can help permanently remove unwanted software.
To remove a computer virus, follow these steps:

  • Install the latest updates from Microsoft Update on the computer.
  • Update the antivirus software on the computer. Then, perform a thorough scan of the computer by using the antivirus software.
  • Download, install, and then run the Microsoft Malicious Software Removal Tool to remove existing viruses on the computer.

What is a wearable computer

A wearable computer is a computer that is subsumed into the personal space of the user, controlled by the user, and has both operational and interactional constancy i.e. is always on and always accessible. Most notably, it is a device that is always with the user, and into which the user can always enter commands and execute a set of such entered commands, and in which the user can do so while walking around or doing other activities. The most salient aspect of computers, in general, (whether wearable or not) is their {\em reconfigurability} and their {\em generality}, e.g. that their function can be made to vary widely, depending on the instructions provided for program execution. With the wearable computer (WearComp), this is no exception, e.g. the wearable computer is more than just a wristwatch or regular eyeglasses: it has the full functionality of a computer system but in addition to being a fully featured computer, it is also inextricably intertwined with the wearer. This is what sets the wearable computer apart from other wearable devices such as wristwatches, regular eyeglasses, wearable radios, etc.. Unlike these other wearable devices that are not programmable (reconfigurable), the wearable computer is as reconfigurable as the familiar desktop or mainframe computer. Wearable computing will now be formally defined in terms of its three basic modes of operation and its six fundamental attributes.

The Nature of Human-Computer Interaction

  • Points of view: HCI as communication, agent paradigm, tool paradigm, the work-centered point of view,human/system/tasks division, supervisory control
  • Objectives (e.g. productivity, user empowerment)
  • History and intellectual roots
  • HCI as an academic topic: journals, literature, relation to other fields, science vs. engineering vs. design aspects

What are the definition of computer.

Definition of computer
1. Electronic data processor; an electronic device that accepts processes, stores, and outputs data at high speed according to programmed instructions.
2. Somebody who computes; some body who calculates figures or amounts using a machine.
3. Virus- A software that damages your computer system
4. Color Cartridges- a color cartridge is the thing that holds the ink for your computer's printer.
5. World Wide Web- A part of the internet that let's you jump from site to site alot quicker.
6. E-mail- A mail accessory that sends mail over the Internet.
7. Online- When your computer is connected to the Internet.
8. Network- A bunch of computers attached together to share information and programs.
9. Speaker- The part of the computer that plays the sounds.
10. RAM (Random Access Memory)- Memory chips in the computer that hold information to run your programs.
11. ROM (Read Only Memory) - A permanent memory chip that cannot be changed. This memory runs the computer.
12. Bit- A small piece of information that gives directions to the computer.

Computer History

History of Computers & Internet. In 1937 Alan Turing's Turing machine pioneered the idea of machines that could complete well-defined tasks by being supplied with programs. In 1938, Konrad Zuse built the first binary digital relay computer. In 1943 saw the first general-purpose digital computer, ENIAC. In 1948 the Manchester Baby became the first stored program computer. In 1955 MIT built the first real-time processing machine. In 1956, IBM created the disk memory system. The next year brought the integrated circuit chip. In 1959 IBM introduced the first desktop machines, which led in 1965 to Digital Equipment Corporation's introduction of the first real microcomputer. The links included herein relate to computer history and the human experience.

What are the uses of computer?

There are several uses of computers: -
  • Word Processing - Word Processing software automatically corrects spelling and grammar mistakes. If the content of a document repeats you don’t have to type it each time. You can use the copy and paste features. You can printout documents and make several copies. It is easier to read a word-processed document than a handwritten one. You can add images to your document.
  • Internet - It is a network of almost all the computers in the world. You can browse through much more information than you could do in a library. That is because computers can store enormous amounts of information. You also have very fast and convenient access to information. Through E-Mail you can communicate with a person sitting thousands of miles away in seconds. There is chat software that enables one to chat with another person on a real-time basis. Video conferencing tools are becoming readily available to the common man.
  • Digital video or audio composition – Audio or video composition and editing have been made much easier by computers. It no longer costs thousands of dollars of equipment to compose music or make a film. Graphics engineers can use computers to generate short or full-length films or even to create three-dimensional models. Anybody owning a computer can now enter the field of media production. Special effects in science fiction and action movies are created using computers.
  • Desktop publishing - With desktop publishing, you can create page layouts for entire books on your personal computer.
  • Computers in Medicine - You can diagnose diseases. You can learn the cures. Software is used in magnetic resonance imaging to examine the internal organs of the human body. Software is used for performing surgery. Computers are used to store patient data.
  • Mathematical Calculations - Thanks to computers, which have computing speeds of over a million calculations per second we can perform the biggest of mathematical calculations.
  • Banks - All financial transactions are done by computer software. They provide security, speed and convenience.
  • Travel - One can book air tickets or railway tickets and make hotel reservations online.
  • Telecommunications - Software is widely used here. Also all mobile phones have software embedded in them.
  • Defense - There is software embedded in almost every weapon. Software is used for controlling the flight and targeting in ballistic missiles. Software is used to control access to atomic bombs.
  • E-Learning – Instead of a book it is easier to learn from an E-learning software.
  • Gambling-You can gamble online instead of going to a casino.

What is a Computer?

A computer is an electronic device, which executes software programs. It consists of 2 parts-hardware and software. The computer processes input through input devices like mouse and keyboard. The computer displays output through output devices like color monitor and printer. 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.

A basic introduction to Key Recorder and Mouse Recorder

Key recorder and mouse recorder are important to much of modern life, but most of you don't have a clue how they work. If you are such a person, here is a basic introduction to the recorders.
Key recorder and mouse recorder are enhanced automation tools, which allow recording and replaying virtually every data input by keyboard and mouse. You may utilize them to record and save mouse movements, mouse clicks, and keyboard keystrokes in any application, such as a word processor, a painting application and so on. When you need them, you can replay the recorded activities over and over again.
The recorders not just record all keyboard and mouse activities in any window, but they also contain more than 50 additional commands. These commands allow controlling the macro run (loops, conditions, go to, variables, etc.), starting or switching to programs, manipulating cursors, searching the image or text, calling external DLL and shutting down the computer, etc. The recorder activities are stored in a clear and compact way. This makes it easy to edit them.
When using key recorder and mouse recorder, you should build a macro first. One method is to capture (record) your keystroke and mouse movements. Start the recording of the macro and enter the keystrokes and mouse movements in your application. When finished, stop the recording and save the macro. The other method is to build your own macros with the macro editor. Select from a list of commands and insert them into the macro.
Then you play back macros you recorded. The recorders allow you to execute (play back) macros in two ways. The most common method is to press a hotkey combination such as CTRL+ ALT+1. There are a number of single keys which can be assigned as a hotkey. The other playback method is to have the macro execute on a schedule. You can specify the macro to play back minute, daily, weekly or monthly. Schedules such as at 10:00 every day or every 10 days can also be accommodated.

Generations of Computer.

First-generation computers, starting with the UNIVAC I in 1951, used vacuum tubes, and their memories were made of thin tubes of liquid mercury and magnetic drums.
Second-generation systems in the late 1950s replaced tubes with transistors and used magnetic cores for memories (IBM 1401, Honeywell 800). Size was reduced and reliability was significantly improved.
Third-generation computers, beginning in the mid-1960s, used the first integrated circuits (IBM 360, CDC 6400) and the first operating systems and DBMSs. Online systems were widely developed, although most processing was still batch oriented using punch cards and magnetic tapes.
Starting in the mid-1970s, the fourth generation brought us computers made entirely of chips. It spawned the microprocessor and personal computer. It introduced distributed processing and office automation. Query languages, report writers and spreadsheets put large numbers of people in touch with the computer for the first time. Even with the hundreds of millions of people using computers every day, we are still in the fourth generation. Some skill is still required to use the computer even if only to surf the Web and send e-mail.

How can I avoid infection? (Computer virus)

There is no way to guarantee that you will avoid infection. However,the potential damage can be minimized by taking the followingprecautions:
make sure you have a clean boot disk - test with whatever (up-to-date!)antivirus software you can get hold of and make sure it is (and stays)write-protected. Boot from it and make a couple of copies.
* use reputable, up-to-date and properly-installed anti-virussoftware regularly. (See below) If you use a shareware packagefor which payment and/or registration is required, do it. Not onlydoes it encourage the writer and make you feel virtuous, it meansyou can legitimately ask for technical support in a crisis.
* do some reading (see below). If you're a home user, you may wellget an infection sooner or later. If you're a business user, it'llbe sooner. Either way you'll benefit from a little background.If you're a business user you (or your enterprise) need a policy.
* don't rely *solely* on newsgroups like this to get you out oftrouble: it may be a while before you get a response (especiallyfrom a moderated group like comp.virus), and the first responseyou act upon may not offer the most appropriate advice for yourparticular problem
if you use a shareware/freeware package, make sure you have hardcopy of the documentation *before* your system falls apart!
* always run a memory-resident scanner to monitor disk access andexecutable files before they're run.
if you run Windows, a reputable anti-virus package which includesDOS *and* Windows components is likely to offer better protectionthan a DOS only package. If you run Windows 95, you need a properWin95 32-bit package for full protection.
* make sure your home system is protected, as well as your work PC.
* check all new systems and all floppy disks when they're broughtin (from *any* source) with a good virus-scanning program.

How does antivirus software work?

Scanner (conventional scanner, command-line scanner, on-demandscanner) - a program that looks for known viruses by checking forrecognisable patterns ('scan strings', 'search strings','signatures' [a term best avoided for its ambiguity]).
* TSR scanner - a TSR (memory-resident program) that checks forviruses while other programs are running. It may have some ofthe characteristics of a monitor and/or behaviour blocker.
* VxD scanner - a scanner that works under Windows or perhaps underWin 95, or both), which checks for viruses continuously whileyou work.
* Heuristic scanners - scanners that inspect executable files forcode using operations that might denote an unknown virus.
* Monitor/Behaviour Blocker - a TSR that monitors programs whilethey are running for behaviour which might denote a virus.
* Change Detectors/Checksummers/Integrity Checkers - programs thatkeep a database of the characteristics of all executable files ona system and check for changes which might signify an attack byan unknown virus
Cryptographic Checksummers use an encryption algorithm to lessenthe risk of being fooled by a virus which targets that particularchecksummer.

How Does Computer Memory Work?

  • A computers memory is addressable,
  • each memory location will contain some sort of `value',
  • Each location has a specific `number' (represented as hexadecimal
  • Fortran 90 allows (English) names to be given to memory locations,
  • the value of a location can be read from or written to.

How Does a Computer Work?

A computer is an information-processing machine that works by converting all kinds of information into binary numbers (ones and zeros) and then using simple mathematics to make decisions about, or to rearrange, those numbers. There are two things essential to understanding the basics of how a computer works. One is that a computer treats any type of information (not only numbers but also letters, words, dates, and so on) as if it consisted simply of binary ones and zeros. For example, a computer can translate the letter “A” typed into its keyboard into a string of ones and zeros, such as 1000001. One reason to do this is that once in binary form, the information can be stored and moved about more easily. On a hard disc, the “ones” could be stored as magnetized spots on the disc, while the zeroes can be stored as unmagnetized spots. Once information has been converted to ones and zeros, the computer can get to work.
The second key to understanding how a computer works it to remember that all of a computer’s functions are based on the movement and transformation of electrical pulses (representing ones and zeroes) in electrical circuits. Inside the computer are electrical circuits that perform computations on the zeros and ones, such as adding and subtracting them. That’s why we call the machine a computer even though we use it for word processing, games, or surfing the Web. These computational circuits are called the logic of the computer, because the calculations they make are similar to simple logic decisions. Everything that a computer can do with information is done by using these logic circuits. For example, if you press the A key on the computer keyboard, circuits inside the computer receive pulses of electricity representing the A in binary form—1000001. Those pulses are sent to logic circuits that make yes or no decisions based on the input they receive. A very simple example would be a circuit that determines whether the input you send it is a one or a zero. The output of the circuit is a new piece of information—a binary one or zero that is the result of the simple yes or no decision. Other groups of such circuits count the number of yeses and no to determine whether the data is an A or some other character. Then the result of that determination is sent to other circuits that store, display, or process that data. Millions and millions of these logic circuits are used together to do much more complex tasks, such as finding, retrieving, and displaying a Web page. Yet everything your computer does is based on digital ones and zeros and the use of logic circuits.

How RAM affects the speed of a computer & the advantage of having enough computer RAM.

In this article I'm going to talk about RAM, also known as computer memory; how RAM affects the speed of a computer, and what exactly is the advantage of having enough computer RAM.
A lot of people don't really understand what RAM is, which is nothing to feel bad about, since it's rare to hear a really easy, understandable explanation.
I have a very simple way of explaining the computer term memory that will make sense to anybody, no matter how little you may understand computers.
By the end of this explanation, you'll understand what computer RAM is and you'll also understand how RAM affects the speed of a computer and just exactly what are the advantages to having more computer memory.
First off, just in case you didn't know, RAM stands for Random Access Memory. It's not important to remember that, just understand that the computer terms RAM or memory mean the same thing: the temporary working area in a computer.
temporary because when you turn off the computer, everything in RAM vanishes instantly. This is unlike a hard drive, or "flash memory", both of which store whatever is on them even when the computer is off.
Just for the sake of clarity, "flash memory" and "memory" (i.e. RAM) are not the same thing, so when you hear someone talking about memory --assuming they're using the term correctly -- they're probably not talking about flash memory (which is like the card in a digital camera, or in the smaller iPods, thumb drives, etc.).
So best way to think of computer RAM is this: think of RAM like a table, or work bench.If you're working on a project -- it could be a student studying for a class, it could be a carpenter working on a bench, or almost any project -- you need a space to work on the project, like the space on a table, or on a workbench.
You take out all of your materials (books, or carpenter's tools, or whatever), and you spread them out on your work space. You work on the project, and when you're done, you put everything away again.
This is exactly how a computer's RAM works -- you open a program like your email program, Word, or whatever, and it loads this into the RAM. When you're done, you close the program, and the computer takes the program out of memory (out of the computer RAM) and stores it back on the hard drive.

What does computer literacy mean?

I had defined in an earlier article 'computer literacy' as the means or the capacity of a person to use computer applications. In other words, a person who knows to use the machine to complete any task is a computer literate. Computer literate often connotes little more than the ability to use several very specific applications (usually Microsoft Word, Microsoft Internet Explorer, and Microsoft Outlook) for certain very well-defined simple tasks, largely by rote

  • Word-processing: This is the most basic of all skills. It involves typing basically, but when using computers it deviates a little from the common typewriter. There is the enter key replacing the career movement and there are commands (simple ones) for paragraph, indent, spacing and so on. The best of word processing is that you can modify with ease any part of the text you entered. The word processing is the minimum one should know because it will be used in each and every application of computers.
  • Performing basic operations: Starting a computer may be a very tricky thing to one who has never seen one. Using the mouse, managing various windows, alternating between the use of keyboard and mouse, minimizing windows, opening and closing files, etc can be daunting tasks for the uninitiated ones. In order to learn to use computers, as with any machine, one needs to acclimatize himself/herself first. First and foremost one should familiarize himself/herself with the parts and functions of the computer - in a similar manner you learn about the functioning of your washing machine or DVD player or dishwasher.

Wednesday, October 8, 2008

Advantage and disadvantage of computer

Advantage:Faster Communication, Massive increase in productivity,Multiple functions in work and entertainment,Keeps kids quiete and destroying the house,Massive Storehouse of information
Disadvantage:Addiction,Minor increase in cancer due to radiation (though unproven),Uses a lot of electricity,Increases Child maturity at ages far below average,Risk of credit card and ID theft.

What are the advantages of being computer literate
The advantage of being a computer literate is almost as clear as saying 'good day'. In today's world where everything has a computer element embedded in the system, having the basic knowledge about this wonder machine is like having a magic key which can open any door for you. Let us see what advantages a computer literate has over one who does not know anything about computers:
· The CV is complete: The CV of one who has on it 'computer training' listed is indeed complete. There is no organization today worth its salt that does not use computers in some or other field in their systems. A person who seeks a job and has some basic training in computers says that the person is upto date with the existing technology and one who can do justice in a modern environment. Thus, one who has the computer training will always be chosen for the job interview/job vacancy over the one who does not - sometimes even if the latter is more qualified.