COMPUTER SOFTWARE HARDWARE

INTEL UNVEILS NEW BUSINESS CHIPS

2010-02-11T06:38:00.000-08:00

INTEL CORP has relesed computerchips aimed at business, as it seeks to maintain dominance over Advanced Micro Devices inc,and move in front of an expected recoverry in coporate IT spending this year .the new micro ,processors are the latest iterationof Intel"s chipsfeaturing smaller transistors, that the company said will increase pefomance and impove energy efficiency.The upgraded chips,based on Intel"s existing vpro line, come with specific features that work with nspecialised computers and software designed by INTEL for its business customers

3G

2009-12-22T04:12:00.000-08:00

Upping the ante against Reliance Communications other new entrants, who

(2G) spectrum auctioned only after all operators have a minimum of 6.2 MHz of radio frequencies per circle, in its latest salvo has warned that the exchequer will lose upwards of 10,000, if the demands by these players are accepted.

Currently, all mobile services (except select services offered by and are using 2G airwaves. So far, 2G airwaves had been allotted based ( operators, this means, every time an operator reached a certain -defined subscriber number, it was given additional 2G spectrum.

But, for the past couple of months, all allocations of 2G spectrum have been put on hold until the government comes up with a new methodology to dish out these airwaves. Earlier this year, a committee set up by the department of recommended that all future allocations of 2G airwaves be made only through an auction process.

The country’s largest by both customers and, is vehemently backing the auction methodology for all future allocations of 2G spectrum. chief regulatory officer Gupta in an interaction with ET told arguments by new entrants that they have ‘contractual rights to obtain 6.2 MHz instantly, or after the SLC, due to which the government cannot auction airwaves beyond 4.4 MHz-mark were totally baseless’.

“If all new entrants, who currently have 4.4 MHz are given an additional 1.8 MHz, based on the existing criteria, the government will loss between 10,000 and 20,000 This is the additional allotment will fetch if auctioned, and the government has every right to the economic value of this scarce resource,” Gupta added.

Countering claims of new entrants, Gupta said as per existing policy, the spectrum is subject to availability, and therefore, ‘after paying the entry fee, the government is not committed to allocate the spectrum even at the initial level (4.4.

“The beyond 4.4 MHz was prescribed in March 2006 and prior to this policy, the spectrum up to 6.2 MHz at a stretch was being allocated to the operators based on need and justification,” Gupta added.

After March 2006, no operator has been allocated 6.2 MHz at a stretch. Today’s circumstances cannot be compared with 1995/1996/2001, and initial allocation cannot be more than 4.4 MHz,” Gupta added.

But, recent entrants in the are opposed to any move to adopt the auction mechanism for all future allocations. For instance, pointed out that such an auction ‘only who have amassed 10 MHz of spectrum completely free based on far more relaxed .

“No one talked of auction at that time when they (incumbents) were amassing spectrum even without proper guidelines and policy framework. Admitting to their views would be highly unfair for new entrants, will distort competition and will result in loss of consumer benefits to subscribers, as all consumer benefits in India, especially so in the recent years, have been driven by new entrant networks,” RCOM added in a recent communication to TRAI.

New entrants also maintain that government revenues can be enhanced by forcing incumbent GSM operators to return all allocations beyond the 6.2-MHz mark in addition to charging them a one-time fee at market value for using these airwaves.

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2009-11-27T21:21:00.000-08:00

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ADDRESSING A PRESS CONFERENCE HERE, SSTL PRESIDENT AND CHIEF EXECUTIVE OFFICER VSEVOLOD ROZANOV SAID: "M BLAZE" WILL BE AVAILABLE IN THE EIGHT CIRCLES THAT MTS HAS LAUNCHED ITS SERVICES AND WILL BE MAID AVAILABLE IN MUM BA I IN DECEMBER. THERE WILL BE NO ROAMING SURCHARGES ON THE MTS NETWORK. AS MANY AS 26 CITIES WILL BE COVERED BY THE M BLAZE SERVICE BY THE M BLAZE SERVICE BY THE FIRST QUARTER OF 2010. ALL M BLAZE TARIFF PLANS ALLOW FREE INTERNET BROWSING OF WEBSITES SUCH AS YAHOO, WI KI PE D IA AND MAKE MY TRIP".

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The Advantages of Digital Cameras
Saturday, November 07, 2009 2:15 PM

There was a time when people could scarcely imagine the pictures they took with their cameras being instantly available, because the procedure of developing and printing a film was so time consuming. Leaving aside the full history of the camera, and just looking at the past two decades, we can see that camera technology has improved dramatically. It was only ten years ago that we used to use cameras with reels of film, with about thirty to forty shots on one reel.

Whenever you went to a picnic, a wedding or a party, you put a new reel of film into your camera and took the photos. Then you went to a photo shop where you handed the reel over to a shop assistant, and after ten to fifteen days, he returned your pictures to you in hard copy form. But if we talk about the past five years, then it's a completely different story. Now you can take your picture and view the image instantly. This has all happened due to the arrival of digital cameras.

The first camera that allowed the transfer of images to the computer was invented in 1994 by Kodak. But at that time, people were not so aware of the technology and the cameras were very expensive. However within the last five to six years digital cameras have become so popular and easy to use that companies like Sony, Canon, Nikon and Kodak have developed mass produced versions of the cameras that are reasonably priced, compact and easy to use. Now all you have to do with your digital camera is just take a shot and see the results for yourself. If you do not like it, you can just delete it.

Another advantage of the digital camera is its capacity. You can have more than a thousand pictures at once on your digital camera. You do not need to worry about the capacity of the camera to save pictures. With the help of a memory card, you can even save the data from your digital camera.

Digital cameras can also be used to make movies, but they do have time limits in this respect. Digital cameras also provide you with some photo editing software that can help you to create, edit, delete and reshape your pictures in different frames and sizes. Digital cameras are built to function with computer systems. You just need a transfer cable which is provided with almost every camera and you can transfer your pictures and movies onto your computer where you can save them for a long time. This can really help people to show their pictures to their relatives worldwide. You can even make hard copy prints of your digital camera photos using your own printer, or by going to the photo shop.

Digital cameras are convenient and easy to carry around. They are more efficient than traditional cameras, and their good resolution with high pixel density makes their images very clear and powerful.

Digital cameras are in common use nowadays and are available at really affordable prices, so it is time for you to get a digital camera for yourself and enjoy your photography
Hardware Tips
Friday, August 28, 2009 11:53 AM

Computer hardware includes the physical parts, digital circuitry inside the computer. Different hardware components collectively make a computer unit. Computer with weaker security settings, faulty hardware devices, misconfigurations and outdated software are suffered with different kind of problems. Regardless of the computer hardware problems, there are few basic steps that can avoid many problems. The hardware problems lead to the error messages, system boot up problems, noise from the devices, blue screen errors and the system crash.

Normally computer hardware problems are easier to resolve than the software problems. To troubleshoot the system’s hardware related problems, you should have the right tools and techniques. To identify the hardware failure in your system, you need to use a diagnostic utility. It will help you to find out the right cause of the problem.

Hard Disk

*
* Use a hard disk diagnos
* tic utility to check the status of your hard disk.
* Use UPS with your system, it will help your hard disk to avoid bad sectors due to the power failure.
*

* Regularly scan your hard disk for the viruses, spware, adware, Trojans and other threats.
* Don’t shake or vibr
*

*

* ate your computer while it is working.
* If your hard disk finds the logical bad sectors, it can be removed with the formatting.

Memory

*
o

* Insert the memory sticks in the memory slots tightly.
* If case of memory related errors, change the memory modules and check the status.
*

* In case of persistent problems, change the memory sticks with the new one.
* If your system freezes up or response slo
*

* w, increase the amount of memory inside your system.

VGA Card

*

* Insert the VGA tightly in the PCI slot of your computer.
* In case of no display on your monitor screen, check the VGA cables and make sure that it connected tightly.
* Make sure that you are using the updated driver for your VGA card.

LAN Card

* Check whether the LED lights of the LAN card are blinking or not.
* Check to see that the UPT/STP cable should be properly connected at both ends i.e. one end in the LAN card and the other in the switch/HUB etc.
* Make sure that the LAN card’s driver is up-to-dated.

If you LAN card’s issue still not resolved, replace it with a new one and reconfigure it.

Printer

* Make sure that you are using the up-to-dated driver for the printer.
* To get the optimized performance from your printer, select the “Best Quality” in the properties of your printer.
* Clean your printer regularly with soft cloth and cleansing lotion.
* Power down your printer properly.
* If you are using more than one printer in your network, make sure that you are using a very descriptive name of your printers.
* For getting the technical and additional information about your printer consult the printer’s manual.
* Run the inkjet printer's cartridge-cleaning utility.

Miscellaneous Tips

* Avoid vibrations and shocks to your computer system while it is working.
* Before changing any hardware device inside your computer first shut down the computer and unplug it.
* Don’t put any liquid or drinks near your computer hardware.
* Keep the air filters and the ventilation paths clean to provide the easy passage to the air in and outside of the computer.
* Plug the computer devices’ cables, connectors and screw tightly.
* Use UPS (uninterrupted power supply) to avoid the data lost of system crash due to the power failure.
* Use POST card in your computer. POST stands for Power On Self Test it helps to troubleshoot the common startup problems.
* Use the Device Manager utility in the Windows based computer to diagnose and troubleshoot the devices problems in your computer.
* To avoid the overheating in your computer, make sure that the processor and the computer fans are working fine.
* Always keep the case of your computer close.
* When your newly installed hardware device does not work, it is most likely due to the hardware conflict, incompatibility, misconfigurations, outdated drives and loose cable connections. You also need to follow the manufacturer’s instructions carefully.
* If you are a computer hardware technician, make sure that your toolkit is equipped with the screw drives, extra jumpers blocks, masking tape, compressed air, flash light, bootable cds, devices’ drivers, hardware diagnostic utilities, connectors and testers.

Seven Essential Hardware Buying Tips
Friday, August 28, 2009 11:31 AM

1.

Buy a recognised brand name or from a reputable dealer.

2.

Buy a complete system from one manufacturer, so there are no arguments about support if things go wrong.

3.

Get a next business day, three-year, on-site warranty.

4.

Don’t cut corners when it comes to your comfort: spend extra on a good mouse and keyboard and a large, high-quality monitor.

5.

Avoid cutting edge technologies and processors. You’ll pay a premium for them and they may still have kinks and bugs that need to be worked out.

6.

Assume your needs will grow. You may think “I don’t need a high-speed Internet connection” or “The only thing I need is a word processor” now; that’s almost guaranteed to change within the life of your hardware.

7.

Don’t buy cheaply and plan to upgrade in a year or so. It’s a much better investment and far less pitfall-ridden to buy a quality, powerful system that will give you a solid three-to-five year’s life.

Windows Vista Review
Friday, August 28, 2009 11:21 AM

It's been five years in the making. Hundreds of thousands of man hours have gone into its development. Millions of words have already been written about it. Some have already written it off, others can't wait to get their hands on a copy.
Finally it's here. This is the latest episode in the Microsoft soap opera. This is Windows Vista. Has it been worth the wait?

On the face of it, Vista has its work cut out. There's no doubt that the move from XP to Vista was never going to be as dramatic or ground shaking as the move from the much-derided Windows 98 to XP, no matter how hard the Microsoft spin machine worked at convincing us it was. After all, there's not nearly quite so much to fix with XP, which has, by-and-large, done a decent job of running home, business and, latterly, entertainment PCs throughout the land for a good while now.

There has been the odd security bump along the way and, sure, it has the odd annoying foible, but apart from the fact that it's beginning to look a little long in the tooth, XP is still in rude health. Has Vista got enough in its locker to persuade millions of users to make the switch? Read on to find out…

Just Window Dressing?
Cynics will tell you that Vista is just XP with a brand new wardrobe - underneath it's just the same old operating system. And yes, to a certain extent that's true. But in the case of Vista's rather swish-looking Aero interface, it's more than just pretty version of XP. This is a makeover that's worthy of the name.

If your PC or laptop has the hardware (we'll deal with this issue in more depth later) you'll get transparent windows that let you see through them to what's behind and much more sophisticated animations than with XP. Minimised Windows fade out and gracefully slide into the taskbar, live previews appear as you hover over minimised application buttons in the taskbar, and the whole look and feel is a lot more mature than XP. If you've downloaded and used Windows Media Player 11, you'll already have a good idea of how Vista shapes up – it's slick, no doubt about it.

There are other ways in which Vista shows off its new 3D capabilities though, apart from the transparency and glass effects. There is now an alternative to the old Alt-Tab method of switching between applications called Flip 3D. Hit the Windows key and Tab and instead of flat, anonymous icons, you get previews of all your currently open windows stacked in 3D. Hit Tab while holding down the Windows key and the stack smoothly cycles through each one, just like a virtual Rolodex. The more frivolous sidebar is a nice touch too. This takes a similar - albeit altogether more attractive - approach to Google's Desktop sidebar. You can dock various 'gadgets' here, including a clock, sticky notes, an RSS news feeder, a photo slideshow, contact list and various other handy mini-applications.
Types of Computer Hardware
Friday, August 28, 2009 11:12 AM
Computer hardware is a physical part of a computer that executes within the hardware. It is unlike computer software or data that can be frequently changed, modified or erased on a computer. Computer hardware is not frequently changed and so is stored in hardware devices such as read only memory (ROM) where it is not readily changed.

Most computer hardware is embedded and so is not visible to normal users. Below are the different types of hardware's found in a computer.

 Motherboard: It is the central or primary circuit board
making up a complex electronic system such as a computer. A motherboard is also known as a main board, logic board or system board.
 Central processing Unit: A CPU is the main component of a digital computer that interprets instructions and process data in computer programs.

 Random Access Memory: A RAM allows the stored data to be accessed in any order. RAM is considered as the main memory of the computer where the working area is used for displaying and manipulating data.
 Basic Input Output System: BIOS prepares the software programs to load, execute and control the computer.
 Power Supply: Power Supply supplies electrical energy to an output load or group of loads.
 Video Display Controller: It converts the logical representation of visual information into a signal that can be used as input for a display medium.
 Computer Bus: It is used to transfer data or power between computer components inside a computer or between computers.
 CD-ROM drive: It contains data accessible by a computer

 Floppy disk: It is a data storage device
 Zip Drive: It is a medium capacity removable disk storage system.
 Hard Disk: It is a non-volatile data storage system that stores data on a magnetic surface layered unto hard disk platters.
Computer Hardware and Software Company in Bangalore ,India
Friday, August 28, 2009 11:00 AM

The Computer Hardware and Software industry of Bangalore is regarded as the focal point of advanced technology that acts as the prime catalyst in the economic growth of the city. Housing the biggest international names of Information Technology, Bangalore is referred as the Silicon Valley of India.

With the widening of the global business horizon, Bangalore has emerged as the key player in the field of Information Technology and Information Technology enabled services. From proposed plans of Hardware Park to a thriving Business Process Outsourcing sector, Bangalore is progressing beyond leaps and bounds.

The city deals with the latest models of Hardware tools, Computer parts, Software programmes and accessories. The newest developments in the Software programming domain enable Bangalore to compete with the best IT brands of the world.

Facilitated by a remarkably skilled and efficient lot of Hardware and Software professionals, the city truly fulfills all the criterion of being the IT capital of the country.

The major IT and ITes organizations of global repute that add credibility to the Computer Hardware and Software contours of Bangalore are:

* Microsoft Corporation
* IBM Global Services Ltd.
* Infosys Technologies Ltd.
* Intel Asia Electronics Inc.
* ITC Ltd. – Information Systems Div.
* Oracle Software (I) Ltd.
* SAP India Pvt. Ltd.
* Satyam Computer Services Ltd.
* Tata Consultancy Services
* Wipro Infotech Group
* Dell Asia Pacific SDN
* Citicorp
* CMC Ltd.
* Aptech Ltd.
* Compaq India
* Tata Infotech Ltd.
* Verifone
* TVS Electronics South Asia (P) Ltd.
* Tata Honeywell Ltd.
* Tektronix India Ltd.

To take India to greater heights of virtual development, the Computer Hardware and Software segment of Bangalore is consistently making new and globally acclaimed technological strides.
Major Types of Software
Friday, August 28, 2009 10:54 AM

Programming Software: This is one of the most commonly known and popularly used forms of computer software. These software come in forms of tools that assist a programmer in writing computer programs. Computer programs are sets of logical instructions that make a computer system perform certain tasks. The tools that help the programmers in instructing a computer system include text editors, compilers and interpreters.

System Software: It helps in running the computer hardware and the computer system. System software is a collection of operating systems; devise drivers, servers, windowing systems and utilities. System software helps an application programmer in abstracting away from hardware, memory and other internal complexities of a computer.

Application Software: It enables the end users to accomplish certain specific tasks. Business software, databases and educational software are some forms of application software. Different word processors, which are dedicated for specialized tasks to be performed by the user, are other examples of application software.

Apart from these three basic types of software, there are some other well-known forms of computer software like inventory management software, ERP, utility software, accounting software and others. Take a look at some of them.

Inventory Management Software: This type of software helps an organization in tracking its goods and materials on the basis of quality as well as quantity. Warehouse inventory management functions encompass the internal warehouse movements and storage. Inventory software helps a company in organizing inventory and optimizing the flow of goods in the organization, thus leading to an improved customer service.

Utility Software: Also known as service routine, utility software helps in the management of computer hardware and application software. It performs a small range of tasks. Disk defragmenters, systems utilities and virus scanners are some of the typical examples of utility software.

Data Backup and Recovery Software: An ideal data backup and recovery software provides functionalities beyond simple copying of data files. This software often supports user needs of specifying what is to be backed up and when. Backup and recovery software preserve the original organization of files and allow an easy retrieval of the backed up data.
OPERATING SYSTEMS
Thursday, August 27, 2009 8:10 PM
Different Types of Operating Systems
Operating systems that create a link between users and the applications form the core of computer systems. It dissociates the programs and the hardware and simplifies resource management. Let us look at the different types of operating systems.
Different Types of Operating Systems
An operating system is a software component of a computer system that is responsible for the management of various activities of the computer and the sharing of computer resources. It hosts the several applications that run on a computer and handles the operations of computer hardware. Users and application programs access the services offered by the operating systems, by means of system calls and application programming interfaces. Users interact with operating systems through Command Line Interfaces (CLIs) or Graphical User Interfaces known as GUIs. In short, operating system enables user interaction with computer systems by acting as an interface between users or application programs and the computer hardware. Here is an overview of the different types of operating systems.

Real-time Operating System: It is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main object of real-time operating systems is their quick and predictable response to events. They either have an event-driven or a time-sharing design. An event-driven system switches between tasks based of their priorities while time-sharing operating systems switch tasks based on clock interrupts.

Multi-user and Single-user Operating Systems: The operating systems of this type allow a multiple users to access a computer system concurrently. Time-sharing system can be classified as multi-user systems as they enable a multiple user access to a computer through the sharing of time. Single-user operating systems, as opposed to a multi-user operating system, are usable by a single user at a time. Being able to have multiple accounts on a Windows operating system does not make it a multi-user system. Rather, only the network administrator is the real user. But for a Unix-like operating system, it is possible for two users to login at a time and this capability of the OS makes it a multi-user operating system.

Multi-tasking and Single-tasking Operating Systems: When a single program is allowed to run at a time, the system is grouped under a single-tasking system, while in case the operating system allows the execution of multiple tasks at one time, it is classified as a multi-tasking operating system. Multi-tasking can be of two types namely, pre-emptive or co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. MS Windows prior to Windows 95 used to support cooperative multitasking.

Distributed Operating System: An operating system that manages a group of independent computers and makes them appear to be a single computer is known as a distributed operating system. The development of networked computers that could be linked and communicate with each other, gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.

Embedded System: The operating systems designed for being used in embedded computer systems are known as embedded operating systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE, FreeBSD and Minix 3 are some examples of embedded operating systems.

The operating systems thus contribute to the simplification of the human interaction with the computer hardware. They are responsible for linking application programs with the hardware, thus achieving an easy user access to the computers.
COMMUNICATION AND COMPUTER NETWORK
Thursday, August 27, 2009 8:09 PM

COMMUNICATION AND COMPUTER NETWORK

4.1 INTRODUCTION

Today computer is available in many offices and homes and therefore there is a need to share data and programs among various computers with the advancement of data communication facilities. The communication between computers has increased and it thus it has extended the power of computer beyond the computer room. Now a user sitting at one place can communicate computers of any remote sites through communication channel. The aim of this chapter is to introduce you the various aspects of computer network.

4.2 OBJECTIVES

After going through this lesson you will be in a position to:

*
explain the concept of data communication
*
understand the use of computer network
*
identify different components of computer network
*
identify different types of network
*
explain communication protocols
*
understand what is internet and email and its uses in modern communication
*
appreciate the use of satellite communication.

4.3 DATA COMMUNICATION

We all are acquainted with some sorts of communication in our day to day life. For communication of information and messages we use telephone and postal communication systems. Similarly data and information from one computer system can be transmitted to other systems across geographical areas. Thus data transmission is the movement of information using some standard methods. These methods include electrical signals carried along a conductor, optical signals along an optical fibers and electromagnetic areas.

Suppose a manager has to write several letters to various clients. First he has to use his PC and Word Processing package to prepare his letter. If the PC is connected to all the client's PCs through networking, he can send the letters to all the clients within minutes. Thus irrespective of geographical areas, if PCs are connected through communication channel, the data and information, computer files and any other program can be transmitted to other computer systems within seconds. The modern form of communication like e-mail and Internet is possible only because of computer networking.

Basic Elements of a Communication System

The following are the basic requirements for working of a communication system.

1.
A sender (source) which creates the message to be transmitted.
2.
A medium that carries the message.
3.
A receiver (sink) which receives the message.

In data communication four basic terms are frequently used. They are

*
Data: A collection of facts in raw forms that become information after processing.

*
Signals: Electric or electromagnetic encoding of data.
*
Signaling: Propagation of signals across a communication medium.
*
Transmission: Communication of data achieved by the processing of signals.

4.3.1 Communication Protocols

You may be wondering how do the computers send and receive data across communication links. The answer is data communication software. It is this software that enables us to communicate with other systems. The data communication software instructs computer systems and devices as to how exactly data is to be transferred from one place to another. The procedure of data transformation in the form of software is commonly called protocol.

The data transmission software or protocols perform the following functions for the efficient and error free transmission of data.

1.
Data sequencing: A long message to be transmitted is broken into smaller packets of fixed size for error free data transmission.
2.
Data Routing: It is the process of finding the most efficient route between source and destination before sending the data.
3.
Flow control: All machines are not equally efficient in terms of speed. Hence the flow control regulates the process of sending data between fast sender and slow receiver.
4.
Error Control: Error detecting and recovering is the one of the main function of communication software. It ensures that data are transmitted without any error.

4.3.2 Data Transmission Modes

There are three ways for transmitting data from one point to another

1.
Simplex: In simplex mode the communication can take place in one direction. The receiver receives the signal from the transmitting device. In this mode the flow of information is Uni.-directional. Hence it is rarely used for data communication.
2.
Half-duplex: In half-duplex mode the communication channel is used in both directions, but only in one direction at a time. Thus a half-duplex line can alternately send and receive data.
3.
Full-duplex: In full duplex the communication channel is used in both directions at the same time. Use of full-duplex line improves the efficiency as the line turn-around time required in half-duplex arrangement is eliminated. Example of this mode of transmission is the telephone line.

f8.gif (2583 bytes)

Fig. 4.1

4.3.3 Digital and Analog Transmission

Data is transmitted from one point to another point by means of electrical signals that may be in digital and analog form. So one should know the fundamental difference between analog and digital signals. In analog signal the transmission power varies over a continuous range with respect to sound, light and radio waves. On the other hand a digital signal may assume only discrete set of values within a given range. Examples are computer and computer related equipment. Analog signal is measured in Volts and its frequency in Hertz (Hz). A digital signal is a sequence of voltage represented in binary form. When digital data are to be sent over an analog form the digital signal must be converted to analog form. So the technique by which a digital signal is converted to analog form is known as modulation. And the reverse process, that is the conversion of analog signal to its digital form, is known as demodulation. The device, which converts digital signal into analog, and the reverse, is known as modem.

f7.gif (2968 bytes)

Fig 4.2:Analog Signal

f6.gif (1897 bytes)

Fig 4.3 :Digital Signal

4.3.4 Asynchronous and Synchronous Transmission

Data transmission through a medium can be either asynchronous or synchronous. In asynchronous transmission data is transmitted character by character as you go on typing on a keyboard. Hence there is irregular gaps between characters. However, it is cheaper to implement, as you do not have to save the data before sending. On the other hand, in the synchronous mode, the saved data is transmitted block by block. Each block can contain many characters. Synchronous transmission is well suited for remote communication between a computer and related devices like card reader and printers.

Following are the major communication devices used to day.

1.
Wire Pairs: Wire pairs are commonly used in local telephone communication and for short distance digital data communication. They are usually made up of copper and the pair of wires is twisted together. Data transmission speed is normally 9600 bits per second in a distance of 100 meter.
2.
Coaxial Cables: Coaxial cable is groups of specially wrapped and insulted wires that are able to transfer data at higher rate. They consist of a central copper wire surrounded by an insulation over which copper mesh is placed. They are used for long distance telephone lines and local area network for their noise immunity and faster data transfer.
3.
Microwave: Microwave system uses very high frequency radio signals to transmit data through space. The transmitter and receiver of a microwave system should be in line-of-sight because the radio signal cannot bend. With microwave very long distance transmission is not possible. In order to overcome the problem of line of sight and power amplification of weak signal, repeaters are used at intervals of 25 to 30 kilometers between the transmitting and receiving end.
4.
Communication Satellite: The problem of line-sight and repeaters are overcome by using satellites which are the most widely used data transmission media in modern days. A communication satellite is a microwave relay station placed in outer space. INSAT-1B is such a satellite that can be accessible from anywhere in India. In satellite communication, microwave signal is transmitted from a transmitter on earth to the satellite at space. The satellite amplifies the weak signal and transmits it back to the receiver. The main advantage of satellite communication is that it is a single microwave relay station visible from any point of a very large area. In microwave the data transmission rate is 16 giga bits per second. They are mostly used to link big metropolitan cities.

Top

IN-TEXT QUESTIONS 1

1. What is communication protocol?

2. What is the difference between asynchronous and synchronous transmission?

3. State whether True or False

(a) The basic requirements for working of a communication system are sender medium and receiver.

(b) Electric or Electromagnetic encoding of data is called Transmission.

(c) In full duplex the communication channel is used in both directions at the same time.

(d) Analog signal is measured in Volts and its frequency in Hertz

(e) The technique by which a digital signal is converted to analog form is known as modulation.

Top

4.4 COMPUTER NETWORK

A computer network is an interconnection of various computer systems located at different places. In computer network two or more computers are linked together with a medium and data communication devices for the purpose of communicating data and sharing resources. The computer that provides resources to other computers on a network is known as server. In the network the individual computers, which access shared network resources, are known as workstations or nodes.

Computer Networks may be classified on the basis of geographical area in two broad categories.

1. Local Area Network (LAN)

2. Wide Area Network (WAN)

4.4.1 Local Area Network

Networks used to interconnect computers in a single room, rooms within a building or buildings on one site are called Local Area Network (LAN). LAN transmits data with a speed of several megabits per second (106 bits per second). The transmission medium is normally coaxial cables.

LAN links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited geographical area because they must be connected by a cable, which is quite expensive. People working in LAN get more capabilities in data processing, work processing and other information exchange compared to stand-alone computers. Because of this information exchange most of the business and government organisations are using LAN.

Major Characteristics of LAN

*
every computer has the potential to communicate with any other computers of the network
*
high degree of interconnection between computers
*
easy physical connection of computers in a network
*
inexpensive medium of data transmission
*
high data transmission rate

Advantages

*
The reliability of network is high because the failure of one computer in the network does not effect the functioning for other computers.
*
Addition of new computer to network is easy.
*
High rate of data transmission is possible.
*
Peripheral devices like magnetic disk and printer can be shared by other computers.

Disadvantages

If the communication line fails, the entire network system breaks down.

Use of LAN

Followings are the major areas where LAN is normally used

*
File transfers and Access
*
Word and text processing
*
Electronic message handling
*
Remote database access
*
Personal computing
*
Digital voice transmission and storage

4.4.2 Wide Area Network

The term Wide Area Network (WAN) is used to describe a computer network spanning a regional, national or global area. For example, for a large company the head quarters might be at Delhi and regional branches at Bombay, Madras, Bangalore and Calcutta. Here regional centers are connected to head quarters through WAN. The distance between computers connected to WAN is larger. Therefore the transmission medium used are normally telephone lines, microwaves and satellite links.

4.4.3 Characteristics of WAN

Followings are the major characteristics of WAN.

1.
Communication Facility: For a big company spanning over different parts of the country the employees can save long distance phone calls and it overcomes the time lag in overseas communications. Computer conferencing is another use of WAN where users communicate with each other through their computer system.
2.
Remote Data Entry: Remote data entry is possible in WAN. It means sitting at any location you can enter data, update data and query other information of any computer attached to the WAN but located in other cities. For example, suppose you are sitting at Madras and want to see some data of a computer located at Delhi, you can do it through WAN.
3.
Centralised Information: In modern computerised environment you will find that big organisations go for centralised data storage. This means if the organisation is spread over many cities, they keep their important business data in a single place. As the data are generated at different sites, WAN permits collection of this data from different sites and save at a single site.

4.4.4 Examples of WAN

1.
Ethernet: Ethernet developed by Xerox Corporation is a famous example of WAN. This network uses coaxial cables for data transmission. Special integrated circuit chips called controllers are used to connect equipment to the cable.
2.
Aparnet: The Aparnet is another example of WAN. It was developed at Advanced Research Projects Agency of U. S. Department. This Network connects more than 40 universities and institutions throughout USA and Europe.

Difference between LAN and WAN

*
LAN is restricted to limited geographical area of few kilometers. But WAN covers great distance and operate nationwide or even worldwide.

*
In LAN, the computer terminals and peripheral devices are connected with wires and coaxial cables. In WAN there is no physical connection. Communication is done through telephone lines and satellite links.

*
Cost of data transmission in LAN is less because the transmission medium is owned by a single organisation. In case of WAN the cost of data transmission is very high because the transmission medium used are hired, either telephone lines or satellite links.

*
The speed of data transmission is much higher in LAN than in WAN. The transmission speed in LAN varies from 0.1 to 100 megabits per second. In case of WAN the speed ranges from 1800 to 9600 bits per second (bps).

*
Few data transmission errors occur in LAN compared to WAN. It is because in LAN the distance covered is negligible.

4.5 NETWORK TOPOLOGY

The term topology in the context of communication network refers to the way the computers or workstations in the network are linked together. According to the physical arrangements of workstations and nature of work, there are three major types of network topology. They are star topology, bus topology and ring topology.

4.5.1 Star topology

In star topology a number of workstations (or nodes) are directly linked to a central node (see, Fig. 4.3). Any communication between stations on a star LAN must pass through the central node. There is bi-directional communication between various nodes. The central node controls all the activities of the nodes. The advantages of the star topology are:

*
It offers flexibility of adding or deleting of workstations from the network.
*
Breakdown of one station does not affect any other device on the network.

The major disadvantage of star topology is that failure of the central node disables communication throughout the whole network.

f9.gif (2765 bytes)

Fig. 4.3: Star Topology

4.5.2 Bus Topology

In bus topology all workstations are connected to a single communication line called bus. In this type of network topology there is no central node as in star topology. Transmission from any station travels the length of the bus in both directions and can be received by all workstations. The advantage of the bus topology is that

*
It is quite easy to set up.
*
If one station of the topology fails it does not affect the entire system.

The disadvantage of bus topology is that any break in the bus is difficult to identify.

f10.gif (3218 bytes)

Fig. 4.4: Bus Topology

4.5.3 Ring Topology

In ring topology each station is attached nearby stations on a point to point basis so that the entire system is in the form of a ring. In this topology data is transmitted in one direction only. Thus the data packets circulate along the ring in either clockwise or anti-clockwise direction. The advantage of this topology is that any signal transmitted on the network passes through all the LAN stations. The disadvantage of ring network is that the breakdown of any one station on the ring can disable the entire system.

f11.gif (2872 bytes)

Fig. 4.5: Ring Topology

IN-TEXT QUESTIONS 2

1.
Differentiate between LAN and WAN.
2.
What are the different types of network topology?
3.
State True or False

(a) Networks used to interconnect computers in a single room, rooms within a building or buildings on one site are called Wide Area Network (WAN).

(b) The term Wide Area Network (WAN) is used to describe a computer network spanning a regional, national or global area.

(c) The speed of data transmission is much higher in WAN than in LAN.

(d) In star topology a number of workstations (or nodes) are directly linked to a central node.

(e) The advantage of the bus topology is that, If one station of the topology fails it does not affect the entire system.

Top

4.6 INTERNET

The Internet is a network of networks. Millions of computers all over the world are connected through the Internet. Computer users on the Internet can contact one another anywhere in the world. If your computer is connected to the Internet, you can connect to millions of computers. You can gather information and distribute your data. It is very much similar to the telephone connection where you can talk with any person anywhere in the world.

In Internet a huge resource of information is accessible to people across the world. Information in every field starting from education, science, health, medicine, history, and geography to business, news, etc. can be retrieved through Internet. You can also download programs and software packages from anywhere in the world. Due to the tremendous information resources the Internet can provide, it is now indispensable to every organisation.

Origin of Internet

In 1969 Department of Defence (DOD) of USA started a network called ARPANET (Advanced Research Projects Administration Network) with one computer at California and three at Utah. Later on other universities and R & D institutions were allowed to connect to the Network. APARNET quickly grew to encompass the entire American continent and became a huge success. Every university in the country wanted to become a part of ARPANET. So the network was broken into two smaller parts MILNET for managing military sites and ARPANET (smaller) for managing non-military sites. Around 1980, NSFNET (National Science Foundation Network) was created. With the advancement of modern communication facilities, other computers were also allowed to be linked up with any computer of NSFNET. By 1990 many computers were looking up to NSFNET giving birth to Internet.

How Internet functions

Internet is not a governmental organisation. The ultimate authority of the Internet is the Internet Society. This is a voluntary membership organisation whose purpose is to promote global information exchange. Internet has more than one million computers attached to it.

E-mail

E-mail stands for electronic mail. This is one of the most widely used features of Internet. Mails are regularly used today where with the help of postage stamp we can transfer mails anywhere in the world. With electronic mail the service is similar. But here data are transmitted through Internet and therefore within minutes the message reaches the destination may it be anywhere in the world. Therefore the mailing system is excessively fast and is being used widely for mail transfer.

Top

IN-TEXT QUESTIONS 3

1.
What is Internet?
2.
What is e-mail?
3.
How does Internet function?

4.7 WHAT YOU HAVE LEARNT

In this lesson we discussed the importance and modes of communication through computers. Computers can communicate with one another through computer networking. There are two types of computer network: LAN and WAN. We discussed about the physical arrangements of computer and peripherals in network topology. There are three types of network topology: star topology, bus topology and ring topology. Also we discussed about Internet and e-mail.

4.8 TERMINAL QUESTIONS

1.
What is computer Network? What are its main objectives?
2.
Differentiate between analog and digital transmission of data.
3.
Explain in brief different communication media.
4.
What is the difference between simplex and full-duplex transmission?

4.9 FEEDBACK TO IN-TEXT QUESTIONS

IN-TEXT QUESTIONS 1

1.
The data communication software instructs computer systems and devices as to how exactly data is to be transferred from one place to another. The procedure of data transformation in the form of software is commonly called protocol.
2.
In asynchronous transmission data is transmitted character by character as you go on typing on a keyboard. On the other hand, in the synchronous mode, the saved data is transmitted block by block.
3.
(a) True (b) False (c) True (d) True (e) True

IN-TEXT QUESTIONS 2

1.
LAN is restricted to limited geographical area whereas WAN covers great distance. In LAN the computer terminals and peripheral devices are connected with wires and coaxial cables whereas in WAN communication is done through telephone lines and satellite links. The speed of data transmission is much higher in LAN than in WAN.
2.
There are three major types of network topology. They are star topology, bus topology and ring topology.
3.
(a) False (b) True (c) False (d) True (e) True

IN-TEXT QUESTIONS 3

1.
The Internet is a network of networks. Information in every field starting from education, science, health, medicine, history, and geography to business, news, etc. can be retrieved through Internet.
2.
E-mail stands for electronic mail. Through e-mail we can transfer data anywhere in the world within seconds.
3.
Internet is not a governmental organisation. The ultimate authority of the Internet is the Internet Society. This is a voluntary membership organisation whose purpose is to promote global information exchange.

Thursday, August 27, 2009 8:06 PM

Hardware device listing

What is hardware?

Hardware is best described as a device that is physically connected to your computer or something that can be physically touched. A CD-ROM,monitor, and printer are all examples of computer hardware.

Cleaning hardware

Information on how to clean any of your computer hardware components can be found on our cleaning page.

drivers

If you are looking for driversfor hardware devices, we have a list on our drivers page.

Adding hardware

Additional information and help with adding or installing computer hardware components can be found ondocument CHADD.

How hardware can cause issues

Computer hardware requires resources to correctly operate with the computer and the software installed in the computer. If your computer does not have the available resources, such as availableIRQs, this will cause your computer to not properly work and/or the devices to not function properly.

In addition to needing resources, not all computer hardware will work properly with all computers, or may have incompatibilities with hardware that is already installed in your computer.

Finally, almost all computer hardware requires some type of software or drivers to be installed before it can properly communicate with the computer. If these drivers contain problems or do not properly work with the computer, this can cause issues with the hardware device you are attempting to install in the computer.

Please click on the below beginning letters of the hardware device you are looking for, or scroll down to see a complete listing.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

COMPUTER COMMUNICATIONS
Thursday, August 27, 2009 8:05 PM

1.INTRODUCTION

The transfer of information between computers is called computer communication. communication between computer is done through computer networks.

2.NETWORK:

The collection of machine / computer that share data and information through interconnected lines of communication is called network. Data and information are

Shard through this network.

3.REASONS FOR NETWORK

Sharing of resources: many valuable resources such as printers, plotters and other devices can be between more than one computer.

Sharing of information: information which is store in one computer can be shard between other computers. communication.

Communication: computer connected in a network can be used for communication between them.

4.APPLICATION OF NETWORK

*
at home. E –mail facility
*
Used for entertainment purpose.
*
Accessing information through world wide web.
*
Video conferencing
*
Providing information to individuals

5.BENEFITS OF NETWORK

*
Interactive environment.
*
Valuable resources can be shared.
*
Access to remote information.
*
Used for entertainment purpose.

6.TYPES OF NETWORK

*
LAN(local area network)
*
MAN(metropolitan area network)
*
WAN(wide area network)
*
GAN(global area network)

7.NETWORK TOPOLOGY

*
Star topology.
*
Bus topology.
*
Ring topology `

Timeline of Computer History
Thursday, August 27, 2009 8:03 PM

'39 '40 '41 '42 '43 '44 '45 '46 '47 '48
'49 '50 '51 '52 '53 '54 '55 '56 '57 '58
'59 '60 '61 '62 '63 '64 '65 '66 '67 '68
'69 '70 '71 '72 '73 '74 '75 '76 '77 '78
'79 '80 '81 '82 '83 '84 '85 '86 '87 '88
'89 '90 '91 '92 '93 '94

Companies
Components
Computers
Graphics & Games
Networking
People & Pop Culture
Robots & Artificial Intelligence
Software & Languages
Storage

WHAT THE TIMELINE IS
This timeline explores the history of computing from 1939 to 1994. Each year features illustrated descriptions of significant innovations in hardware and software technology, as well as milestones in areas such as commercial applications and artificial intelligence. When appropriate, biographical sketches of the pioneers responsible for the advances are included.

HOW THE TIMELINE WORKS
Across the top of this and every timeline is a graphic with the years from 1939 to 1994 displayed as well as seven topical areas. Clicking on any of these will take you to a page of historic information containing photos and descriptive text for that year or topic.

The timeline can either be browsed using the links above (and appropriate Previous/Next and More links on each page) or searched for specific events.

About the Museum Exhibits Collections What's Happening Giving About This Site
Privacy Copyright Feedback Credits Advanced Search Site Map
COMPUTER DEFINITION
Thursday, August 27, 2009 8:02 PM
A computer is a machine that manipulates data according to a set of instructions.

Although mechanical examples of computers have existed through much of recorded human history, the first resembling a modern computer were developed in the mid-20th century (1940–1945). The first electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers (PC).Modern computers based on tiny 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, what most people think of as a "computer", but the embedded computers found in devices ranging from fighter aircraft to industrial robots, digital cameras, and toys are 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 personal digital assistant to a supercomputer are all able to perform the same computational tasks, given enough time and storage capacity.

BOOKS

2009-11-14T22:53:00.000-08:00

BUSINESSLOAN

2009-11-14T22:44:00.000-08:00

LOANS

2009-11-14T22:39:00.001-08:00

The Advantages of Digital Cameras

2009-11-07T00:28:00.000-08:00

There was a time when people could scarcely imagine the pictures they took with their cameras being instantly available, because the procedure of developing and printing a film was so time consuming. Leaving aside the full history of the camera, and just looking at the past two decades, we can see that camera technology has improved dramatically. It was only ten years ago that we used to use cameras with reels of film, with about thirty to forty shots on one reel.

Whenever you went to a picnic, a wedding or a party, you put a new reel of film into your camera and took the photos. Then you went to a photo shop where you handed the reel over to a shop assistant, and after ten to fifteen days, he returned your pictures to you in hard copy form. But if we talk about the past five years, then it's a completely different story. Now you can take your picture and view the image instantly. This has all happened due to the arrival of digital cameras.

The first camera that allowed the transfer of images to the computer was invented in 1994 by Kodak. But at that time, people were not so aware of the technology and the cameras were very expensive. However within the last five to six years digital cameras have become so popular and easy to use that companies like Sony, Canon, Nikon and Kodak have developed mass produced versions of the cameras that are reasonably priced, compact and easy to use. Now all you have to do with your digital camera is just take a shot and see the results for yourself. If you do not like it, you can just delete it.

Another advantage of the digital camera is its capacity. You can have more than a thousand pictures at once on your digital camera. You do not need to worry about the capacity of the camera to save pictures. With the help of a memory card, you can even save the data from your digital camera.

Digital cameras can also be used to make movies, but they do have time limits in this respect. Digital cameras also provide you with some photo editing software that can help you to create, edit, delete and reshape your pictures in different frames and sizes. Digital cameras are built to function with computer systems. You just need a transfer cable which is provided with almost every camera and you can transfer your pictures and movies onto your computer where you can save them for a long time. This can really help people to show their pictures to their relatives worldwide. You can even make hard copy prints of your digital camera photos using your own printer, or by going to the photo shop.

Digital cameras are convenient and easy to carry around. They are more efficient than traditional cameras, and their good resolution with high pixel density makes their images very clear and powerful.

Digital cameras are in common use nowadays and are available at really affordable prices, so it is time for you to get a digital camera for yourself and enjoy your photography

Hardware Tips

2009-08-27T23:04:00.000-07:00

Computer hardware includes the physical parts, digital circuitry inside the computer. Different hardware components collectively make a computer unit. Computer with weaker security settings, faulty hardware devices, misconfigurations and outdated software are suffered with different kind of problems. Regardless of the computer hardware problems, there are few basic steps that can avoid many problems. The hardware problems lead to the error messages, system boot up problems, noise from the devices, blue screen errors and the system crash.

Normally computer hardware problems are easier to resolve than the software problems. To troubleshoot the system’s hardware related problems, you should have the right tools and techniques. To identify the hardware failure in your system, you need to use a diagnostic utility. It will help you to find out the right cause of the problem.

Hard Disk

Use a hard disk diagnos
tic utility to check the status of your hard disk.
Use UPS with your system, it will help your hard disk to avoid bad sectors due to the power failure.
Regularly scan your hard disk for the viruses, spware, adware, Trojans and other threats.
Don’t shake or vibr
ate your computer while it is working.
If your hard disk finds the logical bad sectors, it can be removed with the formatting.

Memory

Insert the memory sticks in the memory slots tightly.
If case of memory related errors, change the memory modules and check the status.

In case of persistent problems, change the memory sticks with the new one.
If your system freezes up or response slo
w, increase the amount of memory inside your system.

VGA Card

Insert the VGA tightly in the PCI slot of your computer.
In case of no display on your monitor screen, check the VGA cables and make sure that it connected tightly.
Make sure that you are using the updated driver for your VGA card.

LAN Card

Check whether the LED lights of the LAN card are blinking or not.
Check to see that the UPT/STP cable should be properly connected at both ends i.e. one end in the LAN card and the other in the switch/HUB etc.
Make sure that the LAN card’s driver is up-to-dated.

If you LAN card’s issue still not resolved, replace it with a new one and reconfigure it.

Printer

Make sure that you are using the up-to-dated driver for the printer.
To get the optimized performance from your printer, select the “Best Quality” in the properties of your printer.
Clean your printer regularly with soft cloth and cleansing lotion.
Power down your printer properly.
If you are using more than one printer in your network, make sure that you are using a very descriptive name of your printers.
For getting the technical and additional information about your printer consult the printer’s manual.
Run the inkjet printer's cartridge-cleaning utility.

Miscellaneous Tips

Avoid vibrations and shocks to your computer system while it is working.
Before changing any hardware device inside your computer first shut down the computer and unplug it.
Don’t put any liquid or drinks near your computer hardware.
Keep the air filters and the ventilation paths clean to provide the easy passage to the air in and outside of the computer.
Plug the computer devices’ cables, connectors and screw tightly.
Use UPS (uninterrupted power supply) to avoid the data lost of system crash due to the power failure.
Use POST card in your computer. POST stands for Power On Self Test it helps to troubleshoot the common startup problems.
Use the Device Manager utility in the Windows based computer to diagnose and troubleshoot the devices problems in your computer.
To avoid the overheating in your computer, make sure that the processor and the computer fans are working fine.
Always keep the case of your computer close.
When your newly installed hardware device does not work, it is most likely due to the hardware conflict, incompatibility, misconfigurations, outdated drives and loose cable connections. You also need to follow the manufacturer’s instructions carefully.
If you are a computer hardware technician, make sure that your toolkit is equipped with the screw drives, extra jumpers blocks, masking tape, compressed air, flash light, bootable cds, devices’ drivers, hardware diagnostic utilities, connectors and testers.

Seven Essential Hardware Buying Tips

2009-08-27T23:01:00.001-07:00

Buy a recognised brand name or from a reputable dealer.
Buy a complete system from one manufacturer, so there are no arguments about support if things go wrong.
Get a next business day, three-year, on-site warranty.
Don’t cut corners when it comes to your comfort: spend extra on a good mouse and keyboard and a large, high-quality monitor.
Avoid cutting edge technologies and processors. You’ll pay a premium for them and they may still have kinks and bugs that need to be worked out.
Assume your needs will grow. You may think “I don’t need a high-speed Internet connection” or “The only thing I need is a word processor” now; that’s almost guaranteed to change within the life of your hardware.
Don’t buy cheaply and plan to upgrade in a year or so. It’s a much better investment and far less pitfall-ridden to buy a quality, powerful system that will give you a solid three-to-five year’s life.

Windows Vista Review

2009-08-27T22:45:00.000-07:00

It's been five years in the making. Hundreds of thousands of man hours have gone into its development. Millions of words have already been written about it. Some have already written it off, others can't wait to get their hands on a copy.

Finally it's here. This is the latest episode in the Microsoft soap opera. This is Windows Vista. Has it been worth the wait?

On the face of it, Vista has its work cut out. There's no doubt that the move from XP to Vista was never going to be as dramatic or ground shaking as the move from the much-derided Windows 98 to XP, no matter how hard the Microsoft spin machine worked at convincing us it was. After all, there's not nearly quite so much to fix with XP, which has, by-and-large, done a decent job of running home, business and, latterly, entertainment PCs throughout the land for a good while now.

There has been the odd security bump along the way and, sure, it has the odd annoying foible, but apart from the fact that it's beginning to look a little long in the tooth, XP is still in rude health. Has Vista got enough in its locker to persuade millions of users to make the switch? Read on to find out…

Just Window Dressing?

Cynics will tell you that Vista is just XP with a brand new wardrobe - underneath it's just the same old operating system. And yes, to a certain extent that's true. But in the case of Vista's rather swish-looking Aero interface, it's more than just pretty version of XP. This is a makeover that's worthy of the name.

If your PC or laptop has the hardware (we'll deal with this issue in more depth later) you'll get transparent windows that let you see through them to what's behind and much more sophisticated animations than with XP. Minimised Windows fade out and gracefully slide into the taskbar, live previews appear as you hover over minimised application buttons in the taskbar, and the whole look and feel is a lot more mature than XP. If you've downloaded and used Windows Media Player 11, you'll already have a good idea of how Vista shapes up – it's slick, no doubt about it.

There are other ways in which Vista shows off its new 3D capabilities though, apart from the transparency and glass effects. There is now an alternative to the old Alt-Tab method of switching between applications called Flip 3D. Hit the Windows key and Tab and instead of flat, anonymous icons, you get previews of all your currently open windows stacked in 3D. Hit Tab while holding down the Windows key and the stack smoothly cycles through each one, just like a virtual Rolodex. The more frivolous sidebar is a nice touch too. This takes a similar - albeit altogether more attractive - approach to Google's Desktop sidebar. You can dock various 'gadgets' here, including a clock, sticky notes, an RSS news feeder, a photo slideshow, contact list and various other handy mini-applications.

Types of Computer Hardware

2009-08-27T22:41:00.000-07:00

Computer hardware is a physical part of a computer that executes within the hardware. It is unlike computer software or data that can be frequently changed, modified or erased on a computer. Computer hardware is not frequently changed and so is stored in hardware devices such as read only memory (ROM) where it is not readily changed.

Most computer hardware is embedded and so is not visible to normal users. Below are the different types of hardware's found in a computer.

 Motherboard: It is the central or primary circuit board
making up a complex electronic system such as a computer. A motherboard is also known as a main board, logic board or system board.
 Central processing Unit: A CPU is the main component of a digital computer that interprets instructions and process data in computer programs.

 Random Access Memory: A RAM allows the stored data to be accessed in any order. RAM is considered as the main memory of the computer where the working area is used for displaying and manipulating data.
 Basic Input Output System: BIOS prepares the software programs to load, execute and control the computer.
 Power Supply: Power Supply supplies electrical energy to an output load or group of loads.
 Video Display Controller: It converts the logical representation of visual information into a signal that can be used as input for a display medium.
 Computer Bus: It is used to transfer data or power between computer components inside a computer or between computers.
 CD-ROM drive: It contains data accessible by a computer

 Floppy disk: It is a data storage device
 Zip Drive: It is a medium capacity removable disk storage system.
 Hard Disk: It is a non-volatile data storage system that stores data on a magnetic surface layered unto hard disk platters.

Computer Hardware and Software Company in Bangalore ,India

2009-08-27T22:28:00.000-07:00

The Computer Hardware and Software industry of Bangalore is regarded as the focal point of advanced technology that acts as the prime catalyst in the economic growth of the city. Housing the biggest international names of Information Technology, Bangalore is referred as the Silicon Valley of India.

With the widening of the global business horizon, Bangalore has emerged as the key player in the field of Information Technology and Information Technology enabled services. From proposed plans of Hardware Park to a thriving Business Process Outsourcing sector, Bangalore is progressing beyond leaps and bounds.

The city deals with the latest models of Hardware tools, Computer parts, Software programmes and accessories. The newest developments in the Software programming domain enable Bangalore to compete with the best IT brands of the world.

Facilitated by a remarkably skilled and efficient lot of Hardware and Software professionals, the city truly fulfills all the criterion of being the IT capital of the country.

The major IT and ITes organizations of global repute that add credibility to the Computer Hardware and Software contours of Bangalore are:

Microsoft Corporation
IBM Global Services Ltd.
Infosys Technologies Ltd.
Intel Asia Electronics Inc.
ITC Ltd. – Information Systems Div.
Oracle Software (I) Ltd.
SAP India Pvt. Ltd.
Satyam Computer Services Ltd.
Tata Consultancy Services
Wipro Infotech Group
Dell Asia Pacific SDN
Citicorp
CMC Ltd.
Aptech Ltd.
Compaq India
Tata Infotech Ltd.
Verifone
TVS Electronics South Asia (P) Ltd.
Tata Honeywell Ltd.
Tektronix India Ltd.

To take India to greater heights of virtual development, the Computer Hardware and Software segment of Bangalore is consistently making new and globally acclaimed technological strides.

Major Types of Software

2009-08-27T22:23:00.000-07:00

Programming Software: This is one of the most commonly known and popularly used forms of computer software. These software come in forms of tools that assist a programmer in writing computer programs. Computer programs are sets of logical instructions that make a computer system perform certain tasks. The tools that help the programmers in instructing a computer system include text editors, compilers and interpreters.

System Software: It helps in running the computer hardware and the computer system. System software is a collection of operating systems; devise drivers, servers, windowing systems and utilities. System software helps an application programmer in abstracting away from hardware, memory and other internal complexities of a computer.

Application Software: It enables the end users to accomplish certain specific tasks. Business software, databases and educational software are some forms of application software. Different word processors, which are dedicated for specialized tasks to be performed by the user, are other examples of application software.

Apart from these three basic types of software, there are some other well-known forms of computer software like inventory management software, ERP, utility software, accounting software and others. Take a look at some of them.

Inventory Management Software: This type of software helps an organization in tracking its goods and materials on the basis of quality as well as quantity. Warehouse inventory management functions encompass the internal warehouse movements and storage. Inventory software helps a company in organizing inventory and optimizing the flow of goods in the organization, thus leading to an improved customer service.

Utility Software: Also known as service routine, utility software helps in the management of computer hardware and application software. It performs a small range of tasks. Disk defragmenters, systems utilities and virus scanners are some of the typical examples of utility software.

Data Backup and Recovery Software: An ideal data backup and recovery software provides functionalities beyond simple copying of data files. This software often supports user needs of specifying what is to be backed up and when. Backup and recovery software preserve the original organization of files and allow an easy retrieval of the backed up data.

OPERATING SYSTEMS

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Different Types of Operating Systems

Operating systems that create a link between users and the applications form the core of computer systems. It dissociates the programs and the hardware and simplifies resource management. Let us look at the different types of operating systems.

An operating system is a software component of a computer system that is responsible for the management of various activities of the computer and the sharing of computer resources. It hosts the several applications that run on a computer and handles the operations of computer hardware. Users and application programs access the services offered by the operating systems, by means of system calls and application programming interfaces. Users interact with operating systems through Command Line Interfaces (CLIs) or Graphical User Interfaces known as GUIs. In short, operating system enables user interaction with computer systems by acting as an interface between users or application programs and the computer hardware. Here is an overview of the different types of operating systems.

Real-time Operating System: It is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main object of real-time operating systems is their quick and predictable response to events. They either have an event-driven or a time-sharing design. An event-driven system switches between tasks based of their priorities while time-sharing operating systems switch tasks based on clock interrupts.

Multi-user and Single-user Operating Systems: The operating systems of this type allow a multiple users to access a computer system concurrently. Time-sharing system can be classified as multi-user systems as they enable a multiple user access to a computer through the sharing of time. Single-user operating systems, as opposed to a multi-user operating system, are usable by a single user at a time. Being able to have multiple accounts on a Windows operating system does not make it a multi-user system. Rather, only the network administrator is the real user. But for a Unix-like operating system, it is possible for two users to login at a time and this capability of the OS makes it a multi-user operating system.

Multi-tasking and Single-tasking Operating Systems: When a single program is allowed to run at a time, the system is grouped under a single-tasking system, while in case the operating system allows the execution of multiple tasks at one time, it is classified as a multi-tasking operating system. Multi-tasking can be of two types namely, pre-emptive or co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. MS Windows prior to Windows 95 used to support cooperative multitasking.

Distributed Operating System: An operating system that manages a group of independent computers and makes them appear to be a single computer is known as a distributed operating system. The development of networked computers that could be linked and communicate with each other, gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.

Embedded System: The operating systems designed for being used in embedded computer systems are known as embedded operating systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE, FreeBSD and Minix 3 are some examples of embedded operating systems.

The operating systems thus contribute to the simplification of the human interaction with the computer hardware. They are responsible for linking application programs with the hardware, thus achieving an easy user access to the computers.

COMMUNICATION AND COMPUTER NETWORK

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COMMUNICATION AND COMPUTER NETWORK

4.1 INTRODUCTION

Today computer is available in many offices and homes and therefore there is a need to share data and programs among various computers with the advancement of data communication facilities. The communication between computers has increased and it thus it has extended the power of computer beyond the computer room. Now a user sitting at one place can communicate computers of any remote sites through communication channel. The aim of this chapter is to introduce you the various aspects of computer network.

4.2 OBJECTIVES

After going through this lesson you will be in a position to:

explain the concept of data communication
understand the use of computer network
identify different components of computer network
identify different types of network
explain communication protocols
understand what is internet and email and its uses in modern communication
appreciate the use of satellite communication.

4.3 DATA COMMUNICATION

We all are acquainted with some sorts of communication in our day to day life. For communication of information and messages we use telephone and postal communication systems. Similarly data and information from one computer system can be transmitted to other systems across geographical areas. Thus data transmission is the movement of information using some standard methods. These methods include electrical signals carried along a conductor, optical signals along an optical fibers and electromagnetic areas.

Suppose a manager has to write several letters to various clients. First he has to use his PC and Word Processing package to prepare his letter. If the PC is connected to all the client's PCs through networking, he can send the letters to all the clients within minutes. Thus irrespective of geographical areas, if PCs are connected through communication channel, the data and information, computer files and any other program can be transmitted to other computer systems within seconds. The modern form of communication like e-mail and Internet is possible only because of computer networking.

Basic Elements of a Communication System

The following are the basic requirements for working of a communication system.

A sender (source) which creates the message to be transmitted.
A medium that carries the message.
A receiver (sink) which receives the message.

In data communication four basic terms are frequently used. They are

Data: A collection of facts in raw forms that become information after processing.

Signals: Electric or electromagnetic encoding of data.
Signaling: Propagation of signals across a communication medium.
Transmission: Communication of data achieved by the processing of signals.

4.3.1 Communication Protocols

You may be wondering how do the computers send and receive data across communication links. The answer is data communication software. It is this software that enables us to communicate with other systems. The data communication software instructs computer systems and devices as to how exactly data is to be transferred from one place to another. The procedure of data transformation in the form of software is commonly called protocol.

The data transmission software or protocols perform the following functions for the efficient and error free transmission of data.

Data sequencing: A long message to be transmitted is broken into smaller packets of fixed size for error free data transmission.
Data Routing: It is the process of finding the most efficient route between source and destination before sending the data.
Flow control: All machines are not equally efficient in terms of speed. Hence the flow control regulates the process of sending data between fast sender and slow receiver.
Error Control: Error detecting and recovering is the one of the main function of communication software. It ensures that data are transmitted without any error.

4.3.2 Data Transmission Modes

There are three ways for transmitting data from one point to another

Simplex: In simplex mode the communication can take place in one direction. The receiver receives the signal from the transmitting device. In this mode the flow of information is Uni.-directional. Hence it is rarely used for data communication.
Half-duplex: In half-duplex mode the communication channel is used in both directions, but only in one direction at a time. Thus a half-duplex line can alternately send and receive data.
Full-duplex: In full duplex the communication channel is used in both directions at the same time. Use of full-duplex line improves the efficiency as the line turn-around time required in half-duplex arrangement is eliminated. Example of this mode of transmission is the telephone line.

Fig. 4.1

4.3.3 Digital and Analog Transmission

Data is transmitted from one point to another point by means of electrical signals that may be in digital and analog form. So one should know the fundamental difference between analog and digital signals. In analog signal the transmission power varies over a continuous range with respect to sound, light and radio waves. On the other hand a digital signal may assume only discrete set of values within a given range. Examples are computer and computer related equipment. Analog signal is measured in Volts and its frequency in Hertz (Hz). A digital signal is a sequence of voltage represented in binary form. When digital data are to be sent over an analog form the digital signal must be converted to analog form. So the technique by which a digital signal is converted to analog form is known as modulation. And the reverse process, that is the conversion of analog signal to its digital form, is known as demodulation. The device, which converts digital signal into analog, and the reverse, is known as modem.

Fig 4.2:Analog Signal

Fig 4.3 :Digital Signal

4.3.4 Asynchronous and Synchronous Transmission

Data transmission through a medium can be either asynchronous or synchronous. In asynchronous transmission data is transmitted character by character as you go on typing on a keyboard. Hence there is irregular gaps between characters. However, it is cheaper to implement, as you do not have to save the data before sending. On the other hand, in the synchronous mode, the saved data is transmitted block by block. Each block can contain many characters. Synchronous transmission is well suited for remote communication between a computer and related devices like card reader and printers.

Following are the major communication devices used to day.

Wire Pairs: Wire pairs are commonly used in local telephone communication and for short distance digital data communication. They are usually made up of copper and the pair of wires is twisted together. Data transmission speed is normally 9600 bits per second in a distance of 100 meter.
Coaxial Cables: Coaxial cable is groups of specially wrapped and insulted wires that are able to transfer data at higher rate. They consist of a central copper wire surrounded by an insulation over which copper mesh is placed. They are used for long distance telephone lines and local area network for their noise immunity and faster data transfer.
Microwave: Microwave system uses very high frequency radio signals to transmit data through space. The transmitter and receiver of a microwave system should be in line-of-sight because the radio signal cannot bend. With microwave very long distance transmission is not possible. In order to overcome the problem of line of sight and power amplification of weak signal, repeaters are used at intervals of 25 to 30 kilometers between the transmitting and receiving end.
Communication Satellite: The problem of line-sight and repeaters are overcome by using satellites which are the most widely used data transmission media in modern days. A communication satellite is a microwave relay station placed in outer space. INSAT-1B is such a satellite that can be accessible from anywhere in India. In satellite communication, microwave signal is transmitted from a transmitter on earth to the satellite at space. The satellite amplifies the weak signal and transmits it back to the receiver. The main advantage of satellite communication is that it is a single microwave relay station visible from any point of a very large area. In microwave the data transmission rate is 16 giga bits per second. They are mostly used to link big metropolitan cities.

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IN-TEXT QUESTIONS 1

1. What is communication protocol?

2. What is the difference between asynchronous and synchronous transmission?

3. State whether True or False

(a) The basic requirements for working of a communication system are sender medium and receiver.
(b) Electric or Electromagnetic encoding of data is called Transmission.
(c) In full duplex the communication channel is used in both directions at the same time.
(d) Analog signal is measured in Volts and its frequency in Hertz
(e) The technique by which a digital signal is converted to analog form is known as modulation.

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4.4 COMPUTER NETWORK

A computer network is an interconnection of various computer systems located at different places. In computer network two or more computers are linked together with a medium and data communication devices for the purpose of communicating data and sharing resources. The computer that provides resources to other computers on a network is known as server. In the network the individual computers, which access shared network resources, are known as workstations or nodes.

Computer Networks may be classified on the basis of geographical area in two broad categories.

1. Local Area Network (LAN)

2. Wide Area Network (WAN)

4.4.1 Local Area Network

Networks used to interconnect computers in a single room, rooms within a building or buildings on one site are called Local Area Network (LAN). LAN transmits data with a speed of several megabits per second (10⁶ bits per second). The transmission medium is normally coaxial cables.

LAN links computers, i.e., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited geographical area because they must be connected by a cable, which is quite expensive. People working in LAN get more capabilities in data processing, work processing and other information exchange compared to stand-alone computers. Because of this information exchange most of the business and government organisations are using LAN.

Major Characteristics of LAN

every computer has the potential to communicate with any other computers of the network
high degree of interconnection between computers
easy physical connection of computers in a network
inexpensive medium of data transmission
high data transmission rate

Advantages

The reliability of network is high because the failure of one computer in the network does not effect the functioning for other computers.
Addition of new computer to network is easy.
High rate of data transmission is possible.
Peripheral devices like magnetic disk and printer can be shared by other computers.

Disadvantages

If the communication line fails, the entire network system breaks down.

Use of LAN

Followings are the major areas where LAN is normally used

File transfers and Access
Word and text processing
Electronic message handling
Remote database access
Personal computing
Digital voice transmission and storage

4.4.2 Wide Area Network

The term Wide Area Network (WAN) is used to describe a computer network spanning a regional, national or global area. For example, for a large company the head quarters might be at Delhi and regional branches at Bombay, Madras, Bangalore and Calcutta. Here regional centers are connected to head quarters through WAN. The distance between computers connected to WAN is larger. Therefore the transmission medium used are normally telephone lines, microwaves and satellite links.

4.4.3 Characteristics of WAN

Followings are the major characteristics of WAN.

Communication Facility: For a big company spanning over different parts of the country the employees can save long distance phone calls and it overcomes the time lag in overseas communications. Computer conferencing is another use of WAN where users communicate with each other through their computer system.
Remote Data Entry: Remote data entry is possible in WAN. It means sitting at any location you can enter data, update data and query other information of any computer attached to the WAN but located in other cities. For example, suppose you are sitting at Madras and want to see some data of a computer located at Delhi, you can do it through WAN.
Centralised Information: In modern computerised environment you will find that big organisations go for centralised data storage. This means if the organisation is spread over many cities, they keep their important business data in a single place. As the data are generated at different sites, WAN permits collection of this data from different sites and save at a single site.

4.4.4 Examples of WAN

Ethernet: Ethernet developed by Xerox Corporation is a famous example of WAN. This network uses coaxial cables for data transmission. Special integrated circuit chips called controllers are used to connect equipment to the cable.
Aparnet: The Aparnet is another example of WAN. It was developed at Advanced Research Projects Agency of U. S. Department. This Network connects more than 40 universities and institutions throughout USA and Europe.

Difference between LAN and WAN

LAN is restricted to limited geographical area of few kilometers. But WAN covers great distance and operate nationwide or even worldwide.

In LAN, the computer terminals and peripheral devices are connected with wires and coaxial cables. In WAN there is no physical connection. Communication is done through telephone lines and satellite links.

Cost of data transmission in LAN is less because the transmission medium is owned by a single organisation. In case of WAN the cost of data transmission is very high because the transmission medium used are hired, either telephone lines or satellite links.

The speed of data transmission is much higher in LAN than in WAN. The transmission speed in LAN varies from 0.1 to 100 megabits per second. In case of WAN the speed ranges from 1800 to 9600 bits per second (bps).

Few data transmission errors occur in LAN compared to WAN. It is because in LAN the distance covered is negligible.

4.5 NETWORK TOPOLOGY

The term topology in the context of communication network refers to the way the computers or workstations in the network are linked together. According to the physical arrangements of workstations and nature of work, there are three major types of network topology. They are star topology, bus topology and ring topology.

4.5.1 Star topology

In star topology a number of workstations (or nodes) are directly linked to a central node (see, Fig. 4.3). Any communication between stations on a star LAN must pass through the central node. There is bi-directional communication between various nodes. The central node controls all the activities of the nodes. The advantages of the star topology are:

It offers flexibility of adding or deleting of workstations from the network.
Breakdown of one station does not affect any other device on the network.

The major disadvantage of star topology is that failure of the central node disables communication throughout the whole network.

Fig. 4.3: Star Topology

4.5.2 Bus Topology

In bus topology all workstations are connected to a single communication line called bus. In this type of network topology there is no central node as in star topology. Transmission from any station travels the length of the bus in both directions and can be received by all workstations. The advantage of the bus topology is that

It is quite easy to set up.
If one station of the topology fails it does not affect the entire system.

The disadvantage of bus topology is that any break in the bus is difficult to identify.

Fig. 4.4: Bus Topology

4.5.3 Ring Topology

In ring topology each station is attached nearby stations on a point to point basis so that the entire system is in the form of a ring. In this topology data is transmitted in one direction only. Thus the data packets circulate along the ring in either clockwise or anti-clockwise direction. The advantage of this topology is that any signal transmitted on the network passes through all the LAN stations. The disadvantage of ring network is that the breakdown of any one station on the ring can disable the entire system.

Fig. 4.5: Ring Topology

IN-TEXT QUESTIONS 2

Differentiate between LAN and WAN.
What are the different types of network topology?
State True or False

(a) Networks used to interconnect computers in a single room, rooms within a building or buildings on one site are called Wide Area Network (WAN).
(b) The term Wide Area Network (WAN) is used to describe a computer network spanning a regional, national or global area.
(c) The speed of data transmission is much higher in WAN than in LAN.
(d) In star topology a number of workstations (or nodes) are directly linked to a central node.
(e) The advantage of the bus topology is that, If one station of the topology fails it does not affect the entire system.

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4.6 INTERNET

The Internet is a network of networks. Millions of computers all over the world are connected through the Internet. Computer users on the Internet can contact one another anywhere in the world. If your computer is connected to the Internet, you can connect to millions of computers. You can gather information and distribute your data. It is very much similar to the telephone connection where you can talk with any person anywhere in the world.

In Internet a huge resource of information is accessible to people across the world. Information in every field starting from education, science, health, medicine, history, and geography to business, news, etc. can be retrieved through Internet. You can also download programs and software packages from anywhere in the world. Due to the tremendous information resources the Internet can provide, it is now indispensable to every organisation.

Origin of Internet

In 1969 Department of Defence (DOD) of USA started a network called ARPANET (Advanced Research Projects Administration Network) with one computer at California and three at Utah. Later on other universities and R & D institutions were allowed to connect to the Network. APARNET quickly grew to encompass the entire American continent and became a huge success. Every university in the country wanted to become a part of ARPANET. So the network was broken into two smaller parts MILNET for managing military sites and ARPANET (smaller) for managing non-military sites. Around 1980, NSFNET (National Science Foundation Network) was created. With the advancement of modern communication facilities, other computers were also allowed to be linked up with any computer of NSFNET. By 1990 many computers were looking up to NSFNET giving birth to Internet.

How Internet functions

Internet is not a governmental organisation. The ultimate authority of the Internet is the Internet Society. This is a voluntary membership organisation whose purpose is to promote global information exchange. Internet has more than one million computers attached to it.

E-mail

E-mail stands for electronic mail. This is one of the most widely used features of Internet. Mails are regularly used today where with the help of postage stamp we can transfer mails anywhere in the world. With electronic mail the service is similar. But here data are transmitted through Internet and therefore within minutes the message reaches the destination may it be anywhere in the world. Therefore the mailing system is excessively fast and is being used widely for mail transfer.

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IN-TEXT QUESTIONS 3

What is Internet?
What is e-mail?
How does Internet function?

4.7 WHAT YOU HAVE LEARNT

In this lesson we discussed the importance and modes of communication through computers. Computers can communicate with one another through computer networking. There are two types of computer network: LAN and WAN. We discussed about the physical arrangements of computer and peripherals in network topology. There are three types of network topology: star topology, bus topology and ring topology. Also we discussed about Internet and e-mail.

4.8 TERMINAL QUESTIONS

What is computer Network? What are its main objectives?
Differentiate between analog and digital transmission of data.
Explain in brief different communication media.
What is the difference between simplex and full-duplex transmission?

4.9 FEEDBACK TO IN-TEXT QUESTIONS

IN-TEXT QUESTIONS 1

The data communication software instructs computer systems and devices as to how exactly data is to be transferred from one place to another. The procedure of data transformation in the form of software is commonly called protocol.
In asynchronous transmission data is transmitted character by character as you go on typing on a keyboard. On the other hand, in the synchronous mode, the saved data is transmitted block by block.
(a) True (b) False (c) True (d) True (e) True

IN-TEXT QUESTIONS 2

LAN is restricted to limited geographical area whereas WAN covers great distance. In LAN the computer terminals and peripheral devices are connected with wires and coaxial cables whereas in WAN communication is done through telephone lines and satellite links. The speed of data transmission is much higher in LAN than in WAN.
There are three major types of network topology. They are star topology, bus topology and ring topology.
(a) False (b) True (c) False (d) True (e) True

IN-TEXT QUESTIONS 3

The Internet is a network of networks. Information in every field starting from education, science, health, medicine, history, and geography to business, news, etc. can be retrieved through Internet.
E-mail stands for electronic mail. Through e-mail we can transfer data anywhere in the world within seconds.
Internet is not a governmental organisation. The ultimate authority of the Internet is the Internet Society. This is a voluntary membership organisation whose purpose is to promote global information exchange.

2009-05-29T23:22:00.001-07:00

Hardware device listing
What is hardware?
Hardware is best described as a device that is physically connected to your computer or something that can be physically touched. A CD-ROM,monitor, and printer are all examples of computer hardware.
Cleaning hardware
Information on how to clean any of your computer hardware components can be found on our cleaning page.
drivers
If you are looking for driversfor hardware devices, we have a list on our drivers page.
Adding hardware
Additional information and help with adding or installing computer hardware components can be found ondocument CHADD.
How hardware can cause issues
Computer hardware requires resources to correctly operate with the computer and the software installed in the computer. If your computer does not have the available resources, such as availableIRQs, this will cause your computer to not properly work and/or the devices to not function properly.
In addition to needing resources, not all computer hardware will work properly with all computers, or may have incompatibilities with hardware that is already installed in your computer.
Finally, almost all computer hardware requires some type of software or drivers to be installed before it can properly communicate with the computer. If these drivers contain problems or do not properly work with the computer, this can cause issues with the hardware device you are attempting to install in the computer.

Please click on the below beginning letters of the hardware device you are looking for, or scroll down to see a complete listing.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

COMPUTER COMMUNICATIONS

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1.INTRODUCTION

The transfer of information between computers is called computer communication. communication between computer is done through computer networks.

2.NETWORK:

The collection of machine / computer that share data and information through interconnected lines of communication is called network. Data and information are

Shard through this network.

3.REASONS FOR NETWORK

Sharing of resources: many valuable resources such as printers, plotters and other devices can be between more than one computer.

Sharing of information: information which is store in one computer can be shard between other computers. communication.

Communication: computer connected in a network can be used for communication between them.

4.APPLICATION OF NETWORK

at home. E –mail facility
Used for entertainment purpose.
Accessing information through world wide web.
Video conferencing
Providing information to individuals

5.BENEFITS OF NETWORK

Interactive environment.
Valuable resources can be shared.
Access to remote information.
Used for entertainment purpose.

6.TYPES OF NETWORK

LAN(local area network)
MAN(metropolitan area network)
WAN(wide area network)
GAN(global area network)

7.NETWORK TOPOLOGY

Star topology.
Bus topology.
Ring topology `

Timeline of Computer History

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WHAT THE TIMELINE IS

This timeline explores the history of computing from 1939 to 1994. Each year features illustrated descriptions of significant innovations in hardware and software technology, as well as milestones in areas such as commercial applications and artificial intelligence. When appropriate, biographical sketches of the pioneers responsible for the advances are included.

HOW THE TIMELINE WORKS

Across the top of this and every timeline is a graphic with the years from 1939 to 1994 displayed as well as seven topical areas. Clicking on any of these will take you to a page of historic information containing photos and descriptive text for that year or topic.

The timeline can either be browsed using the links above (and appropriate Previous/Next and More links on each page) or searched for specific events.

About the Museum Exhibits Collections What's Happening Giving About This Site
Privacy Copyright Feedback Credits Advanced Search Site Map

COMPUTER DEFINITION

2009-05-25T00:08:00.000-07:00

A computer is a machine that manipulates data according to a set of instructions.

Although mechanical examples of computers have existed through much of recorded human history, the first resembling a modern computer were developed in the mid-20th century (1940–1945). The first electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers (PC).Modern computers based on tiny 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, what most people think of as a "computer", but the embedded computers found in devices ranging from fighter aircraft to industrial robots, digital cameras, and toys are 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 personal digital assistant to a supercomputer are all able to perform the same computational tasks, given enough time and storage capacity.