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What is a DVD and How Does It Work ?

What is a DVD and How Does It Work ?

Storage of data for later retrieval has always been a concern in human lives. Before the computer era (around 1950s), journals and ledgers were used for this purpose. But these are bulky and slow. So, the world turned on to computers owing to their capabilities of fast data storage and retrieving capacities. A few of the computer related components which can store data are the Compact Disc (CD), its advancement Digital Versatile Disc (DVD) and the latest Blu-Ray Discs. All these discs more or less work similarly. In this article you will understand what actually a DVD is and how it stores data and retrieves it. Note that CDs and Blu-Rays vary from the DVD only in construction. The way they work is the same as the DVDs.

What is a DVD?

What is a DVD and How Does It Work ?

The Digital Versatile Disc (DVD) is a thin flat, circular disc with a diameter if nearly 12cms. Small amounts of metal and plastic build up its structure. If you take a step further and dig deeper, the DVD you see has a total of three different layers. One of them is a tough, brittle plastic – polycarbonate. And the outer most layer is the protective layer made of – lacquer. In between these two layer is a sandwiched aluminium layer.

But anyways these layers cannot be perceived by merely looking at a DVD. But what you can observe very easily is that the DVD has a shiny side and a dull side. The shiny side (or reflective side) is important because its shiny nature helps laser beam bounce off and read information stored in the disc.

Generally the belief is that the reflexive part is the most important part of the DVD and people get lot worried about the scratches DVDs develop over time. But it simply is a mis-conception. The entire data is stored very close to the plastic layer which is present very closer to the dull side. So, if there are any scratches in the reflective side you can fix them by polishing the DVD. But if the label side (dull side) is effected, the DVD is trash.

How DVDs Store and Retrieve Data?

The DVDs and Blu-Rays are primarily invented to store music and movies. They obey the MPEG -2 compression system. And for audio the Digital Dolby Compression system is used. But basically for the computer to understand music (or) video it needs to be in the binary form.

DVDs which are originally made in the company are called master DVDs. The other entire movie DVDs are the copy of the master. These master DVDs are burned with laser. Due to the laser, there are a lot of bumps created on the surface. Each of the bump represent a binary 0 and the plain area (called land) is the binary 1. So the plain area is unburned and remains flat. Actually these bumps are so small and large in number that you can’t even feel them even if you tried.

So, by now you must be clear that whatever data is stored in the DVD is in the form of numbers (1s and 0s). This is actually done by process called sampling. Based on this process the DVD writer decides where bumps are to be located and where the disc should not be burned. The electronic equipment measures sound and turns it into a number and stores in binary format. So a few minutes song or video is converted into a set of millions of zeros and ones. And an entire movie in a DVD means there are nearly a billions of those pits out there.

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This Is Why The Cable Length For All USB Devices Is Standard

This Is Why The Cable Length For All USB Devices Is Standard

The USB Interface Technology has made life simple and connecting peripherals to computers couldn’t get easier. After the introduction of the USB 2.0 interface technology even devices like external hard disks, printers and scanners started using USB cables.

Anyway, did you ever spare a thought as to why these wires have a standard length? In this article we uncover the reasons behind the standard lengths of these USB cables. Also in addition, we suggest you methods you can implement to increase the cable length without effecting performance.

The USB Cable Length Phenomenon:

The length of cable for all the devices is not constant. It simply depends on the application you have at hand. There are certain USB rules which ought to be followed.

Generally in many interfaces (even other than USB) the cable length is calculated based on the various electrical parameters of the communications system.

Here the point to note is in many of the interfaces (in almost all that we know of) the data transfer rate is inversely proportional to the maximum length of the cable. The same can also be looked at as the slower the transfer rates, the longer can be the cables (mainly due to capacitance effects).

The USB 2.0 Interface limits the length of wire to a 5meters and in the earlier USB 1.0 the maximum length was only 3meters. And these values of maximum length are not a simple hunch. But these are the values obtained after precise calculations keeping in mind the parameters like time delay within the cables. The electrical signals are expected to travel at speeds of light within the cables. But owing to various disturbances and reflections the speed only range up to 65% of the actual expected speeds due to which the concept of time delay comes into picture. (It is 28nsec for USB 2.0 cables).

Even these speeds are not the same when you shift between various interface technologies. The exact speed of transmission within the cable can only be found if the entire parameters of the system are at hand. So simply, if you are looking for a lengthy cable, be it a high quality costly cable or some cheap Chinese copy cable the length just cannot vary and you have to go with it. We don’t recommend going for a cheap and quality-less cable but all we want to establish here is the point that the length cannot vary.

But you don’t necessarily have to get discouraged. There are 2 different solutions to this problem at hand.

Overcoming the cable length limit:

1.)            USB Hubs :

This Is Why The Cable Length For All USB Devices Is Standard

Earlier the computers were just equipped with 1 or 2 USB ports. And what all people had to do was to pick a USB Hub to get more devices connected to the computer. The same can be used to overcome the cable length limitation. You can understand how it is possible only when you know the basic working principle of the USB Hubs. Just to keep the article brief we explain you the principle in a line. (A USB Hub is similar to a repeater and has its own supply and enables delay-less transmission). The USB 2.0 interface allows you to have a maximum of 5 USB hubs between the computer and the device. It means the total length of the USB cables altogether mounts up to 30meters.

2.)            Extension Cables:

This Is Why The Cable Length For All USB Devices Is Standard

Of course you simply shouldn’t join two cables to make a lengthier one, but you can surely choose an extension cable. The USB Extension cables have in them the necessary electronic equipment to regenerate the electrical signal. These cables allow up to a 30 meters active transmission by connecting 5 of these extension cables together.

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A List Of Computer Display Cables Around Us

A List Of Computer Display Cables Around Us

The 21st century has brought about a great revolution in the world of computers. Wireless devices are no longer a dream. In spite of this scenario where wireless technologies have developed many a mile, many computer networks still rely on cables for effective data transfer. In this article we mainly concentrate on the display cables that you are using.

Few Display Cables You Know About:

1.) VGA Cables (Video Graphic Array Cables)

The VGA Cables are the first analog cables which spread universally after they were originally developed in 1987.Initially these cables could only provide a resolution of 640×480 and with several advancements have the capability to provide up to 2048×1536 resolution at a refresh rate of 85 Hz.

A List Of Computer Display Cables Around Us

These advanced models are usually regarded as the SVGA Cables. In spite of their performance they could not resist competition from the DVI Cables.

2.) DVI Cables ( Digital Visual Interface Cables)

The DVI Cables are the other video display interfaces of computers which connect the display controller to display devices (say monitors). Developed in 1999 these cables have the ability to produce uncompressed video.

A List Of Computer Display Cables Around Us

The other important aspect of these cables is that they are compatible with the earlier display interface (the VGA Connectors).

The widespread usage of these display cables is primarily due to their compatibility and uncompressed digital video transmission at a maximum resolution of 2560×1600 at 60Hz (or 3840×2400 at 33Hz).

These are mostly used in modern video cards.

3.) HDMI Cables (High Definition Multimedia Interface Cable)

The HDMI Cables are advancement of the DVI Cables. Along with transferring uncompressed video they even have the capability to transmit compressed or uncompressed audio.

A List Of Computer Display Cables Around Us

These are the most modern cables developed in 2003 and can produce resolutions of 4096×2160 at 60Hz refresh rate. These cables are now prevalent in all the latest audio and video systems including the video cards.

If you are planning to connect your computer to a television, we would recommend you to go for HDMI Cables. It is because no other cables have the ability to transmit both audio and video.

If you have any views to share with us, you can write to us below. 

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The Various Functions Carried Out By A Computer BIOS Software

The Various Functions Carried Out By A Computer BIOS Software

BIOS is a shorthand notation for Basic Input Output System. It actually is simply a software but is unlike the application software or operating system software. It is usually stored in a memory chip on the motherboard and is completely independent of the operating system. BIOS contains the instructions about what operations it has to perform during system start-up (or booting) when the operating system is not active. Actually one of the important roles of BIOS is to load the operating system.

This is what BIOS Software does:

If you just recollect the article we have published previously where we have discussed about the operations that occur during booting or shutdown (you can check it out here), immediately after you press the power button there are some events which occur. The BIOS software has to perform a number of various operations taking up different roles. Here is a comprehensive list of all the various things your computer BIOS does.

1.)      CMOS Setup: BIOS goes through the information (about your system) stored in the Complementary Metal Oxide Semiconductor (CMOS) chip for any recent change in the settings. Further, initializes all the registers and controls the power allocation.

The Various Functions Carried Out By A Computer BIOS Software

2.)      POST: BIOS loads the firmware (the software for hardware after the CMOS stage) and performs a Power-On-Self-Test (POST). This test makes sure all the hardware components are working properly thus eliminating the chance of any errors to creep in while loading the operating system. Once this test is completed many system devices like the CPU, RAM, parts of Chipsets, Optical Disk Drives, Hard Disk Drives including the keyboard and other controllers are activated.

The Various Functions Carried Out By A Computer BIOS Software

3.)      BIOS Chips: BIOS then activates the BIOS chips (if there are any of them) present on the cards installed on the computer (say graphic cards).

The Various Functions Carried Out By A Computer BIOS Software

4.)      Boot-strap  Loader: BIOS looks for the presence of any operating system within the hard drive. Once found, it activates and passes control to the OS.

5.)      Low-Level Routines: It has to provide low level drivers (or routines) that the computer can use to interface with the hardware devices. The main devices that are managed include the keyboard and monitor.

6.)      It also manages and allows you to configure system settings like the clock, various passwords and settings related to hard disks.

These are the primary tasks that the BIOS has to take care of. Other than these the user has the chance to access and configure BIOS through the BIOS Setup Utility. Changing these settings alters the way BIOS instructs the hardware to function. The various things you can change about your computer’s BIOS will be discussed in the further posts.

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5 Most Important Computer Components That Make Computers Work

computer components

Before you try to understand the science of computer functionality you should definitely have a basic idea of all the hardware that make up the computer. In this article we show you the components without which your computer is almost paralyzed. Note that these components are presented in the order they are assembled.

computer components , Important Computer Components

The 5 Important Computer Components:

1.)    Case: The computer case is a very important component of your computer. It houses almost all of the required hardware. In Desktop Computers it is usually a box with lots of ports around it. In laptops it isn’t such a big box and also includes the keyboard and screen. These cases come in different sizes and shapes and these parameters have nothing to do with the performance of your computer. There are also computers which don’t have these and all the components are built into the monitor (say, All-In-One Desktops).

2.)    Motherboard: Motherboard is one of the most important computer components. Computer cases house the motherboards and motherboards hold many other components. The size of the computer case depends on the form-factor of motherboards. If you have ever known about Printed Circuit Boards (PCB) then motherboard is the PCB of your computer. Motherboards also differ from each other in the number of external connections they are capable to handle.

3.)    Central Processing Unit (CPU): The CPU also widely called the Processor is the heart of your computer. Right now you are able to see his webpage, take a glance at your computer’s clock; get notified about any external devices being connected and what not everything is taken care of by the CPU. It is single most important computer component that greatly affects performance. All the hardware and software completely rely on the CPU for their operations.

4.)     Hard-drives: Hard drives constitute the memory unit of the computer. All the computer data, operating systems and software are stored in these computer components. Mainly the significance of Hard-drives is to store and retrieve data every time your computer is turned ON. Also note that drives are different from our next component, RAM.

5.)     Random Access Memory (RAM): Even the fastest processor in the market can’t satisfy you if your RAM is low. The faster the processor the more number of calculations. While performing these calculations it requires an auxiliary component to store data which need not be for long term usage.

It is quite true that each and every component of your computer plays its role but this article is to make you aware of the most important ones.

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Here Are Some Of The Most Used File Name Extensions In 2014

Here Are A Few Most Used File Name Extensions

The file name extension is simply the extended part in the file name which specifies the type of data present in the file. This extension is useful both to the computer and the users. But do you know how many such file name extensions exist?? When I came to know about the answer I was a little amazed or shocked to say the least. Actually there are 6,888 file name extensions in total. And around 7,228 programs which support these file name extensions. Learning about all these file name extensions at once is a hectic job. So in this article we discuss with you about the 5 most used file name extensions.

5 Most Used File Name Extensions:

Here Are A Few Most Used File Name Extensions , Used File Name Extensions 

                                       Image courtesy by : File extensions

Here are the top 5 most used file name extensions by computer users. Note that they follow no necessary order.

1.).doc – The .doc (Document) is the file name extension for files created by a word processing software. Microsoft Office Word is the most famous word processing software. The other word processors include the AbiWord, Apple Pages, IBM Lotus Symphony and so on, which can all read and write .doc files.

2.).jpg – The .jpg is the file name extension for many of the images we see in our computer and over the internet. It is the compressed graphic format of digital photography. The speciatlity of these .jpg or .jpeg images is that we can achieve 10:1 compression with no loss in effects. The files with this file name extension can be accessed through umpteen numbers of software.

3.).exe – The filename extension for many of the executable programs is .exe. This file name extension is highly used in the Windows, Symbian, DOS operating systems. Files with this file name extension are programs and runs automatically when they are opened. No special softwares are required to access these file types.

4.).mp3 – The .mp3 is a audio format file name extension designed by the Moving Pictures Experts Group (MPEG). It is the most common audio format file name extension. The files with these file name extensions contain audio which is very much compressed, yet delivers the audio with good quality (though not as much as the high capacity .AIF files).

5.).html – The .html is a file name extension in web pages. It stands for Hyper Text Markup Language and is used to create almost all of the web pages (excluding .aspx web pages). The .html and .htm extensions are similar. Each and every web page has either of these extensions and you can find it in the address bar of this web page as you read.

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5 Basic Things You Should Know About File Name Extensions

5 Basic Things You Should Know About File Name Extensions

Any average computer user comes across a lot of different file types. But only the curious lot really gives a thought on it.  In this article we talk about a few basic things you need to have in your head about the file name extensions.

 5 Questions Regarding The File Name Extensions :

5 Basic Things You Should Know About File Name Extensions

 

Image courtesy : socialnetworkinglab

1.)          What is File Name Extension?

A file name extension is simply a set of characters (mostly 3 characters) which follow the name of the file. This extended part of the file name helps the user and computer understand what type of data is present in the file. Hence it is called the file name extension.

For instance in the file name OnlineCmag.txt, txt is the file name extension. It conveys the computer that the file by the name OnlineCmag is a text file. It also suggests appropriate programs that can open this type of files both to the computer and user.

 

2.)          Can you see file name extensions?

Filename extensions are usually not shown. This is simply to help the users read file names easily. You can go with it or if interested you can make the file name extensions to be shown as well. There is no problem with that.

 

3.)          Can you change a file name extension?

File name extensions should be changed only if you are sure that the new file name extension is apt with the content in the file. Also the programs that can open that particular file types are also necessary. Failing in either of the cases, the file may not open and becomes dis-functional.

To change an extension, all you have to do is to Rename the original file with the new file name extension. Usually windows will warn you that changing the extension could lead to the file not working properly. So only if you are very sure that the new file name extension will work, click ok and proceed.

 

4.)          Can you control which programs opens files with certain file name extension?

Every program is pre-designed to open certain file types in our computer. It could be only one particular file type or a set of them, this factor depends entirely on the type of the program. You can choose between programs to open a particular file only if there are more than one programs installed in your computer.

 

5.)          Can you use any character in your file name?

No, you cannot. Usually the computer doesn’t allow its users to save file which include characters like \ / ? : * ” > < |. So any other characters can be used. Also make sure your file name doesn’t start with a number.

So this article covers a few aspects you need to be sure about regarding the file name extensions. If you have anything to share or comment you can do it below.

 

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Few Facts About Operating Systems

operating systems

The introduction of the Windows 8 operating system in 2012 is a big leap into the future. Into the future where the computing is lot easier and beyond our imaginations. And machines take over labor of people. There were many operating systems prior to the Microsoft Windows series, their first development dates back to 1956.

Actually there is a lot than that meets the eye with the operating systems. They are the unsung heroes in a computer, and are active the entire time your computer is ON.

Nowadays, most of the computers (by computers we refer to all types of computers) are preloaded with Microsoft Windows operating system and the Macintosh computers are preloaded with Mac OS X. Similarly the Linux operating systems are also the famous lot.

Basically, to quote it in one line the operating system (OS) is the heart of the computer. Though you have some prior idea about the operating systems, this article highlights various key points that help you understand the operating systems much better.

If you consider the broader sense of the word computer, any device which is capable of performing tasks based on its binary calculations can be considered a computer. So many of the electronic devices we use can literally be called computers.

If that particular electronic device performs only one particular task, it doesn’t need any operating system (for instance a washing machine).

The operating system is the most important software in your computer which co-ordinates each and every task within the computer. It is the software which manages all the other software and the computer hardware.

For programs it provides an environment to execute and for users it acts as a communication tool (to interact with the computer).

The modern operating systems differ from each other mainly in the user experience perspective. The most commonly used operating systems include the Microsoft Windows, Mac OS X and Linux.