CRT & LCD

CRT and LCD are visual display units, they are also called monitors or displays. They display images generated from the video output of computer. CRT stands for Cathode Ray Tube and LCD stands for Liquid Crystal Display. The CRT is a vacuum tube containing an electron gun and a fluorescent screen, they are used to create images in the form of light emitted from the fluorescent screen but the LCD is shaped into a thin panel filled with liquid crystals and arrayed in front of a light source (backlight) or reflector. CRT and LCD are different in terms of size, performance and price. I will compare them point by point.

The most notable difference is size. CRT and LCD are very different in size. This is one of the major concerns for people who want to buy a monitor. From above, the CRT contains a vacuum tube and an electron gun so it has a big size, and uses more space. However, based on its size, it is heavy. The CRT is hard to move. On the other hand, the LCD is smaller than CRT because it is replaced with liquid crystals. This makes it possible for users to have larger screens for their computers and makes it more convenient to move than a CRT. Furthermore, the LCD is light and portable.

Performance is another difference to be considered. The primary advantage that CRT holds over LCD is its color rendering. The contrast ratios and depths of colors display of CRT are much greater than LCD. Many graphic designers still use the very expensive large CRT monitors in their work because of the color advantage. The disadvantage of CRT is that it generates excess heat. On the other hand, the biggest advantage of LCD is less eye fatigue. The LCD tends to produce less eye fatigue to the user because the LCD has lower refresh rate than a CRT. The disadvantage of LCD is their fixed or native resolution. An LCD screen can only display the number of pixels in its matrix and no more or less.

Moreover, price also marks a big difference. In 1972, The LCD can cost over twice as much as a CRT. Later, the price of LCD is decreased so much and it is still more expensive than a CRT. However, it is not too hard to buy it. It is up to your requirement. For example, if you want a fresh display, you should buy the CRT because it has higher refresh rate than an LCD or if you want small and light monitor, you should buy an LCD.

In conclusion, I always spend almost all the time staying in front of the monitor so I think the LCD is better than a CRT because it looks beautiful, easy to relocate and causes less eye fatigue. I do not care too much about native resolution of LCD and there is not too much difference in price, thanks to production improvements in LCD and the reduction in the production of CRT. In my opinion, the best choice is an LCD.

Data Storage Device

A data storage device is a device for recording information. The first data storage device is floppy disk and it was released by IBM. It was popular from 1970 to the late 1990 but floppy disk has less capacity. Later, there were many data storage device with increased capacity such as CD-R, Flash drive and Hard disk drive. Now, you can store your file easier and you can choose the device that is appropriate for your file to store. So it is very convenient to store files and they are not too expensive to buy. The data storage device can be classified into CD-R, Flash drive and Hard disk drive by capacity.

The first category is CD-R. It stands for Compact Disc-Recordable but the first name is CD Write-Once. It was released by Sony and Phillip in 1988. CD-R has a storage capacity of 700 MB and it can write only one time. So, it is usually used to store files that do not have to be updated such as images, music or videos. In the present, CD-R is not popular for storing files because it has less capacity, for example, movie has at least size of 1 GB so it can not write in CD-R and another example is if you want to write music you can write a few music, per CD-R.

The second category is Flash drive. It is integrated with a USB (Universal Serial Bus) interface and it is typically removable. The first USB flash drive was released by Trek Technology and IBM in 2000 and had a storage capacity of 8 MB. Nowadays, it has a storage capacity typically ranges from 512MB to 16 GB. Flash drive is suitable for transporting data from place to place and keeping it readily at hand because it implements the USB mass storage device class so that most operating systems can read and write to them without installing device drivers. It is very popular because of the medium capacity and it can rewrite data so you can store files without worry to edit your files but the weak point is the flash drive has many viruses because it does not include a write-protect mechanism. Write-protection makes a device suitable for repairing virus-contaminated host computers without risk of infecting the flash drive itself.

The third category is Hard disk drive. Hard disk drive was introduced in 1953 as data storage for an IBM accounting computer. It was originally developed for use with general purpose computers. Hard disk drive is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Hard disk drive has high capacity storage between 120GB and 1 TB and also Hard disk drive can rewrite data. Hard disk drive is usually used to store a large amount of music or movies but it is too expensive so it is not as popular as its capacity.

In my opinion, I decided to buy Flash drive because it is not too big to carry and I do not have enough money to buy the hard disk drive. If I have enough money I will buy Hard disk drive because it has high capacity and it is suitable to transport files to every computer that I use.

Web Browser

The most popular activity of Computer Science student is surfing the Internet. Internet is very important and close to our life nowadays. You can find everything in the Internet such as images, music or information. You will agree with me that the Internet is very useful but the first thing you do before you surf the Internet is opening the web browser. Web browser is a software application that allows user to display and interact with texts, images or videos on the Web page. It allows you to surf the Internet. In the present, there are many web browsers such as Internet Explorer, Mozilla Firefox and Safari.

The first example is Internet Explorer. This one is the most widely used web browser because it comes with Microsoft Windows. The first version of Internet Explorer was released on August 1995 with Windows 95 and the current version is Internet Explorer version 7.0. In this version, there are many features, for example, tabbed browsing which is a popular feature for web browsers competitor. Another example of feature is quick tabs. It will display a thumbnail preview of opened tabs and it can rearrange tabs by dragging and dropping them and also they improved the graphic user interface of this version too.

Another example is Mozilla Firefox. This one is a free and open source web browser and the second most popular web browser after Internet Explorer. It used to be named Phoenix but it is the same as Phoenix Technologies, so they changed it to Firebird and again it is the same as Firebird free database software project. Therefore, they changed it to Mozilla Firebird but it is still confusing with the database software name. Finally, they changed it from Mozilla Firebird to Mozilla Firefox. Mozilla Firefox has many features such as tabbed browsing, spell checker and search engine. Mozilla Firefox can run on every operating system, such as, Microsoft Windows, Mac and Linux.

The final example is Safari. This web browser was developed by Apple and released on January 2003 for Mac OS. Later, it can be used in Microsoft Windows and other Apple product, such as, iPhone and iPod Touch. The features in Safari are quite similar to other web browser, such as, Tabbed Browsing, Pop-up ad blocking, Text search, spell checking and web-search box in the toolbar Google on Mac and either Google or Yahoo! on Microsoft Windows.

I do not care too much about web browser and I do not like to use tabbed browsing. I use Internet Explorer version 6.0 because I used Windows so I do not need to find other web browsers. Most of my friends use Firefox because it has add-on tools but in my opinion, it is meaningless because I just want it open the Web page without any error. That is enough for my Internet surfing.

Computer Virus

A computer virus is a computer program that can copy itself and infect a computer without a permission of the user. It is not like human viruses. A computer virus can only spread from one computer to other when its host is taken to the uninfected computer, for example, user sending it over a network or the internet or carrying it on a removable medium such as a floppy disk, CD or USB drive. Meanwhile virus can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer. I will talk about computer worm, when your computer has a virus and an anti-virus.

Computer worm is a self-replicating computer program. It uses a network to send copies of itself to other nodes, computer terminals on the network, and it may do so without any user intervention. Unlike a virus, it does not need to attach itself to an existing program. Worms almost always cause harm to the network, if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a target computer. Many worms have been created which are only designed to spread and don't attempt to alter the systems they pass through. A payload is code designed to do more than spread the worm. It might delete files on a host system or send documents via e-mail. The very common payload for worms is to install a backdoor in the infected computer to allow the creation under control of the worm author. On the other hand, there are worms with good intention for example, The Nachi family of worms tried to download and install patches from Microsoft's website to fix vulnerabilities in the host system.

When your computer has a virus, the point is just like a human virus passed from person to person but the computer virus is passed from computer to computer. The virus can be attached to any file that you copy to your computer. Actually, anytime you download files or connect a removable drives into your computer, you are susceptible to virus. Many viruses are spread through e-mail. Generally, you can not get a virus from simply reading e-mail but the danger is you do not even have to open an e-mail attachment to release the virus. Just opening the e-mail itself can release the dangerous bug. The virus becomes active when you execute a program that contains the virus. For instance, if you download a program from the internet and it was infected with a virus. The virus will attack your computer when you activate the program. Viruses are everywhere. Although, it is rare, viruses have even been found in commercial shrink-wrapped software.

Can we detect it? The easy way is to install anti-virus software into your computer. The anti-virus is a computer software application that has two common methods to detect viruses. The first is using a list of virus signature definitions. This works by examining the content of the computer's memory and the files stored on fixed or removable drives and comparing those files against a database of known virus signatures. The disadvantage of this detection method is that users are only protected from viruses that pre-date their last virus definition update. The second method is use a heuristic algorithm to find viruses based on common behaviors. This method has the ability to detect viruses that anti-virus security firms have yet to create a signature for. The other way to detect virus is making regular backups of data and the Operating Systems on different media, that are either kept unconnected to the system most of the time read-only or not accessible for other reasons. This way will help you if the data is lost through a virus you can use backup to restore your data.

In my opinion, I do not worry about virus too much because I will not download files until I make sure that the files will not have a virus inside. To make sure that my computer will not have any virus, I install anti-virus into it and always scan removable drives, such as USB most virus comes from it. Make sure your friend's USB do not have viruses in it.

Evolution of Windows

The famous operating system in Thailand is Microsoft Windows. It is easy to use and very convenient for users because before Microsoft Windows came, we used MS-DOS. We must type command to operate but for Microsoft Windows, we use mouse to click a command instead of typing the command. Microsoft Windows is a series of software operating systems and graphical user interfaces produced by Microsoft. In 1983 Microsoft announced the development of Windows. After that Microsoft released many versions of Windows. The first is Windows 95. Next is Windows 98, Windows ME, Windows XP and Windows Vista.

The first is Windows 95. It was released on August 24 1995.
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was intended to integrate Microsoft's formerly separate MS-DOS and Windows products and includes an enhanced version of DOS. Windows 95 has been released on both floppy disks and on CD-ROM for some computer systems at that time did not include a CD-ROM drive. It used 13 floppy disks for installation. At the release date of Windows 95, Internet Explorer 1.0 was available for surfing the internet but only in the Plus! Add-on pack for Windows 95 which was a separate product but it has a few bugs on it. They developed it better in version 2.0 but there was no uninstaller, it could be deleted difficulty. Finally, the last version of Internet Explorer supported on Windows 95 is Internet Explorer 5.5 which was released in 2000 and Windows 95 shipped with Microsoft's own dial-up online service called The Microsoft Network.

Next is Windows 98. Windows 98 is a graphical operating system released on 25 June 1998 and the successor to Windows 95. Windows 95 was the first operating system to use the Window Driver Model (WDM) and it comes with System tools. For example, ScanDisk, used to maintain the file system and Disk Defragmenter, used to counter the negative effects of filesystem fragmentation. Windows 98 Second Edition is an updated release of Windows 98, released on 5 May 1999. It includes fixes for many minor issues, improved USB support and included Internet Connection Sharing, which allows multiple computers on a LAN to share a single Internet connection through Network Address Translation.

After that, Windows ME or Windows Millennium Edition was released on 14 September 2000. Windows ME was the successor to Windows 98 and it was targeted specifically at home PC users. It included Windows Media Player 7 and the new Windows Movie Maker software which provided basic video editing and was designed to be easy for home users. Windows ME could be upgraded to Internet Explorer 6. Microsoft also updated the graphical use interface and the shell features and Windows Explorer. The updated features in Windows ME is Compressed Folders. Windows ME includes support for ZIP files through a shell extension known as Compressed Folders and Automatic Updates, it will automatically downloads and installs critical updates from the Windows Update Website with little user interaction.

Then Windows XP was first released on 25 October 2001. Windows XP can be used on personal computers including home and business desktops, notebook computers and media centers. Windows XP is the successor to both Windows 2000 Professional and Windows ME and the name “XP” stands for eXPerience. The new features of Windows XP are improved interface, the interface is more task-based than the basic one included since Windows 95 and Fast User Switching, it allows another user to log in and use the system without having to log out the previous user and quit his or her applications. Previously only one user at a time could be logged in and the Remote Assistance allows a Windows XP user to temporarily take over a remote Windows XP computer over a network or the internet.

Finally, Windows Vista was released on January 30 2007. Windows Vista contains many changes and new features, including an updated graphical user interface and visual style called Windows Aero, improved searching features and redesigned networking. Vista also aims to increase the level of communication between machines on a home network using peer-to-peer technology. Windows Vista has been to improve the state of security in the Windows operating system. While these new features and security improvements have garnered positive reviews and Vista has targeted its high system requirements.

From Windows 95 to Windows Vista many things have been changed, for example a graphical user interfaces or a new features system. It takes 12 years. I wonder 10 years later how Microsoft Windows looks like. It may no longer use keyboard and mouse, just touch the screen on the air but for now I use Windows XP because Windows Vista has very high system requirements. I have not enough money to improve my computer to use Windows Vista.

Android Mobile

In the past, a mobile phone was just a device to communicate with each other and it had a big size. Later, they improved to do more than communication such as sending message, connecting to the internet, listening to music, watching the movie and taking photos. Moreover, it has decreased in size so it is easy to move.

Nowadays, the mobile market has high competition. For example, Apple Company produces the iPhone. It is very interesting. But, Google Company produces a mobile that is better than the iPhone which is called “Android”, It comes with the logo like a fat green bin but has legs and arms. Android is not a mobile but it is a software platform or operation system for mobile devices. The first mobile that used android platform is T-Mobile G1, from Google. The important things about android that I will talk about are history about android, open source, Software Development, Android Developer Challenge and T-Mobile G1, the first mobile that includes android platform inside.

The first is the history of android. Google is planning to enter the mobile phone market but it was unclear what function it might perform in the market. Then, in July 2005 Google acquired android from a small startup group in California. Android’s Co-founders are Andy Rubin, Rich Miner, Nick Sears and Chris White. Google entered the mobile-phone market in December 2006 by the way Google collaborate with the big several companies such as HTC, Intel, Motorola, T-Mobile, etc, with the goal to develop open standards for mobile devices. Next is the first mobile that include android, the T-Mobile G1, released on October 2008.

Second is the open source. Android is an open source which means that developers can develop an application for their own or can use application from other developers. For example, you can make an application that can check how far you are from your friends or the application that makes your phone use Thai language. So you can modify your mobile by using the android like you can draw anything in a white paper.

Third, Software Development Kit or SDK is a development tools. When you want to make an application on mobile, you must use android SDK because android SDK includes a debugger. Debugger is a computer program that is used to test and debug your program. This is a very important tool for your coding. Next is the emulator which is used for simulating how your application works in the mobile. Libraries are used for understanding how to code the program.

Fourth is the Android Developer Challenge. This is the way of Google to advertise android platform to people because when Google released android, only few people knew about it. Google offered prices totaling to10 million dollars to developers to develop applications for android. Therefore, many people tried to learn about android like babies having a new toy. Now android is popular in the mobile market.

Finally, T-Mobile G1 is the first mobile running android. T-Mobile G1 is a touch screen mobile like the iPhone but for some who think it is very hard to type by touching the screen, this mobile has a keyboard behind the screen. It has a big screen like a wallet and the color is metallic. It makes me feel beyond the future. The camera is 3.2 mega pixels so you can take photos or record videos like they have real life. Moreover, it has a Bluetooth for sharing files to your friends or use with a Bluetooth stereo headset. It does not have many features that most phones do not include such as running on 3G or wifi. From the above reasons, you can develop an application that you like by using android platform.

In conclusion, android is a platform that makes you develop application for your mobile through open source. If you are not good at coding android platform, you can find any application that you like from the internet to modify your mobile. T-Mobile G1 is the first mobile that runs android but in the future, most mobiles may use android. For me, I am very much interested in android and I am waiting for T-Mobile G1 to be released in Thailand.