Comparison linux and windows

Most standard computer programs are available for Linux. If you depend on specialized programs, such as specific genealogy programs, you will need to run Windows; more about this at the end.

Several Linux programs can read and write Microsoft Office files. So, if all you do with a computer is manage e-mail, create documents, create graphics files and use spreadsheets, Linux programs do all those things very well.

Until recently Linux has been more difficult to install and use than Windows. However, over the last two years there has been a concerted effort by several Linux companies to make Linux easy to use by an average user.

But why should one bother learning to use a new operating system other than the Windows one she is now using?

Here are the reasons:

• Linux hardly ever crashes, mainly because the basic low-level operating program (called the kernel) that keeps the computer running is small. So, even when things go wrong with some higher-level part of the operating system or with a program, the kernel keeps chugging away.
• Linux almost never has to be rebooted after installing a new program. This saves much valuable user time and aggravation over the life time of a machine.
• In most cases the Linux file system does not have to be defragmented regularly, such as Windows does, to keep it from slowing down.
• Linux allows up to 16 different views of the desktop, I use 4 of them. In other words, programs that are running can be associated with different views of the desktop; you will see only the program windows for the desktop view of current interest. It is easy to switch from one desktop view to another by buttons on the task bar.
• There are many free or inexpensive programs available for Linux.
• It cost less to install and operate.

By the way, most of the servers that provide web pages on the Internet are running Linux.

There are several different versions of Linux that are vying now for the desktop market. I have tried Red Hat and Linspire (previously called Lindows, a version of Debian). I highly recommend LinSpire (http://www.linspire.com) for general users for the following reasons:

• It is inexpensive.
• It is designed to look and operate very much like MS Windows.
• It installs easily and fast.
• It comes loaded with all the programs that are needed for web browsing, e-mail, and word processing and many other tasks.
• It has good on-line support.
• It has an inexpensive add-on called Click-N-Run that allows the user to simply click on hundreds of programs toLinspire install them on Linspire. (Buy Linspire and Click-N-Run together to save money.)
• Permission is not needed from Microsoft or Linspire.com to move Linspire from one machine to another owned by the same person. In fact, it can be installed on as many computers as there are in a given home at no extra charge.
• You can install it as a dual boot with a Windows system in order to try it out while still keeping Windows available.
• You can get Linspire on an inexpensive light-weight notebook.

If there is a need for a few specialized programs that are not available for Linux, one can run Win4Lin in Linspire in order to be able to run Windows 98 (Win4Lin Version 9x) or Windows XP (Version Pro 1.1). the total cost for both Win4Lin and Windows 98 is about $200. I have done this on my Linspire notebook and it works very well. You can buy Win4Lin 9x on Click-N-Run.

One last note: Linspire does not automatically set up a non-root account. It is best to do that and always run programs from that account. Then only use the root account when changes need to be made to the system that only a root account is allowed to do.

For information about how I set up a Linspire light-weight notebook to run Windows 98: http://www.roperld.com/GenLinNotebook.htm

Articles source : http://arts.bev.net/roperldavid/Linwincomp.htm

What is CPU

Abbreviation for central processing unit, and pronounced as separate letters. The CPU is the brains of the computer. Sometimes referred to simply as the central processor,but more commonly called processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.

On large machines, CPUs require one or more printed circuit boards. On personal computers and small workstations, the CPU is housed in a single chip called a microprocessor. Since the 1970's the microprocessor class of CPUs has almost completely overtaken all other CPU implementations.

The CPU itself is an internal component of the computer. Modern CPUs are small and square and contain multiple metallic connectors or pins on the underside. The CPU is inserted directly into a CPU socket, pin side down, on the motherboard. Each motherboard will support only a specific type or range of CPU so you must check the motherboard manufacturer's specifications before attempting to replace or upgrade a CPU. Modern CPUs also have an attached heat sink and small fan that go directly on top of the CPU to help dissipate heat.

Two typical components of a CPU are the following:

• The arithmetic logic unit (ALU), which performs arithmetic and logical operations.
• The control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.

How to Choose the Right Webcam For You

What is a Webcam?

A webcam is a camera which is directly connected to a PC and, in many cases, the internet. A webcam is also almost always able to record video, not just still frames (though many can capture both). The objective is to record video directly onto your PC's hard drive, rather than onto a tape or onto the hard drive of an external camera.

Sometimes, people don't use Webcams to record video at all, opting instead to send live video "streaming" across the internet to a website or another computer's monitor.

Important Specifications for Webcams

There aren't a whole lot of technical details for webcams to differ from model to model. Here are a couple of the big ones you should keep in mind:

• Resolution–The size and, ultimately, quality and clarity of the video you'll be recording. Larger numbers are better, but also use more hard drive space.


• Frame Rate–The speed at which your video will be recorded in Frames Per Second, or FPS. This can mean the difference between a choppy set of still images (10 fps) to a smooth, cinema-like flow of sharp video (30 or 60 fps).

How do you choose the best webcam?

Your options for buying a webcam will be largely dependent upon what you want to do with it. People use webcams for all kinds of purposes, including to have video chats, to hold online business meetings or teleconferences, to monitor a situation or location from great distances, or to record and upload video diaries (aka video blogs, or "vlogs") to YouTube or their personal website.

If you plan on mainly video chatting with friends, or uploading video diaries to YouTube, the most simplistic of cameras will serve you just as well as the more expensive brands. These less expensive models will generally have a standard resolution of (640x480)–that's about as low as you should be going when it comes to resolution these days. These cameras will run well less than $100 from any retailer.

More exciting, and a little more expensive (though not as much as you'd think), you can actually buy webcams that record in High Definition resolution (960x720 or greater). These models cost closer to $100 on average, though still not much more than that.

Alternative Solutions

There are a couple of other options consumers have when it comes to more specialized webcam functions. In many cases, a standard video camera that can be found in many households today can be connected to a computer and utilized as a live webcam. This is an interesting option for people looking to have more control over their camera, and who need to utilize features such as zoom, tripod placement, or even multiple cameras simultaneously.

Of course, the more complicated the application, the more software and equipment are needed. But for most users, a simple webcam is a smart, fun way to become even more connected to the world around you.

Articles source :http://peripherals.about.com/od/webcamerasvideoinputs/a/BYBWebcam.htm

Assemble PC

How To Assemble A Desktop PC
Components Procedure

Power Supply (PSU)
Install the power supply into the pc casing. Use the Philips screw driver to put screw for the PSU.

Motherboard
Install the system board.
Connect the system unit with front panel switches and the indicators to the system board. Verify system board jumper & switch setting.

Processor
Install the processor the PGA socket on the motherboard. Beware when pin0in the processor heatsink.

RAM
Install the memory module to the memory slot on motherboard.

Hard Disk
Install hard disk into pc case. Then, connect it with data cable (IDE,SATA) to the motherboard. Connect the hard disk with power cable (molex) from PSU.

Optical Drive
Install the optical drive (DVD Drive or CD Drive) into the pc casing. Then, connect it with data cable (IDE, SATA). Connect it with power cable (molex) from PSU.


Video Card/Graphics Card/GPU
Install the display adapter into the graphics slot (AGP, PCI-E). Then connect the graphics card with the power cable if it need extra power(graphics card requirement)

Keyboard
Connect the keyboard to the PS/2 port at back-side panel of casing.

Mouse
Connect the keyboard to the PS/2 port at back-side panel of casing.

Monitor
Connect the VGA cable from monitor to the graphics card. Then plug the monitor to electric.
Basic tools
Before you begin building or refitting a computer, you will need some basic tools:
1. 2 phillips-head (cross-shaped) screwdriver
2. Needlenose pliers
3. Anti-static Wrist Strap
4. A large level working space

What is RAM?

RAM is an abbreviation for Random Access Memory. It usually refers to "temporary" memory, as when the system is shut down, the memory is lost. This is why the memory is referred to as being "random," as any piece of information can be circulated through the memory regardless of its location and its relation to any other information within the RAM. The first of the many RAMs to come in the future was created in 1951 and was used until the late 1960s and early 1970s.
Types of RAMs

The most widely used RAMs today are SRAMs (static RAMs), which stores data in a state of a flip-flop, or DRAMs (dynamic RAMs), Flash, and EPROM, which stores data as a charge in a capacitor. Another well known type of RAM, a ROM, is a type of a RAM that has permanently enabled/disabled selected transistors by using a metal mask. ROMs thus cannot store any further charges.

Flash memory is also widely used. Because SRAMs and DRAMs are known to be highly volatile, many new products adopt the flash memory technology. Some examples of devices using flash memory include portable music players, scientific calculators, mobile phones, and even certain types of personal computers such as the One Laptop per Child (OLPC) devices. Flash memory is divided into two types: the NOR type and the NAND type. The NOR type is the one able to conduct a random access, therefore being widely used as a ROM in today's market. However, as the NOR is not able to, it is often used in flash USB drives.

In today's computers, RAMs are shipped in a form of module known as DRAM modules or memory modules. It is about the size of a chewing gum and with the Plug n Play technology, these can easily be replaced by taking it out of the port and replacing it with a new one. Not to forget, there is also an extremely small amount of RAM (known as SRAMs) within CPUs, motherboards, hard drives, and other parts of the system.
RAM Swapping

Sometimes people will need more memory than what the RAM installed can offer during intensive application cycles. During these sessions, the computer will conduct a task known as swapping. This is when the computer temporarily uses the hard drive space in place of the memory. Thrashing is the term for constantly swapping, but as the name's connotation suggest, constant thrashing can decrease the overall system performance. More RAM being added can reduce the swapping rate.
Security Concerns

SDRAMs are known to not fully shut off when the power is cut. Instead, the stored memory is faded away. While this fading away only takes seconds in a normal room temperature, which is not the case in lower temperatures, which then the fading away can take up to minutes. Therefore, encrypted information could potentially be leaked as it is still stored in the memory.
Recent Developments

Currently non-volatile RAMs are under development, which will mean that memory can still be stored when the power is shut off. The more advanced step yet to have been taken was in 2004 when Nantero developed a fully functioning carbon nanotube memory type holding 10 GB. Recently in 2006, "Solid State Drives" with sizes of 150 GB and a faster speed than the normal hard drives have been created.

Artical from : http://www.tech-faq.com/ram.shtml

Introduction to computer

Overview of computer

A computer system has three main components which is hardware, software and people

Hardware
The computer itself-and its associated equipment.

Software
The instructions that tell computer what to do. Software is also referred to as programs. More specifically, a program is a set of step-by-step that direct computer to do the task wanted and produces desire results.

People
A computer programmer is a person who write programs. Most of us simply use computer software written by someone else. This means were are users or people who purchase and computer software.

Computer is a machine that accepts data(input) and process it into useful information(output). A computer system consists of four main areas of data of handling which is input, processing, output and storage.

Internet security

Today's Web is vastly different from yesteryear's Web and today's malware is vastly different from yesteryear's virus. No longer a form of digital graffiti, modern day malware is all about money. Your money, that is. This change in intent has also led to a corresponding change in tactics. Modern day malware is made to hide. Social engineering scams are increasingly sophisticated. Man-in-the-middle attacks can forcibly redirect you to hostile websites.

The Web has also changed. No longer a static one-sided delivery method, today's websites host and push content from a variety of sources. And the notion of surfing to only "known good sites" no longer applies. Today's dynamic Web technologies lend themselves to mass compromise of perfectly legitimate websites, outfitted with malicious scripts that turn the "known good site" into a virtual conveyor belt of malware.

The same technologies that foster Web developments also enable attackers to work smarter and faster. An attacker can use virtual hosting providers that redirect (and mask) a site's true origin. Automated tools leverage search engines to ferret out sites vulnerable to compromise. Other automated tools allow attackers to continually churn out repackaged malware designed to thwart signature-based antivirus. And in the darkest recesses of the Internet, the attackers use blogs, forums, and chat to barter malware and exploit frameworks.

And all of this is designed for profit - tricking you into laundering money, stealing your credit card details, siphoning your bank accounts, and even outright identity theft. Don't look to your bank to protect you either - if you don't directly foot the bill for the stolen funds, you'll indirectly pay for it with higher fees and higher prices sometime down the road.

The threat of compromised websites
Web pages are coded in various browser-friendly scripting languages, typically including combinations of HTML, Javascript, ActiveX, and CSS. When a request to a website is made, the source code for that page is loaded and interpreted by the browser. What you see in your browser is the visual manifestation of the source commands.

A Web page isn't just static content from one source. It supports multiple types of active content, including from third-parties. Google Adsense is a good example of that (as is any other third-party advertising included on a site). The same programming techniques used to load third party advertising can be used to load any third party content, including malicious content if so desired. And attackers use that to their advantage.

In other words, when you visit one website, you are in reality pulling content from several different sites and servers. In the past, the biggest web risk was that third party content might be booby-trapped. For example, a rogue advertiser might insert a malicious banner ad into the advertising network, which then was pulled by all participating websites.

Today, the risk has shifted dramatically. Attackers are directly compromising websites and outfitting them with malicious external calls to hostile content.

SQL Injection Attacks
One of the most common forms of Web site compromise are via SQL injection compromise. SQL is short for Standard Query Language, a scripting language used to manage databases. Many/most websites use some sort of database backend. This can be for everything from creating all or most of the site pages to storing information and generating search results pages. SQL injection attacks are malformed SQL queries that instruct the database to take some sort of unintended action beyond just returning requested data. In other words, a SQL injection attack tricks the database into responding to the query as if it were a command to take some specific action, versus just returning some type of information.

A database that is vulnerable to SQL injection can be compromised in a number of ways. Of most concern from an Internet safety standpoint are SQL injection attacks that embed malicious hidden iframes and malicious external references within the source code of the compromised Web pages.

When a Web surfer encounters one of these compromised pages, these hostile third-party references call up exploit code and malware from the attacker-owned sites. This action is invisible to the Web surfer - only a thorough examination of the website source code provides the tell-tale signs of the compromise; the page displayed by the browser looks perfectly normal.

Beginning in late October 2007, a series of SQL injection attacks began which continue to compromise millions of Web pages (past compromises include Ikea and WalMart). And because the malware is being delivered from reputable (but compromised) websites, the old advice to only surf to known reputable sites no longer helps. Worse, the malware foisted by the compromised sites typically consists of password stealers and backdoors. These password stealers and backdoors can be used to steal credit card information, bank account login credentials, and other sensitive financial or personal information.

When encountering one of these compromised sites, chances are you won't notice anything awry. The malware launches silently and once on the system it often uses rootkit technology to hide itself.

Staying Safe Online
Internet safety isn't about avoiding the unknown or untrusted. Today, Internet safety also includes guarding against threats coming from even the most staid, legitimate, and otherwise honorable websites. Or in the words of the X-Files, 'trust no one'.

To avoid being victimized by a compromised website, either use the NoScript addon for Firefox, or disable active scripting in Internet Explorer and Opera. For further details, see Web Browser Security. In addition, follow these computer safety tips to lessen your susceptibility should exposure occur.

article souce : http://antivirus.about.com/od/securitytips/a/internetsafety.htm