Buying a Computer

First Steps

Before beginning your search for your new computer:

- Decide if you want a desktop PC or notebook/laptop PC. Desktop PCs can be more powerful but notebook PCs are portable

- Decide how much approximately you want to spend

- Decide what you will be using the PC for. You won't need a particularly powerful system if you're only going to browse the Web and send e-mails

- Read some computer buying advice magazines such as What PC?, PC Advisor and Personal Computer World

-Talk to friends, relatives and colleagues about what make of PC they use, where they bought it and their experiences, this provides you a good idea before you start your own research.


Where To Buy From
Main street stores may seem the most obvious place for first-time PC buyers but although they do offer some advantages (such as being able to see and touch example PCs and get an idea of the size of the screen) they are not always good value and you may find yourself spending more than you need to.

Often the sales person will also try to sell you warranty packages. These may provide some peace of mind, including things like health checks and repairs, but if you look after your PC and keep your security software up-to-date, you will most likely never use the service and will have paid a lot of extra money for nothing.

You could try small local computer shops who can often put together a PC package to suit your exact needs, though you may find the price a lot higher than the standard packages offered by high-street stores. For first-time buyers a standard package often seems far simpler than trying to figure out the specific types of components you need.

Buying online is another option; if you decide to buy online then begin the process of searching for online stores and comparing packages and prices. As with any large purchase you make, you will want to be cautious and have all the facts in front of you before you make a decision.

What to look for
Often when reading about PC packages you will be confronted with a huge list of specifications which will mean nothing to you if you don't have much knowledge of computer hardware. Some companies may try to confuse you with technical details, hoping that by mentioning large enough numbers you will think the PC is better than it really is.

Computer specifications change all the time, and your needs will determine what size or speed components are appropriate for you. The following is a general guide with some tips on what to look for.

Desktop or Notebook
the type of PC you need will depend on how powerful you need your machine to be and whether you want to be able to do work on the move. Desktop PCs are usually more powerful than notebook/laptop PCs for the same price, but the latter have the advantage of being portable and taking up much less space.

Monitor - it is important to check this is mentioned as although this may seem like an essential part of a desktop PC system, some packages may not include one. TFT (Flat Panel) monitors are common nowadays because of how thin they are compared to the old bulky CRT monitors. When buying a monitor you want the highest resolution, which will give a more detailed and sharper picture. A resolution of 1280x1024 should be fine for most users. Response time is also important - the lower the number, the better.


Tower - the shell of the desktop PC contains all the components which make your system work including the processor, memory and Hard Disk. You should check how many USB ports are included, as you will need one for each peripheral you connect such as scanners and printers.

Keyboard and Mouse - all desktop PCs should include these and there is often little difference between the various models. One thing to note is that some have more than just the left and right buttons on the Mouse - they often also include a Wheel in the center which can be a useful addition. Nowadays you can also get wireless keyboards and mice. If you want to use a mouse with your notebook PC you may need to buy it separately, as many notebooks use a touch pad system instead of a mouse.



Processor - the heart of your PC, this is the engine that powers your computer and processes all the instructions it is given, therefore you want it to be as fast as possible. The higher the processor speed (in Ghz) the faster your PC should be. Dual-core, core 2 duo, Core 2 Quad and latest technology now offers even greater speed. Example of brands are Intel Pentium or Celeron, and AMD Athlon or Sempron.

RAM - the temporary memory the computer uses to do its calculations. The more RAM you have, the faster and more efficient your programs will run. Look for at least 2 - 4 GB of RAM.

Hard Drive - where all your programs and data are stored. As usual, more is better. At least 160-250GB or more will be needed to store lots of music, games or movie files. Hard disk space is relatively cheap, and there are also external drives available that you can plug in to add more memory.

Graphics Card - handles video and display calculations. A more powerful card means better quality video graphics and smooth-running games. The most popular cards are the NVidia GeForce and ATI Radeon series. Another thing to note is that the graphics card also has its own RAM memory, and again the more the better.

Sound Card - most PCs should include decent enough sound for playing music or video, but you can opt for better quality sound cards such as the Creative Audigy series which will improve sound quality and performance in movies and demanding games.

Speakers - 2 normal desktop speakers should be fine for most users, but games players may want to invest in larger setups such as 5.1 (5 small Satellite speakers and 1 large Sub-Woofer to handle the bass sounds).

CD/DVD-ROM Drive - plays CDs/DVDs including data discs, music CDs and DVDs. The higher the speed, the faster files will be loaded from disc though it will depend on the maximum speed permitted by the disc itself. '24x', for example, means it can transfer data from the disc at 24 times the normal playing speed.

CD/DVD R/RW Writer/Burner Drive - as with CD/DVD-ROM Drives but also able to write or 'burn' discs as well as read them. This way you can create your own data, video discs, especially useful for backing up large amounts of data. There are two main categories of writeable discs : Recordable discs such as CD-R or DVD-R or DVD+R are discs that can only be written once and Re-Writeable discs such as CD-RW or DVD-RW or DVD+RW can be written over many times. Its better to have one each in your computer if you need to copy CDs often for your operations.

Operating System - Microsoft's operating system Windows is included with most PCs. Since 2001, Windows XP has been the version for home users but 2007 has seen the launch of its successor Windows Vista.

Software - some packages will include office suites, security programs, DVD creation, games and entertainment software.

Internet Access
many packages come with free Internet trials, but you can choose a different provider if you find a better deal. To access the Internet from home you will need to connect your PC to your phone line. There should be instructions with your PC how to do this. There are many different Internet packages available, and with some you will need to buy additional equipment. To learn more, contact an ISP(Internet Service Provider) or visit their web site.

Wireless Internet
modern PCs often come with built-in wireless support, to allow you to connect to any wireless Internet networks within range. If not, wireless adapters can be bought separately.

Notes
You can usually replace and upgrade your PC components in the future if you decide you need more memory or a faster graphics card, for example. And you can always upgrade or buy new software if you find the included programs too limited for your needs.

Hard Drive description & info.

A hard drive is a mass storage device found in all PCs (with some exclusions) that is used to store permanent data such as the operating system, programs and user files.

The data on hard drives can be erased and/or overwritten. The hard drive is classed as a non-volatile storage device, which means it doesn't require a constant power supply in order to retain the information stored on it (unlike RAM).

Inside every hard drive are small round disk-like objects made of either an aluminium/alloy or a glass/ceramic composite. These are called platters, each platter is coated with a special magnetic coating enabling them to store data magnetically.

Hovering above these platters are read/write heads that transfer data to and from the platters. We will cover platters, heads and the other mechanical elements in more detail in the hard drive mechanics section

Hard Drive Capacities
Hard drives come with many different storage capacities, hard drive capacity is measured in bytes, with common capacities being stated in MB (Megabytes) and GB (Gigabytes).

To understand these figures correctly you need to know the basics of how data is stored/processed in digital systems such as PCs.

Digital data is a series of 1's (ones) and 0's (zeroes) which are referred to as bits
(Binary digITS), a byte is made up of 8 of these bits, so a single byte of data may look like 01001011 (8 consecutive bits).

• 1 Bit = either a 0 (zero) or a 1 (one)
• 1 Byte = 8 bits
• 1 KB (Kilobyte) = 1024 bytes
• 1 MB (Megabyte) = 1024 Kilobytes
• 1 GB (Gigabyte) = 1024 Megabytes
• 1 TB (Terabyte) = 1024 Gigabytes

In the old days it was common to find hard drives with a capacity of just 5MB, nowadays it is hard to buy a new hard drive with less than 80GB, that's 80,960 Megabytes!

Common hard drive capacities these days range from 80GB up to and exceeding 150GB.

As a real world example let's take a colour photo, and let's say the photo takes up 500 Kilobytes of storage space on a hard drive, so if you had a 40GB hard drive you could potentially store up to 81,290 colour photos.

This is obviously hypothetical due to the fact that on the hard drive you would need your operating system and programs, which would take up some of the storage space, but you can see the point.

When you consider that an average letter written in a word processor is around 30KB, it becomes apparent that the storage capacity of modern hard drives is massive!

Hard Drive RPM Speeds
You will often see hard drives advertised as being capable of a certain RPM (Revolutions Per Minute). This figure (as the name suggests) refers to how many times the spindle makes a complete 360º turn in any single minute.

The higher the RPM, the faster the data can be read from the platters, which increases overall performance.

RPM values range from about 5,400RPM to 12,000RPM and above.

What are the bumps at the end of computer cables?

In a typical computer system found in a home or office, you normally see these "bumps" on the mouse, keyboard and monitor cables. You can also find them on power supply wires when a device (like a printer or scanner) uses an external transformer. These "bumps" are called ferrite beads or sometimes ferrite chokes.

Their goal in life is to reduce EMI (electromagnetic interference) and RFI (radio-frequency interference). You can see these beads in the photo on to your right. A ferrite bead is simply a hollow bead or cylinder made of ferrite, which is a semi-magnetic substance made from iron oxide (rust) alloyed with other metals. It slips over the cable when the cable is made, or it can be snapped around the cable in two pieces after the cable is made. The bead is encased in plastic -- if you cut the plastic, all that you would find inside is a black metal cylinder.

Computers are fairly noisy devices. The motherboard inside the computer's case has an oscillator that is running at anywhere from 300 MHz to 1,000 MHz. The keyboard has its own processor and oscillator as well. The video card has its own oscillators to drive the monitor. All of these oscillators have the potential to broadcast radio signals at their given frequencies. Most of this interference can be eliminated by the cases around the motherboard and keyboard.

Another source of noise is the cables connecting the devices. These cables act as nice, long antennae for the signals they carry. They broadcast the signals quite efficiently. The signals they broadcast can interfere with radios and TVs. The cables can also receive signals and transmit them into the case, where they cause problems. A ferrite bead has the property of eliminating the broadcast signals. Essentially, it "chokes" the RFI transmission at that point on the cable -- this is why you find the beads at the ends of the cables. Instead of traveling down the cable and transmitting, the RFI signals turn into heat in the bead.

Next Generation of Computer Displays

Computer displays have been remarkably resistant to the advances that have affected the rest of computer technology. For example, in 1982 the original IBM PC had a 16-bit processor running at 4.77 MHz. Today's processors are about 1,000 faster. Today's monitors, on the other hand, are still small glass rectangles. No major advances have occurred.

The next generation in computer display, a new technology from Elumens that completely revolutionizes the visualization of digital information. In areas such as space design and simulation (flight, driving or battlefield simulation), this new display completely changes the way you interact with the digital environment!

On the right see Photo of The VisionStation has a large parabolic shell that is used to display the image projected by the wide-angle lens. (Photo courtesy Elumens Corporation)

A North Carolina-based company, Elumens, has designed a display system that takes peripheral vision into account. The VisionStation consists of a large, curved surface (reminiscent of a large satellite dish), a high-resolution data projector and a wide-angle projection lens.

The result is a display that shows you a very wide field of view, up to a full 180 degrees. An Elumens display takes over your entire visual field, including your peripheral vision. You see not only what is in front of you, but everything above, below, left and right. When you want to see what is "beside" you, you simply turn your head and look. For example, in a driving simulator, you can look out both side windows by turning your head just like you would in a real car.

The experience when watching an Elumens display is very interesting. Because it uses your peripheral vision, the sense of motion is very real. Turning your head to look at objects is very natural. Because the screen is completely smooth, there are no distractions.

Key benefits of the VisionStation are:

- It provides an immersive experience.
- It does not require cumbersome head gear for virtual environment.
- It accommodates both real and computer-generated 3-D data.
- It can be set up by two people in about two hours (three to four hours with the Optional LightShell enclosure).
- It is portable.
- It is highly scalable.
- It is as simple to operate as a traditional monitor.
- It can be used for a variety of applications.
- It accommodates a large portion of existing 3-D applications without special porting
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Monitor the temperature of CPU

Core Temp is a software that helps you keep checking the temperature of CPU.

The unique point of Core Temp is that it can have separate monitor to check the temperature of separate CPU. As such, if you are using Duo Core CPU, you will then be provided with two meters of temperature.

It can also enable you to know the real-time changes of temperature too. Of course, graphical representation to users is also available.

Causes of a slow PC

There are many possible causes of a slow PC. Because your computer is constantly working with files - moving, copying and deleting from place to place - it will eventually get cluttered with leftover files, some of which are not needed and just take up valuable disk space. You only have a certain amount of disk space available on your hard disk, and as it fills up the computer can begin to struggle to find room to perform its tasks.

If your PC crashes or freezes up, it may be a symptom of a slow or cluttered PC.

The brain of your computer is the Processor, and it may be that your processor is too slow to run today's demanding software. The processor can also struggle if you have multiple programs running at once - for example, if you have Word open to compose a letter while downloading a file from the Internet and also operating another application through your media player.

RAM is the temporary memory the computer uses to do its calculations. If you do not have enough RAM, your programs will run slowly.

Other components of your PC can contribute to poor performance, particularly your Graphics Card when it comes to running media and games software. Some hardware needs special programs called Drivers and these need to be kept up to date.

You may also have programs running in the background using up memory that you are unaware of, and in some cases, the problem may be a malicious program such as a virus or spyware.

How To Use Your PC Mouse

The Mouse is the device you will use for most of your interactions with your PC. It is primarily used to move the pointer arrow around the screen and to select and activate options.

The mouse buttons are used to interact with whatever is on the screen where the pointer is located. The left mouse button is the one you will use most often. Clicking this tells the PC to select an item and is called 'left-clicking'. To activate an item and use it, you will often need to click the button twice or 'double-click'.

If you click and hold the left button and move the mouse, this has the effect of 'dragging' a selected object about the screen until you release the button.

Left-clicking on text in a document will place a flashing cursor at that point, which allows you to begin typing there.

The right mouse button is usually used to bring up a small menu window that gives options specific to the selected object. To use a particular option you just left-click it.Common right-click menu options for an object include: Open (activate, same as if you double-click), Cut (remove to be placed elsewhere), Copy (make a copy of this object) , Create Shortcut (create a shortcut link elsewhere to give quick access to this object), Delete (remove permanently), Rename (give a new name), and Properties (find out information).

You may have a third smaller button in the center of your mouse that can be rolled forwards and backwards. This mouse-wheel can be used to move up and down through documents.

How do optical mice work?

It appears that the venerable wheeled mouse is in danger of extinction. The now-preferred device for pointing and clicking is the optical mouse.

Developed by Agilent Technologies and introduced to the world in late 1999, the optical mouse actually uses a tiny camera to take 1,500 pictures every second. Able to work on almost any surface, the mouse has a small, red light-emitting diode (LED) that bounces light off that surface onto a complimentary metal-oxide semiconductor (CMOS) sensor. The CMOS sensor sends each image to a digital signal processor (DSP) for analysis. The DSP, operating at 18 MIPS (million instructions per second), is able to detect patterns in the images and see how those patterns have moved since the previous image. Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has moved and sends the corresponding coordinates to the computer. The computer moves the cursor on the screen based on the coordinates received from the mouse. This happens hundreds of times each second, making the cursor appear to move very smoothly.

Optical mice have several benefits over wheeled mice:

· No moving parts means less wear and a lower chance of failure.
· There's no way for dirt to get inside the mouse and interfere with the tracking sensors.
· Increased tracking resolution means smoother response.
· They don't require a special surface, such as a mouse pad.

What if I am out of USB ports in my PC?

Just about every peripheral made now comes in a USB version. Here's a list of some of the USB devices that you can buy today:

Printers, Scanners, Mice, Joysticks, Digital cameras, Webcams, Modems, Speakers, Telephones, Video phones, Storage devices like Zip drives, Network connections, etc.

Computers that you buy may come with only one or two USB sockets. With so many USB devices on the market today, you easily run out of USB sockets very quickly.

For example, on the computer that I am typing on right now, I have a USB printer, a USB scanner, a USB Webcam and a USB network connection. My computer has only one USB connector on it, so the obvious question is, "How do you hook up all the devices?"

The easy solution to the problem is to buy an inexpensive USB hub. The USB standard supports up to 127 devices.

A hub typically has four new ports, but may have many more. You plug the hub into your computer, and then plug your devices (or other hubs) into the hub. By chaining hubs together, you can build up dozens of available USB ports on a single computer.

Hard Disk Basics

Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

At the simplest level, a hard disk is not that different from a cassette tape. Both hard disks and cassette tapes use the same magnetic recording techniques. Hard disks and cassette tapes also share the major benefits of magnetic storage -- the magnetic medium can be easily erased and rewritten, and it will "remember" the magnetic flux patterns stored onto the medium for many years.

Nearly every desktop computer and server in use today contains one or more hard-disk drives. Every mainframe and supercomputer is normally connected to hundreds of them. You can even find VCR-type devices and camcorders that use hard disks instead of tape. These billions of hard disks do one thing well -- they store changing digital information in a relatively permanent form. They give computers the ability to remember things when the power goes out.

Keyboard Basics

When you look at all the extras and options that are available for new computer keyboards, it can be hard to believe that their original design came from mechanical typewriters that didn't even use electricity. Now, you can buy ergonomic keyboards that bear little resemblance to flat, rectangular models with ordinary square keys. Some flashier models light up, roll up or fold up, and others offer options for programming your own commands and shortcuts. They use switches and circuits to translate a person's keystrokes into a signal a computer can understand.

A keyboard's primary function is to act as an input device. Using a keyboard, a person can type a document, use keystroke shortcuts, access menus, play games and perform a variety of other tasks. Keyboards can have different keys depending on the manufacturer, the operating system they're designed for, and whether they are attached to a desktop computer or part of a laptop. But for the most part, these keys, also called keycaps, are the same size and shape from keyboard to keyboard. They're also placed at a similar distance from one another in a similar pattern, no matter what language or alphabet the keys represent.

Most keyboards have between 80 and 110 keys, including:

- Typing keys
- A numeric keypad
- Function keys
- Control keys

The typing keys include the letters of the alphabet, generally laid out in the same pattern used for typewriters. According to legend, this layout, known as QWERTY for its first six letters, helped keep mechanical typewriters' metal arms from colliding and jamming as people typed. Some people question this story – whether it’s true or not, the QWERTY pattern had long been a standard by the time computer keyboards came around. typing keys include the letters of the alphabet, generally laid out in the same pattern used for typewriters. This layout, known as QWERTY for its first six letters, helped keep mechanical typewriters' metal arms from colliding and jamming as people typed. Because this pattern had been long established as a standard, manufacturers developed keyboards for computers using the same layout, even though jamming was no longer an issue.

What does Alt+F4 do?

This is one of those jokes people play on each other -- it's in the same category with squirting flowers and exploding cigars. This joke works on machines running the Windows operating system because Windows happens to define certain keystrokes that work the same way in all applications. Just about everyone knows that Alt+Ctrl+Del interrupts the operating system, but most people don't know that Alt+F4 closes the current window. So if you had pressed Alt+F4 while playing a game, the game window would have closed.

It turns out there are several other handy keystrokes like that built into Windows. For example, Ctrl+Esc will pop up the Start menu, Alt+Esc will bring the next window to the foreground, and Alt+Tab or Alt+Shift+Tab will let you cycle through all available windows and jump to the one you select.

On keyboards that have the little "Windows" key (let's call it WK here) down near the space bar, you probably know that you can press that key to open the Start menu.

You can also use that key with other keys like you use the shift key. For example:

WK+e - starts the Windows Explorer
WK+f - starts the Find in Files dialog
WK+Ctrl+f - starts the Find a Computer on the Network dialog
WK+M - minimizes all the windows to clear the desktop
WK+Shift+M - restores all the minimized windows
WK+r - starts the Run dialog
WK+F1 - starts Windows Help
WK+Pause - starts System Properties

How do CD-R discs work?

The basic idea behind data storage on a normal CD is simple. The surface of the CD contains one long spiral track of data. Along the track, there are flat reflective areas and non-reflective bumps. A flat reflective area represents a binary 1, while a non-reflective bump represents a binary 0. The CD drive shines a laser at the surface of the CD and can detect the reflective areas and the bumps by the amount of laser light they reflect. The drive converts the reflections into 1s and 0s to read digital data from the disc.

Normal CDs can not be modified -- they are read-only devices. A CD-R disc needs to allow the drive to write data onto the disc. For a CD-R disk to work, there must be a way for a laser to create a non-reflective area on the disc. A CD-R disc therefore has an extra layer that the laser can modify. This extra layer is a greenish dye. In a normal CD, you have a plastic substrate covered with a reflective aluminum or gold layer. In a CD-R, you have a plastic substrate, a dye layer and a reflective gold layer.

On a new CD-R disc, the entire surface of the disc is reflective -- the laser can shine through the dye and reflect off the gold layer. When you write data to a CD-R, the writing laser (which is much more powerful than the reading laser) heats up the dye layer and changes its transparency. The change in the dye creates the equivalent of a non-reflective bump. This is a permanent change, and both CD and CD-R drives can read the modified dye as a bump later on. It turns out that the dye is fairly sensitive to light -- it has to be in order for a laser to modify it quickly. Therefore, you want to avoid exposing CD-R discs to sunlight.