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David A. Wimsett
Providing Technological Solutions

David's interest in technology extends back to his teen years with science fairs and amateur radio. He is fascinated with hardware, but his real interest is how people use technology. David's goal in providing technological solutions has always been to listen to the end users.

Buying That New Computer: Part II - The Essentials

The power and features of the computer you buy need to match the jobs you intend to use it for. You want enough horsepower for the tasks at hand, but buying more computer than you need is a waste of money.

The heart of any computer is the Central Processing Unit (CPU). It performs the calculations, processes the data, and routes the information you work on. The processor is controlled by a special program called the operating system, or OS. When you use application programs, such as Word, Firefox, Photoshop, and iTunes, they communicate with the OS, which, in turn, makes requests of the processor.

A processor's speed is rated in terms of how many cycles it can process in a second. One cycle per second is 1 hertz (abbreviated Hz). Today's processors operate in the range of millions of cycles (known as megahertz and abbreviated MHz) and even billions of cycles (known as gigahertz and abbreviated GHz). It is not uncommon to find 2 GHz and even 3 GHz processors in today's computers.

If you want to cut out images from several photos to assemble into a collage, edit a home video to share with friends and family, create graphic designs such as brochures, or play the latest video game, you should look for a computer with a 2 GHz processor or faster. Otherwise, you may see jerky motion and have to wait long periods for commands to finish.

Word processing, surfing the web, emailing, or figuring your taxes could easily run on a processor with a speed of between 800 MHz and 1 GHz. You will certainly see an added boost in response when using a more powerful CPU, but it may not be enough to justify the extra cost.

The CPU has some internal storage to hold instructions and data, but not nearly enough to hold a photo or letter. For that you need Random Access Memory (RAM). It acts as a temporary scratch pad where a CPU stores the data and instructions it is currently working on.

The basic unit of storage in a computer is the byte. One byte can hold a single keyboard character, a portion of a sound or the colour and luminance values from a pixel of a digital image. When you put together enough bytes you get a novel, a symphony or a photograph.

Bytes are composed of 8 bits. A bit is the smallest unit of storage in a computer. It represents a binary digit. It's called binary because it uses the base 2 numbering system in which there are just two digits, 0 and 1, as opposed to our normal base 10 numbering system where we have 10 digits, 0 through 9.

In base 2, the value 0 means zero and 1 means one the same as in base 10. But, the value 2 in base 2 is written 10, three is 11, and 4 is 100. The value 255 is 11111111. The letter A has the binary code 01000001. This is why electronic devices such as computers, cameras, MP3 players, DVD's and CD's are all called digital. The music, movies, photos and data are stored as zeros and ones in a pattern.

Early microcomputers measured RAM in thousands of bytes (known as kilobytes and abbreviated KB). When larger memory chips became available, it was measured in millions of bytes (known as megabytes and abbreviated MB). Today, memory can reach billions of bytes (known as gigabytes and abbreviated GB). Having more RAM is like having a bigger desk to work on.

Imagine you are creating a poster to hang on the wall that will be 34 wide and 44 long. Your desk is only large enough to hold one 8.5 x 11 sheet of paper at a time, so you divide the poster into 16 pieces arranged in 4 rows of 4 columns.

You get out the first sheet and place the others in a filing cabinet. When you complete sheet number 1 you take it to the filing cabinet and place it in a folder. Then, you get out another blank sheet, place it in on the desk, and continue. While you're working on sheet 7 you get an order to change sheets 1 and 3. You put sheet 7 back in the filing cabinet, take out sheet number 1, alter it, put it back in the filing cabinet , take out sheet number 3, change it, and put it back. Then, you get out sheet 7 and continue where you left off. When you're finished with all of the sheets, you put them in the filing cabinet until you're ready to tape them together and hang them on the wall.

This is similar to what happens in memory. Computers don't have a very large repertoire of actions they can perform. Their power is in the ability to perform small tasks over and over in rapid succession. When you build up enough small steps you get a big one. Everything a computer does is divided into little pieces, like the poster. As much as possible is held in memory, but RAM is a finite resource. When it gets full, programs and data that aren't being used at that moment are temporarily moved to the hard disk which runs at a fraction of the speed. This can drag a computer to its knees. It's not just a matter of one large photo. Modern machines are multi-tasking, meaning they can run more than one application at a time. Every one of those applications requires memory, including the OS. When additional RAM is added, less data gets rolled out to disk and more is available for immediate processing. Our hypothetical poster would have been much easier to draw if our desk could hold all sixteen sheets at once.

Memory was once very expensive. In 1981, I bought 32 KB of RAM for $350. Today, I can purchase 2 GB for $35. For programs that manipulate large photos, edit video and play 3D games, you should load your computer with 2 GB or more. If you are only dealing with text, I still recommend at least 1 GB. As operating systems, games and applications are developed, programmers continue to add new features that require more memory. At the current price of RAM it is worth anticipating future needs by buying more than you might need.

RAM only holds your files while they are being processed. When an application ends, the memory it was using is erased. When the computer is shut off, RAM is cleared. You need somewhere to store your files permanently. A hard disk is the most popular way of doing this. It consists of spinning platters and magnetic read/write heads that put down a pattern of bits to form bytes.

When purchasing a hard disk, there are two things to consider.

  1. The capacity. How much data can the disk hold?
  2. The average seek time. How fast does the disk find the data?

Disk capacity was once measured in megabytes. Today, the smallest hard disk you can find is 40 GB. It is not uncommon to see models that store 150 GB, enough to hold the text of 150,000 novels. This may seem an absurdly large capacity, however, a high resolution picture from a modern camera digital can exceed 25 MB, and a Photoshop file to manipulate it could triple or even quadruple that. As with memory, disk drives have dropped dramatically in price. A 40 GB drive can be had for about $60 and a 500 GB drive for around $110. If you are handling large photos or want to load lots of games, look for a higher capacity drive. If not, you would likely be very happy with a 40 GB drive.

Average seek time tells how long the disk takes to scan the platter and locate the desired data. It is expressed in millionths of a second (know as milliseconds and abbreviated ms). The lower the number, the less time a search takes and the faster the response will be. Typical values range from 9 ms to 16 ms.

If you want to surf the world wide web or use email, you must connect to the Internet. The first step is to contact an Internet Service Provider (ISP). You can find them in the phone book and on-line with a search engine. Often, local telephone and cable providers supply Internet connections.

When shopping for hardware to connect you to the Internet, you will not see kilobytes or megabytes mentioned. Instead, networking gear and connections are rated in kilobits per second(kbps), megabits per second (Mbps) and gigabits per second (Gbps). Notice the lower case b' for bit as opposed to the uppercase B' for byte. Since a byte is made up of 8 bits, a 56 Kbps connection would transfer a maximum of 7 KBps (kilobytes per second). The reason marketing departments use bits per seconds instead of bytes is that 56 sounds faster than 7.

There are three basic kinds of services, dial-up through a standard telephone line, high-speed and WiFi.

To use dial-up, you need a device called a telephone modem that converts digital data into sounds that travel over the telephone line at a rate of between 23 to 53 Kbps, or 3 to 6 bytes per second (modems are rated as 56 Kbps, but due to limitations in telephone lines, dropped data and retransmission, the best a modem can achieve is 53 KBps and the actual rate can be far below that). The service is called dial-up because the telephone modem has to dial the ISP over a conventional phone line to connect to the Internet. When the computer is turned off, the connection is broken.

High-speed connects at rates of around 5 to 10 Kbps, or 600 KB to 1.6 MB per second. The ISP supplies a special modem that plugs into a Local Area Network (LAN) port on your computer. High-speed is always on and available when you power up.

WiFi is wireless network access. It allows you to connect to the world wide web without cables. You can sit in any room in your house or in a coffee shop and surf the web or send email. Your computer must have a wireless network card either built in or installed. Then, you must be in range of a WiFi transmitter. These are called wireless routers because they route the Internet connection to one or more computers. The router itself is attached to a high-speed Internet connection with a wire or fibre optic cable. Many coffee shops, civic centers, airports and other public spaces have installed WiFi routers for people to use free of charge. Some municipalities are setting up WiFi transmitters that cover their entire city.

You can create a WiFi zone in your own house by subscribing to high-speed internet and installing a wireless router. You can then access the Internet from any room in your house. You can put WiFi cards in other computers and create a network in which all the machines can share the Internet connection, printers and hard disk files. If you do set up a wireless network, put a password on it that makes certain only your computers can use it. Otherwise, someone with a WiFi card out on the street could access your private files without you knowing about it.

The speed of WiFi cards has increased over the years. Today, you will find two kinds, type G and type N. Type G wireless networks transmit data at a rate of 10 Kbps, which is as fast as most Internet connections you will get for your home. Type N wireless networks transmit at 100Kbps. This may not get you any more speed on the Internet, but it would allow faster access to other computers in your network.

Prices and availability of these services vary by provider and region.

The keyboard and mouse are used to enter data and commands. Some plug directly into your computer with a cord and others (cordless models) use radio or infrared signals to transmit commands through the air. This allows you greater freedom of placement and movement.

For keyboards, you can select one with a standard key layout or opt for a multi-media keyboard that allows you to play music and movies with buttons controlling volume, play, fast forward and stop. They can also perform tasks such as sending email with the touch of one button. If you play music and watch movies, a multi-media keyboard is very handy. As well, being able to start tasks like email or web browsing with a single button is a real time saver. Still, a plain, vanilla keyboard will work fine for most applications.

Besides choosing between cord and cordless models, mice come in two different versions. Mechanical mice use a ball that rolls along a surface and captures the operator's hand movement, translating them into cursor movement on the screen. Optical mice shine a light on the surface and use it to gauge hand movement.

Mechanical mice pick up dirt as they roll across surfaces and require regular cleaning.

Optical mice do not have this problem. In addition, optical mice are more accurate, especially the new line of laser models. However, an optical mouse needs to have some visual break-up on the surface it moves over. It will not work well when run over a dark, even surface.

Mice, like keyboards, can have multi-function buttons that perform complex tasks with a single press. One of the best time saving features is the wheel mouse. This allows you to scroll text and graphics on the screen or zoom in and out by just turning the wheel. On PC mice, this is located between the left and right mouse buttons. On Apple Macintosh computers, their Might Mouse allows 360º scrolling through a touch sensitive area.

Text and graphics are generated electronically inside the video card. It contains a separate microprocessor and memory that is specifically designed to create images. Some deliver life-like 3D renderings that can be rotated, scaled and moved, features used in many games. If you are working with text or manipulating still images, a basic video card at under $100 will suffice. If you intend to edit video or you want to play the most recent action games, you will want to invest in a high end video card, although it could set you back as much as $500.

Some motherboards come with a standard video card built in. If this meets your needs, you don't have to add one. If you want more power than the on-board model, you can still plug a high end card into an expansion slot and override the built in circuitry.

A monitor displays the virtual images created in the video card. The standard today is a flat screen LCD display that has a smaller footprint and uses less power than the older television type models. They come in a variety of sizes from 15 up to 28 diagonal. You can also buy projection monitors to show an image that fills a wall. These are often used for presentations where a room full of people have to view the display. There are standard aspect ratio screens shaped like a television as well as wide screen models. Some will rotate on their axis to take the same shape as a 8.5 x 11 piece of paper. Your video card must support rotation for you to do this.

If you are not dealing with intense graphic, a 15 to 17 monitor will give you a good, clear picture for word processing, spreadsheets, web surfing, and the like. For those who are doing intense graphic work, a larger monitor makes it easier to compose and manipulate images. A larger monitor can also enhance your gaming experience.

If you are doing desktop publishing, the ability to rotate the monitor so it is the same aspect ratio as a piece of paper allows you to work with bigger objects and see an entire presentation at a glance. A wide screen monitor allows you to display more data on the desktop and view more windows at a tine. It is extremely handy with graphic programs such as Photoshop where a standard screen can become cluttered with toolbars and palettes. Wide screen monitors allow these to be moved to the side to give more room for the image.

To play something other than simple beeps requires a sound card. Some computers come with a sound system built into the motherboard. As with the video card, you can plug a more powerful audio card into an expansion slot and override the built in one.

For many people, a $50 card will deliver good stereo sound. If you are really into games or movies, you should consider a high end sound card. Available for under $200, they can produce simple stereo or full digital surround sound, which dramatically enhances the gaming and movie experience. You will also need headphones or speakers that match the sound card's capabilities. For simple stereo, a pair of $10 speakers or headphones may do fine. For digital surround sound, investigate a surround speaker setup with a center channel and subwoofer. They can run $250 or more.

These are the essentials that every computer buyer should consider. However, there are still more options that can enhance your computing experience.

Next: Part III Not So Optional Options


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