To start off, information is stored is a bit. It consists of simply a 0 or 1, 0 being off, 1 being on. When eight bits are stored together, it becomes a byte. Anything measured in bits is abbreviated with a small "b". Bytes are represented with a capital "B". A byte is used to represent a single character, such as “A”, “3" or “@.” Standard metric prefixes are used to modify the number of bytes.
A standard 3 ½ “ floppy hold 1.44 megabytes, while a ZIP disk holds 100 MB. A standard hard drive is about 13 gigabytes, and some are even 50 gigabytes or more. That’s a whopping 35,000 floppy disks. Storage space on a personal computer ranges from about $60 for a 2 GB hard drive or 3 cents a megabyte to $275 for a 50 GB hard drive or ½ cent per megabyte. So how much storage space do you really need? Well, that all depends. Lets look at some common operating systems. Microsoft Windows 95 needs between 75 and 125 megabytes of storage just for itself. Windows 98 requires between 150 and 295 megabytes of storage, while Windows 2000 requires 2 GB hard disk with a minimum of 650 MB of free space. Eight to thirteen gigabytes would be a reasonable amount of storage space for the average user, though someone who was looking at digital video editing on their computer would probably want upwards of 20 gigabytes. After we have chosen our hard drive, we probably want to decide on the CPU (central processing unit) or “brains” of the computer. The speed, Megahertz (MHz), is basically how fast the computer can calculate or perform tasks. There are many different choices, AMD K-7, AMD Athlon, or Intel’s Celeron, Pentium II, or Pentium III. A Celeron processor is a stripped down version of the Pentium chip. This means performance is degraded slightly. However, a Celeron 500 MHz chip is about $90 while a Pentium 500 MHz chip is closer to $200. Unless you plan on doing lots of 3D animation, graphics manipulation, or gaming, a Celeron processor will probably do, and will save you a little money as well. For normal word-processing and internet use, a 350 MHz Celeron or K-7 processor is adequate. All of us could use more memory, and a computer is no different. With the strain of today’s software and hardware on the computers resources, 64 megabytes are a must and if possible, 128 or 256 is even better, especially for power users. The video cards of today also have memory, ranging from 2 megabytes to 64 megabytes. The more memory the card has, the better performance will be. For most business applications, 2-4 megabytes of memory is adequate, for newer games, 8 megabytes is probably the least you’d want. The cards can also provide video capture and video out to allow for editing of home movies. Many also include TV in, so you can watch TV on your monitor and TV out which allows the information to be sent to a television set. They come in one of two flavors, PCI (Peripheral Component Interconnect) or AGP (accelerated graphics port). AGP video cards provide better performance but only newer motherboards have an AGP slot. Prices for PCI and AGP cards are comparable. The computer monitor comes in many sizes, with 14, 15, 17, 19, and 21 inch models readily available. Screen size is measured diagonally like a television. However, be warned that a 14 inch monitor actually only has a 13.3 inch viewable screen. This may be adequate for some who use the computer only on occasion, most will find they will start suffer from eye strain. The size that most will find agreeable is the 17 inch model. Starting at about $175 to $200 they are quite affordable and will pay for themselves quickly. Modems are necessary if you want to connect to the internet. The speed of modems is measured in kilobits per second. The current standard is 56 kbps or a transfer speed of about 56,000 characters per second. Many models also come with caller ID and Fax capabilities and allow your computer to do even more. Newer technologies such as DSL and cable modems are 10-50 times faster than a standard modem. A sound card and speakers are necessary to play music CD’s or hear sound effects or music in games. The cost for an inexpensive set is about $30 to $40 while high end systems can cost upward of $200. Rounding out your system is a good printer. Color printers can cost as little as $50. However, you must keep in mind that new ink cartridges can cost between $20 and $35 each. Ideally, look for a printer that has separate cartridges for color and for Black. That way if you run out of Black, you only have to replace one cartridge rather than all four colors at the same time. The other determining factor in printers is the quality at which they print. This is measured in dots per inch or DPI. The old standard is 360 dpi or 129,600 dots in 1 square inch. By contrast, many printers print at 720 dpi, or even 1200 dpi. Though this may seem like a small difference, it creates massively different results. To be sure, the more dots per inch, the better the end product. Many newer systems also include a CD writer (CD-R) or CD re-writer (CD-RW). Although a CD-RW drive can write to a regular CD, the reverse is not true. A CD-R disc allows you to create your own music or data CD’s. However, the limitation of these is that you can only put information on them once. CD-RW’s on the other hand allow you to put information on a CD up to 999 times. This means they are very good for a weekly backup of your important files. The limitation of CD-RW discs is that they will only run on the very newest CD players. The cost of a CD-RW disk is about $3 while a CD-R disk will only set you back a dollar. Another useful peripheral device is a scanner. This allows you to scan photos or other objects for use in a newsletter, computer montage, or on your very own web page. As with printers, scanner quality is measured in dpi. However, scanners are dpi of input rather than output. Optical resolution is the important measurement, because interpolated resolution is merely the scanning’s software’s “best guess” at what should be at each location. A good scanner should have a resolution of at least 600x600 optical resolution.. Because of the nature of technology, computers are always changing. One of the best ways to keep up with the latest and greatest is the internet. Some sites I recommend are: |
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