Before You BuyHardware Basics

When you're done working, you need a permanent place to store your stuff in the computer. The hardware to meet that requirement is the disk drive-specifically, the computer's hard drive. You direct the software that you're using to "save" your stuff on the hard drive, by making a permanent copy that you can use later.

• The most popular, inexpensive, and reliable form of permanent storage is the hard drive.
• Some computers even have several forms of disk storage: a hard drive, CD-ROM drive or DVD drive (or both), and maybe a floppy drive. Each of these has specific uses.
• Some handheld computers don't have physical disk drives. Instead, they contain special memory that isn't erased when the power is turned off.

Some advertisements refer to permanent storage as "disk memory." Although that term is technically correct, the term is confusing. Don't mistake disk memory for the memory inside your computer. Disk storage and RAM are two different places in a computer.

What is a disk, and what is a drive?

Simply put, the drive is the thing that contains or eats the disk. So, although your computer has a hard disk, it's more proper to say "hard drive." Similarly, you may have a CD-ROM drive, floppy drive, DVD drive, and even a digital media drive.

The disk is literally a disk. The computer writes information to the disk, where it's stored exactly like information is recorded on a cassette tape, only the disk media is flat and round-like a pancake. The drive is the device that spins the disk, reading and writing information. Sometimes, hard drives are referred to as fixed disks. This means that the disk is "fixed," as in nonmovable.

With some drives, the disk can be removed. This is true for CD-ROM, DVD, floppy, and other removable disks. With the hard drive, however, the disk cannot be removed. That's because the disk (or disks) inside the drive needs to be hermetically sealed to avoid contamination by rogue particles in the air.

Types of drives

Figure 1 illustrates a typical hard drive. The entire unit is the hard drive. Inside the unit are the hard disks.

Inside a typical computer, you find several types of permanent storage. Consider the following list of common permanent storage devices as an overview of what's available:

Hard drive: This standard, high-capacity, high-speed drive is found in all personal computers, desktops, and laptops. This drive is the primary form of permanent storage. Don't buy a computer without a hard drive!

CD-ROM: Nearly all computer software comes on CD, which makes the CD-ROM drive a must-have part of all standard desktop and laptop configurations. The standard CD-ROM drive, however, cannot be used to create your own CDs. For that you need a CD-R/RW drive.

DVD: Just as DVD is replacing videotape for the home theater market, DVD discs are slowly replacing CDs for computers. Just as with creating your own CDs, if you want to create your own DVDs, you need to get a special type of DVD drive that creates discs.

Note that all DVD drives can read CDs. So, you don't really need separate CD and DVD drives on a computer. Special combo drives are even available (for a price) that can be used to create both CDs and DVDs.

Beyond the hard drive and a CD or DVD drive are several optional types of disk drives found on many PCs. Here's the list:

Floppy: Though traditionally the first type of disk drive found on a personal computer, floppy drive technology has not kept up with computer disk storage capacities. Some manufacturers still toss a floppy drive into the computer console, but relatively few computer users ever use it.

Zip: The Zip drive was introduced to replace the floppy drive, and it was very popular for many years. Now that most computers have the ability to create their own CDs, just like the floppy drive, the Zip drive is falling out of fashion.

Digital media cards: These nonspinning drives use solid-state memory that doesn't require power in order to retain its contents. Some of these drives, such as the USB Flash Drive or Jump Drive, are designed specifically for the desktop computer and prove to be an excellent way to transfer files between two computer systems.

Disk drive capacity

The first measure of all permanent storage is how much information can be stored. As with computer memory, the measuring rod of disk storage is the byte.

The following list shows the storage capacities of the common, popular types of permanent storage drives:

• Floppy: 1.4 MB.
• Zip: 100 MB, 250 MB, and 750 MB.
• CD: Up to 720 MB.
• Flash memory: Up to 8 GB.
• DVD: Up to 8 GB (16 GB on two sides of the disk).
• Hard drive: Up to 1,000 GB (1 TB-and higher).

The only figure you really need to pay attention to is for hard drive storage. Hard drives don't come in standard sizes. Instead, you find hard drives that store anywhere from 40 GB of information up to a whopping 400 GB and higher.

Remember that a megabyte (MB) is 1 million bytes and a gigabyte (GB) is 1 billion bytes (or 1,000 MB). Technology is rapidly approaching the terabyte (TB), or 1,000 GB drive.

How much storage capacity do you need? That depends on your software and how you use the computer. Disk storage is relatively cheap. Buy more than you need, if you can afford it.

Even if you do run out of disk storage, most computers have room to add a second hard drive internally, which gives you even more storage.

Copyright © 2008 & Trademark by Wiley Publishing, Inc. All rights reserved. Please read our Privacy Policy.