Class 2 Components. StorageSometimes one can distinguish between "fixed media" (the hard drive) that is more or less permanently mounted inside the computer case, and "removable media" (just about every other kind of media) that is easy to pull from one computer and put into another computer. Floppy Disk drives. The first 8-inch floppy disk design was invented in the late 1960s by IBM, but these floppies were used only by a very limited group of people. Some time later 5.25" floppy disc was introduced and used in the 1980s. And only 3.5" floppies are supposed to be the most commonly used storage media. They hold from 400KB up to 1.44 MB. Floppy disks have largely been superseded by flash drives as a transfer medium, but are used as backup storage in our country. At the beginning of 2006 it was announced that all the floppy manufacturers would stop to produce such a product. A hard drive (often called HDD) consists of one or more magnetic disks and a read arm with two electromagnetic coils for each disk. Each hard disk is divided into many sectors, each containing a certain amount of data. It is the cheapest and most common way to store a lot of data in a small space. CD-ROM drive is a standard format for storing a variety of data. A CD-ROM holds about 700 MB of data. The media look like a small, somewhat flexible plastic disc. Any scratch or abrasion on the data side of the disc can lead to it being unreadable. CD-RW drive supports the creation of CD-R and CD-RW discs, and also function as CD-ROM drives. These drives use low-powered lasers to 'burn' data into the active layer of the disc. Many CD writers (also known as 'burners') are now combination drives which also function as DVD-ROM drives. Most DVD-RW drives also have CD-RW capabilities. DVD-ROM drive. This optical drives work on a similar principle to the CD-ROM, with a laser being used to read data stored in pits on the surface of a reflective disk. DVDs are read using a shorter wavelength of light. Besides a greater data-density, DVDs may be double sided and may be "dual layer". DVD-RW drive works with DVD-discs and dual-layer disks (dual layer equipment and disks are now becoming more affordable).
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