Текст.
Optical disks and drives.

   Optical disks can store information at much higher densities than magnetic disks. Thus, they are ideal for multimedia applications where images, animation and sound occupy a lot of disk space. Besides, they are not affected by magnetic fields. This means that they are secure and stable, e.g. they can be transported through airport metal detectors without damaging die data. However, optical drives are slower than hard drives. While there are hard drives with an average access time of 8 ms, most CD-ROM drives have an access time of 150 to 200 ms. ....
    Смотреть>>>     Скачать>>>


Текст.
Technical details

   Floppy disks are so called because they consist of flexible plastic material which has a magnetizable surface.
   The surface of a disk is divided into concentric circles or 'tracks', which are then divided into 'sectors'. When you insert a blank disk into a disk drive, it must be 'initialized', or formatted, before information can be recorded onto it. This means that magnetic areas are created for each track and sector, along with a catalogue or 'directory' which will record the specific location of files. ....
    Смотреть>>>     Скачать>>>


Текст.
Unit 4. Topic: Input/Output devices.

II. Reading
1. Read the text and see if you correctly classified the devices.
A. Input devices are pieces of hardware which allow us to enter information into the computer. The most common are the keyboard and the mouse. We can also name a lightpen, a scanner, a trackball, a graphics tablet, a joystick, etc.
B. A mouse is a palm-sized device, slightly smaller than a pack of cards. On top of the mouse there are one or more buttons for communicating with the computer. ....
    Смотреть>>>     Скачать>>>