Task 6. Answer the following questions

1. What is the Webster’s dictionary definition of the hardware? 2. What groups of hardware exist? 3. What is input hardware? What are the examples of input hardware? 4. What is the mouse designed for? 5. What is processing hardware? 6. What are the basic types of memory used in a PC? 7. What is a storage hardware? What is CD-ROM used for? 8. Can a user record his or her data on a CD? 9. What kind of storage hardware can contain more information: CD-ROM, RAM or ROM? 10. What is modem used for? 11. Can a PC user communicate with other people without a modem?

Task 7. Decide whether the following statements are true or false in relation to the information in the text.

1. The purpose of the input hardware is to collect data and convert them into a form suitable for computer processing.

2. Scanner is used to input graphics only.

3. CPU reads and interprets software and prints the results on paper.

4. User is unable to change the convents of ROM.

5. Printer is a processing hardware because it shows the information.

6. Modem is an electronic device that makes possible the transmission of data from one computer to another via telephone or other communication lines.

7. The purpose of storage hardware is to store computer instructions and data.

Task 8. Read the text and try to guess the meaning of any new words in the box below. Refer to the dictionary if necessary.

dot pixel display resolution cathode ray tube electron beam

scan (verb) hertz refresh rate flicker bit-mapped visualize

The monitor

The characters and pictures that we see on the screen are made up of dots, also called picture elements (pixels). The total number of pixels in which the display is divided both horizontally and vertically is known as the resolution. If the number of pixels is very large, we obtain a high resolution display and therefore a sharp image. If the number of pixels is small, a low resolution is produced.

Typical resolutions are 640×480 or 1,024×768 pixels. Pixel density affects the image: a large number of pixels gives a much clearer image.

The cathode ray tube of the monitor is very similar to that of a TV set. Inside the tube there is an electron beam which scans the screen and turns on or off the pixels that make up the image. The beam begins in the top left corner, and scans the screen from left to right in a continuous sequence, similar to the movement of our eyes when we read, but much faster. This sequence is repeated 50, 70 or 85 times per second, depending on the system. If the rate of this repetition is low, we can perceive a flickering, unsteady screen, which can cause eye fatigue. However, a fast-moving 75 Hz ‘refresh rate’ eliminates this annoying flicker.

What we see on the screen is created and stored in an area of RAM, so that there is a memory cell allocated to each pixel. This type of display is called bit-mapped. On monochrome monitors, bits 0 are visualized as white dots, and bits 1 as black dots. On color displays, there are three electron guns at the back of the monitor’s tube. Each gun shoots out a beam of electrons for each of the primary colours: red, green and blue. These electrons strike the inside of the screen which is coated with substances called phosphors that glow when struck by electrons. Three different phosphor materials are used – one each for red, green and blue. To create different colours, the intensity of each of the three electron beams is varied.

The monitor is controlled by a separate circuit board, known as the display adaptor, which plugs into the motherboard of the computer. Different boards drive different types of displays. For example, the VGA (video graphics array) card has become a standard for colour monitors.

Now flat-screen monitors are fashionable. They are inherently flat, and therefore require less space. In addition, they give crisp, clear images and eliminate screen flicker.

Portable computers use a flat liquid-crystal display (LCD) instead of a picture tube. An LCD uses a grid of crystals and polarizing filters to show the image. The crystals block the light in different amounts to generate the dots in the image.