II. Which input device would you use for these tasks?

1 to play computer games

2 to copy images from paper into a computer

3 to read price labels in a shop

4 to select text and click on links on web pages

5 to enter drawings and sketches into a computer

6 to input voice commands and dictate text

7 to draw pictures or select menu options directly on the screen

8 to take and store pictures and then download them to a computer

III. Complete each sentence by choosing from the following devices: touch screen, trackball, touchpad, webcam.

1. A................................is a stationary device that works like a mouse turned upside down.

You roll the ball with your hand to move the pointer on the screen.

2. Interactive................................are used in museums, information centres and Internet kiosks.

You use your finger to point directly to objects on the screen.

3. A................................is used to send live video images via the Internet.

4. A................................is found on notebook PCs. You use it by pressing the sensitive pad

with a finger.

IV. Identify the keys described below (use the paragraph ”The Keyboard” to help you).

1. It produces upper-case letters, but it does not affect numbers and symbols.

2. It removes the character to the left of the cursor or any selected text.

3. It works in combination with other keys, e.g. you press this key and С to copy the selected text.

4. It is used to confirm commands; in a word processor, it creates a new paragraph.

 

V. Complete these sentences with the correct “mouse action” (use the paragraph ”The Mouse” to help you).

1. To start a program or open a document you................................on its icon - that is, you

rapidly press and release the mouse button twice.

2. If you want to select a menu option, you just................................on the left button.

3. If you want to find the commands for a particular text, image, etc., you have to................................on it.

4. If you want to move an object, press the button and............................the object to the

desired location.

 

TEXT II

 

Output devices: printers

I. Read and translate the text

Technical details

• A printer is a device that prints your texts or graphics on paper.
• The output on paper or acetate sheets is called printout or hard copy.
• A program in your computer, called the printer driver, converts data into a form that your printer can understand.
• A print spooler stores files to be printed when the printer is ready.

It lets you change the order of documents in the queue and cancel specific print jobs.

• The output quality, or resolution, is measured in dpi or dots per inch.
• The speed of your printer is measured in pages per minute (ppm).

In a network, users can share a printer connected to a print server, a computer that stores the files waiting to be printed.

 

Types of printers

A dot-matrix printer uses a group, or matrix, of pins to create precise dots. A print head containing tiny pins strikes an inked ribbon to make letters and graphics. This impact printing technology allows shops, for example, to print multi-part forms such as receipts and invoices, so it's useful when self-copying paper is needed. It has two important disadvantages: noise and a relatively low resolution (from 72 to 180 dpi).

An ink-jet (also called bubble-jet) printer generates an image by spraying tiny, precise drops of ink onto the paper. The resolution ranges from 300 to 1,200 dpi, suitable for small quantities or home use.

A standard ink-jet has a three-colour cartridge, plus a black cartridge. Professional ink-jets have five-colour cartridges, plus black; some can print in wide format, ranging from 60 cm up to 5 metres (e.g. for printing advertising graphics).

Some ink-jet based printers can perform more than one task. They are called multi-function printers because they can work as a scanner, a fax and a photocopier as well as a printer. Some units accept memory cards and print photos directly from a camera.

A laser printer uses a laser beam to fix the ink to the paper. A laser works like a photocopier; a powder called toner is attracted to paper by an electrostatic charge and then fused on by a hot roller.

Laser printers are fast and produce a high resolution of 1,200 to 2,400 dpi, so they are ideal for businesses and for proofing professional graphics work.

Lasers use a page description language or PDL which describes how to print the text and draw the images on the page. The best-known languages are Adobe PostScript and HP Printer Control Language.

A professional imagesetter is a typesetting printer that generates very high-resolution output (over 3,540 dpi) on paper or microfilm. It's used for high-quality publications.

A plotter is a special type of printer which uses ink and fine pens held in a carriage to draw detailed designs on paper. It's used in computer-aided design, maps, 3-D technical illustrations, etc.

 

II. Complete these sentences with words from the paragraph “Technical details”.

1. The differences in................................are noticeable: the more dots per inch, the clearer the

image.

2. A print resolution of between 600................................and 2,400................................ensured that even text as small as 2 pt was legible.

3. Passengers with an electronic ticket will need a................................of ticket confirmation or

a boarding pass to be admitted to secured gate areas.

4. The key advance of recent years is printing speed: the latest generation of ink-jets prints black-and-white text at 15..........................................................................(................................).

5. With appropriate software, you can view the images on a computer, manipulate them, or send them to a................................and produce excellent quality colour copies.

6. A...............................................................is a dedicated computer that connects a printer to a

network. It enables users to share printing resources.

7. A................................................................is a utility that organizes and arranges any documents waiting to be printed.

8. In computers, a................................................................is a program installed to control a particular type of printer.

 

III. Choose the most appropriate type of printer for these situations.

1. a home user who wants to print text documents and family photographs

2. business people who need to print in large quantities at high quality in an office

3. engineers who want to make detailed line drawings

4. professional typesetters in desktop publishing (e.g. to publish catalogues and magazines)

5. a company that wants to print carbon copies of bills and receipts

IV. Find terms which correspond to these definitions.

1. a container that holds the ink in an ink-jet printer

2. powdered ink used in laser printers

3. small needles that press on the inked ribbon to make the characters on paper

4. printer technology that produces text and pictures by hammering pins against a ribbon and the paper

5. a language that tells a printer how to print a document

6. a peripheral which combines a printer, a fax machine and photocopying and scanning capability into one device

 

 

TEXT III

Output devices: display screens

I. Read and translate the text

CRTs and LCDs

The screen of a computer is often known as the monitor, or VDU (visual display unit). Inside the computer, there is a video card which processes images and sends signals to the monitor.

When choosing a monitor, you have to take into account a few basics.

■ Type of display - the choice is between a CRT or an LCD screen.

The Cathode Ray Tube of a monitor is similar to a traditional TV set. It has three electron guns (one for each primary colour: red, green and blue) that strike the inside of the screen, which is coated with substances called phosphors, which glow and create colours. CRTs are cheap, but they are heavy, can flicker and emit radiation.

A Liquid Crystal Display is made from flat plates with a liquid crystal solution between them. The crystals block the light in different quantities to create the image. Active-matrix LCDs use TFT (thin film transistor) technology, in which each pixel has its own transistor switch. They offer better quality and take up less space, so they are replacing CRTs.

■ Screen size - the viewing area is measured diagonally: in other words, a 17" screen measures 17 inches from the top left corner to the bottom right.

■ Resolution - the clarity of the image depends on the number of pixels (short for picture elements) contained on a display, horizontally and vertically. A typical resolution is 1,024 x 768. The sharpness of images is affected by dot pitch, the distance between the pixels on the screen, so a dot pitch of 0.28 mm or less will produce a sharp image.

■ Brightness - the luminance of images is measured in cd/m- (candela per square metre).

■ Colour depth - the number of colours a monitor can display. For example, a VGA monitor produces 256 colours, enough for home use; a SuperVGA can produce up to 16.7 million colours, so is ideal for photographic work and video games.

■ Refresh rate - the number of times that the image is drawn each second. If a monitor has a refresh rate of 75 Hertz (Hz), it means that the screen is scanned 75 times per second. If this rate is low, you will notice a flicker, which can cause eye fatigue.

A colon' pixel is a combination of red, green snd blue subpixeis