Types of computer systems

A supercomputer is extremely powerful and is capable of performing hundreds of millions of instructions per second. It can be used for very complex tasks, such as computer modeling of weather systems. These computers are extremely expensive, and are generally used by educational or scientific institutions, rather than individual users.

A mainframe is a powerful computer which is capable of processing large amounts of data, often enabling many people to use it, and to carry out many tasks, at the same time. A network of smaller computers or terminals is used to access the files and programs on the mainframe. Mainframes are therefore described as multi-user, multi-tasking machines. The central system is a large server connected to hundreds of terminals over a network. Mainframes are used for large-scale computing purposes in banks, big companies and universities.

A smaller computer in a network connected to a mainframe, or other more powerful computer, is often called a workstation. A workstation may, however, also be a relatively powerful computer, usually with good graphics capabilities, that may be either attached to a network or used as a standalone machine. Some computers can only which are part of a network do not have all the hardware needed to operate as a standalone computer. This type of computer can only work when it is connected to a network and is called a dumb terminal. Workstation is also used to refer to the physical place where a user works with a computer, usually at a desk.

A small computer designed to be used by an individual, for example at home or in an office, is sometimes called a PC, or a personal computer. This kind of machine used to be called a microcomputer because when they were introduced they were the smallest type of computer available.

PC, or personal computer, is often used to refer to a personal computer which is not an Apple Macintosh machine. Apple Macintosh machines are known as Macs. This can be confusing, as Macs are also personal computers. However the distinction is often made between Mac users and PC users.

A desktop PC has its own processing unit (or CPU), monitor and keyboard. It is used as a personal computer in the home or as a workstation for group work. Typical examples are the IBM PC and the Apple Macintosh. Many users have desktop computers either at home, at work or in educational institutions. A desktop is not designed to be portable, which means it does not have an independent power supply, and is too big and heavy to be carried easily. Some people use the term ‘desktop’ to refer to the case which sits under the computer screen on a desk, distinguishing it from a tower case (a vertical case), which stands vertically next to the screen or on the floor. The vast majority of modern PCs are tower case.

A laptop (also called a notebook PC) is a lightweight computer that you can transport easily. It can work as fast as a desktop PC, with similar processors, memory capacity, and disk drives, but it is portable and has a smaller screen. Modern notebooks have a TFT (Thin Film Transistor) screen that produces very sharp images. Instead of a mouse, they have a touchpad built into the keyboard – a sensitive pad that you can touch to move the pointer on the screen. They offer a lot of connectivity options: USB (Universal Serial Bus) ports for connecting peripherals, slots for memory cards, etc. They come with battery packs, which let you use the computer when there are no electrical outlets available.

A netbook is like a laptop, but is smaller and the memory is not so big.

A tablet PC looks like a book, with an LCD (Liquid Crystal Display) screen on which you can write using a special digital pen. You can fold and rotate the screen 180 degrees. Your handwriting can be recognized and converted into editable text. You can also type at the detached keyboard or use voice recognition. It's mobile and versatile.

A handheld computer, usually called a palmtop or a PDA (Personal Digital Assistant), is small enough to fit into the user’s hand. The term PDA refers to a wide variety of handheld devices, palmtops and pocket PCs. For input, you type at a small keyboard or use a stylus – a special pen used with a touch screen to select items, draw pictures, etc. As a handheld computer (or hand-held) is so small, it users handwriting recognition and touch screen keyboard. Some PDAs recognize spoken words by using voice recognition software. A basic handheld usually includes a clock, date book, address book, memo pad and calculator and is useful for everyday tasks. Handhelds can also be used to:

· access the Internet via Wi-Fi or Bluetooth technology

· send and receive emails

· store and listen to MP3 audio files

· play games

· record and view both still and video picture files

· check words in a dictionary

· store data

Handhelds can also function as mobile phone and GPS (General Positioning System) navigator. Another very useful feature of handhelds is that they are able to synchronize data with the other computers.

A wearable computer runs on batteries and is worn on the user's body, e.g. on a belt, backpack or vest; it is designed for mobile or hands-free operation. Some devices are equipped with a wireless modem, a small keyboard and a screen; others are voice-activated and can access email or voice mail.

Embedded computers are found inside other machines such as fridges, cars and ticket machines. They receive input data from the host machine and use this to send output data back to the machine. An example of this might be an embedded computer in a car that constantly checks tyre pressure and tells the driver when the pressures below the safety limit. Embedded computers are probably the smallest type of the computers.

 

5. Prepare a short summary of the text using the following expressions:

The main idea of the text is…

The problems/statements/points mentioned/discussed/described in the text are…

The text is divided into… logical parts…

The first/second/third logical parts deals with the problems/statements/points of/contains information about/ gives the definition of…

In my opinion/ to my mind the text is…

6. Match the terms with their definitions:

 

1. a mainframe	a) a hand-held computer which can be used as a telephone, a web explorer and a personal organizer
2. a desktop computer	b) a typical computer found in many businesses and popular for home use
3. a laptop	c) a large computer used for intensive data processing and often linked to many terminals
4. a tablet PC	d) a small computer that fits into items of clothing
5. PDA	e) a portable computer that can be closed up like a briefcase, but it can be as powerful as a desktop PC
6. a wearable computer	f) a full-function PC, though it only weighs about 1.2 kg - you can go to a meeting and write your notes on it, like a paper notepad; its screen mode can be changed from portrait to landscape

 

Part II. Language

7. Rewrite the following active sentences into passive voice:

1. We use different Internet browsers.

2. My boss wrote an e-mail of confirmation.

3. Someone uses my computer.

4. In case of doubts you must contact the Internet Service Provider.

5. You can download new updates from the Internet.

6. In order to install this plug in you must disable the antivirus.

7. Before installation you should plug the power cord.

8. You must enable the “Automatic Detection” option.

8. Write passive sentences from the words in brackets (All sentences are present):

1. (all these computers / scan / every day)

2. (this processor / make / of silicon)

3. (how often / these printers / cleaned)

4. (the firewall / disable)

5. (all the resources / share / with the other PCs)

6. (the transfer rate / check / automatically)

7. (what / this machine / use for?)

8. (the processor / place / into the socket)

 

9. Write the sentences in Present Perfect:

1. I (fix) the computer.

2. Jimmy (buy) the most expensive audio card.

3. I (run) scandisk.

4. Sue and Walter (format) their laptops.

5. He (defragment) my local hard drive.

6. John and I (create) a new user account for you.

7. I (remove) the Recycle Bin icon from the desktop.

8. When I (click) OK, a pop-up menu (appear).

 

10. Write the questions in Present Perfect:

1. You / buy / a new ink cartridge.

2. You / check / your mail.

3. Sue / send / you / an email.

4. The computer experts / install / network.

5. The designer / finish / the web page.

6. You / delete / the spam messages.

7. You / verify / the free hard disk space.

8. They / try / to reboot the computer.

 

11. Make questions about the information in bold:

1. Adam has installed this new antivirus.

2. I’ve been in the office all day.

3. Sue has deleted all the startup programs.

4. She’s done it because the computer was running slow.

 

12. Use Complex Subject:

1. (Известно, что) A supercomputer is extremely powerful and capable of performing hundreds of millions of instructions per second. 2. (Ожидается, что) Handhelds access the Internet via Wi-Fi or Bluetooth technology. 3. (Сообщают, что) Banks, big companies and universities use mainframes for large-scale computing purposes. 4. (Говорят, что) Laptops offer a lot of connectivity options. 5. (Известно, что) A netbook is like a laptop, but is smaller and the memory is not so big. 6. (Ожидается, что) Handwriting is recognized and converted into editable text.