3. You are going to read a text about computers. Check that you know these words and expressions from the text.

to carry out sequence to embed to receive data to follow instructions to process to produce information hardware software processing unit

to store to deliver to unplug manual to restart helpline to fiddle with sth hard disk floppy disk backing up to remove

4. Read the information about personal computers and choose the best heading for each paragraph (1 – 8). There is extra heading which you don’t need to use.

A. Computer Error & Human Error

B. What Happens Inside?

C. Numerous Modern Computers

D. Organizing Files

E. Hardware and Software

F. Health Problems

G. Times of Trouble

H. The First Electronic Computers

I. Common Information about a Computer

Personal Computer

1. A personal computer is a programmable machine which is designed to sequentially and automatically carry out a sequence of arithmetic and logical operations. The first electronic computers were developed in the mid-20^th century (1940 – 1945). Originally, they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs).

2. Modern computers, which are based on integrated circuits, are millions to billions of times more capable than the early machines, and occupy a fraction of the space. Personal computers in their various forms are icons of the Information Age and are what most people think of as ‘computers’. However, the embedded computers, which are found in many devices from MP3 players to fighter aircraft and from toys to industrial robots, are the most numerous.

3. A computer receives facts, which are known as data, and following instructions, it processes these facts to produce information. Computers can process vast amounts of data in a very short time. Data and information can be numbers, letters, sounds, pictures or symbols. Pictures and symbols, which a computer produces, are called graphics.

4. A computer cannot think for itself. It will do exactly as it is told – no more and no less. People often talk about ‘computer error’, but usually this means human error. If you are sent an electricity bill for millions of dollars when you only use one light bulb, it means that the computer was given the wrong instructions.

5. In order to process data computers need two things – hardware and software. Hardware is the computer’s machinery – the parts you can see and touch, like the monitor and all the electronic devices and circuits inside. Software is all the facts and the lists of instructions that a computer receives in order to carry out its tasks. All the different tasks of instructions are called programs.

6. Let’s see what goes on inside the brain of your computer – its processing unit.

• Input. Data and instructions are fed into the computer.

• The control unit. Input comes here first and is sent to the correct part of the computer to be processed. When work is completed, the control unit collects the information.

• The arithmetic unit. The computer carries out all its work in the arithmetic unit. The control unit and the arithmetic unit are together called the Central Processing Unit (CPU).

• Memory. Data and instructions are stored here.

• Output. The processed data is delivered to the user.

7. If your computer stops working, first check that all your cables are properly connected. It’s funny to call a technician only to find that your dad unplugged your machine to do the vacuuming. Read your manual and try switching off and restarting the system. Most hardware and software manufacturers have a helpline you can call for advice. Don’t attempt to fiddle with electronics yourself. If your manuals are too full of jargon to understand, you can buy simpler guides that explain things more clearly.

8. Make sure that your files on the hard disk are organized into different directories so you can find them easily. You may copy the files from the hard disk onto compact, external hard, USB (Universal Serial Bus) flash disks or any other portable devices. Then if you lose any files from the hard disk, you will still have a copy of your work. This is called backing up. Try to remove unnecessary files from the hard disk. If it gets too full, data can become jumbled and your computer starts working more slowly.