What is a computer?
A computer is an electronic machine which can accept data in a certain form, process the data, and give the results of the processing in a specified format as information.
First, data is fed into the computer's memory. Then, when the program is run, the computer performs a set of instructions and processes the data. Finally, we can see the results (the output) on the screen or in printed form (see Fig. 1 below).
A computer system consists of two parts: hardware and software. Hardware is any electronic or mechanical part you can see or touch. Software is a set of instructions, called a program, which tells the computer what to do. There are three basic hardware sections: the central processing unit (CPU), main memory and peripherals
Perhaps the most influential component is the central processing unit. Its function is to execute program instructions and coordinate the activities of all the other units. In a way, it is the'brain'of the computer. The main memory (a collection of RAM chips) holds the instructions and data which are being processed by the CPU. Peripherals are the physical units attached to the computer. They include storage devices and input/ output devices.
Storage devices (hard drives, DVD drives or flash drives) provide a permanent storage of both data and programs. Disk drives are used to read and write data on disks. Input devices enable data to go into the computer's memory.The most common input devices are the mouse and the keyboard. Output devices enable us to extract the finished product from the system. For example, the computer shows the output on the monitor or prints the results onto paper by means of a printer
On the rear panel of the computer there are several ports into which we can plug a wide range of peripherals - a modem, a digital camera, a scanner, etc. They allow communication between the computer and the devices. Modern desktop PCs have USB ports and memory card readers on the front panel.
A USB port A USB connector
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11*
Input
Data is collected and entered
Expenses
(e.g. payroll, services, publicity)
Income
(e.g. sales, stocks, interest)
Processsing
Data is manipulated
It
Storage
| Balance |
Files and programs are held on disk
Output
The results are shown on the monitor or in print form
Fig. 1
T Computer essentials
Match these words from the text (1-9) with the correct meanings (a-i).
1software a
2peripherals b
3main memory с
4hard drive (also known as hard disk)
5hardware d
6input e
7ports f
8output 9
9central processing unit (CPU) the brain of the computer
physical parts that make up a computer system
programs which can be used on a particular computer system
the information which is presented to the computer
results produced by a computer
input devices attached to the CPU
section that holds programs and data while they are
executed or processed
magnetic device used to store information
sockets into which an external device may be
connected
Different types of computer
CEListen to an extract from an ICT class. As you listen, label the pictures (a-e) with words from the box.
laptop desktop PC PDA mainframe tablet PC
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у».Listen again and decide whether these sentences are true or false. Correct the false ones.
1A mainframe computer is less powerful than a PC.
2A mainframe is used by large organizations that need to process enormous amounts of data.
3The most suitable computers for home use are desktop PCs.
4A laptop is not portable.
5Laptops are not as powerful as desktop PCs.
6Using a stylus, you can write directly onto the screen of a tablet PC.
7A Personal Digital Assistant is small enough to fit into the palm of your hand.
8A PDA does not allow you to surf the Web.
Language work: classifying
Look at the HELP box and then use suitable classifying expressions to complete these sentences.
1A computer..._______________
hardware and software.
2Peripherals............................ three
types: input, output and storage devices.
3A word processing program
--------------- software which lets
the user create and edit text.
4--------------- of network
avchtectute-. peev-to-peer, where all computers have the same capabilities, and client-server (e.g. the Internet), where servers store and distribute data, and clients access this data.
PI In pairs, describe this diagram, using classifying expressions from the HELP box. Make reference to your own devices.
Classifying
Classifying means putting things into groups or classes. We can classify types of computers, parts of a PC, etc. Some typical expressions for classifying are:
• ... are classified into X types/categories
• ... are classified by ...
• ... can be divided into X types/categories
Digital computers can be divided into five main types: mainframes, desktop PCs, laptops, tablet PCs and handheld PDAs.
• ... include(s)...
• ... consist(s) of...
The basic configuration of a mainframe cons'ists of a central system which processes immense amounts of data very quickly.
• There are X types/classes of...
• X is a type of...
A tablet PC is a type of notebook computer.
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Output devices
• monitor
| Input devices • mouse • keyboard • camera |
• printer
Storage media
• magnetic, e.g. hard drive
• optical, e.g. DVD
• Flash memory, e.g. pen drive
Benefits of laptops and tablet PCs
ИYour school is considering buying tablet PCs to use in the classroom. Write an email to your teacher explaining the benefits for the students and the school.
or
Your company is considering replacing all of the office PCs with laptops. Write an email to your boss explaining the benefits for the employees and the company.
| unit з Inside the system Technical specifications |
Read the advertisement and translate the technical specifications into your own language.
| Dell Inspiron 9200 |
| О Intel Core 2 Duo processor at 2.4GHz О 2048MB RAM, expandable to 4GB О 500GB hard drive О Comes with Windows Vista Home Premium |
r" 1
In pairs, answer these questions. If necessary, look at the Glossary.
1What is the main function of a computer's processor?
2What unit of frequency is used to measure processor speed?
3What does RAM stand for?
What is inside a PC system ?
Read the text on page 12 and then answer these questions.
1What are the main parts of the CPU?
2What does ALU stand for? What does it do?
3What is the function of the system clock?
4How much is one gigahertz?
5What type of memory is temporary?
6What type of memory is permanent and includes instructions needed by the CPU?
7How can RAM be increased?
8What term is used to refer to the main printed circuit board?
9What is a bus1
10 What is the benefit of having expansion slots?
Look at these extracts from the text. What do the words in bold refer to?
1This is built into a single chip, (line 2)
2... which executes program instructions and coordinates... (line 3)
3... that is being executed, (line 22)
4... performance of a computer is partly determined by the speed of its processor, (line 25)
5... the CPU looks for it on the hard disk ... (line 35)
6... inside the computer to communicate with each other, (line 52)