Basic english for information technology

Memory Unit The Memory Unit is the part of the computer that holds data and instructions for processing.. input device a peripheral used primarily to enter data into a computer The mous

Hanoi open university

Faculty of Information technology

Nowadays English is one of the most common languages in the world It is widely used in every sphere of life, especially in Information Technology The aim of this book is to provide

a basic knowledge of how English is used in Information Technology (IT) This book is designed particularly for the students in the Faculty of Information Technology of Hanoi Open University (FITHOU), who will use English not only for communicating but also for studying, researching and working in the future It is a highly recommended material for those who want to improve their English proficiency in order to acquire a better basic knowledge in both English and English for IT

There are 10 units covering major aspects of Information Technology using a variety of relevant materials taken from reliable sources such as specialized books and magazines With the purpose of helping students to acquire the basic computing knowledge and English for

IT, the emphasis is on developing reading and writing skills Instruction on grammar and specialized language structures are also provided throughout the units The book also includes a very useful glossary, review questions as well as the answer keys and many teaching notes

It is designed as a user-friendly book with a clear layout, with many photos and graphics to illustrate the topics and better assist students in their study

The authors have devoted a lot of time and effort in compiling this book Nevertheless, the book cannot escape from some shortcomings and the authors would like to apologise for any deficiencies found by readers The authors would highly appreciate users’ comments and remarks for further improvements in the next edition

Finally, the authors would like to express a sincere gratitude to Professor Thai Thanh Son, the former Dean of FITHOU for his valuable support in completion of this book

We hope that all teachers and students will find this book an interesting and useful resource

CONTENTS

Page

10.4 Barriers to Business and Consumer Target Markets 82

Throughout the 1950s and 1960s, computers captured the public's imagination in literature, films, and TV More and more companies wanted computers, even if they didn't always have

a good reason to own one As a result, computers gradually became smaller, cheaper, and more practical to own This was thanks in part to companies like IBM, which mass-produced computers for the first time and promoted them to medium and large businesses to do things like payroll, accounting, and other number-crunching tasks

In the 1970s and 1980s a new type of computer started to gain in popularity It was called the

PC or personal computer For the first time in history, computers were now for everyone The PC started a revolution which affects nearly everything we do today The ways we work, play, communicate, and access information have all been radically reshaped due to the invention and evolution of the PC

PCs are everywhere you look today At home, at the office, and everywhere in between Many people still mistakenly believe the term PC is synonymous with a desktop computer running Windows This is not really true Really, any computer you use by yourself for general purposes could be called a PC You probably already own at least one of these types

Besides PCs, there are other types of computers you probably see at work or school These include:

- file servers

- web servers

But not all types of computers are so obvious as the ones above There are still other kinds of computers that fit inside of other devices and control them These computers are known as embedded systems

Embedded systems can be found in traffic lights, TV sets, refrigerators, coffee machines and many more devices Embedded systems are typically controlled by inexpensive, specialized processors which can only handle very specific tasks

Types of computers go in and out of fashion as times changes Older kinds of computers which were very popular in the 20th century (1900's) are now referred to as legacy systems These include:

- mainframes

- minicomputers

- IBM clones

Mainframe Minicomputer IBM clone

New types of computers are always coming out and replacing or augmenting existing computer types Examples of new types of computers emerging would be netbooks, tablet PCs, and even wearable computers

As you complete this unit, you will learn to differentiate between different computer types Keep in mind that the lines between computer types are constantly being blurred This phenomenon is known as convergence

1.3 Parts of an Information System

The way to think about a microcomputer is a part of an information system and not only as

an equipment An information system has five parts:

-Software:

It is another name for a program A program is step –by-step instructions that tell the computer how to do its work The purpose of software is to convert data, that is, unprocessed facts into information (processed facts) As such there are 2 types of software: Application software and System software

Application software may be described as end-user software, System software enables the application software to interact with the computer, System software is referred to as background software

-Hardware:

The hardware consists of the physical equipment: keyboard, monitor, system unit and other devices Hardware is controlled by software It actually processes the data to create information It falls into 5 categories: -input devices, system unit, secondary storage, output devices and communication devices Other extra parts called peripheral components or devices include mouse, printers, modems, scanners, cards (sound, color, and video) and so

on

Thus hardware is divided into four basic categories:

+processing: microprocessor chips and memory

-Data:

Data consists of the raw, unprocessed facts Examples of raw facts are hours worked After data is processed through the computer it is called information An example of such information is the total wages for a week’s work

Useful Vocabulary:

1 convergence

The evolution of devices towards common functionality

The iPhone is a good example of convergence It has all the features of a PDA, mobile phone, and an MP3 player in one package

2 embedded system

a computer using a relatively slow and specialized processor and ROM chip, normally used

to control a particular device such as a washing machine or an MP3 player

Nearly all electronics you can buy today are controlled by embedded systems

6 PC ( personal computer)

a computer designed for use by one person at a time

When people use the term 'PC', they are often referring to a desktop computer running Windows

7 PDA(personal digital assistant)

a handheld computer about the size of wallet used as an organizer, web

browser, game machine, mobile phone, or message recorder; also known

as a hand-held computer

The modern traveling businessman depends on his PDA to organize all

8 print server

a physical or software device connecting and facilitating a network with a printer

The secretary could not get a hard copy because the print server was broken

9 router

a specialized computer which connects two networks

The DSL router allowed the entire office to share a single Internet connection

1 What is a computer?

2 How many types of computers are there? List them

3 What does the hardware of a computer system consist of?

4 What is the hardware?

5 What is the software?

B LANGUAGE WORK: DESCRIBING FUNCTIONS

What does X do?

What is X (used) for?

What is the function of X?

X is a device for + Ving…

X is/ are used to V…

X is/ are used for Ving…

X + V ( in the Present Simple tense) The function of X is to V…

The function of X is Ving…

This is a device which…

This is a device which is used to V…

X + (work) by Ving

E.g: A mouse is a device for controlling the cursor and selecting items on the screen

C PRACTICE: Describe the function of the following components using the given words

and structures above

1 router / be/ a specialized computer / which / connect / two networks

………

2 PDA / be used as / organizer / web browser / game machine, mobile phone, or message recorder / also known / hand-held computer

D PRACTICE: Circle the correct answer

1 The most powerful type of computer is a………

A mainframe B supercomputer C laptop D PDA

2 Computers can be used to……… products and check you out at the cash registers

in shops

A keep track of B store C calculate D send off

3 A scanner is ……… that reads images and converts them into electronic codes

which can be understood by a computer

A software B a peripheral C a storage device D an output device

4 How many………….are there in a byte?

A zeros B bits C pits D digits

5 ………… is the physical parts of a computer system including any peripheral

equipment such as printers, modems and mouse devices

A software B a storage device C hardware D application

6 There are millions of ………in a today’s chip

A pixel B applications C transistors D pits

7 The first……… computer which was as big as a house was built in the 1940s

A digital B analogue C portable D personal

8 At the back of a computer there are ports into which we can plug (e.g a

scanner, a modem, etc.)

A internal device B internal devices C external devices D external device

9 Apple and IBM are the first two companies that produced…………

A mainframes B servers C portable computers D personal computers

10 To run highly demanding applications, you need a fast processor, ……… RAM and a spacious

disk

A many B lot C plentiful D so

Unit 2: The Central Processing Unit

(CPU)

The computer is composed of the following functional parts: the central processing unit (CPU), the memory, and one or more input-output (I/O) units

2.1 What is a Central Processing Unit?

In order to work, a computer needs some sort of “brain” or “calculator” The Central Processing Unit (CPU) is the “brain” of the computer; it reads and executes program instructions, performs calculations, and makes decisions The CPU is responsible for storing and retrieving information on disks and other media It also handles information on from one part of the computer to another like a central switching station that directs the flow or traffic throughout the computer system The central processing unit is the essential component of a computer because it is the part that executes the programs and controls the operation of all the hardware Powerful computers may have several processors handling different tasks, although there will need to be one central processing unit controlling the flow of instructions and data through the subsidiary processors

The CPU resides inside a box, known as the system unit, along with various support devices and tools for storing information

2.2 Main Components and Structure of the CPU

What does the CPU do?

It carries out instructions and tells the rest of the computer system what to do This is done by the Control Unit of the CPU, which sends command signals to the other components of the system

It performs arithmetic calculations and data

manipulations, e.g comparisons, sorting, combining, etc

The computer’s calculator is a part of the CPU known as the Arithmetic Logic Unit

It holds data and instructions, which are in current use These are kept in the Main Store or Memory

To understand how the whole system

works, consider the diagram shown in

Figure 2.2 An actual CPU may have

these components or other with different

names that provide the same function

Control Unit

The control unit of the CPU contains circuitry that uses electrical signals to direct the entire computer system to carry out, or execute, stored program instructions Like an orchestra leader, the control unit does not execute program instructions; rather, it directs other parts of the system to do so It is the “brain within the brain”, as it controls what happens inside the processor, which in turn controls the rest of the PC The control unit must communicate with both the arithmetic/logic unit and memory The functions performed by the control unit vary greatly by the internal architecture of the CPU, since the control unit really implements this architecture On a regular processor the control unit performs the tasks of fetching, decoding, managing execution and then storing results The control unit uses the instruction contained

in the Instruction Register to decide which circuits need to be activated It co-ordinates the activities of the other two units as well as all peripherals and auxiliary storage devices linked

to the computer The control unit instructs the arithmetic logic unit which arithmetic operations or logical operation is to be performed It is literally in control

Memory Unit

The Memory Unit is the part of the computer that holds data and instructions for processing Although it is closely associated with the CPU, in actual fact it is separate from it Memory associated with the CPU is also called primary storage, primary memory, main storage, internal storage and main memory There are two types of computer memory inside the computer, RAM and ROM

RAM ( Random Access Memory)

This is really the main store and is the place where the programs and software we load gets stored When the Central Processing Unit runs a program, it fetches the program instructions

from the RAM and carries them out If the Central Processing Unit needs to store the results

of calculations it can store them in RAM Random Access Memory can have instructions read from it by the CPU and also it can have numbers or other computer data written to it by the CPU The more RAM in your computer, the larger the programs can run When we switch a computer off, whatever is stored in the RAM gets erased

ROM ( Read Only Memory)

ROM is “built-in” computer memory containing data that normally can only be read, not written to ROM contains the programming that allows your computer to be “booted up” or regenerated each time you turn it on The data in ROM is not lost when the computer power

is turned off The ROM is sustained by a small long-life battery in your computer If you ever

do the hardware setup procedure with your computer, you effectively will be writing to ROM

Arithmetic Logic Unit

The arithmetic logic unit executes arithmetic and logical operations Arithmetic operations include addition, subtraction, multiplication and division Logical operations compare numbers, letters and special characters

Comparison operations test for three conditions:

Equal –to condition: ALU compares two values to determine if they are equal For example:

If the number of tickets sold equal the number of seats in the auditorium, then the concert is declared sold out

Less-then condition: The computer compares values to determine if one is less than another For example: If the number of speeding tickets on a driver’s record is less than three, the insurance rates are $425; otherwise, the rate are $ 500

Greater- than condition: The computer determines if one value is greater than another For example: If the hours a person worked this week are greater than 40, then multiply every extra hour by 1.5 times the usual hourly wage to compute overtime pay

Relational operations (= <, >) are used to describe the comparison operations used by the arithmetic logic unit

The arithmetic logic unit performs logic functions such as AND, OR and NOT

The accumulator is used to accumulate results It is the place where the answers from many operations are stored temporarily before being put out to the computer’s memory The other general-purpose registers hold data on which operations are to be performed by the arithmetic logic unit

2.2 How the CPU works

The CPU is centrally located on the mother board Since the CPU carries out a large share of the work in the computer, data pass continually through it The data come from the RAM and the units (keyboard, drives, etc.) After processing, the data is sent back to the RAM and the

units The CPU continually receives instructions to be executed Each instruction is a data processing order The work itself consists mostly of calculations and data transport

The CPU performs four steps in executing and instruction:

The control unit gets the instruction from memory

The control unit decides what the instruction means and directs the necessary data to be moved from the memory to the arithmetic logic unit

The arithmetic logic unit performs the actual operation on the data

The result of the operation is stored in memory or a register

The first two instructions make up what is called the instruction time The last two instructions make up what is called the execution time The combination of these two is called a machine cycle Each central processing unit has an internal clock (or system clock), which produces pulses at a fixed rate to synchronize all computer operations A single machine cycle instruction is made up of a number of sub-instructions, each of which must take at least one clock cycle Each type of CPU is designed

to understand a specific group of instructions called the

instruction set

2.3 Definition of a microprocessor

In a microcomputer, the CPU is contained on a single silicon

chip called the microprocessor A microprocessor, as shown

in figure, is a computer processor on a microchip It’s

sometime called a logic chip It is the “engine” that goes into

motion when you turn your computer on A microprocessor

is designed to perform arithmetic and logic operations that make use of small holding areas called registers Typical microprocessor operations include adding, subtracting, comparing two numbers, and fetching numbers from one area to another When the computer

number-is turned on, the microprocessor number-is designed to get the first instruction from the Basic Input/ Output System (BIOS) that comes with the computer as part of its memory

MATCH THE SENTENCE BEGINNING (1-6) WITH THE CORRECT ENDINGS f)

(a-1 The CPU processes data and a areas within the CPU

2 The control unit is the part of the CPU

that b you cannot make changes to it

3 The arithmetic and logic unit is able to

make

c controls the way instructions are executed

4 The registers are high- speed storage d the computer is turned off

5 Data contained in RAM is lost when e coordinates the other parts of the

computer

6 ROM memory can only be read f calculations: adds, subtract, multiply,

and divide

ANSWER THE FOLLOWING QUESTIONS:

1 What does the CPU do?

2 What does the CPU consist of?

3 What does the control unit of the CPU do?

4 What is the function of the memory unit?

5 What is the difference between the data in RAM and ROM?

C LANGUAGE WORK: DESCRIBING COMPONENTS

consist(s) of comprise(s) is/are composed of

X contain(s) include(s) is/are made up of is/are build up of

A and B

A, B and C

D PRACTICE:

a Underline the structure of describing components in the passage

b Describe the components of the CPU, using the structure in Language Work

Unit 3: Input and Output Devices

3.1 Input devices

We use input devices every time we use a computer Simply speaking, it is these devices which allow us to enter information Without them, the computer would not know what we want it to do

Some of the things we do with input devices are: move a cursor around the screen, enter alphanumeric text, draw pictures, and even enter binary data in the form of graphics or audio wave forms

Input devices have a history as long as computers themselves Perhaps the first input device was the simple electronic switch (similar to a light switch) which turned bits on or off There were hundreds or even thousands of these switches on larger computers It used to take a team of programmers hours or even days to set up a computer to perform a single calculation

Switches and jumpers are still used today on computers For instance the power button on the computer is a switch which is also an input device telling the computer to power on or power off Tiny switches called jumpers are also widely used on mother boards to change important settings such as processor clock speed or memory speed

Most likely in front of you right now are two of the most popular input devices: the keyboard and the mouse And instead of a mouse on a laptop computer you normally have a touchpad

As computers evolved throughout the late 20th century, computers became more and more interactive Input devices came and went Some lasted and some did not The light pen and the joystick are almost unknown today, although they were popular before the mouse and the gamepad became well-known Touch screens are already replacing keypads on mobile phones and may come to replace or augment keyboards and mice on PCs and laptops in the near future

Different people prefer different input devices for doing same task For instance, many graphic artists prefer to use a stylus and graphics tablet rather than a mouse It might offer them a greater deal of artistic freedom, or precision while performing their work

Sufferers of carpal tunnel syndrome often prefer a trackball or stylus to a mouse Handicapped computer users have invented a wide array of input devices designed to replace the mouse including devices controlled by foot or even eye movement

Not only PCs and mainframes use input devices Almost all computers feature some kind of input devices Special scanners are used in many stores and warehouses called barcode readers to enter stock and sell items at the cashier These are input devices as well Even microphones can technically be called input devices as a computer can respond to them and interpret them as incoming data

Corporations and especially government institutions are already implementing the second generation of input devices to improve security These include retina scanners and/or fingerprint readers to replace or improve accuracy of username and password authentication You will be seeing more of this kind of biometric authentication in the coming years as a general remedy for weak passwords or leaked passwords

In summary, input devices are how you interact with a computer The computer responds to your input and hopefully does what you need it to do It seems really simple, and that's the way it was meant to be!

Useful Vocabulary:

1 barcode reader

a hardware peripheral designed to 'scan' products into an inventory tracking system

Harry got into trouble during inventory because he forgot to charge his remote barcode scanner

2 click

To press and release the primary (left-side) mouse button

The screen prompt read, "Click next to continue."

3 double-click

To depress and release the left mouse button twice in quick succession

The Macintosh user did not know that in order to open a file in Windows you need to

double-click it

4 fingerprint reader

a device which forms a digitized image of a human finger print for the purpose of biometric authentication

The security firm was so tired of people choosing weak passwords that they installed

fingerprint scanners to increase the security of their systems

5 graphic tablet

an input device or mouse alternative using a sensitive rectangular surface and a stylus

The graphic designer used a graphics tablet in addition to a mouse in Illustrator

6 input device

a peripheral used primarily to enter data into a computer

The mouse and the keyboard are two examples of common input devices

a handheld input device for computers with one or more buttons and a rounded body meant

to be slid around on a pad or flat surface

The older wheel mouse preformed poorly after a few months, and needed to be replaced with an optical mouse

the ability of a computer to determine standard letters and numbers based on fuzzy logic

Instead of retyping the stack of documents, the secretary decided to OCR them to save time

13 right-click

to press the right-side mouse button

Windows 95 was the first major operating system to popularize the right-click

14 speech recognition

the ability of a computer to convert spoken words from a user into usable data

The new phone system used speech recognition to help reduce the number of customer

service representatives

15 stylus

a part of an input device resembling a pen used to draw on the surface of a graphics tablet

The man lost his stylus and thus could no longer enter text on his PDA until he replaced it

a display that also acts as an input device by allowing a user to navigate a program by

touching specific locations of the screen

Most information kiosks in airports make use of touchscreens instead of keyboards or mice

3.2 The keyboard entry

The keyboard is the most common input device found on computers today

You should be familiar with all the keys in order to have a successful career in Information Technology

Here are some common keys you should be familiar with in order to complete this unit:

The alternate key

The control key

The tab key

The escape key

The function key

The arrow keys

The page down key

The page up key

The delete key

The print screen key

The caps lock key

The hash key

The carpet key

The tilde key

The scroll lock key

Please note: in the USA the ‘hash key’ is most often called the ‘pound sign’ This is very confusing because if you say 'pound key' to a British English speaker he will probably assume you are referring to the British pound currency symbol ( £ )

Hash key Caret key Tilde key Scroll lock key

Useful Vocabulary:

1 Alt (alternate key)

a specific key on a computer keyboard that when pressed in conjunction with other keys produces a wider range of characters

Pressing the alt key with another letter key can often result in a program shortcut

2 arrow keys

a set of four input buttons on a keypad or keyboard often used for navigation in interfaces or applications

The girl used the arrow keys to move the space ship in the video game

3 Caps lock key

a key which when pressed will toggle characters in upper or lower case

Users leaving Caps Lock on is a frequent problem when logging into secure systems

a computer key which changes the meaning of another key

A popular shortcut in Microsoft Word is to hit Ctrl-S to save a document

6 Del (delete key)

a key which moves the cursor one space to the right deleting any character which might be there

Jeremy accidentally fell asleep at his computer, his nose hitting the delete key, and his term paper was completely erased

7 Esc (escape key)

a key normally in the upper left corner of a keyboard labeled with program specific functions such as backing out of a menu

The student had never used the escape key before he started programming the Unix shell

8 Function key

any one of several "F" keys on the keyboard that performs a programmable input

Most people have function keys on their keyboards, but only advanced users ever use them for anything

10 Pgdn (page down key)

a key which jumps the cursor a preset amount of distance towards the bottom of a document

Because of varying concepts of a 'page', many programs react differently to the page down key

11 Pgup (page up key)

a key which jumps the cursor a preset amount of distance towards the top of a document

The teacher told the students to hit the page up key several times to get to the top of the document

12 Pr Scr (print screen key)

a key which normally captures the current screen to the clipboard to be pasted into an

imaging program

Many graphic designers use the print screen key to take screen shots of applications to be used in tutorials or brochures

13 scroll lock key

a key, normally with a corresponding LED light, which normally has no assigned use in modern computing

The computer operator suddenly realized after 10 years he had never used the Scroll Lock key for anything

14 tab key

a key that, when pressed, moves the insertion point to the next preset marker

The usability expert showed the office workers how to save time by using tab instead of the mouse

15 ~ (tilde key)

this key serves a variety of uses, most notably in Unix systems to mark a home folder

The student learned that his home directory was 'home/~

3.3 Output devices

What is a Computer Output Device?

In the world of computers, input/output (I/O) refers to the communication between a

computer and the user Input is the data sent to the system, whereas output is the data sent

by the system to the outside world Computer output devices are computer hardware

equipments, that are used to communicate the results of data processing carried out by a computer to the user There are a number of devices, which produce data in different forms, which includes audio, video or hard copy Output device of computer are types of peripheral hardware connected that is connected to the computer, either using cables or over a wireless network Immaterial whether you have desktop computers, laptop computers,

supercomputers, etc., you will require at least one computer output device

Which Devices are Computer Output Devices?

An output given by the computer can be in the form of a display on the screen or a printed document or a song that is played Most of the computer output devices are common to home as well as office environments At the same time, there are some devices, which are not as commonly available Having said that, let’s take a look at computer output devices

Printer

The next of the computer output devices is the printer, which is an external hardware device, which takes processed data from the computer to generate a hard copy of the data After the monitors, printers are the most used peripherals on computers and they are commonly used

to print text data, images, etc There are three main types of computer printers, namely ink jet, laser printers and dot matrix Each of these printers uses a different technology to print

Speaker

A speaker is a hardware device, that is connected to a computer’s sound card, which outputs sound generated by the card Audio data generated by the computer is sent to the audio card, that is located in the expansion slot The card translates the data into audio signals, which are then sent to either the speakers or headphones In the initial phase, computers had on-board speakers, which generated series of different tones and beeps When the popularity of multimedia and computer games grew, higher quality computer speakers came into the market These new speakers were known for higher quality sound effects and music

Projector

It is a hardware device, with which an image like a computer screen is projected onto a flat screen Image data is sent to the video card, by the computer which is then translated into a video image and sent to the projector A projector is often used in meetings or to make presentations, because they allow for a large image to be shown, with which the display is available for a large audience

Plotter

Plotters, like printers, create a hard copy rendition of a

digitally rendered design The design is sent to a plotter

through a graphics card and the image is created using a pen

In simple words, plotters basically draw an image using a

series of straight lines This computer output device is used

with engineering applications

Discs

There are different types of discs, such as CDs, DVDs and floppy discs, which are output devices, that are also used to store data, hence they are also input devices at the same time The data is sent to the disc and the data is embedded on the disc, which is retrieved, when required

This is computer output devices information in short All

computers might not have all the computer output devices, but it certainly does have one of the visual output devices,

namely either a monitor or projector

A ANSWER THE FOLLOWING QUESTIONS:

1 What are input devices?

2 List all the input devices mentioned in the passage

3 What are output devices?

4 List all the output devices mentioned in the passage

5 Can you name any device that is both an output and input device?

B LANGUAGE WORK: CLASSIFYING

There are X types/ classes of …………

A is a type of ………

Use the suitable classifying expressions to complete these sentences:

1 Peripherals ………three types: input, output and storage devices

2 A word processing programs ………software which lets the user create and edit text

3 ……… 2 types of network architecture: peer-to-peer where all computers have the same capabilities and client-server (eg The Internet), where servers store and distribute data and clients access this data

4 A touchpad is a ……… of input device

5 ……… three main types of computer printers, namely ink jet, laser printers and dot matrix printers

C USE THE FOLLOWING HINTS TO FIND OUT WHAT IS THE MOST SUITABLE INPUT/OUTPUT DEVICES FOR THE NEEDS GIVEN:

Inputting printed graphics Building cars

Controlling the screen cursor in a fast action game Making choices on the screen of smart devices such as Iphones, Ipads

Recording moving images Reading a book loan in a library Printing very high quality text and graphics Creating drawings

Printing building plan drawings Recording sound

Listening to music without disturbing others Inputting a lot of text

to draw on the computer screen Showing large images on a flat screen in presentations, meetings etc

Identifying a person by using finger print

Unit 4: Storage and Memory

4.1 Main Memory

Memory is used to store the information (programs and data) that the computer is currently using It is sometimes called main or primary memory One form of memory is called RAM, which stands for Random Access Memory This means that any location in memory may be accessed in the same amount of time as any other location The address of a memory cell is used when we wish to access that particular memory location This means that we must know the address of a cell in memory before we can access its contents A byte is a small unit of storage, capable of storing unsigned numbers in the range 0 to 255 In order to allow you to store larger quantities in memory, the hardware allows you to treat a number of consecutive cells as a unit For example, by using two consecutive cells, 16 bits are

By using 4 consecutive cells, 32 bits are available, allowing numbers in excess of 1 billion

to be manipulated

RAM is a form of short term of volatile memory Information stored in short term storage is lost when the computer is switched off or when power fails There is therefore a requirement for permanent or long term storage which is also referred to as secondary storage This role

is fulfilled by disk and tape storage

4.2 Types of Main Memory

There are two major forms of RAM called static RAM (SRAM) and dynamic RAM (DRAM)

SRAM is the more expensive of the two as it is more complexly manufactured but it is

considerably faster to access than DRAM DRAM has an access time in the range of 60-100 nanoseconds upwards, while SRAM access times range from 4 or 5 nanoseconds upwards It

is not uncommon for a computer system to have a small amount of SRAM and a large volume of DRAM, making up its total RAM capacity The SRAM is used to construct a

cache memory which stores frequently accessed information and so speed up memory access for the system There are other forms of Primary memory such as ROM, PROM, EPROM, EEPROM and flash memory

4.3 Computer memory and computer storage

In this unit you will learn the differences between computer memory and computer storage Memory and storage are important concepts to master in Information Technology The two terms are sometimes used interchangeably, so it is important to understand some key differences

Computer memory needs to be quick It is constantly feeding the CPU with data to process Since nobody likes to wait for a computer, high-quality computers will have fast processors and lots of quick memory

Computers do not normally process all the information they have at once They also need to save some data for long term use This is where storage comes in Think of all the video files, mp3s, photos, documents, etc on your PC These files are not always being processed by the CPU, they are mostly just hanging around waiting to be used at some point Storage does not need to be as quick as memory, but there does need to a lot more of it This is a key difference between memory and storage

Because memory needs to be much faster than storage, it is rather more expensive than storage per KB A typical desktop computer today (in 2009) typically has between 512 MB and 8 GB of memory running at speeds of anywhere from 300 MHZ to 1.2 GHZ Don't worry if you don't know what those measurements mean at this point We will get to them in

a later unit

Memory is almost always based on semiconductor technology Examples of common computer memory include RAM, ROM, and video memory Memory is typically volatile in nature, meaning that it needs power in order to retain its state There are exceptions however, such as EPROMs, which can retain their state even when the power is off

Computer storage is typically cheaper, slower, and more plentiful than computer memory Storage comes in many different types including magnetic storage, optical storage, and more recently semiconductor storage Storage is typically non-volatile in nature, meaning that it retains its state even when the power is off A typical computer today comes with anywhere between 50 GB and 1 TB of computer storage

The most popular example today of magnetic storage is the hard disk drive These devices use rotating, magnetically-charged platters to store data Hard disk drives are popular because they can store a lot of data very reliably with relatively quick access times Other examples of magnetic storage devices include the tape drive and diskette Tape drives and diskettes are both good examples of legacy devices It's unlikely they will even be made much past 2010

Trends in computer storage are always changing Now it looks as if traditional magnetic hard disk drives might eventually be replaced by SSDs or solid state drives SSDs have many key advantages over magnetic storage including 1) no moving parts and 2) less power consumption This makes them very good for laptops where battery life and overall durability can be big issues If the technology continues to improve, we may even see them

in desktop computers as well

Optical storage is another technology strategy used in computer storage, and is particularly useful for sharing audio, video, and larger programs Optical storage works by a laser burning or reading data off a plastic disc coated with various types of light sensitive material

in it Due to reliability and space limitations, optical storage is seldom used as a primary means of data storage You will learn more about optical storage in later units In case you don't understand what optical storage is, look no further than your CD-ROM, or DVD-ROM drive Here are some optical storage solutions in action!

Okay now you know the difference between memory and storage That wasn't so hard, was it?

Discussion Questions

1 What are the major differences between memory and storage? How much memory does

your computer have? How much storage does your computer have?

2 Do you think semi-conductor storage will ever completely replace magnetic storage?

When and why?

3 What is meant above when the author says that volatile memory needs power in order to

"retain it's state?"

Useful Vocabulary:

1 EPROM (erasable programmable read only memory)

non-volatile (permanent) memory type that is erasable via ultra-violet light and reprogrammable

EPROMs are popular for use in critical firmware applications, such as BIOS's, because they are both non-volatile and they can be updated when necessary

2 floppy disk drive

a legacy storage device which can read and write data slowly from a removable magnetic medium (normally 3.5" in diameter and holding 1.44 MB of data)

Floppy disk drives were once included with almost all computers, but are now considered obsolete They have been gradually replaced by DVD-R and USB drive technology

3 hard disk drive

a storage device using rotating magnetic platters to quickly store and retrieve digital data

A hard disk drive can fail at any time, normally causing data corruption and loss So it is vitally important to have a backup routine in place

6 RAM (random access memory)

a type of computer memory known for being volatile (temporary) and fast

My computer was performing slowly when changing programs, so my technician installed more RAM and this solved the problem

7 ROM (read-only memory)

a type of memory which is manufactured with permanent contents which cannot be modified

The boy gave a puzzled look when the man showed him an old Atari 800 computer ROM cartridge

8 Semiconductor storage

a type of storage using integrated circuits to store data; examples include RAM, ROM, and flash memory

All computers created today use at least some form of semiconductor storage

9 SSD (solid state drive)

a newer data storage device meant to replace a traditional hard disk drive; these are characterized by non-moving parts and lower energy consumption

Many new laptop models use solid-state drives, although they are more expensive and have less capacity than traditional hard disk drives

Modern games such as Quake IV load textures which can fill 512 megabytes of dedicated video memory

4.4 Units of memory

Bit-basic units of memory

Information is processed and stored in computers as electrical signals A computer contains thousands of electronic circuits connected by switches that can only be in one of two possible states: ON (the current is flowing through the wire) or OFF (the current is not flowing through the wire) To represent these two conditions we use binary notation in which 1 means ON and 0 means OFF This is only way a computer can ‘understand’ any thing Everything about computers is based upon this binary process Each 1 or 0 is call a binary digit or bit

Bytes and characters

1s or 0s are grouped in to eight-digit codes that typically represent characters (letters, numbers and symbols) Eight bits together are called a byte Thus, each character in a keyboard has its own arrangement of eight bits For example, 01000001 for the letter A,

01000010 for B and 01000011 for C

The ASCII code

The majority of computers use a standard system for the binary representation of characters This is the American Standard Code for Information Interchange, known popularly as

‘ASSCII’ (pronounced “ask-key’ There are 256 different ways of combining 0 and 1 bits in

a byte So they can give us 256 different signals However, the ASCII code only uses 128 bytes to represent characters The rest of the bytes are used for other purposes

The first 32 codes are reserved for characters such as the Return key, Tab, Escape, etc each letter of the alphabet, and many symbols (such as punctuation marks) as well as ten numbers, have ASCII representations What makes this system powerful is that these codes and standard

Kilobytes, megabytes and gigabytes

In order to avoid astronomical figures and sums in the calculation of bytes, we use units such

as kilobytes, megabytes and gigabytes One kilobyte is 1,024 bytes (210) and it is represented

as KB, or more informally as K one megabyte is equivalent to 1,024KB, and one gigabyte is 1,024 MB

We use these units (KB, MB, GB) to describe the RAM memory, the storage capacity of disks and the size of any application or document

A ANSWER THE FOLLOWING QUESTIONS WITH A PARTNER:

1 How many digits does a binary system use? What is a ‘bit’?

2 What is the difference between binary notation and the decimal system? Give some examples?

3 What is a collection of eight bits called?

4 One kilobyte (1K) equals 1,024 bytes

Can you work out the value of these units? (kilo: one thousand)

1 megabyte = ………… bytes/kilobytes (mega: one million)

1 gigabyte= ……….bytes/1,024 megabytes (giga: one thousand million)

5 What does the acronym ‘ASCII’ stand for? What is the purpose of this code?

B COMPLETE THE FOLLOWING SENTENCES WITH DIFFERENT TYPES OF MEMORY:

1 Computer storage can be classified as _, _ and

2 _ is a type of fast memory that uses a separate clock signal in addition to the normal control signals

3 _ provides extremely fast access for sections of a program and its data

4 _ is the memory used to store graphics data on a graphic card

5 _is a common storage device that reads and writes data on metal disks inside a sealed case

6 _is a new data storage device that uses non-moving parts and lower energy consumption

7 _is a popular storage device that reads and writes data on a floppy disk

8 _ is a type of memory that can be accessed in any order

9 _ is a type of memory that holds instructions which are needed to start up the computer

10 _is a type of storage that can be read by a laser light

C COMPLETE THE FOLLOWING PARAGRAPH WITH THE WORDS GIVEN:

A Memory chips B of C expanded D purchasing E computer

Random Access Memory or RAM is the memory that the computer uses to temporarily store the information as it is being processed The more information being processed the more RAM the (1) needs

RAM memory chips come in many different sizes and speeds and can usually be (2) Older computers came with 512 Kb of memory which could be expanded to

a maximum of 640 Kb In most modern computers the memory can be expanded by adding

or replacing the memory chips depending on the processor you have and the type of memory your computer uses (3) range in size from 1 Mb to 4 Gb As computer technology changes, the type (4) memory changes as well making old memory chips out of date Check your computer manual to find out what kind of memory your computer uses before (5) new memory chips

4 PCs usually have one hard, , called C

6 DVD-RW means Digital Versatile Disc-

7 Non- _memory is computer memory that can retain the stored information even when not powered

DOWN

2 Flash memory _ are used to store information in digital cameras and other handheld devices

3 Unit of memory equivalent to 1,024 megabytes

5 When a disk is formatted, its surface is divided into concentric circles known as _

Unit 5: Types of Removable Memory

Optical storage Semiconductor storage Flash drive Diskette

In this unit you will learn about removable storage

The main idea behind removable storage is that data can be easily transferred between computers via a portable medium For many years the diskette (also known as a floppy disk) was the best example of this kind of storage

In recent years, you are much more likely to see optical storage devices such as CD-ROM, CD-R, DVD-ROM, and DVD-R devices being used to store larger software and data archives These devices can store between 650 MB and 50 GB of data

But optical devices do have their drawbacks As you probably know, these discs scratch easily Also, optical drives have lower performance than hard disk drives, and they can normally only be written to one time with any degree of reliability

Because of the need for ever greater capacity and performance for removable storage, a new device called the flash drive has taken over the industry by storm Based on semiconductor storage technology, these devices can store up to 16 GB (or greater) of data Data read and write times are very fast due to USB 2.0 technology

As is true with most other types of computer equipment, the speed and capacity of removable storage is always increasing, while prices generally decrease for all but the newest technologies

2 BD-RE (Blu-Ray Disc Rewritable)

an optical disc format technology which can be re-recorded multiple times Disc capacities are up to 50GB;

Blu-Ray Disc Rewritable technology holds 6 times as much data as a traditional DVD-RW They are used for high definition movie storage and to backup large file archives

3 CD –ROM (compact disc read only memory)

a storage medium popular in modern computers; one of these can hold approximately 650

MB of data

The CD-ROM has almost been completely replaced by the much more efficient DVD-ROM technology

4 CD-R (compact disc recordable)

a recordable storage medium that allows a user to write one time up to 650 megabytes of data

The nervous author backed up his novel every day on a new CD-R

5 DVD (digital versatile disc)

a portable storage medium which can hold between 4.7 and 17 gigabytes of data, often used for storing movies, games, and operating systems

The salesperson said that once he saw a film on DVD, he was never satisfied with VHS technology again

6 DVD-R (digital versatile disc recordable)

a portable recordable storage medium which allows a user to write one time up to 4.7 gigabytes of data

A DVD-R can store many times as much information as a CD-R, so they are great for making backups of larger files and folders

a physical transmission device or storage device of information

The purpose of software stays the same even though there is always a new medium every decade or so

A Discussion Questions

1 How will removable storage most likely change in the future? Why?

2 What types of removable storage does your computer support?

3 What is your preferred (favorite) type of removable storage?

4 What are the disadvantages of optical devices?

5 What technology has the flash memory based on?

B LANGUAGE WORK: LINKING WORDS

We use the linking words to connect the clauses to make longer sentences and express the relation between the clauses

CONTRASTING IDEAS

S + V, but S+V However, S + V

C FILL IN THE GAPS USING THE CORRECT LINKING WORDS IN THE BOX:

reason

Floppies are very cheap, (1) they are slow and have a limited capacity Hard disks are fast and can store large amounts of data (2) they are fixed inside the computer, (3) you cannot use them to transfer data You can transfer data with removable hard disks, (4) they are expensive CD-ROM disks can hold quite large amounts of data (5) , they are usually read-only (6) you cannot change the information on them Magneto-optical disks are like CD-ROMs (7) you can write data on to them They are removable and have large capacities, (8) they are expensive and do not conform to standard (9) , they are not very common Magnetic tape is cheap and has a large capacity (10) it does not allow random access and drives are slow (11) it is only suitable for backups

D FIND OUT THE WORDS RELATED TO THE COMPUTER VERTICALLY AND HORIZONTALLY AS SOON AS POSSIBLE:

Unit 6: Software

6.1 Definition of Software

As mentioned before, software is another name for programs Programs are the instructions

that tell the computer how to process data into the form you want A program is a sequence

of related instructions, performed one step at a time by the CPU to accomplish some tasks

Programs determine how computers respond to input, what will be displayed and output

There are three types of programs: system software, language interpreters and compilers and

application programs

Therefore any document that you create, graphic, sound you compose, file you make, letter

you write, email you send or anything that you create on your computer is referred to as

software

For as long as there has been computer hardware, there has also been computer software But

what is software? Software is just instructions written by programmer which tells the

computer what to do Programmers are also commonly known as 'software developers', or

just plain 'developers'

Nothing much is simple about software Software programs can have millions of lines of

code If one line doesn't work, the whole program could break! Even the process of starting

software goes by many different names in English Perhaps the most correct technical term is

‘execute', as in "the man executed the computer program." Be careful, because the term

'execute' also means ( in another context ) to put someone to death! Some other common

verbs used to start a software program you will hear are 'run', 'launch, and even 'boot' (when

the software in question is an operating system)

Software normally has both features and bugs Hopefully more of

the former than the latter! When software has a bug there are a

few things that can happen The program can crash and terminate

with a confusing message This is not good End users do not like

confusing error messages such as:

Site error: the file

/home7/businfc6/public_html/blog/wordpress/wp-content/plugins/seo-blog/core.php requires the ionCube PHP Loader ioncube_loader_lin_5.2.so to be installed by

the site administrator

Sometimes when software stops responding you are forced to manually abort the program yourself by pressing some strange combination of keys such as ctrl-alt-delete

Because of poor usability, documentation, and strange error messages, programming still seems very mysterious to most people That's too bad, because it can be quite fun and rewarding to write software To succeed, you just have to take everything in small steps, think very hard, and never give up

It is clear that everyone studying Information Technology should learn at least one programming language and write at least one program Why? Programming forces you to think like a computer This can be very rewarding when dealing with a wide range of IT-related issues from tech support to setting up PPC ( pay-per-click ) advertising campaigns for

a client's web site Also, as an IT professional, you will be dealing with programmers on a daily basis Having some understanding of the work they do will help you get along with them better

Software programs are normally written and compiled for certain hardware platforms It is very important that the software is compatible with all the components of the computer For instance, you cannot run software written for a Windows computer on a Macintosh computer

or a Linux computer Actually, you can, but you need to have special emulation software or a virtual machine installed Even with this special software installed, it is still normally best to run a program on the kind of computer for which it was intended

6.2 Basic types of Software

There are two basic kinds of software you need to learn about as an IT professional The first

is closed source or proprietary software, which you are not free to modify and improve An example of this kind of software is Microsoft Windows or Adobe Photoshop This software model is so popular that some people believe it's the only model there is But there's a whole other world of software out there

The other kind of software is called open source software, which is normally free to use and modify (with some restrictions of course) Examples of this type of software include most popular programming languages, operating systems such as Linux, and thousands of applications such as Mozilla Firefox and Open Office

But what is the real difference between open source and closed source software? Is open source software just about saving money? Let's investigate Let's say for instance you find a bug in the latest version of Mozilla Firefox The bug is causing a major project to fail and you need to fix it right away This is not very likely to happen, but it's just an example You might take the following steps:

Step 1 Download and unzip (or uncompress) the source code from Mozilla

Step 2 Use an Integrated Development Environment (IDE) and a debugger to find and fix

the bug in the source code Please note that you will need to know a little C++ to debug applications such as this

Step 3 Test the fix and then use a compiler to turn the source code into a binary file This

can take a long time for big programs Once the source code is compiled then the program should work!

Step 4 You are almost done Now send the bug fix back to the Mozilla Firefox team They

may even use your bug fix in the next release!

Now imagine you find a bug in a proprietary code base such as Microsoft Word What can you do? Not much, just file a bug report and hope someone fixes it at some point

This is a rather radical example, but it illustrates to a large degree why programmers generally prefer open source software to closed source alternatives Good programmers love code and they want access to it Hiding the code from a programmer is like hiding the car engine from an auto mechanic

Useful Vocabulary:

1 abort

to end a program or a process before its completion

When the program crashed the user had to abort and lose all the unsaved changes

a computer failure due to faulty hardware or a serious software bug

The user was advised to reboot the computer after a serious crash in which the computer no longer responded

6 end user

a person who uses a product or service on a computer

Developers must maintain a close relationship with end users if they want to have a successful career