МИНИСТЕРСТВО ОБРАЗОВАНИЯ И НАУКИ
РОССИЙСКОЙ ФЕДЕРАЦИИ
Федеральное государственное образовательное учреждение
Высшего профессионального образования
«Чувашский государственный университет имени И.Н. Ульянова»
АНГЛИЙСКИЙ ЯЗЫК
ТЕКСТЫ ДЛЯ ЧТЕНИЯ И ПЕРЕВОДА
ЧЕБОКСАРЫ 2010
Составитель: О.Я. Карпеева
УДК 811.011(075.8)
ББК Ш12=432.1Я73
Английский язык: сборник текстов для чтения и перевода /
сост. О.Я. Карпеева; Чуваш. ун-т. Чебоксары, 2010. 53 с.
Содержит тексты из оригинальной литературы, посвященные
теме «Компьютеры и информационные системы», а так же
общетехническим знаниям, которые необходимы для уверенной
ориентировки в мире информации и повышения технологических
возможностей пользователя при работе с компьютером.
Для студентов факультетов информатики и вычислительной
техники и для других технических факультетов.
Утверждено Методическим советом университета
Отв. редактор д-р пед. наук, профессор Н.Г. Краснов
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What Is a Computer?
A computer is a machine with an intricate network of electronic
circuits that operate switches or magnetize tiny metal cores. The
switches, like the cores, are capable of being in one or two possible
states, that is, on or off; magnetized or demagnetized. The machine is
capable of storing and manipulating numbers, letters, and characters
(symbols).The basic idea of a computer is that we can make the
machine do what we want by inputting signals that turn certain
switches on and turn others off, or magnetize or do not magnetize the
cores.
The basic job of computers is processing of information. For this
reason computers can be defined as devices which accept
information in the form of instructions, called a program, and
characters, called data, perform mathematical and / or logical
operations on the information, and then supply results of these
operations. The program, or part of it, which tells the computers what
to do and the data, which provide the information I needed to solve
the problem, are kept inside the computer in a place called memory.
It is considered that computers have many remarkable powers.
However most computers, whether large or small, have three basic
capabilities.
First, computers have circuits for performing arithmetic
operations, such as: addition, subtraction, division, multiplication
and exponentiation.
Second, computers have a means of communicating with the
user. After all, if we couldn't feed information in and get results
back, these machines wouldn't be of much use. Some of the most
common methods of inputting information are to use terminals,
diskettes, disks and magnetic tapes. The computer's input device (a
disk drive or tape drive) reads the information into the computer. For
outputting information two common devices are used: a printer,
printing the new information on paper, and a cathode-ray-tube
display, which shows the results on a TV-like screen.
Third, computers have circuits which can make decisions. The
kinds of decisions which computer circuits can make are not of the
type: "Who would win the war between two countries?" or "Who is
the richest person in the world?" Unfortunately, the computer can
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only decide three things, namely: Is one number less than another?
Are two numbers equal? and, Is one number greater than another? A
computer can solve a series of problems and make thousands of
logical decisions without becoming tired. It can find the solution to a
problem in a fraction of the time it takes a human being to do the job.
A computer can replace people in dull, routine tasks, but it
works according to the instructions given to it. There are times when
a computer seems to operate like a mechanical 'brain', but its
achievements are limited by the minds of human beings. A computer
cannot do anything unless a person tells it what to do and gives it the
necessary information; but because electric pulses can move at the
speed of light, a computer can carry out great numbers of arithmeticlogical operations almost instantaneously. A person can do the same,
but in many cases that person would be dead long before the job was
finished.
The First Calculating Devices
Let us take a look at the history of computers that we know
today. The very first calculating device used was the ten fingers of a
man's hands. This, in fact, is why today we still count in tens and
multiples of tens.
Then the abacus was invented. People went on using some form
of abacus well into the 16th century, and it is still being used in some
parts of the world because it can be understood without knowing
how to read.
During the 17th and 18th centuries many people tried to find
easy ways of calculating. J. Napier, a Scotsman, invented a
mechanical way of multiplying and dividing, which is now the
modern slide rule works. Henry Briggs used Napier's ideas to
produce logarithm tables which all mathematicians use today.
Calculus, another branch of mathematics, was independently
invented by both Sir Isaak Newton, an Englishman, and Leibnitz, a
German mathematician. The first real calculating machine appeared
in 1820 as the result of several people's experiments.
In 1830 Charles Babbage, a gifted English mathematician,
proposed to build a general-purpose problem-solving machine that he
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called "the analytical engine". This machine, which Babbage showed
at the Paris Exhibition in 1855, was an attempt to cut out the human
being altogether, except for providing the machine with the
necessary facts about the problem to be solved. He never finished
this work, but many of his ideas were the basis for building today's
computers.
By the early part of the twentieth century electromechanical
machines had been developed and were used for business data
processing. Dr. Herman Hollerith, a young statistician from the US
Census Bureau successfully tabulated the 1890 census. Hollerith
invented a means of coding the data by punching holes into cards. He
built one machine to punch the holes and others to tabulate the
collected data. Later Hollerith left the Census Bureau and established
his own tabulating machine company. Through a series of merges the
company eventually became the IBM Corporation.
Storage and processing Ch.
Babbage's analytical engine
Until the middle of the twentieth century machines designed to
manipulate punched card data were widely used for business data
processing. These early electromechanical data processors were
called unit record machines because each punched card contained a
unit of data.
In the mid – 1940s electronic computers were developed to
perform calculations for military and scientific purposes. By the end
of the 1960s commercial models of these computers were widely
used for both scientific computation and business data processing.
Initially these computers accepted their input data from punched
cards. By the late 1970s punched cards had been almost universally
replaced by keyboard terminals. Since that time advances in science
have led to the proliferation of computers throughout our society,
and the past is but the prologue that gives us a glimpse of the future.
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Four Generations of Computers
The first vacuum tubes computers are referred to as first
generation computers, and the approximate period of their use was
from 1950 to 1959. UNIVAC 1 (Universal Automatic Computer) is
an example of these computers which could perform thousands of
calculations per second. Those devices were not only bulky, they
were also unreliable. The thousands of vacuum tubes emitted large
amounts of heat and burned out frequently.
The transistor, a smaller and more reliable successor to the
vacuum tube, was invented in 1948. So-called second generation
computers, which used large numbers of transistors, were able to
reduce computational time from milliseconds to microseconds, or
millionths of seconds. Second-generation computers were smaller,
faster and more reliable than first-generation computers.
Advances in electronics technology continued, and
microelectronics made it possible to reduce the size of transistors and
integrate large numbers of circuit elements into very small chips of
silicon. The computers that were designed to use integrated circuit
technology were called third generation computers, and the
approximate time span of these machines was from 1960 to 1979.
They could perform many data processing operations in
nanoseconds, which are billionths of seconds. Fourth generation
computers have now arrived, and the integrated circuits that are
being developed have been greatly reduced in size. This is due to
microminiaturization, which means that the circuits are much smaller
than before; as many as 100 tiny circuits are placed now on a single
chip. A chip is a square or rectangular piece of silicon, usually from
1/10 to 1/4 inch, upon which several layers of an integrated circuit
are etched or imprinted, after which the circuit is encapsulated in
plastic or metal.
Data Processing and Data Processing Systems
The necessary data are processed by a computer to become
useful information. In fact this is the definition of data processing.
Data are a collection of facts — unorganized but able to be organized
into useful information. Processing is a series of actions or
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operations that convert inputs into outputs. When we speak of data
processing, the input is data, and the output is useful information. So,
we can define data processing as a series of actions or operations that
converts data into useful information.
We use the term data processing system to include the resources
that are used to accomplish the processing of data. There are four
types of resources: people, materials, facilities, and equipment.
People provide input to computers, operate them, and use their
output. Materials, such as boxes of paper and printer ribbons, are
consumed in great quantity. Facilities are required to house the
computer equipment, people and materials.
Computer data processing system
The need for converting facts into useful information is not a
phenomenon of modern life. Throughout history, and even
prehistory, people have found it necessary to sort data into forms that
were easier to understand. For example, the ancient Egyptians
recorded the ebb and flow of the Nile River and used this
information to predict yearly crop yields. Today computers convert
data about land and water into recommendations to farmers on crop
planting. Mechanical aids to computation were developed and
improved upon in Europe, Asia, and America throughout the
seventeenth, eighteenth, and nineteenth centuries. Modern computers
are marvels of an electronics technology that continues to produce
smaller, cheaper, and more powerful components.
Basic data processing operations
Five basic operations are characteristic of all data processing
systems: inputting, storing, processing, outputting, and controlling.
They are defined as follows.
Inputting is the process of entering data, which are collected
facts, into a data processing system. Storing is saving data or
information so that they are available for initial or for additional
processing. Processing represents performing arithmetic or logical
operations on data in order to convert them into useful information.
Outputting is the process of producing useful information, such as a
printed report or visual display.
Controlling is directing the manner and sequence in which all of
the above operations are performed. Data storage hierarchy
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It is known that data, once entered, are organized and stored in
successively more comprehensive groupings. Generally, these
groupings are called a data storage hierarchy. The general groupings
of any data storage hierarchy are as follows. 1) Characters, which are
all written language symbols: letters, numbers, and special symbols.
2) Data elements, which are meaningful collections of related
characters. Data elements are also called data items or fields. 3)
Records, which are collections of related data elements. 4) Files,
which are collections of related records. A set of related files is
called a data base or a data bank.
Computer System Architecture
As we know all computer systems perform the functions of
inputting, storing, processing, controlling, and outputting. Now we'll
get acquainted with the computer system units that perform these
functions. But to begin with let's examine computer systems from the
perspective of the system designer, or architect.
It should be noted that computers and their accessory equipment
are designed by a computer system architect, who usually has a
strong engineering background. As contrasted with the analyst, who
uses a computer to solve specific problems, the computer system
architect usually designs computer that can be used for many
different applications in many different business. For example, the
product lines of major computer manufacturers such as IBM, Digital
Equipment Corporation and many others are the result of the efforts
of teams of computer system architects.
Unless you are studying engineering, you don't need to become
a computer system architect. However, it is important that as a
potential user, applications programmer or systems analyst you
understand the functions of the major units of a computer system and
how they work together. Types of computers
The two basic types of computers are analog and digital. Analog
computers simulate physical systems. They operate on the basis of an
analogy to the process that is being studied. For example, a voltage
may be used to represent other physical quantities such as speed,
temperature, or pressure. The response of an analog computer is
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based upon the measurement of signals that vary continuously with
time. Hence, analog computers are used in applications that require
continuous measurement and control.
Digital computers, as contrasted with analog computers, deal
with discrete rather than continuous quantities. They count rather
than measure. They use numbers instead of analogous physical
quantities to simulate on-going, or real-time processes. Because they
are discrete events, commercial transactions are in a natural form for
digital computation. This is one reason that digital computers are so
widely used in business data processing.
Machines that combine both analog and digital capabilities are
called hybrid computers. Many business, scientific, and industrial
computer applications rely on the combination of analog and digital
devices. The use of combination analog devices will continue to
increase with the growth in applications of microprocessors and
microcomputers. An example of this growth is the trend toward
installing control systems in household appliances such as
microwave ovens and sewing machines. In the future we will have
complete indoor climate control systems and robots to do our
housecleaning. Analog sensors will provide inputs to the control
centres of these systems, which will be small digital computers.
Hardware, Software, and Firmware
The units that are visible in any computer are the physical
components of a data processing system, or hardware. Thus, the
input, storage, processing and control devices are hardware. Not
visible is the software — the set of computer programs, procedures,
and associated documentation that make possible the effective
operation of the computer system. Software programs are of two
types: systems software and applications software.
Systems software are the programs designed to control the
operation of a computer system. They do not solve specific
problems. They are written to assist people in the use of the
computer system by performing tasks, such as controlling all of the
operations required, to move data into and out of a computer and all
of the steps in executing an application program. The person who
prepares systems software is referred to as a systems programmer.
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Systems programmers are highly trained specialists and important
members of the architectural team.
Applications software are the programs written to solve specific
problems (applications), such as payroll, inventory control, and
investment analysis. The word program usually refers to an
application program, and the word programmer is usually a person
who prepares applications software.
Often programs, particularly systems software, are stored in an
area of memory not used for applications software. These protected
programs are stored in an area of memory called read-only memory
(ROM), which can be read from but not written on.
Firmware is a term that is commonly used to describe certain
programs that are stored in ROM. Firmware often refers to a
sequence of instructions (software) that is substituted for hardware.
For example, in an instance where cost is more important than
performance, the computer system architect might decide not to use
special electronic circuits (hardware) to multiply two numbers, but
instead write instructions (software) to cause the machine to
accomplish the same function by repeated use of circuits already
designed to perform addition.
From the History of Computer Development In Russia
As it is well known, Russian scientists made great contribution
into the development of computers. Russian mathematician P.
Chebyshev who lived in the 19th century was interested in
calculators. Among many other mechanisms invented by him there
was an arithmometer designed in 1876. It was one of the most unique
calculating machines of the time. At the beginning of the 20th
century Academic A.Krylov constructed a mechanical integrator for
solving differential equations.
The first Soviet computer, a small-size computing machine
(MESM) was tested in 1950 under Academician S.Lebedev. Next
year it was put into operation. In a year MESM was followed by
BESM, a large-size electronic computing machine, with 8000
operations per second.
Serial production of computers in the USSR has been started
since 1953. That year U.Basilevsky headed the design and
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manufacture of computer STRELA. 1958 witnessed the production
of M-20, computers of the first generation under the guidance of
S. Lebedev. The first generation of electron tube computers was
followed by the second generation of foto transistor computers, using
magnetic logic elements.
Starting with 1964 semiconductor computers Academician
B.M. Glushkov URAL, BESM-4 and M-220 were produced. Under
Academician Glushkov small-size computers MIR, MIR-2 and
DNEPR were designed and tested at the Institute of Cybernetics.
In the late 60s together with other members of the Council of
Mutual Economic Assistance the Soviet Union started on the
program of Unified Computer System, the program concerned with
the third generation of computers with high-speed performance and
program compatibility.
Central Processing Unit
It is well known in computer science that the words 'computer'
and 'processor' are used interchangeably. Speaking more precisely,
'computer' refers to the central processing unit (CPU) together with
an internal memory. The internal memory, control and processing
components make up the heart of the computer system. Manufactures
design the CPU to control and carry out basic instructions for their
particular computer.
The CPU coordinates all the activities of the various components
of the computer. It determines which operations should be carried
out and in what order. The CPU controls the operation of the entire
system by issuing commands to other parts of the system and by
acting on responses. When required it reads information from the
memory, interprets instructions, performs operations on the data
according to the instructions, writes the results back into the memory
and moves information between memory levels or through the inputoutput ports.
In digital computers the CPU can be divided into two functional
units called the control unit (CU) and the arithmetic-logical unit
(ALU). These two units are made up of electronic circuits with
millions of switches that can be in one of two states, either on or off.
The function of the CU within the central processor is to
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transmit coordinating control signals and commands. The control
unit is that part of the computer that directs the sequence of step-bystep operations of the system, selects instructions and data from
memory, interprets the program instructions, and controls the flow
between main storage and the arithmetic-logical unit.
The ALU, on the other hand, is that part of the computer in
which the actual arithmetic operations, namely, addition, subtraction,
multiplication, division and exponentiation, called for in the
instructions are performed.
Control unit functional diagram
Programs and the data on which the CU and the ALU operate,
must be in internal memory in order to be processed. Thus, if located
in secondary memory devices, such as disks or tapes, programs and
data are first loaded into internal memory.
The CPU Main Components
As it is known the two functional units of the CPU are the
control unit (CU) and the arithmetic-logical unit (ALU). The control
unit manages and coordinates the entire computer system. It obtains
instructions from the program stored in main memory, interprets the
instructions, and issues signals that cause other units of the system to
execute them.
The control unit operates by reading one instruction at a time
from memory and taking the action called for by each instruction. In
this way it controls the flow between the main storage and the
arithmetic-logical unit.
The control unit has the following components: a counter that
selects the instructions, one at a time, from memory; a register that
temporarily holds the instructions read from memory while it is
being executed; a decoder that takes the coded instruction and breaks
it down into individual commands necessary to carry it out; a clock,
which produces marks at regular intervals. These timing marks are
electronic and very rapid.
The sequence of control unit operations is as follows. The next
instruction to be executed is read out from primary storage into the
storage register. The instruction is passed from the storage register to
the instruction register. Then the operation part of the instruction is
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decoded so that the proper arithmetic or logical operation can be
performed. The address of the operand is sent from the instruction
register to the address register. At last the instruction counter register
provides the address register with the address of the next instruction
to be executed.
The arithmetic-logical unit (ALU) executes the processing
operations called for by the instructions brought from main memory
by the control unit. Binary arithmetic, the logical operations and
some special functions are performed by the arithmetical-logical
unit. .
Data enter the ALU and return to main storage through the
storage register. The accumulator serving as a register holds the
results of processing operations. The results of arithmetic operations
are returned to the accumulator for transfer to main storage through
the storage register. The comparer performs logical comparisons of
the contents of the storage register and the accumulator. Typically,
the comparer tests for conditions such as "less than", "equal to", or
"greater than".
So as you see the primary components of the arithmetic-logical
unit are banks of
bitable devices, which are called registers. Their purpose is to
hold the numbers involved in the calculation and hold the results
temporarily until they can be transferred to memory. At the core of
the ALU is a very high-speed binary adder, which is used to carry
out at least the four basic arithmetic functions (addition, subtraction,
multiplication and division). The logical unit consists of electronic
circuitry which compares information and makes decisions based
upon the results of the comparison.
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Input Output Environment
Data and instructions must enter the data processing system, and
information must leave it. These operations are performed by input
and output (I/O) units that link the computer to its external
environment.
The I/O environment may be human-related or humanindependent. A remote banking terminal is an example of a humanrelated input environment, and a printer is an example of a device
that produces output in a human-readable format. An example of a
human-independent input environment is a device that measures
traffic flow. A reel of magnetic tape upon which the collected data
are stored in binary format is an example of a human-independent
output.
Input-Output Interfaces. Data enter input units in forms that
depend upon the particular device used. For example, data are
entered from a keyboard in a manner similar to typing, and this
differs from the way that data are entered by a bar-code scanner.
However, regardless of the forms in which they receive their inputs,
all input devices must provide a computer with data that are
transformed into the binary codes that the primary memory of the
computer is designed to accept. This transformation is accomplished
by units called I/O interfaces. Input interfaces are designed to match
the unique physical or electrical characteristics of input devices to
the requirements of the computer system. Similarly, when output is
available, output interfaces must be designed to reverse the process
and to adapt the output to the external environment. These I/O
interfaces are also called channels or input-output processors (IOP).
The major differences between devices are the media that they use
and the speed with which they are able to transfer data to or from
primary storage.
Input-Output Device Speed. Input-output devices can be
classified as high-speed, medium-speed, and low-speed. The devices
are grouped according to their speed. It should be noted that the
high-speed devices are entirely electronic in their operation or
magnetic media that can be moved at high speed. Those high-speed
devices are both input and output devices and are used as secondary
storage. The low-speed devices are those with complex mechanical
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motion or operate at the speed of a human operator. The mediumspeed devices are those that fall between — they tend to have
mechanical moving parts which are more complex than the highspeed devices but not as complex as the low-speed.
High-speed devices: magnetic disk; magnetic tape. Mediumspeed devices: card readers; line printers; page printers; computer
output microfilms; magnetic diskette; optical character readers;
optical mark readers; visual displays.
Low-speed devices: bar-code readers; character printers;
digitizers; keyboard input devices; plotters; voice recognition and
response units.
Input Devices
There are several devices used for inputting information into the
computer: a keyboard, some coordinate input devices, such as
manipulators (a mouse, a track ball), touch panels and graphical
plotting tables, scanners, digital cameras, TV tuners, sound cards etc.
When personal computers first became popular, the most
common device used to transfer information from the user to the
computer was the keyboard. It enables inputting numerical and text
data. A standard keyboard has 104 keys and three more ones
informing about the operating mode of light indicators in the upper
right corner.
Later when the more advanced graphics became to develop, user
found that a keyboard did not provide the design capabilities of
graphics and text representation on the display. There appeared
manipulators, a mouse and a track ball, that are usually used while
operating with graphical interface. Each software program uses these
buttons differently.
The mouse is an optic-mechanical input device. The mouse has
three or two buttons which control the cursor movement across the
screen. The mouse provides the cursor control thus simplifying user's
orientation on the display. The mouse's primary functions are to help
the user draw, point and select images on his computer display by
moving the mouse across the screen.
In general software programs require to press one or more
buttons, sometimes keeping them depressed or double-click them to
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issue changes in commands and to draw or to erase images. When
you move the mouse across a flat surface, the ball located on the
bottom side of the mouse turns two rollers. One is tracking the
mouse's vertical movements, the other is tracking horizontal
movements. The rotating ball glides easily, giving the user good
control over the textual and graphical images. In portable computers
touch panels or touch pads are used instead of manipulators. Moving
a finger along the surface of the touch pad is transformed into the
cursor movement across the screen.
Graphical plotting tables (plotters) find application in drawing
and inputtig manuscript texts. You can draw, add notes and signs to
electronic documents by means of a special pen. The quality of
graphical plotting tables is characterized by permitting capacity, that
is the number of lines per inch, and their capability to respond to the
force of pen pressing.
Scanner is used for optical inputting of images (photographies,
pictures, slides) and texts and converting them into the computer
form.
Digital video cameras have been spread recently. They enable
getting video images and photographs directly in digital computer
format. Digital cameras give possibility to get high quality photos.
Sound cards produce sound conversion from analog to digital
form. They are able to synthesize sounds. Special game-ports and
joysticks are widely used in computer games.
Output Devices. Printers
Printers provide information in a permanent, human-readable
form. They are the most commonly used output devices and are
components of almost all computer systems. Printers vary greatly in
performance and design. We will classify printers as character
printers, line printers and page printers in order to identify three
different approaches to printing, each with a different speed range. In
addition, printers can be described as either impact or nonimpact.
Printers that use electromechanical mechanisms that cause hammers
to strike against a ribbon and the paper are called impact printers.
Nonimpact printers do not hit or impact a ribbon to print.
Character printers print only one character at a time. A
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typewriter is an example of a character printer. Character printers are
the type used with literally all microcomputers as well as on
computers of all sizes whenever the printing requirements are not
large. Character printers may be of several types. A letter-quality
printer is a character printer which produces output of typewriter
quality. Letter-quality printers typically have speeds ranging from 10
to 50 characters per second. Dot-matrix printers form each character
as a pattern of dots. These printers have a lower quality of type but
are generally faster printers than the letter-quality printers — in the
range of 50 to 200 characters per second. One of the newest types of
character printer is the ink-jet printer. It sprays small drops of ink
onto paper to form printed characters. The ink has a high iron
content, which is affected by magnetic fields of the printer. These
magnetic fields cause the ink to take the shape of a character as the
ink approaches the paper.
Line printers are electromechanical machines used for highvolume paper output on most computer systems. Their printing
speeds are such that to an observer they appear to be printing a line at
a time. They are impact printers. The speeds of line printers vary
from 100 to 2500 lines per minute. Line printers have been designed
to use many different types of printing mechanisms. Two of the most
common print mechanisms are the drum and the chain. Drum
printers use a solid, cylindrical drum, rotating at a rapid speed.
Speeds of drum printers vary from 200 to over 2000 lines per minute.
Chain printers have their character set on a rapidly rotating chain
called a print chain. Speeds of chain printers range from 400 to 2400
lines per minute. Page printers are high-speed nonimpact printers.
Their printing rates are so high that output appears to emerge from
the printer a page at a time. A variety of techniques are used in the
design of page printers. These techniques, called electrophotographic
techniques, have developed from the paper copier technology. Laserbeam printers use a combination of laser beam and
electrophotographic techniques to create printer output at a rate equal
to 18000 lines per minute.
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Keyboard Devices
1. There is a wide variety of keyboard devices, or terminals,
available for use in entering data directly into a computer.
The visual display terminal (VDT) is the most popular type of
I/O device in use today. It consists of a typewriter like keyboard for
inputting and a cathode ray tube (CRT) for displaying output data.
Each character entered through the keyboard is also displayed on the
CRT. When keyed the data are held in a small memory, called a
buffer, within the terminal itself. The data are not sent on to the
computer until the operator presses an enter key on the keyboard.
This allows the operator the opportunity to proofread or verify the
data being entered by reading the data displayed on the screen. There
are three major uses of VDT's: alphanumeric displays, graphic
displays, and input through a light pen.
Alphanumeric displays. The most common use of the visual
display terminal is to display alphanumeric data, that is, character
data. Because of their relatively fast output rates and their ability to
provide a viewer with an "instant" output, video displays have
replaced printers for many applications.
Graphic displays. Visual display terminals with a graphic
display capability provide a very powerful and versatile tool for
many users. Graphic-display devices provide not only a means of
displaying high-resolution drawings but also the capability of
manipulating and modifying the graphic display. The business
person can use the graphic display to present data in the form of line
charts, bar charts, or pie charts. Graphic displays can be very
effective in information systems for business manager.
2. Different types of keyboard devices, such as visual display
terminals, teleprinter terminals, and point-of-sale devices are among
the keyboard devices.
A light pen is a photosensitive penlike instrument which can
sense a position on the cathode ray tube (CRT) when the end of the
pen is held against the screen. The light pen is an input device. By
sensing the position on the screen when you touch it by the light pen,
you are inputting data to the main storage. The light pen is
commonly used by engineers to modify designs.
Teleprinter terminals. There are situations where it is desirable
18
to have a printed copy of data outputted to a terminal. If a user finds
a printed copy to be required, the solution could be a teleprinter
terminal. A teleprinter terminal has a keyboard for input and a typewriter like printer for output. These printers are character printers
and are therefore slower output devices than CRT displays.
A point-of-sale (POS) device is the electronic equivalent of a
cash register, however it is capable of capturing more data than a
cash register. Most point-of-sale devices are online terminals
attached to a computer for processing the transaction while the
customer is making the purchase. The significant features of most of
the current electronic POS devices include: the capability of entering
extensive information about the sale, the guiding of the operator
through the possible transactions by a series of lighted indicators or
messages, a provision for transmission of the data to a central
computer, and the provision for a local computational capability such
as price extensions and tax calculations.
Scanners
Scanners provide a capability for direct data entry into the
computer system. The major advantage of this direct data entry is
that humans do not have to key the data. This leads to faster and
more accurate data entry. The two major types of scanners are optical
scanners and magnetic-ink character recognition devices. Optical
scanners are input devices hat can "read" data recorded on paper. The
scanning techniques used involve a light source and light sensors;
thus, they are called optical devices. The data to be scanned may be
typed or handwritten characters, data-coded as pencil marks, or datacoded as bars. The common optical scanner devices are called optical
character readers, optical mark readers, and bar-code readers*.
An optical character reader (OCR) inputs data by using optical
scanning mechanisms that can detect or scan alphabetic and numeric
characters printed on paper. If the data are typewritten, they must be
typed using a special type font**, called an OCR font. Examples of
the use of OCR devices include the scanners used by the Postal
Service to aid in sorting bulk mail, and as first-draft input for word
processing system.
Optical mark readers (OMR) are able to detect pencil marks,
19
made on special paper forms. The actual inputting of data through an
OMR device involves shining a light on the page being scanned and
detecting the reflections from the pencil marks. Pencil marks made
with a soft lead pencil (high graphite content) will reflect the light. It
is this reflection that the OMR device detects.
Optical bar-code readers detect combinations of marks or
printed bars that represent the data. Bar codes have been used for a
number of years for some types of credit card processing and by the
post office for mail sorting. It is very common to use bar-code
readers in conjunction with point-of-sale devices***. The most
widely known bar code is the Universal Product Code (UPC), which
now appears on almost all retail packages.
Magnetic-ink character recognition (MICR) devices were
developed to assist the banking industry. MICR devices speed up
data input for the banking industry by reading characters imprinted
on paper documents using a magnetic ink (an ink that contains iron
oxide particles). Check and deposit form processing is the largest
application of MICR.
Personal Computers
Personal computers are supposed to appear in the late 1970s.
One of the first and most popular personal computers was the Apple
II, introduced in 1977 by Apple Computer. During the late 1970s and
early 1980s, new models and competitive operating systems seemed
to appear daily. Then, in 1981, IBM entered the fray with its first
personal computer, known as the IBM PC. The IBM PC quickly
became the personal computer of choice, and most other personal
computer manufacturers fell by the way-side. One of the few
companies to survive IBM's onslaught was Apple Computer, which
is sure to remain a major player in the personal computer
marketplace. In less than a decade the microcomputer has been
transformed from a calculator and hobbyist's toy into a personal
computer for almost everyone. What is a personal computer? How
can this device be characterized?
First, a personal computer being microprocessor-based, its
central processing unit, called a microprocessor unit, or MPU, is
concentrated on a single silicon chip.
20
Second, a PC has a memory and word size that are smaller than
those of minicomputers and large computers. Typical word sizes are
8 or 16 bits, and main memories range in size from 16 К to 512 K.
Third, a personal computer uses smaller, less expensive, and less
powerful input, output and storage components than do large
computer systems. Most often, input is by means of a keyboard, softcopy output being displayed on a cathode-ray tube screen. Hard-copy
output is produced on a low-speed character printer.
A PC employs floppy disks as the principal online and offline
storage devices and also as input and output media.
Finally, a PC is a general-purpose, stand-alone system that can
begin to work when plugged in and be moved from place to place.
Probably the most distinguishing feature of a personal computer
is that it is used by an individual, usually in an interactive mode.
Regardless of the purpose for which it is used, either for leisure
activities in the home or for business applications in the office, we
can consider it to be a personal computer.
Microcomputer System Organization
1. The organization of a microcomputer system is the same as
that of a larger computer system. The microprocessor unit (MPU),
usually concentrated in a single chip, consists of the control unit and
the arithmetic logical unit. Internal memory is made up of random
access memory (RAM) and read-only memory (ROM). Because
RAM is only temporary storage, all microcomputers require some
instructions to get started after they are turned on, and these are
contained in ROM. A microcomputer includes both an MPU and
internal memory.
The portion of the system software that is in ROM brings into
RAM the additional instructions required to operate the
microcomputer. Typically these instructions are stored on a magnetic
disk; hence, they are called a disk operating system, or DOS. This
start-up process is called bootstrapping*. ROM also contains other
programs that help to make personal computers easy to use, such as a
programming language. Computer games are also stored in ROM
cartridges.
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In addition to the MPU, RAM, ROM, and associated control
circuits, other components, called peripheral devices, are needed to
make a complete microcomputer system. The principal peripheral
units are: input devices, output devices, mass storage units, and
communication components. Like a DOS, the programs that control
the flow of data between a microcomputer and its peripheral devices
are a part of systems software.
The most common input device used witlwersonal computers is
the keyboard. Most personal computer keyboards have extra keys
that perform special functions and that can be used to control the
movement of a cursor on a screen. A leverlike device, called a
joystick, is also used as an input device, commonly for playing video
games.
2. The CRT (cathode-ray tube) screen used with personal
computers is called a monitor. Keyboards and monitors may be part
of a single unit that also contains the microcomputer and the disc
drives, or they may be separate units. Besides the monitor, the most
common input units are dot-matrix and letter-quality printers. Dotmatrix printers are suitable for most microcomputer applications.
Letter-quality printers are usually used for high-quality office
correspondence. Both types of printers are considered to be lowspeed character printers.
Mass storage units are available over a range of capacities and
access times. Floppy disks, or diskettes, are the most common mass
storage media. They store patterns of bits on magnetically coated,
flexible plastic platters. A floppy disk platter is sealed permanently
in a paper jacket with a small window for reading and writing. Hard
disk storage systems are also available. They may be fixed or
removable. Some mass storage units contain both floppy and hard
disk devices.
Low-cost modulator-demodulator devices, called modems, that
allow microcomputer systems to communicate over telephone lines
have become increasingly popular. Modems permit networks of
personal computer owners to exchange information or to access large
data banks. These data banks may be dedicated to special
applications, such as law or medicine, or they may provide a variety
of consumer services.
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Computer Programming.
Programming is the process of preparing a set of coded
instructions which enables the computer to solve specific problems
or to perform specific functions. The essence of computer
programming is the encoding of the program for the computer by
means of algorithms. The thing is that any problem is expressed in
mathematical terms, it contains formulae, equations and calculations.
But the computer cannot manipulate formulae, equations and
calculations. Any problem must be specially processed for the
computer to understand it, that is — coded or programmed.
The phase in which the system's computer programs are written
is called the development phase. The programs are lists of
instructions that will be followed by the control unit of the central
processing unit (CPU). The instructions of the program must be
complete and in the appropriate sequence, or else the wrong answers
will result. To guard against these errors in logic and to document the
program's logical approach, logic plans should be developed.
There are two common techniques for planning the logic of a
program. The first technique is flowcharting. A flowchart is a plan in
the form of a graphic or pictorial representation that uses predefined
symbols to illustrate the program logic. It is, therefore, a "picture" of
the logical steps to be performed by the computer. Each of the
predefined symbol shapes stands for a general operation. The symbol
shape communicates the nature of the general operation, and the
specifics are written within the symbol. A plastic or metal guide
called a template is used to make drawing the symbols easier.
The second technique for planning program logic is called
pseudocode. Pseudocode is an imitation of actual program
instructions. It allows a program-like structure without the burden of
programming rules to follow. Pseudocode is less time-consuming for
the professional programmer than is flowcharting. It also emphasizes
a top-down approach to program structure.
Pseudocode has three basic structures: sequence, decision, and
looping logic. With these three structures, any required logic can be
expressed.
The Advantages and Disadvantages of Living in the
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Twentieth Century
The advantages of living in the twentieth century are clear to
anyone who spends time in one of the world's highly developed
nations. The disadvantages of modern life, however, are sometimes
not so quickly seen. Consider the average man today in contrast with
man 200 years ago. Without doubt, man's life has been eased
considerably. Machines now perform for him many of the services
that he previously had to do for himself. They cut his grass, wash his
car, open and close his doors, walk for him, climb stairs for him,
serve him coffee, and both put him to sleep and wake him up to
music. In two major areas – transportation and communications –
great progress has been made. Mass publishing practices have spread
newspapers, magazines, and paperback books around the globe.
Relayed across oceans by Telstar satellites, television informs and
entertains people in every hemisphere. Mail moves swiftly and
efficiently; telephone cables connect all continents. More than any
other single invention, the gasoline engine has revolutionized
modern life. City streets, clogged with automobile traffic tell us that.
More recent discoveries have led to the surge of jet and supersonic
plane travel. Even as man darts throughout the world, he is protected
from disease as no man before him has been, and he can look
forward to living a longer life than his grandfather did. Furthermore,
man now commands a more plentiful supply of the world's goods.
He may own not only a car and a home but also a stove, a
refrigerator, a washing machine, books, phonograph records and
cameras. Even his old age is better provided for through pension and
retirement plans offered by the government and by industry. Thus the
advantages of living in the twentieth century are many.
In contrast, one finds that progress can also have its drawbacks.
It is true that today man moves more swiftly through the world. But
in doing so, he often loses track of the roots and traditions that give
substance and meaning to life. Nor does the fact that he is better
informed through television, radio, newspapers, and books
necessarily mean that he is wiser than men of earlier generations.
Instead, the ease with which the written and spoken word are
produced today sometimes seems to lead to superficiality of thought.
Although man has been given the gift of leisure and a longer life, he
24
has become more restless and is often uncomfortable when he is not
working. Flooded with goods and gadgets, he finds his appetite for
material things increased, not satisfied. Man invented machines to
replace his servants. But some current observers feel that man is in
danger of becoming the servant of his machines. Mass production
lowered the cost of many products, but as prices went down, quality
also often decreased. Another distressing aspect of modem life is its
depersonalization. In many offices, automation is beginning to
replace human workers. Some colleges identify students not by their
names, hut by their IBM numbers. Computers are winning the
prestige that philosophers had in an earlier age. The frenzied pace in
many cities is another of the less attractive byproducts of an
industrial society. Soon, man may even fall victim to the subtle loss
of privacy that threatens him. Even today, he can be watched on
closed circuit television screens as he walks in stores and hotels. He
may be tracked by radar while driving on the highway or listened to
by means of a microphone concealed in his heating system. He might
even be sharing his telephone conversation with an unknown auditor.
Certainly many problems face men living in the most technologically
advanced era in history. As old enemies have been overcome, new
enemies come into view, just like the old ones. Yet if modern man
remains the master of his own fate, he can still fashion a satisfying
life in this fast-moving century.
Alfred Nobel – a Man of Contrast
Alfred Nobel, the great Swedish inventor and industrialist, was a
man of many contrasts. He was the son of a bankrupt, but became a
millionaire, a scientist who cared for literature, an industrialist who
managed to remain an idealist. He made a fortune but lived a simple
life, and although cheerful in company he was often sad when
remained alone. A lover of mankind, he never had a wife or family to
love him, a patriotic son of his native land, he died alone in a foreign
country. He invented a new explosive, dynamite, to improve the
peacetime industries of mining and road building, but saw it used as
a weapon of war to kill and injure people. During his useful life he
often felt he was useless. World-famous for his works, he was never
expected any reward for what he had done. He once said that he did
25
not see that he had deserved any fame and that he had no taste for it.
However, since his death, his name has brought fame and glory to
others.
He was born in Stockholm on October 21, 1833 but moved to
Russia with his parents in 1842, where his father, Emmanuel, made a
strong position for himself in the engineering industry. Emmanuel
Nobel invented the landmine and got plenty of money for it from
government orders during the Crimean War, but then, quite suddenly
went bankrupt.
Most of the family went back to Sweden in 1859. Four years
later Alfred returned there too, beginning his own study of
explosives in his father's laboratory. It so occurred that he had never
been to school or University but had studied privately and by the
time he was twenty was a skilful chemist and excellent linguist
having mastered Swedish, Russian, German, French and English.
Like his father, Alfred Nobel was imaginative and inventive, but he
had better luck in business and showed more financial sense. He was
quick to see industrial openings for his scientific inventions and built
up over 80 companies in 20 different countries. Indeed his greatness
lay in his outstanding ability to combine the qualities of an original
scientist with those of a forward-looking industrialist.
But Nobel was never really concerned about making money or
even making scientific discoveries. Seldom happy, he was always
searching for a meaning to life, and from his youth had taken a
serious interest in literature and philosophy. Probably because he
could not find ordinary human love - he never married - he began to
care deeply about the whole mankind. He took every opportunity to
help the poor: he used to say that he would rather take care of the
stomachs of the living than glory of the dead in the form of stone
memorials. His greatest wish, however, was to see an end to wars,
and thus peace between nations, and he spent much time and money
working for the cause until his death in Italy in 1896. His famous
will, in which he left money to provide prizes for outstanding work
in physics, chemistry, physiology, medicine, economics, literature
and promotion of world peace is a memorial to his interests and
ideals. And so the man who often believed that he was useless and
had done little to justify his life is remembered and respected long
after his death. Nobel's ideals which he expressed long before the
26
threat of nuclear war have become the ideals of all progressive
people of the world.
According to Nobel's will the capital was to be safely invested to
form a fund. The interest on this fund is to be distributed annually in
the form of prizes to those who, during the previous year did work of
the greatest use to mankind within the field of physics, chemistry,
physiology or medicine, economics, literature and to the person who
has done the most for brotherhood between nations, for the abolition
or reduction of permanent armies and for the organization and
encouragement of peace conferences.
In his will Nobel wrote that it was his firm wish that in choosing
the prize winner no consideration should be given to the nationality
of the candidates, but that the most worthy should receive the prize,
whether he be a Scandinavian or not. This will was written in Paris,
on November 27, 1895.
Since Nobel's death many outstanding scientists, writers and
public figures from different countries have become Nobel Prize
winners.
Computer Uses from A to Z
Once upon a time there were no computers. The world was a lot
different. All sorts of things were not possible. There were no video
games, CD-ROM players, modern TV, grocery store scanners, fast
phone connections or space probes.
Right after World War II, engineers built the first digital all
electronic computers. The information Age began. Computers linked
to TV, telephone and satellite networks spread information
throughout the world.
Before computers, most people made a living by making and
selling goods and farm products. Today, more and more people are
earning their living using computers. Many are producing and selling
information.
Here are some examples of the many ways we use computers
today:
AUTOMOBILES - Cars use computers to control the flow of
gas to the engine. This gives better gas mileage. Also, many cars
have computers that control displays such as the temperature, speed
27
and. gas gauges.
BANKS - Computers in banks can transfer money from one
account to another.
CARTOONS - Computers can be used to organize thousands of
single pictures used to make cartoons.
DRAWINGS - Computers can be used to create drawings for
engineering or designing.
EXERCISE MACHINES - Some exercise machines use
computers to calculate miles or calories.
FAX MACHINES - Computers in fax machines are used to send
and print the signal from machine to machine.
GAMES - Some games such as chess can be played with the
help from a computer. The computer can analyze and decide which
move would be the best. Other games played with computers are
very popular.
HOSPITALS - A hospital patient's heart (pulse) rate can be
recorded and analyzed by a computer.
INDUSTRIAL ROBOTS - Some companies use computercontrolled robots to do such things as weld parts, work on assembly
lines and deliver parts.
JET PLANES - Computers help guide planes by giving pilots
important information such as speed and altitude.
KITCHEN APPLIANCES - Microwaves, for instance, use
computers to set the time and temperature.
LIBRARIES - Books and other materials are checked out by
using computers. Each book has a bar code. When it is checked out,
it is placed under a laser reader. The laser reader, controlled by a
computer, records the title of the book. In addition, most libraries
have a listing of their books and other materials on computers so you
can find out what is available.
MUSICAL INSTRUMENTS - Many performers use computercontrolled machines such as electronic drum kits to create special
sounds.
NEWSPAPERS - Reporters write their stories on the computer.
Photographers and editors edit pictures and stories on the computer.
OLYMPIC ATHLETES - Athletes use computers to help with
their training. For example, computers can measure how well an
athlete's lungs are working.
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PAY TELEPHONES - A computer at a central location figures
out how much a call will cost. Computers connect your call to the
correct number.
QUAKES - Computers are used to help predict earthquakes.
RESTAURANTS - A restaurant manager can use a computer to
keep track of food orders and supplies.
SPORTS - Computers are used to record times and scores at
games.
TELEVISION - Computers are used to control much in
television. Using data produced by computers, networks can make
their decisions about what shows stay on the air.
UNDERGROUND GAS RESERVES - Scientists use computers
to help create models of underground gas reserves. This helps keep
up with the supply.
VIDEOCASSETTE RECORDERS - Computers change
magnetic pulses on the tape into electronic signals that then turn into
pictures you see on your TV.
WASHING MACHINES - A tiny computer chip (microchip)
controls your washing machine (washer).
X-RAY SCANNERS - Detailed pictures of the inside of the
body can be taken from different angles. Computers are also used to
sort, process and show pictures.
YACHTS - Captains use computers to help navigate courses for
their yachts.
ZOOS - Zoos use computers to help keep track of animals used
for breeding purposes.
GLOSSARY:
network - here a group of radio or television stations in different
places using many of the same broadcasts
mileage - the distance that is traveled, measured in miles
gauge - instrument for measuring
weld - to join by heating and fusing (melting)
deliver - here take to a place
kit - set of equipment
edit - prepare smth. for printing or showing
keep/lose track (of) - to keep/not keep oneself informed about a
person, state of affairs, etc.
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on the right/wrong track - thinking or working
correctly/incorrectly microchip - a tiny set of connected electrical
parts produced as a single unit on a
slice of material such as silicon
process - to put information (data) into a computer for
examination to produce
young
Computer Viruses
A bit of history
On the 2 of November, 1988 Robert Morris, a graduate student
of computer science faculty of Cornwall University (USA) infected a
great amount of computers, connected to the Internet network. This
network unites machines of university centres, private companies
and governmental agents, including National Aeronautics Space
Administration, as well as some military scientific centres and labs.
On the 4th of November the author of the virus - Morris - came
to FBI headquarters in Washington on his own. FBI has imposed a
prohibition on all material relating to the Morris virus.
On the 22nd of January, 1989 a court of jurors has acknowledged
Morris guilty. If the denunciatory verdict had been approved without
modification, Morris would have been sentenced to 5 years of prison
and 250 000 dollars of fine. However Morris' attorney immediately
lodged a protest and directed all papers to the Circuit Court with the
petition to decline the decision of court. Finally Morris was
sentenced to 3 months of prisons and fine of 270 thousand dollars,
but in addition Cornwall University carried a heavy loss, having
excluded Morris from its members. Author then had to take part in
liquidation of its own creation.
nd
What is a computer virus?
It is an executable code able to reproduce itself. Viruses are an
area of pure programming, and, unlike other computer programs,
carry intellectual functions on protection from being found and
destroyed. They have to fight for survival in complex conditions of
30
conflicting computer systems. That's why they evolve as if they were
alive.
Yes, viruses seem to be the only alive organisms in the computer
environment, and yet another their main goal is survival. That is why
they may have complex crypting/decrypting engines, which is indeed
a sort of a standard for computer viruses nowadays, in order to carry
out processes of duplicating, adaptation and disguise.
It is necessary to differentiate between reproducing programs
and Trojan horses. Reproducing programs will not necessarily harm
your system because they are aimed at producing as many copies of
their own as possible by means of so-called agent programs or
without their help. They are referred to as "worms".
Meanwhile Trojan horses are programs aimed at causing harm
or damage to PC's.
Destructive actions are not an integral part of the virus by
default. However virus-writers allow presence of destructive
mechanisms as an active protection from finding and destroying their
creatures, as well as a response to the attitude of society to viruses
and their authors.
As you see, there are different types of viruses, and they have
already been separated into classes and categories. For instance:
dangerous, harmless, and very dangerous. No destruction means a
harmless one, tricks with system halts means a dangerous one, and
finally devastating destruction means a very dangerous virus.
But viruses are famous not only for their destructive actions, but
also for their special effects, which are almost impossible to classify.
Some virus-writers suggest the following: funny, very funny and sad
or melancholy (keeps silence and infects). But one should remember
that special effects must occur only after a certain number of
contaminations. Users should also be given a chance to restrict
execution of destructive actions, such as deleting files, formatting
hard disks. Thereby a virus can be considered to be a useful program,
keeping a check on system changes and preventing any surprises
such as deletion of files or wiping out hard disks.
It sounds quite unusual to say such words about viruses, which
are usually considered to he a disaster. The less a person understands
in programming and virology, the greater influence will have on him
31
the possibility of being infected with a virus. Thus, let's consider
creators of viruses as the best source.
Who writes computer viruses?
To write something really new and remarkable programmer
should have some extra knowledge and skills, for example:
1) good strategic thinking and intuition — releasing a virus and
its descendants live their own independent life in nearly
unpredictable conditions. Therefore the author must anticipate a lot
of things;
splendid knowledge of language of the Assembler1 and the
operating system he writes for - the more there are mistakes in the
virus the quicker its will be caught;
attention to details and a skill to solve the most varied tactical
questions – one won't write a compact, satisfactory working program
without this abilities;
4)a high professional discipline in order to join all the preceding
points together.
A computer virus group is an informal non-profit
organization, uniting.
Programmers – authors of viruses regardless of their
qualifications. Everyone can become a member of the club, if he
creates viruses, studies them for the reason of creation and spreading.
You don't have to know any computer language or write any
program code to become a member or a friend of the group. But
programming in Assembler is preferred, Pascal, С++ and other high
level languages are considered to be suitable.
Writing viruses usually don't bring profits to the author. At least
when the author and the healer are different persons. The situation is
quite different when they are not, especially when the person
manages to hide the fact of double - dealing. Developers of antiviral
software gain money from selling their remedy to new viruses.
But don't forget that creation, use and spreading harmful
programs is a crime, as well as cracked versions of programs. Our
penal code establishes a punishment up to seven years of jail.
32
DNA Computers
All the indications are that the era of traditional silicon
computers is coming to the close. A discovery made by scientists at
the Weizmann Institute can turn around the high - tech market.
The history of DNA and DNA computers began in Match 1953
(nineteen fifty three) when two young scientists James Watson and
Francis Crick discovered "the secret of life". The breakthrough the
two had made was, indeed, extraordinary, for they had worked out
the molecular structure of DNA the chemical substance found in the
nucleus of every living cell. The double helix structure they had
deduced revealed that DNA could do two crucial things it could
carry information and it could replicate itself. It was a discovery that
would revolutionize biology. By the early 1950s, scientists had
already identified DNA as the molecule that carried the biochemical
information that enables all living things to exist, and so a race was
on to discover exactly how it did this.
By today scientists discovered that DNA was composed of four
chemical bases known as adenine, thymine, guanine and cytosine.
These four bases are arranged like steps on the ladder. Adenine
always links with (thymine, guanine always links with cytosine, and
the precise sequence in which the pairs are arranged is the code that
genes use to give instructions for the manufacture of the many
proteins needed for the formation and functioning of the living
organism throughout its life. The idea of building calculating devices
on the basis of DNA molecules is really molecules."
Contrary to claims by Microsoft specialists, an ordinary
computer is unable to perform several tasks simultaneously. It
performs them consecutively - true, very fast, so fast in fact that
users arc unaware of the defect. If a defect it is. The Nanocomputer
is free from any such shortfall. DNA molecules work "as a team,"
and this is why the new machine is "polyphonic," so to speak, being
able to perform several tasks at once. According to professor
Shapiro, "the Turing machine should process information and store it
in the form of the chain of symbols. Just as a life DNA does." So far
the Israelis have created just one of possible Turing machine
versions. Designed at the Weizmann Institute, the Nanocomputer
operates with only two symbols, the way ordinary computers operate
33
with the notions of "logical 0" and "logical 1." Thus far the system is
too elementary to perform any specific tasks. But it can serve as a
platform for DNA computers of the future. They will be able to work
directly in a human cell, identifying potential diseases and curing
them. It may still be a long way from Ehud Shapiro's discovery to the
shining pinnacles of the future. But the first step has already been
made.
Internet: How It Affects US
We live in a multi-media society. How does the internet affect
our lives? It can be very helpful to people who carefully choose
websites that they visit. The internet can increase our knowledge of
the outside world; there is much high-quality information that can
help us understand many fields of study: science, medicine, the arts
and so on. In this global network you can find any information in a
few minutes. Otherwise you would have to search for the necessary
information in directories, libraries or on the phone for a long time.
The internet has already revolutionized the way we live and
work. But these are still earl days for the internet. We don't know
how much it is still changing the world. The internet era is yet to
come. The internet is an up-to-date wonder. As the proverb says:
"nothing is wonderful, when you get used to it", that is why the
internet fails to astonish us any more.
One of the most valuable functions of the internet is its
information function. The internet keeps people informed about
current events, as the latest achievements in science and culture. You
can even find out how to pass from the underground station to the
house of your girlfriend, who recently moved to London.
Recently a system of distance learning became popular. You can
study foreign languages and even study in universities. Individual
educational programs can be developed especially for you.
The internet is also widely used in business. Thanks to the
internet, we have rapid connections with partners from all corners of
the world. You can even conduct negotiations, hear and see your
contacts, and exchange graphic and textual information.
On the other hand, there are several serious disadvantages to the
internet. Of course, it provides us with a pleasant way to relax and
34
spend our free time, but some people spend an average of six hours
or more a day on the network. Many children look at a screen for
more hours each day than they do anything else, including studying
and sleeping. It's clear that the network has a powerful influence on
their lives, and that its influence is often negative.
Another disadvantages is that for many people the internet
becomes more "real" than reality, and their own lives seem boring.
Also, many people get upset or depressed when they can't solve
problems in real life as quickly as they can do in internet games. In
real life they can not simply press "escape".
The most negative effect of the internet might be people's
addiction to it. People often feel a strange and powerful need to
spend time on the network. Addiction to a computer screen is similar
to drug or alcohol addiction: people almost never believe they are
addicted.
One more disadvantage of the internet is the absence of
information control. Children receive wide access to porno sites and
sites with violence and promoting hate.
From that, how much we know about the internet depends on the
choices we make world how effectively we use the opportunities of
the internet in our time.
Internet in Business
The Internet, a global computer network which embraces
millions of users all over the world, began in the United Slates in
1969 as a military experiment. It was designed to survive a nuclear
war. Information sent over the Internet takes the shortest path
available from one computer to another. Because of this, any two
computers on the Internet will be able to stay in touch with each
other as long as there is a single route between them. This
technology is called packet switching. Owing to this technology, if
some computers on the network are knocked out (by a nuclear
explosion, for example), information will just route around them.
One such packet-switching network already survived a war. It was
the Iraqi computer network which was not knocked out during the
Gulf War. Most of the Internet host computers (more than 50 %) are
in the United States, while the rest are located in more than 100 other
35
countries. Although the number of host computers can be counted
fairly accurately, nobody knows exactly how many people use the
Internet, there are millions, and their number is growing by
thousands each month world wide.
The most popular Internet service is e-mail. Most of the people,
who have access to the Internet, use the network only for sending
and receiving e-mail messages. However, other popular services are
available on the Internet: reading USENET News, using the WorldWide Web, telnet, FTP, and Gopher.
In many developing countries the Internet may provide
businessmen with a reliable alternative to the expensive and
unreliable telecommunications systems of these countries.
Commercial users can communicate over the Internet with the rest of
the world and can do it very cheaply. When they send e-mail
messages, they only have to pay for phone calls to their local service
providers, not for calls across their countries or around the world.
But who actually pays for sending e-mail messages over the Internet
long distances, around the world? The answer is very simple: an user
pays his/her service provider a monthly or hourly fee. Part of this fee
goes towards its costs to connect to a larger service provider. And
part of the fee got by the larger provider goes to cover its cost of
running a worldwide network of wires and wireless stations.
But saving money is only the first step. If people see that they
can make money from the Internet, commercial use of this network
will drastically increase. For example, some western architecture
companies and garment centers already transmit their basic designs
and concepts over the Internet into China, where they are reworked
and refined by skilled – but inexpensive – Chinese computer-aideddesign specialists.
However, some problems remain. The most important is
security. When you send an e-mail message to somebody, this
message can travel through many different networks and computers.
The data are constantly being directed towards its destination by
special computers called routers. Because of this, it is possible to get
into any of computers along the route, intercept and even change the
data being sent over the Internet. In spite of the fact that there are
many strong encoding programs available, nearly all the information
being sent over the Internet is transmitted without any form of
36
encoding, "in the clear". But when it becomes necessary to send
important information over the network, these encoding programs
may be useful. Some American banks and companies even conduct
transactions over the Internet. However, there are still both
commercial and technical problems which will take time to be
resolved.
Programming Languages
Hundreds of programming languages have been developed for
computer systems. Some languages can be used only for specific
applications or with a special computer system. Other languages are
general-purpose; they are used for many problem-solving situations
and are easy to learn and use.
All the programming languages are divided into high-level
languages and machine-level languages.
High-level languages, like BASIC and FORTRAN, are machineindependent languages because language statements are such that
any program written in the language can usually be executed on
different computer systems.
Machine-level languages, on the other hand, such as the
assembly language, require that you should know about the computer
and the peripheral devices and how they work together.
That is why, machine-level languages are machine-dependent
languages. Machine-level language programs can be efficient
because the knowledgeable programmer will choose the fastest and
most exact instructions to execute them.
Beginning programmers and students usually use high-level
languages because they are less difficult to learn and to use, and they
produce fast results. System programmers, on the other hand, may
use machine-level languages for writing programs that must often be
as fast and efficient as possible. If you already know a language
supported by the computer system, you may continue to use that
language rather than spend time to learn a new one.
If you are a beginning programmer, you may start with a
language like BASIC-II which is a conversational language.
Language statements use simple, English-like worlds and common
37
mathematical expressions. It had many industry and business
applications.
You write a BASIC-program as a series of one or more program
line with a number that both identifies the line and indicates the order
in which the line will be processed.
Today We Are in the Twenty-First Century.
Today we are in the twenty-first century. This is an occasion to
strike the balance of the twentieth century in the progress, of modern
science. We can name the fruits of this progress:
Television in every home
Nuclear energy giving electricity
Laser in communications, in aviation and in clinics
Phone contacts across the oceans and continents
Personal computers hooked into Internet
Infection diseased that carried off millions of lives are stamped
out Gene engineering opening the way for new medicines and new
methods of treatment and many others.
But still many problems facing people on the earth remain.
Shortage of energy is one of them. The available reserves of gas and
oil will last for a few decades. Hydraulic power stations cannot solve
the problem either. Atomic power stations can supply any amount of
heat and electricity, but they are not reliable. In the opinion of many
experts, thermonuclear power can be the best solution. But we are
still on the initial stage of our work toward controlled nuclear fusion.
In January this year Russian scientists were reported to make a
sensational discovery. They found a new kind of radiation which can
give a non-stop supply of cheap energy.
Nuclear physicists from Kurchatov Institute became interested in
the action of electromagnetic pulses upon the earth crust. The energy
of a high intensity electromagnetic field is known to be liberated in
an earthquake focus. This phenomenon usually lasts 10-20 seconds.
An immense amount of electromagnetic energy acts upon the crust of
the earth.
So a research team having modeled earthquake in laboratory
conditions got quite unlooked-for results. The devices registered a
new kind of non radioactive radiation, emergence of ball light-nings
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and turning elements of Mendeleyev system into new ones. The
scientists repeated the experiment again and again but the result
remained the same. And they supposed that magnetic unipolar
radiation caused this phenomenon. This kind of radiation is not
studied yet, it manifests itself in certain conditions.
During this process the amount of energy released is much
higher than the amount of energy consumed. It may be hundreds of
times as high as that provided by thermonuclear reaction. This
discovery may appear to have the greatest significance for economy,
power engineering, industry and defense.
But the scientists refused to comment on the phenomena until
they are properly studied and explained, because they can basically
change our life. Such elements as titanium, plumbum and others can
be turned into iron, copper, silver, gold and other rare elements. This
property can be used to clean our planet from radioactive waste. As I
have said this newly discovered kind of radiation is connected with
earthquakes and gravitational forces. So the scientists will be able to
prognosticate strong earthquakes and suggest new ideas in studying
gravitation.
The discovery under consideration has been patented both in
Russia and abroad. Members of the Goverment Ilya Klebanov and
Sergei Shoigu have informed the President Vladimir Putin about this
achievement of Russia science.
Virtual Reality Applications, Today and Tomorrow.
Virtual reality may be one the most important technologies in
our future reaching many fields. While most people now focus on
VR's use in entertainment areas, its real impact will be in the arts,
business, communication, design, education, engineering, medicine,
and many other fields. More and more objects exist first in computer
graphics and later in real form. Computer graphics is a way of seeing
and creating the world. We are just beginning to see the potential of
virtual reality. I would like to suggest some important applications it
will have in future. Architecture and Construction. Virtual reality is
already showing its potential in the architecture and construction
industry. A building can be created as electronic prototype while still
39
being designed, so that both architect and client can experience the
structure, modify it and costly changes during or after construction
are avoided. In the future clients will not only be able to see the
structure, but hear sounds from within it and feel its texture. Home
builder are particularly excited about the potential of virtual reality to
sell their designs. Why build expensive model homes when
prospective buyers can see the range of options electronically? City
planners will use virtual reality to redesign streets without leaving
the room.
The Arts. At present you can see "virtually" a number of actual
art galleries and museums via the Internet. Some museums conduct
special exhibits of virtual reality art works. Virtual reality will
change our conception of what constitutes art. A work of art may
become a physically interactive experience. You may travel into a
virtual painting, which will actually be a mini-world for you to
explore. You may interact with its elements, perhaps even change
them. You may enter a sculpture gallery and interact with the art
pieces. You will actually become part of the art as you interact with
it. Virtual techniques are used in film making to generate the very
realistic characters and scenery in feature films.
Medicine. Virtual reality is just beginning to be used in medicine
and medical research. The University of North Carolina uses it in
biochemical engineering. They test the docking of molecules using
visual displays and a force-feedback device. Several companies in
Maryland and Connecticut are creating virtual bodies, a kind of
"body electronic" to enhance medical training. In the future medical
students will study anatomy by virtual dissecting which is cost
effective and efficient way of studying the human body. Medical
students and surgeons will practice virtually. They may even practice
an operation for a specific patient, whose unique body characteristics
have been scanned into the computer. Different diseases can also be
simulated to test a medical student's or doctor's knowledge regarding
treatment. Likewise virtual reality could help improve relaxation
techniques, providing a pleasant world in which to relax.
Education and Training. Virtual reality is just beginning to be
applied in education and training. Students can study anatomy or
explore our galaxy. Some training applications relate to health and
safety. They allow trainees to walk through a virtual factory and
40
learn more about hazards than reading a manual or attending a
lecture. In the future students will be able to learn through studying
in virtual worlds. Chemistry students will be able to conduct
experiments without risking an accidental explosion in the lab.
Astronomy students will be able to visit a range of virtual galaxies to
study their properties. History students will be able to visit different
historical events and perhaps even participate in the action with
historical figures. English students could be on stage at the Globe
Theater as it was when Shakespeare's plays were first presented.
They will also able to enter into a book and interact with its
characters.
Virtual reality will also be used in teaching adults. Trainees in a
wide variety of environments will be able to safely try out new
techniques. They will be able to learn by doing tasks virtually before
applying them in the real world. They will use these practice tasks in
hazardous environs and also practice dealing with emergencies on
the job. However, much remains to be done to bring virtual reality
fully into the classroom.
Engineering. Engineers of all descriptions are already using
virtual reality simulations to create and test prototypes. Each of the
Big Three automakers is using some form of virtual reality to test
new models. In the aerospace industry, the new Boeing 777 was the
first aircraft to be designed and tested using virtual-reality
technology.
Physical prototypes take a great deal of time to produce and are
very costly. Changes to electronic or simulated prototypes can be
done rapidly and inexpensively, shortening development time.
Hoping to save money in prototyping and avoid cost overruns, the
U.S. military has even coined the phrase, "Sum it before you build
it!" In the future, nearly every engineering project will use virtualreality prototypes. Even the manufacturing process and expected
repairs will be simulated, saving money. Given advances in
electronic networks, virtual work benches will be created with
engineers in distant locations around the globe working in teams to
design products.
Entertainment. Virtual reality is already being applied in
entertainment. Entertainment centers are cropping up in major cities
around the globe and travelling virtual-reality entertainment shows
41
are on the ground. Soon, nearly ail video arcades will be VR centers;
all games will be 3-D, interactive, and immersive. While the number
of such entertainment centers will increase in the future, home based
virtual reality will also grow dramatically. Current system are
primitive, due to lack of computing power and the high cost of most
virtual-reality equipment, but advanced virtual reality it set to invade
the home entertainment scene in the years ahead. While stand-alone
entertainment systems will be offered, perhaps the most important
form of home VR will come over wide distances.
Imagine an adventure game in which you are immersed in a
three-dimensional world, interacting with other participants. It can
become a real, role-playing event. Imagine a movie in which you are
a participant interacting with the plot and other characters. While
these kinds of entertainment have been seen as separating
participants in the past, in the future they may be seen as a new kind
of socializing, one which may lead to richer relationship in the "real"
world.
Marketing. Virtual reality is just beginning to be used by
companies who want customers to experience their products and to
understand them better. They" с found that a new technology, such
as virtual reality, draws people to their exhibits and involves them
with a product much more than standard displays. Cabletron, a cable
network company in Rochester.
Business. Already, several companies have created threedimensional visualization of the stock market. This arrangement
shows the rise and fall of stock prices and a stock broker can quickly
see the activity of stocks. A click can bring information t the screen
and given the broker an opportunity to rapidly buy or sell a stock.
The use of virtual reality in stock market trading will greatly increase
in the future. The companies will apply virtual reality to identify
trends on stock markets and make trades more rapidly. They will, in
fact, be interacting with the stock markets in real time. Their work
will be much like playing a large and complex video game. Some
virtual reality software developers have been working on a product
called Data Spaces, a step beyond the data base. Data Spaces
represents information so as object that differ in size, colour, shape
and spatial relationships. You will surf through information in a
world of three-dimensional objects, selecting the information you
42
need by clicking on the appropriate one. In the next few years you
will be a' e to conduct this kind of search on the Internet using a
recently accepted standard called Virtual Reality Modeling Language
(VRML).
The Promise of Virtual Reality. These are just some present and
tutu e applications of virtual reality. As you can see, there are many
potential applications for virtual reality. Perhaps, in the future, we
will only be limited by our imagination: regarding the uses of virtual
reality. Virtual reality is neither good nor bad. It is a new tool that
will have important implications in our future.
In working in the field of virtual reality, I have found a very
important aspect of it that is often overlooked. In order to create
virtual worlds, one must have an in-depth understanding of how our
everyday world works. Perhaps one of virtual reality's greatest gifts
will be helping us to understand better our own reality.
John C. Briggs
Technology to Change Our life
Speech, bei ng a means of communi cat i on peopl e
f eel comf or t abl e wi t h, has gr eat pot ent i al as a way t o
di r ect our comput er s. Peopl e ar e qui t e eager t o t al k t o
t hei r machi nes. Any number of sci ence f ict i on mo vi es
t est if y t o t he per cepti on t hat , i nevi t abl y, we wi l l t al k
t o our machi nes...
Yet speech r ecogni t i on i s one of t hose technol ogi es
t hat seems per pet ual ly ar ound t he comer . It i s easy t o
si mul at e i n sci ence fict i on mo vi es, but a l i ve, usef ul ,
and br oad i mpl ement at i on has been el usi ve. T he mai n
pr obl em i s not get t i ng t he co mput er t o speak up. E ven
a cr ude syst em l i ke t he earl y Maci n T alk al l owed a
human l i st ener t o under st and a li ne of t ext . T he r eal
pr obl em i s f i gur i ng o ut what we say. Lea ve asi de t he
quest i on of what we mean - t her e ar e enough pr obl e ms
i n ma ki n g co mput er s smar t enou gh t o t ake di ct ati on.
When humans speak, t hey use co mpl ex l angua ges,
l oaded wi t h ambi gui t i es, col ored by i nf l ect i on and
t one. And each human speaks di ff er entl y - t her e ar e
43
accent s, st r eet di al ects, sl ang. What 's mach i ne goi ng t o
do?
Yet t he f i el d abounds wi t h opt i mi st s who t hi nk t hat
aut omat i c speech r ecogni t i on i s a beast to be br oken.
J ohn Ober t euf f er , t he pr esi dent of V oi ce Inf or mat i on
Associ at es, a f i r m t hat f ol l ows t he t echnol og y, i nf or ms
me t hat , i ndeed, comput er s wi l l soon be abl e t o
i nt er pret speech at l aest as wel l as human s. We won 't
t ype i nt o our compu t er s, but t al k t o t hem. «In t en
year s, peopl e wi l l l ook at a comput er ke y -boar d t he
way t hey now l ook at a sli de r ul e, » Obe r t euff er
pr edi ct s. «An yt hi n g you do on a keyboar d, you wi l l do
by spea ki n g. You wi l l have a mo use and a
mi cr ophone ».
Ever Tried Talking to a Computer?
T echnol ogy has chan ged peopl e and t hei r l i ves. No
per i od i n hi st or y has had as man y si gni f i cant changes
as t he past cent ur y. Impr o ve ment s of al l ki nds, such as
t hose i n communi c at i on and t r anspor tat i on have
ser i ousl y changed man y peopl e 's l i ves - not al l
posi t i vel y. Many peopl e ar e conser vat i ve. T hey do not
l i ke and cannot accept t he ne w r esul t s of t echnol ogy.
Conser vat i ve peopl e of t en r esi st t he new. T hey mi ght
pr ef er t o t ake t r ai ns inst ead of air pl anes and t o r ecei ve
l et t er s i nst ead of phone cal l s. T hey mi ght l i ke sof t ,
gent l e musi c r at her t han f ast , noi sy mo der n musi c.
Above al l , man y co nser vat i ve peopl e f ind t he i n cr easi ng use of comput er s conf usi ng, annoyi n g and i m per sonal .
Co mput er s ar e an obvi ous par t of t echnology t hat
r eaches i nt o most peopl e's l i ves. Co mpu t er s answer
t el ephones, r et ri eve i nf or mat i on i nst ant l y, r ead and
answer l et t er s, and make mat he mat i cal co mput at i ons i n
much l ess t i me t han a per son can. Howe ver , how do
peopl e r eact as t he use of t he comput er i ncr eases i n
t hei r dail y l i ves? T her e i s a bi g di f f er ence bet ween
44
t al ki ng t o a hu man be i ng about a mi s t ake o n a bi l l a nd
t r yi ng t o t el l a co mp ut er . A co mput er does not t r eat
peopl e i n a human way. Af t er al l , i t is onl y a machi ne.
A per son who l ear ns t o use any machi ne can benef i t
f r om i t s ser vi ces. T he same i s t r ue f or t he com put er .
T he i nvest ment of t i me and pat i ence t h at a per son
ma kes i n l ear ni ng ho w t o use a co mput er p ays of f man y
t i mes. What can a comput er do? A comput er can easil y
per f or m si mpl e and c ompl ex cal cul at i ons. It can r ecor d
al l ki nds of i nf or mat i on. It can sor t mat er i al ei t her
al phabet i call y or i n number sequence. It can cl assi f y,
r epor t , and edi t dat a, i nf or mat i on t hat i s put i n. T he
onl y r equi r e ment i s t h at t he comput er must be cor r ect l y
pr ogr a mmed t o per f orm t hese f unct i ons, or j obs. Once
a pr ogr am i s set , many peopl e can use i t t o make i t
wor k f or t h em. A c omput er pr ogr a mmer i s a per son
who i s t r ai ned t o pr o gr a m or comm uni cat e wit h
comput er s. In a sense, he teaches t he comput er t o do
t he wor k by wr i t i ng a pr o gr a m. He uses speci al
comput er l angua ges t o contr ol and inst r uct t he
di f f erent part s of t he comput er . He wr i t es a pr ogr am,
t he det ai l ed set of i nst r ucti ons f or t he comput er , i n a
comput er l angua ge.
Co mput er s have so man y e ver yda y uses t hat t he
business wor l d would st op wi t hout t hem. T hey can
r eser ve ai r plane t icket s, keep bank account s, r ent ca r s,
cont r ol pr i ces, or der goods and suppl ies, pr ocess
r egi st r at i on car ds, keep i nvent or i es, recor d gr ocer y
i t ems, and l i st houses f or sal e. Al l of t hese j obs can be
done, and man y mor e, i n a f r act i on of t he t i me t hat a
per son woul d need. By usi ng co mput er s , peopl e i n
busi ness save l ar ge amount s of t i me. Whe t her peopl e
r eal i ze it or not , comput er s con t r ol so many par t s of
soci et y t hat , wi t hout t hem, peopl e 's l i ve s woul d be
much mor e di f f i cult . For ever y mi st ake on a bi l l , t he
comput er does a mi l l i on ot hers r i ght . Comput er s save
gr eat amount s of t i me by doi n g uni nt er esting j obs t hat
t ake peopl e a l ong t i me. Co mput er s ar e desi gned f or
45
r epet it i ve pr oj ect s, for pr ocessi ng and st or i ng a l ar ge
amount of dat a, and f or accur acy and speed. By usi n g
comput er s, hu man bei ngs can f r ee t hems el ves t o do
mor e hu man pr oj ect s.
46
ОГЛАВЛЕНИЕ
What Is a Computer?................................................................. 3
The First Calculating Devices ................................................... 4
Four Generations of Computers ................................................ 6
Data Processing and Data Processing Systems ......................... 6
Computer System Architecture ................................................. 8
Hardware, Software, and Firmware .......................................... 9
From the History of Computer Development In Russia ......... 10
Central Processing Unit .......................................................... 11
The CPU Main Components ................................................... 12
Input Output Environment ...................................................... 14
Input Devices .......................................................................... 15
Output Devices. Printers ......................................................... 16
Keyboard Devices ................................................................... 18
Scanners .................................................................................. 19
Personal Computers ................................................................ 20
Microcomputer System Organization ..................................... 21
Computer Programming. ......................................................... 23
The Advantages and Disadvantages of Living in the Twentieth
Century .................................................................................... 23
Alfred Nobel – a Man of Contrast .......................................... 25
Computer Uses from A to Z ...................................................... 27
Computer Viruses ................................................................... 30
DNA Computers ..................................................................... 33
Internet: How It Affects US....................................................... 34
Internet in Business ................................................................... 35
Programming Languages ........................................................ 37
Today We Are in the Twenty-First Century. .......................... 38
Virtual Reality Applications, Today and Tomorrow. ............. 39
Technology to Change Our life................................................. 43
Ever Tried Talking to a Computer?............................................ 44
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