CSC 113 Lecture Materials

CSC 113
Computer For Arts, Social Science

And Management Science
CSC 113: Computer For Arts, Social Science And Management P a g e |1

CSC 113: Computer For Arts, Social Science And Management
Contents:-
Section A: Introduction to Computer Science

Meaning and Histrory of Computer Science
Generations of Computer Science
Practical Introduction to using personal computer hardware and software.
Section B: Computer Hardware and Software

Computer Hardware: functional components, modern input and output units
Computer Software: Operating systems, application packages
Section C: Program Development: Algorithm, Pseudocode and Flowchart

Explain the meaning of program
Mention and use programming development tools
Section D: Applications of Computing

Computer application areas and technological trends
Using personal computers as effective problem solving tools for the present and the future

Section A: Introduction to Computer Science
Meaning and History of Computer Science
Generations of Computer Science
Practical Introduction to using personal computer hardware and software
1.0 Meaning of Computer Science

The following definitions are the various ways people have made attempt to explain the meaning
of computer science.
a. Computer Science is the study of computing, programming, and computation
in correspondence with computer systems. This field of study utilizes theories on
how computers work to design, test, and analyze concepts. Computer science usually has
a stronger mathematical foundation than a scientific one and on some occasions may not
focus directly on computers and their systems.
b. Computer science is the scientific and practical approach to computation and its
applications. It is the systematic study of the feasibility, structure, expression, and
mechanization of the methodical procedures (or algorithms) that underlie the acquisition,
representation, processing, storage, communication of, and access to information,
whether such information is encoded as bits in a computer memory or transcribed
in genes and protein structures in a biological cell.
c. Computer science is the study of automating algorithmic processes that scale.
A computer scientist specializes in the theory of computation and the design of
computational systems. Its subfields can be divided into a variety of theoretical and
practical disciplines.
d. Computer Science is a branch of science that deals with the theory of computation or the
design of computers. It is the study of computers, their design, and their uses for
computation, data processing and systems control, including design and development of
computer hardware and software, and programming. The field encompasses theory,
mathematical activities such as design and analysis of algorithms, performance studies of
systems and their components, and estimation of reliability and availability of systems by
probabilistic techniques. Because computer systems are often too large and complicated
for failure or success of a design to be predicted without testing, experimentation is built
into the development cycle.
e. The study of computation and computer technology, hardware, and software.
f. Computer is the science that deals with the theory and methods of processing information
in digital computer hardware and software, and the applications of computers.

g. The study of the design and operation of computers and their application to science, busin
ess, and the arts.
h. Computer science is a discipline that involves the understanding and design of computers
and computational processes. In its most general form it is concerned with the
understanding of information transfer and transformation. Particular interest is placed on
making processes efficient and endowing them with some form of intelligence. The
discipline ranges from theoretical studies of algorithms to practical problems of
implementation in terms of computational hardware and software.
1.1 Who is a Computer Scientist:
Computer science is a discipline that spans theory and practice. It requires thinking both in
abstract terms and in concrete terms. The practical side of computing can be seen everywhere.
Nowadays, practically everyone is a computer user, and many people are even computer
programmers. Getting computers to do what you want them to do requires intensive hands-on
experience. But computer science can be seen on a higher level, as a science of problem solving.
i. Computer scientists must be adept at modeling and analyzing problems. They must also
be able to design solutions and verify that they are correct. Problem solving requires
precision, creativity, and careful reasoning.
ii. Computer scientists often become proficient in other subjects since computer science also
has strong connections to other disciplines. Many problems in science, engineering,
health care, business, and other areas can be solved effectively with computers, but
finding a solution requires both computer science expertise and knowledge of the
particular application domain.
iii. Computer Science is practiced by mathematicians, scientists and engineers. Mathematics,

the origins of Computer Science, provides reason and logic. Science provides the
methodology for learning and refinement. Engineering provides the techniques for
building hardware and software.
iv. A computer scientist must have a firm foundation in the crucial areas of the field and will
most likely have an in-depth knowledge in one or more of the other areas of the
discipline, depending upon the person's particular area of practice.
v. A well-educated computer scientist should be able to apply the fundamental concepts and
techniques of computation, algorithms, and computer design to a specific design problem.
The work includes detailing of specifications, analysis of the problem, and provides a design that
functions as desired, has satisfactory performance, is reliable and maintainable, and meets
desired cost criteria.

Clearly, the computer scientist must not only have sufficient training in the computer science
areas to be able to accomplish such tasks, but must also have a firm understanding in areas of
mathematics and science, as well as a broad education in liberal studies to provide a basis for
understanding the societal implications of the work being performed.
1.2 Major Subject Areas within Computer Science include:
Computer science has a wide range of specialties. These include computer architecture, software
systems, graphics, artificial intelligence, computational science, algorithms and data structures,
programming methodology and languages, and software engineering. Drawing from a common
core of computer science knowledge, each specialty area focuses on particular challenges. Other
areas include software engineering, artificial intelligence, computer networking and
communication, database systems, parallel computation, distributed computation, computer-
human interaction, computer graphics, operating systems, and numerical and symbolic
computation.
i. Operating Systems: concerned with the development and structure of complex programs
which facilitate man-machine communications.
ii. Computational Science: the analysis of numerical methods for solving mathematical
problems with a computer.
iii. Programming Languages: the study of the design and properties of languages by which
humans communicate with computers.
iv. Digital Logic & Computer Architecture: the study and use of mathematical logic to
design electronic circuits.
v. Intelligent Systems: concerned with means by which computers may perform tasks which
might be characterized as "intelligent" if performed by humans.
vi. Automata Theory: an abstract study of computers and their capabilities.
vii. Information Storage and Retrieval: the study of methods for storing a vast amount of data
in a computer and methods for searching and retrieving this data.
viii. Software Engineering: the study of tools and techniques for software design,
development, testing and maintenance.
ix. Database Systems: A database is an organized collection of data which typically model
aspects of reality in a way that supports processes requiring information. Database
management systems are computer software that interacts with user, other applications,
and the database itself to capture and analyze data.
x. Network & Data Communications: Network systems and data communications analyst
plan, design, build, maintain, and test networks and other data communication systems.
The principal focus is to make computers and other electronic device to share data, files
and other computing resources.
xi. Artificial Intelligence & Experts Systems: The study of designing and developing
computer system that emulates the decision making ability of human experts.
xii. Discrete Mathematics: the study of mathematical structures that is fundamentally discrete
rather than continuous. The study focus on combinatorics, graph theory, theory of
computation, and number theory: congruence and recurrence relations.

1.3 Techniques and Methods used in Computer Science
One to view or understand any science is to study the methods used within that science. In some
sense these methods are similar in many sciences, but they can take on different characteristics in
each discipline. Four important methods used in the study of computer science are:
i. Invention/Conceptual Modeling: formulation of new algorithmic and new architectural

paradigms
ii. Design: software engineering uses design principles to build complex systems to solve
computational problems
iii. Analysis: certainly a major focus within computer science is the analysis and evaluation
of software, algorithms and architecture.
iv. Experimentation: use of experiments to reveal computing principles is an important
method of scientific investigation within computer science.
v. Simulation: A computer simulation is a simulation run on a single computer, or a network
of computers, to reproduce the behavior of a system. The simulation uses an abstract or
conceptual computational model to simulate the system.
1.4 History of Computer Science

The historical development of any subject discipline (Computer Science not an exemption) is
vital to studying, learning and understanding the key components required towards gaining
mastery of the subject.
Here's a brief history of "computer science". Really it's a mix of hardware and software
innovations over the years.
 1834: Babbage/Lovelace design "Analytical Engine"

 1854: Bool published "Laws of Thought" (Boolean Algebra and logic)
 1928: ENIGMA coding machine, Germany
 1930: Model 1, electromechanical computer, Bell Labs
 1938: COLOSSUS, Alan Turing primitive computer
 1941: Electromechanical calculator,Korad Zuse, Austria, 64 word memory, 3 secs
multiplication.
 1944: Mark I, Electromechanical computer, Howard Aiken
 1945: ENIAC, Electrial Numerical Integrator and Computer, J.W. Mauchly/J.P. Eckert.
 1948: 1st transistor, Bell Labs
 1949: EDVAC, built by Alan Turing, acoustic memory storage tubes, oscilloscope display, 1st
library of subroutines * 1st Assembly Language for UNIVAC I
 1951: EDVAC, operational, built by John von Neumann and team
 1952: 1st commercial compiler * Microprogramming announced by Maurice Wilkes
 1954: UNIVAC I, 1st computer sold to U.S. Defense Dept. (built at Harvard) * MATH_MATIC,
1st compiled language for UNIVAC I * FORTRAN, developed at IBM * 1st Assembler, IBM *
IBM 650, 1st mass produced computer
 1955: TRIDAC, 1st computer to use transistors
 1957: DEC founded * IPL, Information Processing Language
 1958: ALGOL 58, ALGOrithmic Language * Atlas, designed at University of Manchester,
England * LISP, LISt Processor
 1959: COBOL, COmmon Business Oriented Language * DEC PDP-1
 1960: ALGOL 60, popular in Europe
 1962: CTSS, Compatible Time-Sharing System
 1964: PL/1 and APL * DEC PDP-8, 1st mass produced minicomputer
 1965: Control Data 6600, 1st successful commercial computer * Control Data PDP-8, 1st
commercial supercomputer * BASIC programming language * XDS-940, University of
California at Berkeley, time-shared system * Simula * ARPANet
 1966: OS/360 * MULTICS, time sharing operating system, MIT
 1968: THE, operating system, Netherlands, layer structure and concurrent processing *
Burroughs B2500/3500, 1st commercial computer to use IC chip
 1969: Laser Printer * UNIX (Thompson and Ritchie, AT&T)
 1970: Pascal * RC 4000, designed by Regenecentralen, operating-system nucleus, or kernel
 1971: Intel, 1st commercial microprocessor (4004), 4 bit, .06 MIPS, $300
 1972: C * Smalltalk
 1973: Ethernet at Xerox PARC * Winchester hard disk
 1975: Altair, 1st hobbyist desktop computer, Intel 8080, 256 bytes, $480
 1976: MCP, multi-CPU operating system * SCOPE, multi-CPU system * Cray 1
supercomputer, 138 megaFLOPS
 1977: Personal computers: Apple II, Radio Shack TSR80, Commodore PET * CPM operating
system
 1978: DEC VAX with VMS operating system
 1979: UNIX 3BSD * Ada * Visicalc
 1981: IBM PC, 16K of RAM * Xerox Alto, 1st workstation, graphic-user interface, ethernet,
mouse, smalltalk
 1982: Compaq, 1st portable computer * Turbo Pascal * Modula 2
 1984: Apple Macintosh, 1st personal computer w/ graphic-user interface * TrueBASIC *
SunOS * PostScript
 1985: C++ * Microsoft Windows
 1987: OS/2 * 4Mbit DRAM chip * Introduction of LANS (Local Area Networks) within large
organizations
 1988: NeXT, UNIX workstation, object oriented system, graphic-user interface
 1989: Motif, standard graphic-user interface for UNIX workstation * Intel 80486 chip
 1990: Windows 3.0 * Modula 3
 1992: Sun Solaris multi-threaded, multi-processing, real-time UNIX operating system
 1993: Windows NT * IBM/Apple/Motorola PowerPC processor * Intel Pentium
Some interesting notes for those of you keeping score:
1. Computer science has always been a progressive field. The first programmer, Ada
Lovelace, was female.
2. About the time I was busy being born, they had just invented the modern hard drive
design. Today, something about half the size of a bar of soap can hold 500 megabytes of
data. And the really expensive drives can put at least 100 megabytes of data on a drive
platter the size of a half dollar. (And there was a point a 10 megabyte harddrive was the
size of a briefcase, and they thought you'd never need to store more than 10 megs. Gee,
they obviously didn't have Tie Fighter back then.)
3. For all of you getting so very excited about the new "Information Superhighway" (and if
I hear that one more time, I'm going to scream): It's already here, you're just now finding

out about it. The rest of us call it the Internet; and it isn't new. It first started evolving way
back in 1965 with ARPAnet, a Defense Department project. Another note, for those of
you wanting censorship and control and all that... ARPAnet (and therefore Internet) was
designed to ALWAYS get data through, even if large portions of it are wiped out, say, by
nuclear war. You can't stop it, it was designed to be a free-form anarchy.
4. Interesting thing to know: Digital logic (ie: processors) shrink by half every 3 years, and
double in speed every 4. Memory and hard drive capacity quadruples every 3 years, and
are 1.4x faster every 10 years. Pretty soon, re-writeable CD's will become commonplace,
storing 650 megabytes per disk. (And yet, 8086's and tape drives still do useful things,
and FORTRAN is written in columns because of punchcards.)
1.5. Generations of Computers
The history of computer development is often referred to in reference to the different generations
of computing devices. Each of the five generations of computers is characterized by a major
technological development that fundamentally changed the way computers operate, resulting in
increasingly smaller, cheaper, more powerful and more efficient and reliable computing devices.
In this section, you'll learn about each of the five generations of computers and the technology
developments that have led to the current devices that we use today. Our journey starts in 1940
with vacuum tube circuitry and goes to the present day -- and beyond -- with artificial
intelligence.
Each of the five generations of computers is characterized by a major technological development

that fundamentally changed the way computers operate.
First Generation (1940-1956) Vacuum Tubes

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were
often enormous, taking up entire rooms. They were very expensive to operate and in addition to
using a great deal of electricity, generated a lot of heat, which was often the cause of
malfunctions.
First generation computers relied on machine language, the lowest-level programming language
understood by computers, to perform operations, and they could only solve one problem at a
time. Input was based on punched cards and paper tape, and output was displayed on printouts.
The UNIVAC and ENIAC computers are examples of first-generation computing devices. The
UNIVAC was the first commercial computer delivered to a business client, the U.S. Census
Bureau in 1951

A UNIVAC computer at the Census Bureau. Image Source: United States Census Bureau
Second Generation (1956-1963) Transistors

Transistors replaced vacuum tubes and ushered in the second generation of computers. The
transistor was invented in 1947 but did not see widespread use in computers until the late 1950s.
The transistor was far superior to the vacuum tube, allowing computers to become smaller,
faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors.
Though the transistor still generated a great deal of heat that subjected the computer to damage,
it was a vast improvement over the vacuum tube. Second-generation computers still relied on
punched cards for input and printouts for output.
Second-generation computers moved from cryptic binary machine language to symbolic, or

assembly, languages, which allowed programmers to specify instructions in words. High-level
programming languages were also being developed at this time, such as early versions of
COBOL and FORTRAN. These were also the first computers that stored their instructions in
their memory, which moved from a magnetic drum to magnetic core technology.
The first computers of this generation were developed for the atomic energy industry.
Third Generation (1964-1971) Integrated Circuits

The development of the integrated circuit was the hallmark of the third generation of computers.
Transistors were miniaturized and placed on silicon chips, called semiconductors, which
drastically increased the speed and efficiency of computers.
Instead of punched cards and printouts, users interacted with third generation computers through
keyboards and monitors and interfaced with an operating system, which allowed the device to
run many different applications at one time with a central program that monitored the memory.
Computers for the first time became accessible to a mass audience because they were smaller
and cheaper than their predecessors.
Fourth Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated
circuits were built onto a single silicon chip. What in the first generation filled an entire room
could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the
components of the computer—from the central processing unit and memory to input/output
controls—on a single chip.
In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the
Macintosh. Microprocessors also moved out of the realm of desktop computers and into many
areas of life as more and more everyday products began to use microprocessors.
As these small computers became more powerful, they could be linked together to form
networks, which eventually led to the development of the Internet. Fourth generation computers
also saw the development of GUIs, the mouse and handheld devices.
Fifth Generation (Present and Beyond) Artificial Intelligence

Fifth generation computing devices, based on artificial intelligence, are still in development,
though there are some applications, such as voice recognition, that are being used today. The use
of parallel processing and superconductors is helping to make artificial intelligence a reality.
Quantum computation and molecular and nanotechnology will radically change the face of
computers in years to come. The goal of fifth-generation computing is to develop devices that
respond to natural language input and are capable of learning and self-organization. One major
technology that has characterized the fifth generation is the development of smart technology
devices.
1.6 Definition of Computer

A computer is an electronic device for storing and processing data, typically in binary
form, according to instructions given to it in a variable program.
A computer is a device that accepts data and manipulates it for some result based on a
program or sequence of instructions on how the data is to be processed.
A computer generally means a programmable machine. The two principal characteristics

are: it responds to a specific instruction in a well-defined manner, and it can execute a
pre-recorded list of instructions (program).
1.7 Basic Characteristics (Strenghts/Capabilities) of a Computer

The power of computers is derived from their capability to process information with speed,
reliability, accuracy, resilience, fault-tolerance and huge storage capacity. Here, we explain why
computers are powerful processing tools.
1. Speed: - Computer can work very fast and requires only few seconds to complete
calculations that will take hours to complete by humans. Computer can perform millions
(1,000,000) of instructions and even more per second. Thus, the processing speed of
computers is in the range of millions to billions of instructions per second.
The speed of computer is therefore measured in terms of microsecond (10-6 part of a

second) or nanosecond (10 to the power -9 part of a second). In other words, the time
required to execute an instruction can be measured in nanoseconds or picoseconds. From
this you can imagine how fast your computer performs work.
For example, it may take you about three minutes to find the location of a book in the
library by searching the index cards. However, if you use a computerised library system
to search the book's location, it may only take you about a few seconds, depending on
how fast you can type. Normally, the computer only takes less than a second to process
your request.
Units of Time :- Computer operations are measured in milliseconds, microseconds,

nanoseconds, and picoseconds. The table below summarized how computer operation are
measured in units of time.
Units of time Abbreviation Fraction of a second

Millisecond Ms Thousandth: 0.001
Microsecond µs Millionth: 0.000001
Nanosecond ns Billionth: 0.000000001
Picosecond ps Trillionth: 0.000000000001
2. Accuracy: - The degree of accuracy of computer is very high and every calculation is
performed with the same accuracy. The accuracy level is determined on the basis of
design of computer. The errors in computer are due to human and inaccurate data.
Computers can generate accurate results, provided that the input data is correct and the
program of instructions is reliable.
They are not affected by emotion and do what they are programmed to do. Hence, they
can produce consistent result.
 If inaccurate data is entered, the computers will generate incorrect results. This is
known as "Garbage In; Garbage Out" (GIGO).
 Most of the "computer errors" can be traced to human errors such as incorrect input
data and unreliable programs.
 For example, the item prices determined by scanning the bar-codes at the point-of-
sale terminals in supermarkets are far more accurate than those typed in by cashiers.
3. Reliability (Diligence)
Computers built with integrated circuits are more reliable. They have a low failure rate. A
computer is free from tiredness, lack of concentration, fatigue, etc. It can work for hours
without creating any error. Computers are most suitable to handle repetitive tasks because
they do not take tea breaks and sick leaves, and they never complain. If millions of
calculations are to be performed, a computer will perform every calculation with the
same accuracy and resilince. Due to this capability it overpowers human being in routine
type of work. For example, the automatic teller machines (ATM) are in operation 24
hours a day, 7 days a week.
4. Versatility: - It means the capacity to perform completely different type of work. You
may use your computer to prepare payroll slips. Next moment you may use it for
inventory management or to prepare electric bills.
5. Power of Remembering: - Computer has the power of storing any amount of

information or data. Any information can be stored and recalled as long as you require it,
for any numbers of years. It depends entirely upon you how much data you want to store
in a computer and when to lose or retrieve these data.
6. No Intelligent Quotient (IQ): - Computer is a dumb machine and it cannot do any work
without instruction from the user. It performs the instructions at tremendous speed and
with accuracy. It is you to decide what you want to do and in what sequence. So a
computer cannot take its own decision as you can.
7. No Feeling: - It does not have feelings or emotion, taste, knowledge and experience.
Thus it does not get tired even after long hours of work. It does not distinguish between
users.
8. Storage: - The Computer has an in-built memory where it can store a large amount of
data. You can also store data in secondary storage devices such as floppies, which can be
kept outside your computer and can be carried to other computers.
Imagine, if you can, how many filing-cabinet drawers would be required to hold the
thousands of student records kept by your school. It would take a lot of space to store
data and information in paper form. However, computers can store them on several disks
that take up less space than a first-aid box.
 Units of computer storage
Units of storage Abbreviation Number of bytes

Kilobyte KB 1,024 or (210)
Megabyte MB 1,048,576 or (220)
Gigabyte GB 1,073,741,824 or (230)
Terabyte TB About one trillion or (240)
 How much is a MB?

A diskette of 1.44 MB capacity can store 300 pieces of composition of 500 words each.
1.8. Classification of Computers
Computers differ based on their data processing abilities. They are classified according to
i. Purpose,
ii. Data handling,
iii. Size, and
iv. Functionality
i. According to Purpose, computers are either general purpose or specific purpose.
General purpose computers are designed to perform a range of tasks. They have the ability to
store numerous programs, but lack in speed and efficiency.
Specific purpose computers are designed to handle a specific problem or to perform a specific
task. A set of instructions is built into the machine.
ii. According to data handling, computers are analog, digital or hybrid.

Analog computers work on the principle of measuring, in which the measurements obtained are
translated into data. Modern analog computers usually employ electrical parameters, such as
voltages, resistances or currents, to represent the quantities being manipulated. Such computers
do not deal directly with the numbers. They measure continuous physical magnitudes.
An analog computer (spelt analogue in British English) is a form of computer that uses
continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model
the problem being solved
Digital computers are those that operate with information, numerical or otherwise, represented
in a digital form. Such computers process data into a digital value (in 0s and 1s). They give the
results with more accuracy and at a faster rate.
A digital computer performs calculations and logical operations with quantities represented as
digits, usually in the binary number system
Hybrid computers incorporate the measuring feature of an analog computer and counting
feature of a digital computer. For computational purposes, these computers use analog
components and for storage, digital memories are used.
A combination of computers those are capable of inputting and outputting in both digital and
analog signals. A hybrid computer system setup offers a cost effective method of performing
complex simulations.
iii. According to size, computers are classified as Super Computer, Mainframe Computer,
Mini Computer, and Micro Computer or Personal Computer.
Computer
Analog Digital Hybrid
Super Computers Mainframe Mini Micro

Computers Computers Computers
a. Super Computer:- The fastest and most powerful type of computer Supercomputers are
very expensive and are employed for specialized applications that require immense amounts of
mathematical calculations. For example, weather forecasting requires a supercomputer. Other
uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy
research, and petroleum exploration.
The chief difference between a supercomputer and a mainframe is that a supercomputer channels
all its power into executing a few programs as fast as possible, whereas a mainframe uses its
power to execute many programs concurrently.
b. Mainframe Computer:- A very large and expensive computer capable of supporting

hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple
microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top,
mainframes are just below supercomputers. In some ways, mainframes are more powerful than
supercomputers because they support more simultaneous programs. But supercomputers can
execute a single program faster than a mainframe.
c. Mini Computer: - A midsized computer. In size and power, minicomputers lie between
workstations and mainframes. In the past decade, the distinction between large minicomputers
and small mainframes has blurred, however, as has the distinction between small minicomputers
and workstations. But in general, a minicomputer is a multiprocessing system capable of
supporting from 4 to about 200 users simultaneously.
d. Micro Computer or Personal Computer

 Desktop Computer: a personal or micro-mini computer sufficient to fit on a desk.
 Laptop Computer: a portable computer complete with an integrated screen and keyboard.
It is generally smaller in size than a desktop computer and larger than a notebook
computer.
 Palmtop Computer/Digital Diary /Notebook /PDAs: a hand-sized computer. Palmtops
have no keyboard but the screen serves both as an input and output device.
 Smaller microcomputers are also called mobile devices:
 Tablet computer – Like laptops, but with a touch-screen, entirely replacing the
physical keyboard.
 Programmable calculator– Like small handhelds, but specialized on mathematical
work.
 Handheld game consoles – The same as game consoles, but small and portable.
iv. According to functionality, computers are classified by function such as Servers,

Workstations, Information appliances, and Embedded computers.
a. Server usually refers to a computer that is dedicated to provide a service. For example, a
computer dedicated to a database may be called a "database server". "file servers" manage a
large collection of computer files. "Web servers" process web pages and web applications. Many
smaller servers are actually personal computers that have been dedicated to provide services for
other computers.
b. Workstations:- A terminal or desktop computer in a network. In this context,

workstation is just a generic term for a user's machine (client machine) in contrast to a "server"
or "mainframe."
Workstations are computers that are intended to serve one user and may contain special hardware
enhancements not found on a personal computer. By the mid 1990s personal computers reached
the processing capabilities of Mini computers and Workstations. Also, with the release of multi-
tasking systems such as OS/2, Windows NT and Linux, the operating systems of personal
computers could do the job of this class of machines.
c. Information appliances are computers specially designed to perform a specific "user-

friendly" function—such as playing music, photography, or editing text. The term is most
commonly applied to mobile devices, though there are also portable and desktop devices of this
class.
d. Embedded computers are computers that are a part of a machine or device. Embedded
computers generally execute a program that is stored in non-volatile memory and is only
intended to operate a specific machine or device.
Embedded computers are very common and are typically required to operate continuously
without being reset or rebooted, and once employed in their task the software usually cannot be
modified.
An automobile may contain a number of embedded computers; however, a washing machine and
a DVD player would contain only one. The central processing units (CPUs) used in embedded
computers are often sufficient only for the computational requirements of the specific application
and may be slower and cheaper than CPUs found in a personal computer.
Section B: Computer Hardware and Software
Computer Hardware: functional components, modern input and output units
Computer Software: Operating systems, application packages
2.1 Computer Hardware
2.1.1 Introduction
Computers are often compared to human beings since both have the ability to accept data, store,
work with it, retrieve and provide information. The main difference is that human beings have
the ability to perform all of these actions independently. Human beings also think and control
their own activities. The computer, however, requires a program (a predefined set of instructions)
to perform an assigned task. Human beings receive information in different forms, such as eyes,
ears, nose, mouth, and even sensory nerves. The brain receives or accepts this information,
works with it in some manner, and then stores in the brain for future use. If information at the
time requires immediate attention, brain directs to respond with actions. Likewise the Central
Processing Unit (CPU) is called the brain of the computer. It reads and executes program
instructions, performs calculations and makes decisions.
2.1.2 Computer system components

1. Hardware – provides basic computing resources (CPU, memory, I/O devices).
2. Operating system – controls and coordinates the use of the hardware among the various
application programs for the various users.
3. Applications programs – define the ways in which the system resources are used to solve
the computing problems of the users (compilers, database systems, video games, business
programs).
4. Users (people, machines, other computers).
2.2 Computer Hardware
A computer system is the integration of physical entities called hardware and non-physical
entities called software. The hardware components include input devices, processor, storage
devices and output devices. The software items are programs and operating aids (systems) so that
the computer can process data. The main components of a computer system are showing in
figure 1 below.
Figure 1: Main components of a computer system
2.2.1 Functional Units of a Computer System
Computer system is a tool for solving problems. The hardware should be designed to operate as
fast as possible. The software (system software) should be designed to minimize the amount of
idle computer time and yet provide flexibility by means of controlling the operations. Basically
any computer is supposed to carry out the following functions.
 Accept the data and program as input - Store the data and program and retrieve as and
when required.
 Process the data as per instructions given by the program and convert it into useful
information.
 Communicate the information as output.
Based on the functionalities of the computer, the hardware components can be classified into
four main units, namely
1) Input Unit
2) Output Unit
3) Central Processing Unit
4) Memory Unit
These units are interconnected by minute electrical wires to permit communication between
them. This allows the computer to function as a system. The block diagram is shown below.
Figure 2: Functional Units of a Computer System
Input Unit
A computer uses input devices to accept the data and program. Input devices allow
communication between the user and the computer. In modern computers keyboard, mouse, light
pen, touch screen etc, are some of the input devices.
Output Unit
Similar to input devices, output devices have an interface between the computer and the user.
These devices take machine coded output results from the processor and convert them into a
form that can be used by human beings. In modern computers, monitors (display screens) and
printers are the commonly used output devices
Central Processing Unit
Figure 3. Central Processing Unit
Central processing unit (CPU) is the brain of any computer system. It is just like the human brain
that takes all major decisions, makes all sorts of calculations and directs different parts of the
computer function by activating and controlling the operation. It consists of arithmetic and logic
units, control unit and internal memory (registers). The control unit of the CPU coordinates the
action of the entire system. Programs (software) provide the CPU, a set of instruction to follow
and perform a specific task.
Between any two components of the computer system, there is a pathway called a bus.
A bus is a group of wires on the main circuit board of the computer. It is a pathway for data
flowing between components. Most devices are connected to the bus through a controller which
coordinates the activities of the device with the bus.
Control unit controls all the hardware operations, i.e, those of input units, output units, memory
unit and the processor. The arithmetic and logic units in computers are capable of performing
addition, subtraction, division and multiplication as well as some logical operations. The
instructions and data are stored in the main memory so that the processor can directly fetch and
execute them.
Memory Unit
RAM is also known as main memory: A fast central processing unit is useless without an
adequate amount of RAM (Random Access Memory). RAM is usually referred to as a
computer's memory -- meaning it stores information that is used by running programs or
applications. More memory lets you run more applications at the same time without degrading
your system's performance.
The main memory holds data and program only temporarily. Hence there is a need for storage
devices to provide backup storage. They are called secondary storage devices or auxiliary
memory devices. Secondary storage devices can hold more storage than main memory and is
much less expensive. All modern computers use Von – Neumann concept to store program.
The essentials of the stored program concept are

I. The program and data are stored in a primary memory (main memory).
II. Once a program is in memory, the computer can execute it automatically without manual
intervention.
III. The control unit fetches and executes the instructions in sequence one by one.
IV. An instruction can modify the contents of any location in the stored program concept is
the basic operating principle for every computer.
Central Processing Unit
The CPU is the brain of the computer system. It performs arithmetic operations as well as
controls the input, output and storage units. The functions of the CPU are mainly classified into
two categories:
 Co – ordinate all computer operations

 Perform arithmetic and logical operations on data
The CPU has three major components.

1. Arithmetic and Logic Unit
2. Control Unit
3. Registers (internal memory)
The arithmetic and logic unit (ALU) is the part of CPU where actual computations take place.
It consists of circuits which perform arithmetic operations over data received from memory and
are capable of comparing two numbers.
The control unit directs and controls the activities of the computer system. It interprets the
instructions fetched from the main memory of the computer, sends the control signals to the
devices involved in the execution of the instructions.
While performing these operations the ALU takes data from the temporary storage area inside
the CPU named registers. They are high-speed memories which hold data for immediate
processing and results of the processing.
Some other parts of the computer that are inside
Hard Disk Drive: The hard disk drive (HDD) of the computer is where permanent information
is stored. Documents, databases, spreadsheets, and programs are all stored on the hard disk. The
larger the hard disk, the more you can fit on the drive. The size of the HDD does not affect the
speed at which a program can run, but the HDD speed can affect how fast you can access your
files.
Video Card: The video card is a board that plugs into the PC motherboard to give it display
capabilities. New video cards come with their own RAM and processor to help speed up the
graphics display. Many computers come with video chips built in. That makes a separate video
card unnecessary, unless the computer is going to be used for high-end multimedia work or to
play video games.
Sound Card: Like video cards, sound cards are expansion boards used for enabling a computer
to manipulate sound. Most sound cards give you the power to plug in speakers and a
microphone. Some even give you the jacks for hooking your computer up to a common stereo.
As with video cards, many computers come with sound chips, making it unnecessary to buy a
separate card, unless you need higher sound quality for your work.
Modem: The modem allows your computer to use a telephone line to communicate and connect
to the Internet.
Network Card: A network card allows your computer to be connected either to other computers
or to the Internet if you are using a fast Internet connection such as cable or dsl.
Fans: One or more fans inside the computer keep air moving and keep your computer cool.
Cables: Numerous wires and flat, ribbon-like cables provide power and communication to the
various parts inside your computer.
2.2.2 Operating System
What is an Operating System?
An Operating System (OS) is a program that acts as an intermediary between the user of a
computer and computer hardware. It provides an environment in which other programs can do
useful work. It controls execution of programs to prevent errors and improper use of the
computer. The OS manages these resources and allocates them to specific programs and users.
With the management of the OS, a programmer is rid of difficult hardware considerations.
Figure 4: System Units
Functions of an Operating System
1. Simplify the execution of user programs and make solving user problems easier.
2. Allow sharing of hardware and software resources.
3. Make application software portable and versatile.
4. Provide isolation, security and protection among user programs.
5. Improve overall system reliability, fault tolerance, reconfiguration.
Reasons for Studying Operating Systems
a) There is need to understand interaction between the hardware and applications e.g new
applications, new hardware.
b) Need to understand basic principles in the design of computer systems for efficient resource
management, security, and flexibility.
c) Increasing need for specialized operating systems e.g. embedded operating systems for
devices - cell phones, sensors and controllers. Other areas include real-time operating
systems such as vehicles, aircraft control, multimedia services.
Operating System services
a) An operating system provides services to programs and to the users of those programs. It
provided by one environment for the execution of programs.
b) The common service provided by the operating system is listed below.
i. Program execution: Operating system loads a program into memory and executes the
program. The program must be able to end its execution, either normally or abnormally.
ii. Input/output Operation: I/O means any file or any specific I/O device. Program may
require any I/O device while running. So operating system must provide the required I/O.
iii. File system manipulation: Program needs to read a file or write a file. The operating
system gives the permission to the program for operation on file.
iv. Communication: Data transfer between two processes is required for some time. The both
processes are on the one computer or on different computer but connected through computer
network. Communication may be implemented by two methods:
a. Shared memory
b. Message passing.
v. Error detection: error may occur in CPU, in I/O devices or in the memory hardware. The
operating system constantly needs to be aware of possible errors. It should take the
appropriate action to ensure correct and consistent computing.
Batch system
Batch operating system is one where programs and data are collected together in a batch before
processing starts. Some computer systems only did one thing at a time. They had a list of the
computer system may be dedicated to a single program until its completion, or they may be
dynamically reassigned among a collection of active programs in different stages of execution.
Memory is usually divided into two areas in batch system: Operating system and user program
area.
Figure 5: Memory layout of a simple Batch system
Advantages of Batch System

 Move much of the work of the operator to the computer.
 Increased performance since it was possible for job to start as soon as the previous job
finished.
Disadvantages of Batch System

 Turn around time can be large from user standpoint.
 Difficult to debug program.
 A job could corrupt the monitor, thus affecting pending jobs.
Time-sharing system
Time-sharing system or multitasking: multiple users have terminals (not computers) connected
to a main computer and execute her task in the main computer. It allows many users to share the
computer simultaneously, each user is given the impression that she has her own computer,
whereas actually one computer is being shared among many users.
Figure 6: Time-sharing system
Multiprocessor system
A multiprocessor is a computer system having two or more processing units (multiple

processors) each sharing main memory and peripheral devices, in order to simultaneously
process programs. The processors are tightly connected by a ―high-speed‖ interconnect.
Examples of multiprocessor Operating System are Solaris, Linux, and Windows 2000.
Multiprogramming system
Multiprogramming: When two or more programs are in memory at the same time, sharing the
processor is referred to the multiprogramming operating system. Multiprogramming assumes a
single processor that is being shared. It increases CPU utilization by organizing jobs so that the
CPU always has one to execute. The operating system keeps several jobs in memory at a time.
This set of jobs is a subset of the jobs kept in the job pool. The operating system picks and
begins to execute one of the jobs in the memory.
Advantages
1. High CPU utilization.
2. It appears that many programs are allotted CPU almost simultaneously.
Disadvantages
1. CPU scheduling is requires.
2. To accommodate many jobs in memory, memory management is required.
Distributed system
Distributed : Distributes computation among several physical processors. The processors do not
share memory or a clock. Instead, each processor has its own local memory. They communicate
with each other through various communication lines.
2.2.3 Application Packages
Application packages are bundle of two or more computer programs or packages designed to
enable the computer to solve a specific task. For example, the word processor package will
enable the user to type, print and store documents in their computer in a manner they appreciate
and understand.
Examples of application packages:
Word processing: for writing letters, reports and other documents. Examples: Microsoft Word,
Word Perfect. Facilities include: editing of text, font & size changing, find & replace, spell
checker, word count, mail merging (combining data from a database with text in a standard
letter to produce customised letters).
Spreadsheet modeling: for producing invoices and cost plans. It can be used to create models,
simulations or expert systems for others to use. Examples: Microsoft Excel, Microsoft Access.
Facilities include: entry of formulas to perform calculations, also ability to display data in
graphical and chart form. Acts rather like a multifunction pocket calculator, but once set up for a
particular purpose there is no need to remember all the formula and functions each time you use
it.
Graphics package: for drawing and painting. Examples: Microsoft Paintbrush, Serif Photoshop.
Facilities include: cropping, resizing, various digital filters, drawing, painting and editing tools.
Presentation software: for demonstrations and lectures to live audiences.

Examples: Microsoft PowerPoint.
Facilities provided to produce and edit on screen multimedia presentations involving text,
images, video and sound.
Music (Audio) software: for composing a musical performance.

Example: Sibelius.
Facilities provided to create, edit, store, print and play scripts; to record, process and
replay a variety of sounds via input from a music keyboard and other "midi" instruments.
Advantages of application packages

The advantages of application packages are more than the disadvantages as discussed
1. An application package meets the exact needs of the user. Since it is designed specifically
with one purpose in mind, the user knows that he has to use one specific package to
accomplish his task.
2. The threat of viruses invading custom-made applications is very small, since any business
that incorporates it can restrict access and can come up with means to protect their
network as well.
3. Licensed application software gets regular updates from the developer for security
reasons. Additionally, the developer also regularly sends personnel to correct any
problems that may arise from time to time.
4. They are efficient in terms of speed, storage and documentation.
5. They are properly documented.
Disadvantages of application packages

There are certain disadvantages of application packages. Though these are not spoken
about very often, nor are they highlighted, the fact is that they do exist and affect certain
users. But people have accepted these misgivings and still continue to use such software
because their utility and importance is much more profound than their disadvantages.
1. Developing application software designed to meet specific purposes can prove to be quite
costly for developers. This can affect their budget and their revenue flow, especially if
too much time is spent developing software that is not generally acceptable.
2. Some software that are designed specifically for a certain business, may not be
compatible with other general software. This is something that can prove to be a major
stumbling block for many corporations.
3. Developing them is something that takes a lot of time, because it needs constant
communication between the developer and the customer. This delays the entire
production process, which can prove to be harmful in some cases.
4. Application software that is used commonly by many people, and then shared online,
carries a very real threat of infection by a computer virus or other malicious programs.
5. If computer virus or other malicious programs enter your whole data then packages will
be damaged including computer.
Practice Questions
1. List four main components of a computer system.

2. Explain the following terms. Give examples of each
 Input unit
 Output unit
 Memory unit
3. What is a bus in a component of computer system?
4. Differentiate between main memory and hard disk drive (HDD).
5. What are the functions of CPU in a computer?
6. Define Operating System?
7. Explain various function of operating system?
8. Differentiate between Multitasking and Multiprogramming
9. Explain the term multiprocessor.
10. List and explain five operating system serves.
11. List five application programs and give two functions of each.
12. Give four advantages and three disadvantages of application packages.
Section C: Program Development: Algorithm, Pseudocode and
Flowchart
Objectives:
Explain the meaning of program
Mention and use programming development tools
3.1 Computer Program

A computer program, or just a program, is a sequence of instructions, written to perform a
specified task with a computer. A computer requires programs to function, typically executing
the program's instructions in a central processor. Computer programs are written by computer
programmer.
Computer programs can be classified into:

Machine Program;
Assembly language program and
High Level program.
Thus there are three levels of programming languages: Machine language, Assembly language
and High level language.
Machine language is the fundamental language of the computer’s processor, also called Low
Level Language; all programs are converted into machine language before they can be executed;
it consists of combination of 0’s and 1’s that represent high and low electrical voltage. Programs
written in machine code do not need further conversion. Assembly language is a low level
language that is similar to machine language; it uses symbolic operation code to represent the
machine operation code; it makes use of an assembler to convert the language code to machine
code.
High level language is computer (programming) languages that are easier to learn; uses English
like statements. Examples are C ++, Visual Basic, Pascal, Fortran and C# etc. Program written in
high level language need to be translated into machine readable code using either compiler or
interpreter. That is there are two ways to run programs written in a high-level language. The
most common is to compile the program; the other method is to pass the program through an
interpreter. An interpreter is a computer program that directly executes, i.e. performs,
instructions written in a programming or scripting language, without previously compiling them
into a machine language program. An interpreter generally uses one of the following strategies
for program execution:
1. parse the source code and perform its behavior directly
2. translate source code into some efficient intermediate representation and immediately
execute this.
3. explicitly execute stored precompiled code made by a compiler which is part of the
interpreter system.
An interpreter translates high-level instructions into an intermediate form, which it then executes.
In contrast, a compiler translates high-level instructions directly into machine language.
A compiler is a computer program (or set of programs) that transforms source code written in
a programming language (the source language) into another computer language (the target
language, often having a binary form known as object code). The most common reason for
converting a source code is to create an executable program. Compiled programs generally run
faster than interpreted programs.
The advantage of an interpreter, however, is that it does not need to go through the compilation
stage during which machine instructions are generated. This process can be time-consuming if
the program is long. The interpreter, on the other hand, can immediately execute high-level
programs. For this reason, interpreters are sometimes used during the development of a program,
when a programmer wants to add small sections at a time and test them quickly. In addition,
interpreters are often used in education because they allow students to program interactively.
Both interpreters and compilers are available for most high-level languages.
However, BASIC and LISP are especially designed to be executed by an interpreter. In
addition, page description languages, such as PostScript, use an interpreter. Every
PostScript printer, for example, has a built-in interpreter that executes PostScript instructions.
3.2 Program Development Steps/Stages

Step 1: Understand the Problem
 What is the input?
 What is the output?
 What is the relationship between the input and output? What formulas or techniques do
we need?
Step 2: Do a small example by hand
Step 3: Write an algorithm to solve the problem: use pseudocode or flowchart
Step 4: Coding: translate the algorithm into a programming language
Step 5: Test the program. Testing may result in Compilation (parse) errors, Logic errors
Errors and the will require you to return to some step.
Step 6: Implementation of correct running program to solving the required tasks.
Note that in each of the stages above, proper documentation is required with the view of keeping
the records and details of activities in each stage. Proper documentation makes it easy for quick
understanding of the program details by people that were not involved at the initial development
of the program.
3.3 Algorithm
Before writing one piece of computer code, it is important to know what the program is supposed
to do. Hence going straight to coding can be very confusing. It is a good idea to write a program
in a simple way first to ensure that all requirements are included before writing one line of code
in any language. Thus this can be achieved using Algorithm.
Definition: An algorithm is a systematic logical approach used to solve problems in a computer.
It is a finite set of steps defining the solution of a particular problem.

To be an algorithm, a set of rules must be unambiguous and have a clear stopping point.
Algorithms can be expressed in any language, from natural languages like English or French to
programming languages like FORTRAN, C, Basic etc.
An algorithm is procedure consisting of a finite set of unambiguous rules (instructions) which

specify a finite sequence of operations that provides the solution to a problem, or to a specific
class of problems for any allowable set of input quantities (if there are inputs).
In other word, an algorithm is a step-by-step procedure to solve a given problem.
Alternatively, we can define an algorithm as a set or list of instructions for carrying out some
process step by step.
A recipe in a cookbook is an excellent example of an algorithm. The recipe includes the

requirements for the cooking or ingredients and the method of cooking them until you end up
with a nice cooked dish.
In the same way, algorithms executed by a computer can combine millions of elementary steps,
such as additions and subtractions, into a complicated mathematical calculation. Also by means
of algorithms, a computer can control a manufacturing process or coordinate the reservations of
an airline as they are received from the ticket offices all over the country. Algorithms for such
large-scale processes are, of course, very complex, but they are built up from pieces.
3.3.1 Rules for constructing an Algorithm
The following points should be kept in mind when creating algorithms:

a. Input: These are data to be supplied for processing.
b. Output: At least one result is to be produced.
c. Definiteness: Each step must be clear and unambiguous.
d. Finiteness: If the steps of an algorithm are traced, then for all cases, the algorithm must
terminate after a finite number of steps.
e. Effectiveness: Each step must be sufficiently basic that a person using only paper and
pencil can in principle carry it out. In addition, not only that each step is definite, it must
also be feasible.
f. Comment Session: Comment is additional info of program for easy modification. In
algorithm comment would be appear between two square bracket
3.3.2 Tools to Represent Algorithm
There are two commonly used tools to help to represent algorithm (or document program logic).
These are: Pseudocode and Flowcharts.
3.4 Pseudocode
Pseudocode is a simple way of writing programming code in English. Pseudocode is not an
actual programming language. It uses short phrases to write code for programs before you
actually create it in a specific language. Once the objective of a program is known and how it
functions, then pseudocode can be used to create statements to achieve the required results for
the program.
Pseudocode is a detailed yet readable description of what a computer program or algorithm must
do, expressed in a formally-styled natural language rather than in a programming language.
Pseudocode is sometimes used as a detailed step in the process of developing a program. It
allows designers or lead programmers to express the design in great detail and provides
programmers a detailed template for the next step of writing code in a
specific programming language.
Because pseudocode is detailed yet readable, it can be inspected by the team of designers and
programmers as a way to ensure that actual programming is likely to match design
specifications. Catching errors at the pseudocode stage is less costly than catching them later in
the development process. Once the pseudocode is accepted, it is rewritten using the vocabulary
and syntax of a programming language. Pseudocode is sometimes used in conjunction with
computer-aided software engineering-based methodologies.
Examples of pseudocode
Example 1: Write the pseudocode to calculate the sum and average of two numbers.
Solution
[pseudocode for calculate sum and average of two numbers]

Step1 : Start
Step2 : Read two numbers n,m
Step3 : Calculate sum=n+m
Step4 : Calculate avg=sum/2
Step5 : Print sum,avg
Step5 : Stop
[End of pseudocode for calculate sum and average of two numbers]
Example 2: Write the pseudocode to compute the area of a triangle given the base and the
height of the triangle. (Hint: Area = ½ * base * height)
Solution
[pseudocode for calculate area of a triangle]
Step1 : Start
Step2 : Read two numbers base, height
Step3 : Calculate area = ½ * base * height
Step4 : Print area, base , height
Step5 : Stop
[End of pseudocode for calculate sum and average of two numbers]
Example 3. Write the psuedocode to find out number is odd or even?
Solution
[psuedocode to find out if a number is odd or even]

step 1 : start
step 2 : input number
step 3 : rem=number mod 2
step 4 : if rem=0 then
print "number even"
else
print "number odd"
endif
step 5 : stop
[End of pseudocode to find out number is odd or even]
Example 4: Sola AD Ltd is into plastic production and the required working hours is between
8.00am to 4.00pm daily. An employee can choose to work extra hours for a
minimum of 3 hours and maximum of 5 hours on daily basis in addition to the
regular daily working hours. On regular working hour, employee wage per hour is
N500.00. On extra hour hours worked, wage per extra hour worked is N50.00.
The company is opened for work only from Monday to Friday every week. Write
the pseudocode that will accept employee ID number, employee name, daily
working hours of employee and help the company to compute the daily wage
received by employee
Solution
[psuedocode to compute employee daily wage]

Step 1: Start
Step 2: Read the employee ID Number, employee name, employee daily working hour
Step 3: Test if employee daily working hour exceed 8 hours and calculate the extra hour
worked and compute the employee daily wage.
If employee daily working hour > 8 hours then
Employee extra hour = employee daily working hour – 8
Employee daily wage = 8 * 500.00 + (employee extra hour * 50.00)
Otherwise
Employee daily wage = employee daily working hour * 8
End If
Step 5: Output the employee ID number, employee name, employee daily wage
Step 6: Stop
[End of pseudocode to compute employee daily wage]
Example 5 Write the pseudocode that will accept continuous assessment (CA) mark scored
by student, examination mark scored by student. CA is a maximum of 30% while
examination mark is a maximum of 70%. There are instances where the total
marks of CA done by lecturer may be above 30% and also the total marks of
examination set be lecturer may be above 70%. The pseudocode should scale
down the student’s CA and examination mark to 30% and 70% respectively if it
happens that the CA and examination marks exceed the 30% and 70%
respectively. The sum of the CA and the examination mark is computed. The
pseudocode should display whether a student is successful or not. A student is
successful if the overall mark (i.e. sum of CA and Examination mark) is greater
than or equal to 45%.
Solution
[psuedocode to compute student performance]

Step 1: Start
Step 2: Input values for Total_CA_Score_by_lecturer,
Total_Exam_score_from_lecturer, CA_scored_by_student,
Exam_Mark_scored_by_student,
Step 3: [Test if both CA and Exam_Mark exceed their respective maximum and
scale down where needed]
If CA_scored_by_student > 30 then

CA_scored_by_student = (CA_scored_by_student /
Total_CA_Score_by_lecturer) * 30
End if
If Exam_Mark_scored_by_student > 70 then

Exam_Mark_scored_by_student = (Exam_Mark_scored_by_student /
Total_Exam_score_from_lecturer) * 70
End if
Step 4: [Compute student overall mark]
Student_overall_mark = CA_scored_by_student +
Exam_Mark_scored_by_student
Step 5: [Test to determine if a student is successful or not]
If Student_overall_mark > = 45 then
Output ―The student is successful‖
Else
Output ―The student is not successful‖
End if
Step 6: Stop
[End of pseudocode to determine student performance]
3.5 Flowchart
(Dictionary definition): Flowchart is a schematic representation of a sequence of operations, as in
a manufacturing process or computer program.
Technically, a flowchart is a graphical representation of the sequence of operations in an

information system or program is called a flowchart. Information system flowcharts show how
data flows from source documents through the computer to final distribution to users. Program
flowcharts show the sequence of instructions in a single program or subroutine. Different
symbols are used to draw each type of flowchart.
Flowcharting is a tool developed in the computer industry, for showing the steps involved in a
process. A flowchart is a diagram made up of boxes, diamonds and other shapes, connected by
arrows - each shape represents a step in the process, and the arrows show the order in which they
occur. Flowcharting combines symbols and flow lines, to show figuratively the operation of an
algorithm.
Computer program flowcharts are used to show control flow in a computer program. It is
sometimes used to show an algorithm without writing the code. Sometimes they are used
for training purposes for beginner programmers who don't know programming codes but can
understand graphical symbols in flowcharts.
A flowchart is a logic diagram to describe each step that the program must perform to arrive at
the solution. A popular logic tool used for showing an algorithm in graphics form.
A Flowchart
a. shows logic of an algorithm
b. emphasizes individual steps and their interconnections
c. control flow from one action to the next
Sometimes flowcharts are partitioned into 4 groups:

a. Document flowcharts: showing controls over a document-flow through a system.
b. Data flowcharts: showing controls over a data flows in a system.
c. System flowcharts: showing controls at a physical or resource level.
d. Program flowchart: showing the controls in a program within a system.
Flowchart symbols:
Example 1: Draw the flowchart and write the pseudocode to determine a student’s final grade
and indicate whether it is passing or failing. The final grade is calculated as the
average of four marks.
Step 1 Start
Step 2: Input M1,M2,M3,M4
Step 3: GRADE 
(M1+M2+M3+M4)/4
Step 4: if (GRADE <50) then
Print “FAIL”
else
Print “PASS”
Endif
Step 5: Stop
Example 2: Draw the flowchart and write the pseudocode to convert the length in feet to
centimeter
Step 1: Start
Step 2: Read Lft
Step 3: Lcm = Lft *30.48
Step 4: Print Lcm
Step 5: Stop
Example 3: Draw the flowchart and write the pseudocode that will read the two sides of a
rectangle and calculate its area.
Pseudocode Flowchart
Step 1: Start
Step 2: Read Length, Breadth
Step 3: [Compute Area]
Area = Length * Breadth
Step 4: Print Area
Step 5: Stop
Example 4: Draw the flowchart and write the pseudocode that reads two values, determines
the larger value and prints the larger and smaller value with an identifying
message.
Pseudocode Flowchart
Step 1: Start
Step 2: Input A, B
Step 3: if (A< B) then
MAX  B
SMALL  A
else
MAX  A
SMALL  B
endif
Step 4: Print “The largest value is”, MAX, SMALL
Step 5: Stop
Example 5: Draw the flowchart and write the pseudocode that reads three numbers and prints
the value of the largest number.
Pseudocode
Step 1: Start
Step 2: Input N1, N2, N3
Step 3: if (N1>N2) then
if (N1>N3) then
MAX  N1 [N1>N2, N1>N3]
else
MAX  N3 [N3>N1>N2]
endif
else if (N2>N3) then
MAX  N2 [N2>N1, N2>N3]
else
MAX  N3 [N3>N2>N1]
endif
endif
Step 4: Print “The largest number is”, MAX
Step 5: Stop
Section D: Applications of Computing
 Computer application areas and technological trends
 Using personal computers as effective problem solving tools for the present and the
future
4.0 Application areas of Computer Science

The applications of computers have been widely accepted and deployed in almost every human
endeavours. It is a known requirement for today’s professionals to know about computers in
other to enhance their on-the-job performance effectively in this information age. The purpose of
this section is to:
 introduce the computer applications in various areas
 present the effects of computers on society
4.1.1 Computers in Scientific Applications

Computers are used extensively in science. For example, meteorologists use computers to study
the formation of tornadoes. Computers can also be used to simulate automobile accidents on
screen. In this unit, we will introduce the use of computers in modeling and simulation, and
weather forecasting.
1. Modeling
Computer modeling is the use of computers to create abstract models of real life objects,
organisms, situations, or systems. A computer model is not static, you can feed data in
and examine how it behaves under certain conditions. E.g. A financial manager can
create a spreadsheet to project the profit and loss of his company.
2. Simulation of experiments
A computer simulation refers to the use of computers to execute a model. It is represented
by a computer program that gives information about the object, situation or system being
examined.
Advantages of computer modeling and simulation:

 It is much cheaper to use a simulator to train pilots rather than using the real planes
or ships.
 Some demonstrations or experiments are too dangerous to be conducted. A
simulation is an alternative.
 Computer simulations can serve as a time machine for exploring the future. For
example, it could take the biologists many years to study whether the rising tiger
population in a forest threatens other animals. A computer model of the forest would
speed up the biological processes, and the biologists can study their effects over
several generations in a few minutes.
 In many cases, the experiments are required to repeat with different conditions.
Replication on a computer model is simple and requires just a matter of changing
some input data and running a new simulation.
 In some experiment simulations, users can control the speed of the simulated motion
or process. This facilitates users to see and understand the relationships.
3. Weather forecasting
Several government agencies collect a lot of weather data from satellites, weather
balloons, airplanes in flight, ground weather stations and overseas reports on a per minute
basis every day. It is however, practically cumbersome or impossible for the scientists to
process and analyze them manually. Hence, high-speed computers play a significant role
in gathering and analyzing these data.
In order to provide more timely and reliable weather forecasts, the Hong Kong
Observatory has acquired a CRAY supercomputer. This supercomputer takes less than
one hour to produce a 24-hour forecast using a 20 km by 20 km grid high-resolution
numerical weather prediction model. Note that the old computer takes more than 5
months to perform the same calculation.
The computers also support scientists to develop new weather models for improving the
quality of weather forecast.
4.1.2 Computers in Medicine
4.1.3 Computers in Industrial Applications

Although drafting tables and T-squares are still around, more and more engineers and architects
are designing products with computers. In this unit, we will introduce the use of computers in
design, manufacturing and transportation.
1. Computer-Aided Design (CAD)

Computer-aided design is a term that refers to the use of computers and graphics-oriented
software to aid in the design process. CAD systems allow engineers to create two-
dimensional or three-dimensional electronic objects. They also enable the designers to
view the objects from different perspectives.
What are the advantages of a CAD system?

 It allows a designer to modify the design more easily than traditional manual drafting.
 It allows a designer to view the object from different perspectives. Hence, the
designer does not need to produce a different drawing for each view.
 It allows a designer to change the size of the object.
 It reduces the design time.
2. Computer-Aided Manufacturing (CAM)

Computer-aided manufacturing is a term that refers to the use of computers to control
equipment drilling, welding and milling in the manufacturing process.
What are the advantages of CAM?

 The computer-controlled robot can perform tasks with precision and it is more
accurate than a human.
 The computer-controlled equipment can perform dangerous and repetitive tasks for
humans.
 The computer-controlled equipment reduces production costs because it does not
require any annual leave, sick leave and other fringe benefits.
3. Transportation systems
Traffic lights control:- In order to optimise a traffic flow, a computer system can
be used to coordinate the signal timings of the adjacent traffic lights in a district. The
system can monitor the traffic flows in real time by collecting traffic flow data from
different traffic sensors placed at various locations. . Based on the current traffic flow
situation, the system will send signal control instructions to the traffic lights to adjust
their signal timings in order to minimise delays and reduce stopping time.
To flag the possible incidents on the road network, the system can also compare the
current traffic flow profiles with a typical one. If there are significant differences, the
system will give warning signals.
Bus/Train/Airline scheduling:- it is practically impossible to produce an optimised

transportation timetable manually due to the complexity in manipulating vehicular, train
and aircraft movements. Hence, a computer is used with a timetabling algorithm to
generate a travel schedule to dispatch and reverse buses, trains and aircrafts based upon
the required headway (time between two successive trips) at different periods in time.
4.1.4 Computers in Education

The capability of interacting with learners makes computers as powerful tools for enhancing the
process of learning. In addition, computers also play an important role in searching information
and school administration. Computers are used in the educational sector as learning and teaching
tools, and as administrative tools.
1. Computer Assisted Learning (CAL)

Computer assisted learning is a term which refers to the use of computers in assisting
learning. For example, a teacher may use a graph plotting software to demonstrate the
behaviour of different functions in a mathematics lesson; a student may use a drill-and-
practice program to practice what he/she has just learnt from a lesson or use a tutorial
program to enhance a skill or a subject.
What are the advantages of CAL?

 The multimedia contents, such as special sound effects, animation and video can
arouse students' interest in learning.
 Tedious practices in arithmetic and spelling can be turned into entertaining games.
This makes learning more exciting and interesting.
 Some CAL softwares include testing and diagnostic features which allow teachers to
identify common misconceptions of their students.
 CAL can provide immediate feedback to students.
 The automatic grading of exercises feature frees up teachers' resources that can be
used for additional attention toward students.
 Students can learn at their own pace. This alleviates the pressure on the slow learners
so that they can keep up with their peers.
 Students are free to make wrong answers because there is no peer group pressure.
This encourages them to learn by trials and errors.
 Multimedia contents can help make difficult or abstract concepts simple.
2. Information searching
The World Wide Web is a system of interlinked hypermedia documents that enables
users to find and retrieve information by navigating. A hypermedia document is a
document that contains text, graphics, sounds, video and animation.
 How does a search engine work?
Most search engines keep a huge index of the Web pages on the World Wide Web.
This index is maintained by software agents, sometimes called spiders or software
robots. They automatically search for new information on the Web and update the
index. When the search engine receives a search request, it compares the input
keywords to the entries in the index, and returns the results.
 Searching information on a CD-ROM

Dictionaries, encyclopedias, maps and other specialized references are now available
in CD-ROMs. Many of them also include multimedia capabilities.
 What are the advantages of the above-mentioned searching of information?

o The World Wide Web is a tremendous information resource. It is your on-line
library and information centre. With the access to this rich resource, you can
work faster and smarter.
o The use of graphics, sound, animation, and video can better explain certain
topics or concepts than just using words.
3. Cyber schools (e-learning)

A cyber school is a school that uses the Internet as a delivery tool to offer courses. The
hyperlinked multimedia course materials and video lectures are made available on the
Web. By utilizing video-conference, tutors can talk to students in various locations and
answer their questions in real time. Students can also exchange ideas through interactive
discussion groups.
What are the advantages of cyber schools?

 Students can attend classes anytime, anywhere, and anyplace.
 Handicapped students can attend classes without commuting.
 The tuition fee of cyber schools is usually lower than that of the traditional schools.
4. Administrative tools
There quite a number of School Administration and Management Software System which
have been implemented to provide administration and management supports for schools.
These educational administration software aims to provide a computerized network
system to schools for supporting the administrative and management processes, and for
transmitting electronically information between schools and the Education and
Manpower Bureau.
Some of the major functions of the educational administration software include the
followings:
 School management
- To maintain school information.
- To collate data for the preparation of statistical reports and forms.
 Students' records and attendances

- To maintain students' personal, performance and extra-curricular information.
- To transmit students' information to the Education and Manpower Bureau through
an electronic data exchange system.
- To keep records of students' attendances.
 Students' assessments
- To print students' assessment reports.
- To support the operation of the allocation systems with assessment data.
 Staff records and deployments

- To maintain teachers' and staffs' personal and duty information.
 Staff deployments
- To keep records of staffs' absences.
- To automate the process of deploying substitute teachers.
- To transmit the vacation leave applications and substitute teachers appointment
applications to the Education and Manpower Bureau through an electronic data
exchange system.
 Timetabling
- To schedule timetables which show lesson arrangements for classes, teachers and
venues respectively.
4.1.5. Computers in Office Applications

The advance of computer technology supports a range of improved office activities. Here we
introduced the applications of computers in various general office works.
1. Office automation (OA)

Office automation is the use of hardware, software and networks to enhance general
office works such as communication among employees, and documents typing and filing.
2. Software in OA
Word processing software
Suppose your school wants to send a personalized letter to invite all the parents to attend
a meeting. The contents of each letter are the same except for the names and addresses of
the parents. Since typing individual letters to so many parents is a time-consuming task,
with the help of the mail merge function of a word processing software, you can generate
these personalized letters in a short time.
 Spreadsheet software
Suppose you want to know the effects of the change of import levy on the balance
(surplus or deficit) of the budget. With the spreadsheet software, you only have to enter
the new fee and the software will do the recalculation automatically. Without this
software, you may have to spend a lot of time recalculating all the data to get to your new
budget balance.
 Database management software
Suppose a teacher wants to find out how many students are living in Igbo Elerin. She
enters the query into the computer and the database management software will give her
the results instantly. Without this database management software, she will have to search
the student records from the student files manually.
 Presentation software
Suppose you have to make a project presentation. With the presentation software, you
can create all the slides easily with the layout provided by the software. You can also
enhance your slides by applying special effects to the slide contents and the transitions
between each slide. However, it is difficult to produce these effects manually.
 Electronic mail (e-mail)
Suppose the principal wants to hold an urgent meeting after school. He/She can inform
every teacher by just sending one e-mail and the e-mail will be received almost instantly.
Without an e-mail facility, he/she may have to circulate a memo among the teachers or
post a notice on the notice board of each staff room.
4.1.6 Computers in Business Applications

Computers are widely used in business nowadays. In this subsection, we will introduce their uses
in banking, supermarkets and transaction payments.
1. Automatic Teller Machine (ATM)

An ATM is a terminal specially designed for self-service banking. A typical ATM has the
following input and output devices.
Input devices:
 A card reader: to capture the account information stored on the magnetic strips of the
users' plastic cards.
 A keypad: to allow the users to enter transaction information.
Output devices:
 A monitor: to display information and instructions to users.
 A printer: to print transaction receipts.
 A cash dispenser: to deliver bank notes to users.
Services available on an ATM include
 Cash withdrawal
 Money transfer from one account to another
 Bills payment
 Checking of account balances
- request cheque books and bank statements
- change personal identification number
Design Framework for a typical transaction on an ATM

The following steps illustrate how an ATM works when a customer is withdrawing cash
from it:
1. The customer inserts his/her plastic card into the card reader in the ATM.
2. The account information such as account number stored on the magnetic strip on the
back of the plastic card is captured by the card reader.
3. The ATM will ask for a personal identification number (PIN).
4. Both the account information and the PIN are sent to the bank computer through the
telephone network.
5. The bank computer verifies if the PIN is correct.
6. If the account number and PIN are valid, the customer can proceed with the
transaction, otherwise, he/she has to re-enter the PIN.
7. The ATM requests the customer to select a type of transaction.
8. The customer selects the withdrawal transaction type and enters the amount to be
withdrawn.
9. This information is sent to the bank computer.
10. The bank computer checks if the customer has sufficient balance for withdrawal. If
yes, it authorises the ATM to dispense cash.
11. The ATM has a device to count each bank note as it exits the dispenser. The bank
note count and all the information relating to the transaction are recorded in a journal.
This journal will be referred to whenever the customer has a dispute about the
transaction.
12. In addition to the bank note counting device, the ATM has a sensor to measure the
thickness of each bank note. If two or more bank notes are stuck together, they will be
diverted to a reject bin instead of being dispensed to the customer.
Advantages of an ATM
 It provides routine banking services 24 hours a day, 7 days a week.
 It helps banks save human resources, hence reducing their labour cost.
2. Internet banking
The following services can be accessed via the Internet banking platform of commercial
banks:
 Fund transfer from one account to another.
 pay bills now or schedule future payments.
 check account balances and transaction history.
 access previous account statements.
 request cheque books.
 initiate stop payment requests.
 change personal identification number.
 trade stocks, view major indices and get stock quotes.
 view currency exchange and interest rates.
 place fixed-time deposits and change maturity instructions.
 apply for credit cards and various types of loans.
 enroll in insurance plans.
Equipment/Tools required to use Internet Banking services:

 a computer installed with communication device such as a modem.
 a reliable connection to the Internet through an Internet Service Provider.
 a secure browser to send and receive information over the Internet.
 a token
Operational Framework for Internet Banking

The following steps illustrate the operations of Internet banking:
 The customer connects his/her computer to the Internet.
 The customer accesses the homepage for the Internet banking services by typing the
bank's URL.
 The customer enters his/her user ID and PIN.
 This information will be encrypted (i.e. coded) and transferred to the bank computer
through the Internet.
 When the bank computer receives this encrypted information, it will decrypt (i.e.
decode) it. All the information transferred between the customer computer and the
bank computer are encrypted. The sender encrypts the information while the receiver
decrypts it. This process is required in order to ensure no third party can reveal and
use the information.
 The bank computer will check if both the user ID and PIN are valid.
 If so, the customer can proceed with the transaction, otherwise he/she is asked to re-
enter the information again.
Advantages of Internet Banking

 It provides an access to a variety of banking services 24 hours a day, 7 days a week.
 The customers can manage their finances anytime, anywhere without visiting the
bank in person.
 It helps to save the bank's human resources, hence reducing the operation cost.
3. Supermarket checkout counter

The checkout process in a supermarket involve the use of an Universal Product Code,
Barcode Scanner and a Point of Sale terminal.
The Universal Product Code (UPC) is a system for uniquely identifying different
products. Each product has its own unique code number on its label represented by a
pattern of light and dark bars.
The Point of Sale (POS) terminal is a special-function elctornic device used to process
card payments at retail outlets. In retail outlets, it is a combination of an electronic cash
register, a bar code scanner or reader and software, a A POS terminal generally does the
following:
 Reads the information off a customers credit or debit card

 Checks whether the funds in a customer’s bank account are sufficient
 Transfer the funds from the customer’s account to the seller;s account for the transfer
withcredit/debit card network
 Records the transaction and prints a receipt
An Electronic Cash Register (ECR) is an electronic system for registering, calculating

and storing sales transactions, and is usually attached to a printer that can print out
receipts for record keeping purposes. ECR help large retail outlets to track sales,
minimize register errors, collect and collate inventory data, and much more. It typically
processed goods by
 Reading the information contained on a UPC using a barcode scanner or reader

 Checking the price database for the price mathing the information in the UPC
 Adding that price to the running total of all products being purchased by a customer
 Sending data to sales and inventory software after the sales transaction is completed
 The sales system is incomplete without other software that turn ECR data into
operational signals.
A bar code scanner or reader (also called a price scanner or point-of-sale ( POS )
scanner), is a hand-held or stationary input device used to capture and read information
contained in a bar code .
A barcode reader consists of a scanner , a decoder (either built-in or external), and a cableused to
connect the reader with a computer. Because a barcode reader merely captures and translates the
barcode into numbers and/or letters, the data must be sent to a computer so that a software
application can make sense of the data.
Barcode scanners can be connected to a computer through a serial port , keyboard port , or an
interface device called a wedge . A barcode reader works by directing a beam of light across
the bar codeand measuring the amount of light that is reflected back. (The dark bars on a barcode
reflect less light than the white spaces between them.) The scanner converts the light energy into
electrical energy, which is then converted into data by the decoder and forwarded to a computer.
There are five basic kinds of barcode readers -- pen wands, slot scanners, Charge-Couple Device
( CCD ) scanners, image scanners, and laser scanners.
 A pen wand is the simplest barcode reader. It contains no moving parts and is known for its
durability and low cost. A pen wand can present a challenge to the user, however, because it
has to remain in direct contact with the bar code, must be held at a certain angle, and has to
be moved over the bar code at a certain speed.
 A slot scanner remains stationary and the item with the bar code on it is pulled by hand
through the slot. Slot scanners are typically used to scan bar codes on identification cards.
 A CCD scanner has a better read-range than the pen wand and is often used in retail sales.
Typically, a CCD scanner has a "gun" type interface and has to be held no more than one
inch from the bar code. Each time the bar code is scanned, several readings are taken to
reduce the possibility of errors. A disadvantage of the CCD scanner is that it cannot read a
bar code that is wider than its input face.
 An image scanner, also called a camera reader, uses a small video camera to capture an
image of the bar code and then uses sophisticated digital image processing techniques to
decode the bar code. It can read a bar code from about 3 to 9 inches away and generally costs
less than a laser scanner.
 A laser scanner, either hand-held or stationary, does not have to be close to the bar code in
order to do its job. It uses a system of mirrors and lenses to allow the scanner to read the bar
code regardless of orientation, and can easily read a bar code up to 24 inches away. To
reduce the possibility of errors, a laser scanning may perform up to 500 scans per second.
Specialized long-range laser scanners are capable of reading a bar code up to 30 feet away.
Advantages of a computerised checkout system

 Prices retrieved by the computer from the file are more accurate than being retrieved
by typing manually.
 It is easier to change prices because only updating the computer file is needed.
Without the system, repeatedly restamping the price on each piece of the product is
required.
 Checkout is faster.
 The labour cost is reduced.
 The computer can keep track of the quantity of each product left on the shelves and in
the warehouse inventory; it can inform the manager when restocking and reordering
are necessary.
 The raw sales data collected by the computer can be analysed to discover customer
preferences and purchasing habits.
4. Smart cards
A smart card looks like a credit card in size and shape, but instead of a magnetic strip it
contains an embedded microprocessor and memory. One popular use of smart cards is its
stored value. Each time you use the card, the available of amount of currency (e.g Naira)
is reduced.
Other applications of smart cards:

 Smart cards can be used to store personal data and medical information. In case of an
emergency, the cardholder can be identified rapidly and doctors or hospitals can then
provide improved treatments.
 Smart cards can be used as keys to log on to an online bank.
 Smart cards can be used as identity cards for students and employees. Since the
identity with access privileges are stored on them, the cardholders can be granted
access to certain departments/offices, facilities, equipment and data according to their
status.
 They can also be used to track information such as business transactions or employee
attendance.
What are the advantages of a smart card?

 It improves the convenience and security of any transaction.
 It provides reliable and fast payment.
 It eliminates the service provider's need to handle heavy coins. For example, the
weight of the coins (bus fares) collected by KMB every day is reduced from 55 tons
to 25 tons with Octopus in operation. This also reduces the operation cost.
 It provides a convenient way to carry data between systems.
4.1.7 Computers in Government and Democratic Studies
4.1.8 Computers in Mass Communications
Broadcasting, Journalism, Advertisement, Public Relations, Social Media
4.1.9 Computers in Legal and Jurispudence
4.1.10. Computers in Sports and Recreation

Sports and recreation are another areas area of computer application. You can play electronic
golf at home. You can play chess with the computer as your opponent. Some software combine
entertainment and education. In this unit, we will describe different types of computer games and
explain why they have 'intelligence', edutainment and special movie effects produced by
computers.
1. Computer games
Types of computer games:
 Adventure games
In adventure games, the players become characters in situations they know only a little
about. The characters will then encounter different phases of the adventure, and only
successful problem solvings with the given resources and information will move them
one step ahead to accomplish the required mission.
 Arcade games
Arcade games are similar to games such as pinball and darts found in an amusement
arcade.
 Strategy games
Strategy games require the players to use strategies to win. They are often implemented
as board games such as chess and backgammon.
 Simulation games
Simulation games allow players to explore artificial environments, imaginary or based on
the real world. The players can experience the consequences of their actions.
 Role-play games
Role-play games assume the player the guise of a character and acts out that role.
 Psychomotor games
Psychomotor games require intellectual and motor skills. Joysticks or game paddles are
often used for input. For example, space games and computer-simulated sports games.
 Combat games
Combat games require players pitting against each other until there is a clear winner.
2. Edutainment
Edutainment comes from two words: EDUcation and EnterTAINMENT. It means the
combination of education with entertainment. Most of the edutainment software use
multimedia elements to entertain users while they learn.
General guidelines for selecting educational software:
 Aims and objectives:- Does the software meet its stated aims and objectives?
Does the software meet your instructional aims?
 Subject content:- Is the content appropriate to the curriculum?

Is the content accurate? Is the content free of spelling, grammar and punctuation errors?
Is the content free of racial and gender discrimination and other bias?
Is the content free of violence?
 Presentation:- Is the presentation interesting? Is the sequence of presentation

appropriate?
Does the presentation encourage a high degree of learner involvement?
 Surface features:- Is the use of colours effective? Is the use of graphics and/or
animations effective?Is the use of sound effective? Is the text easily readable on the
screen?
 Feedback:- Does the software present effective feedback for correct responses?
Does the software present effective feedback for incorrect responses?
Does the software provide learners with a summary of performance?
 Language:- Is the readability of text appropriate for intended learners?

Are the technical terms and jargon relevant?
 Ease of use:- Is minimum computer skills needed to use the software? Is the user
interface easy to use? Are potential errors trapped?
Does the software provide helpful messages to correct learner errors?
 Student control:- Can the learners control the rate of presentation? Can the learners
control the sequence of learning? Can the learners control the time allowed for
responding? Can the learners control the level of difficulty?
Can the learners temporarily suspend the learning and resume it from the point of
suspension? Can the learners review previous information?
 Documentation:- Are the user manual and installation guide included? Are the
instructions clear and easy to understand? Are the aims and objectives clearly stated?
Are the intended learners clearly stated? Are suggested ways to use included?
Are other resource materials included?
4.2 Effects of Computers on Society

Even if you never touch a computer, computer technology still has an impact on your life. For
example, your student record is kept on a computer, your bank statement is printed by a
computer, the special effects in movies and TV commercials are produced by computers, and so
on.
4.2.1 Information privacy

Information privacy refers to one's right to restrict or deny the collection and use of one's
personal information.
Examples of ways personal information are collected through the Internet
Many web sites send cookies ( a small file that allows a web site to record users'
data) to the user browsers to collect personal information such as users' interests,
preferences, and surfing patterns on the web sites.
In order to establish an e-mail account or become a member of a web site, you
have to do a registration. In the registration process, you need to complete a
questionnaire from which your personal information such as name, postal and e-
mail addresses, telephone number and so on are gathered by the web site.
The misuse of personal information
New technology sometimes is not accepted by everybody. One may refuse to use e-mail
or a credit card. The most common reason cited for this attitude is the fear of one's
personal information being misused. Here are some examples of misuse of personal
information:
 A magazine publisher may sell subscriber lists to direct marketers, fund-raisers, and
others.
 An employee of a telephone company may be bribed by a loan collection company to
provide addresses and telephone numbers of loan borrowers by performing computer
searches.
 A company may send employees to the Registrar of Marriages offices to gather
publicly accessible information about people who will marry in the next few weeks.
Then, this information is sold to restaurants, bridal photography salons, travel
agencies, real-estate agencies and so on so that they can market their business.
Guidelines for the collection and dissemination of personal information

 Individuals must be made aware of the organisation's policy on privacy information prior
to the collection of their personal information.
 Individuals must be made aware of their choices as to how their personal information
may be used. For example, individuals may have the option of not receiving any direct-
mail advertisements.
 Information collected should be limited to what is required to fullfill the original stated
purpose.
 There is a method of enforcement restricting the access to the information to those staffs
who need it to perform their duties.
 Individuals must be assured that the information is accurate and secure.
 Individuals must have the opportunity to access their personal information and determine
the accuracy of the data.
4.2.2. Computer crimes
i. Theft by computers:- Computers are being used to steal money, information, goods
and computer services. Here are two examples:
 A programmer in a bank modified a program to bypass the checking of the

overdraft limit on his account. He then drew money from his account without a
limit being imposed.
 A student stole her teacher's computer account password by spying. She then
made a copy of the examination questions file from her teacher's computer
account.
ii. Computer viruses:- A computer virus is a piece of software written with a

malicious intent to cause the computer to be infected and change its behaviour
unexpectedly without the user's permission. Viruses are often designed to spread to
other computers automatically. They can be transmitted by downloading infected
game programs or files from other sites, sending them as e-mail attachments, or
being present on a diskette.
Some viruses are activated as soon as the infected programs or files are used; other
viruses lie dormant until certain conditions, such as a specific date or time, cause
their code to be executed. Some viruses do nothing, displaying some unexpected
messages on the screen, but some do destroy data on a disk or reformat a hard disk.
Since many data are stored on computers today, loss of them by virus attacks will
cost work time and financial loss.
4.2.3 Intellectual property

In order to combat intellectual property copyright infringements, the Intellectual Property
(Miscellaneous Amendments) Ordinance 2000 was enacted by the Legislative Council in
June 2000. The amended law came into operation on April 1, 2001.
a. Software acquisition:- Software licence: when a buyer is purchasing a software,

he/she is not actually purchasing the software, but the licence to use the software
on a computer. The licencing agreement specifies how the software should be
used. For example, the number of copies users are allowed to make.
 Site licence: it is an agreement that grants the buyer of the software the right
to use that software on a given number of computers. The price is less than
that of buying a separate copy for each computer.
 Network version: it permits the buyer to purchase just one copy of the
software (in network version) that can legally load into his/her network server.
 Shareware: it is a software distributed free for a trial period. If the user wants
to use it regularly, he/she should pay for it on a honour system.
 Freeware: it is a software that is provided to users at no cost, but it is still
copyrighted. It means resale of it is not allowed.
b. Public-domain software:- it is a freeware with no copyright restrictions.
Here are two examples of committing a criminal offence after the amended law t akes
effect:
 An IT training instructor buys one copy of a software which is licenced for use in one
computer only. But he installs this software in all the computers in the computer
laboratory.
 An IT manager of a trading company buys one copy of an accounting software which
is licenced for use in one computer only. But he asks his subordinate to install it in a
LAN server for shared use by all the employees in the accounting department.
4.2.4 Ethical issues:- Ethics deals with what is considered right or wrong. In theory,
one can distinguish between illegal acts and unethical acts. An illegal act breaks the law, but an
unethical act may not break the law. In many cases, illegal acts are unethical as well.
Examples of ethical issues
 A teacher reads a student's e-mail.
 A student forwards an e-mail message to the whole class without permission from the e-
mail sender.
 Your friend, who is not studying in your school, asks you to borrow your password to get
access to your school computer system.
 The use of computers monitors the job performance of employees. For example, a
computer program is used to monitor the typing speed of typists without the knowing of
the typists.
4.2.5 Employment trends:- Computer usage can lead to displacement of some jobs
which are formerly performed by humans, but it also creates new job opportunities.
Somebody has to be employed to develop software, operate and repair computers and their
peripherals, market computers and software and so on. The followings are some of the
typical jobs generated by computers:
 Computer operators
 System analysts
 Application programmers
 System programmers
 Database administrators
 Network administrators
 Customer service engineers
 Web masters
 Computer instructors
Change of job skills

As the use of computers continues to grow in our society, jobs in every profession are being
redefined. For example, twenty years ago the use of typewriters is a necessary skill for
applying the post of secretary. Today, secretaries are required to know word processing
software, e-mail and so on.
Here are some of other professions that might require computer knowledge:
 Real-estate agents, lawyers, researchers and teachers need to use computers to search
information.
 Reporters and writers need to use word processing software to write and change
documents.
 Accountants, budget controllers, stockbrokers and insurance agents need to use
spreadsheet software to analyse data.
 Engineers and architects need to use CAD software to design products or buildings.
References (Credits)
(Computer Science) the study of computers and their application. Collins English Dictionary:
Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
comput′er sci`entist,
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright
2005, 1997, 1991 by Random House, Inc. All rights reserved.
The American Heritage® Dictionary of Student Science, Second Edition. Copyright © 2014 by
Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt
Publishing Company. All rights reserved.
Another definition from http://www.csab.org/comp_sci_profession.html
http://www2.cs.unb.ca/ Problem solving.
Property of Quinstreet Enterprise. Copyright 2015 QuinStreet Inc.

All Rights Reserved. http://quinstreetenterprise.com/about_us
Peter Denning, CACM, April 2005/Vol. 48, No. 4, pp. 27 - 31, "Is Computer Science, Science?"
Operating Systems Concepts, 4th Ed. by Silberschatz and Galvin.

http://www.cc.gatech.edu/ugrads/c/Dane.ChinLoy/pyrodude.html
Dinesh Thakur http://www.ysurfing.com/
Areas of Computer Applications (IT01) June 2002. By Hong Kong Baptist University (Department of
Computer Science) and Newise Supply Limited Education and Manpower Bureau
http://resources.edb.gov.hk/com-lit/index.htm#
TechTarge . Barcode Reader. All Rights Reserved,Copyright 1999 - 2015,.

http://whatis.techtarget.com/definition/barcode-reader-POS-scanner-bar-code-reader-price-
scanner
Barcode reader. (2015, March 21). In Wikipedia, The Free Encyclopedia. Retrieved 11:12, April
11, 2015, from http://en.wikipedia.org/w/index.php?title=Barcode_reader&oldid=652838653

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CSC 113

Computer For Arts, Social Science

CSC 113: Computer For Arts, Social Science And Management P a g e |1

Section A: Introduction to Computer Science

Generations of Computer Science

Practical Introduction to using personal computer hardware and software.

Section B: Computer Hardware and Software

Computer Software: Operating systems, application packages

Section C: Program Development: Algorithm, Pseudocode and Flowchart

Section D: Applications of Computing

CSC 113: Computer For Arts, Social Science And Management P a g e |2

1.0 Meaning of Computer Science

e. The study of computation and computer technology, hardware, and software.

CSC 113: Computer For Arts, Social Science And Management P a g e |3

1.1 Who is a Computer Scientist:

iii. Computer Science is practiced by mathematicians, scientists and engineers. Mathematics,

CSC 113: Computer For Arts, Social Science And Management P a g e |4

1.2 Major Subject Areas within Computer Science include:

CSC 113: Computer For Arts, Social Science And Management P a g e |5

i. Invention/Conceptual Modeling: formulation of new algorithmic and new architectural

1.4 History of Computer Science

 1834: Babbage/Lovelace design "Analytical Engine"

Some interesting notes for those of you keeping score:

CSC 113: Computer For Arts, Social Science And Management P a g e |7

1.5. Generations of Computers

Each of the five generations of computers is characterized by a major technological development

First Generation (1940-1956) Vacuum Tubes

CSC 113: Computer For Arts, Social Science And Management P a g e |8

Second Generation (1956-1963) Transistors

Second-generation computers moved from cryptic binary machine language to symbolic, or

Third Generation (1964-1971) Integrated Circuits

Fifth Generation (Present and Beyond) Artificial Intelligence

1.6 Definition of Computer

A computer generally means a programmable machine. The two principal characteristics

1.7 Basic Characteristics (Strenghts/Capabilities) of a Computer

The speed of computer is therefore measured in terms of microsecond (10-6 part of a

Units of Time :- Computer operations are measured in milliseconds, microseconds,

Units of time Abbreviation Fraction of a second

5. Power of Remembering: - Computer has the power of storing any amount of

 Units of computer storage

Units of storage Abbreviation Number of bytes

 How much is a MB?

ii. According to data handling, computers are analog, digital or hybrid.

Analog Digital Hybrid

Super Computers Mainframe Mini Micro

b. Mainframe Computer:- A very large and expensive computer capable of supporting

d. Micro Computer or Personal Computer

iv. According to functionality, computers are classified by function such as Servers,

b. Workstations:- A terminal or desktop computer in a network. In this context,

c. Information appliances are computers specially designed to perform a specific "user-

2.1 Computer Hardware

2.1.2 Computer system components

2.2 Computer Hardware

2.2.1 Functional Units of a Computer System

Central Processing Unit

Figure 3. Central Processing Unit

The essentials of the stored program concept are

Central Processing Unit

 Co – ordinate all computer operations

The CPU has three major components.