basics of computers

1. UNIT-I
Computer Applications in Management
Role of Computers
• Computers are now affecting every sphere of human activity and are bringing
about many changes in Industry, Government, Education, Medicine, Scientific /
Business Research, Law, Social Sciences and even in arts like music and painting,
etc.
• The areas of applications of computers are confined only by limitations on human
creativity and imagination.
• It is essential, therefore, for every educated person to know about computers, their
strengths, weaknesses, and their internal structure.
Personal Benefits of Learning about Computers
• Improved Employment Prospects: computer related skills have become
essential in many careers. Knowledge of computers will make you marketable to
prospective employers.
• Skills that span different aspects of life: You will find your computer skills
valuable regardless of the setting – at home, work, college, or play.
• Greater Self Sufficiency: Computers are tools, and you can use them in several
situations to become actually more self sufficient.
• Foundation Knowledge for Life Time Learning: By mastering the fundamental
concepts, you will develop a strong base that will support your learning for years
to come.
• Normally, we do not study computers in isolation.
• In the age of convergence of technologies, it is more appropriate to consider a
wider perspective of computers, viz., the Information Technology.
• IT is a term that encompasses all forms of technology used to create, store,
exchange, and use information in its various forms – Business data, Voice
conversations, Still images, Motion Pictures, Multimedia presentations, and other
forms, including those not yet conceived.
• It is Information Technology that is driving what has often been called “The
Information Revolution”.
Influence of IT on Business Organizations
• Modern business organizations today are facing extreme competitive pulls and
need to develop systems to cope with such pressures:
• Pressures
– Globalization of Industry
– Enlarged scope of Business

2. – Enlarged geographical spread.
– Increasing competition
– Increase in expectation of customers in terms of
• Better quality, Lower costs, newer products, more variety, quicker
deliveries.
• Growing environmental demands:
– Faster response to customer inquiries
– Reduction in turnaround time
– Faster design
– Faster communication
– Total Quality Management
– Up-to-date information with all concerned.
The Drivers of Change
Business Pressures on an Organization that force change
What is in IT for Me?
As students of Management, it is important for you to know how computers or
Information Technology is being applied in various management areas.
ACCOUNTING
• Data and Information are integral to the accounting function.
• Information Systems capture, organize, analyze and disseminate data and
information throughout modern organizations.
• Virtually no companies in the modern business world handle their accounting
without support from computers.
• Accounting IS commonly integrates with other IS so that transactional
information from a sales or marketing IS becomes input for the accounting IS.
FINANCE

3. • The modern financial world turns on speed, volume, and accuracy of information
flow, all facilitated by advanced information systems and telecommunications.
• IS can monitor world financial markets, support financial decision making, e.g.,
for portfolio Management, provide quantitative analyses, e.g. for cash flow
projections, and support a host of other financial functions.
MARKETING
• The Internet and the World Wide Web (WWW) have opened an entirely new
channel for marketing from business to business and business to consumer.
• They have also dramatically increased the amount of information available to
customers, allowing rapid and thorough product and price comparisons.
• The Internet also provides for much closer contact between the consumer and the
supplier.
• The e-commerce venue continues to grow in size and sophistication so that every
one contemplating a career in marketing must be thoroughly trained in its unique
technologies and techniques.
•
PRODUCTION / OPERATIONS
MANAGEMENT
• Every process in a product or service’s value chain can be enhanced by the use of
computer-based IS.
• In Manufacturing, these processes occur everywhere from supplier production and
logistics, through the manufacturing process, through outbound logistics, and after
the sale of the product.
• The value chains in service industries are also a series of processes that benefit
from IS support.
• IS have transformed the competitive landscape by the use of IT from CAD and
CIM, through Internet-based Order systems.
Human Resources Management
• HRM is changing radically with the use of IS.
• Record Keeping has greatly improved in terms of speed, convenience and
accuracy.
• Dissemination of HR information throughout the company via private company
intranets helps employees to handle much of their personal business (e.g.
configuring their benefits) themselves, without direct intervention of the HR
personnel.
• The Internet makes a tremendous amount of information available to the job
seeker, increasing the fluidity of the labor market.
• IS skills are becoming imperative in many careers – HR professionals must have
an understanding of these systems and skills to best support hiring, training, and
retention.
Trends & Importance of IT

4. • IT has become a major facilitator of business activities in the world today.
• It is also a catalyst of fundamental changes in the structure, operations, and
management of organizations.
• The capabilities of IT support the following business objectives:
– Improving Productivity
– Reducing Costs
– Improving Decision Making
– Enhancing Customer Relationships and improved communication within
the organization, and
– Developing new strategic applications
Impact of Convergence
• Telecommunications networks are carrying signals for data, text, video, graphics,
and voice
• Many services are becoming accessible from home – Banking, Ordering, work at
home, News, mail, On-line Education, Medical consultation, Voting.
• Cultural impact will be visible – Telecommuting, Cashless Society, Very little
town/city differences
• E-commerce is emerging a very significant global economic element in the 21st
Century
• Networked computing is emerging as the standard computing environment in
business, home, and Govt.
Definition of a Computer
“A computer is an electronic device, operating under the control of instructions stored in
its own memory unit that can accept data (input); process data arithmetically and
logically, produce information (output) from the processing done, and store the results for
future use.”
Components of Computer System
What is the difference between the computer and computer system?
Computer refers to the actual physical electronic device. Whereas the computer system
includes following:
1. Software – data contained in the hardware, similar to songs in audio cassette.
2. Live ware (user) – the computer operator
3. Hardware – any physical component which we can touch/see.
Five Generations of Computers
Introduction
 The history of computer development is often referred to in reference to the
different generations of computing devices.

5.  Each generation of computer is characterized by a major technological
development that fundamentally changed the way computers operate, resulting in
increasingly smaller, cheaper, and more powerful and more efficient and reliable
devices.
First Generation: 1940 – 1956 – Vacuum Tubes
 The first computers used vacuum tubes for circuitry, and magnetic drums for
memory.
 Were often enormous, taking up entire rooms.
 Were very expensive to operate and in addition to using great deal of electricity,
generated a lot of heat, which was often the cause of malfunctions.
 Relied on machine language to perform operations, only one problem at a time.
 Input was based on punched cards and paper tape, and output was displayed on
printouts.
 Very low memory capacities: 2KB – 10KB on magnetic drums.
 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.
Second Generation: 1956 – 1963 – Transistors
 Transistors replaced vacuum tubes and ushered in the second generation
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.
 Programming environment moved from the cryptic binary machine language to
symbolic, or assembly language, which allowed the programmers to specify
instructions in words and made their task much easier.
 High level programming languages were also being developed at this time, such
as early versions COBOL and FORTRAN.
 The memory technology moved from a magnetic drum to magnetic core
technology.
 Memory size increased to an order of tens of thousands of Kilobytes.
 The first computers of this generation were developed for the atomic energy
industry.
 Examples: IBM 1400 & 1600 series, Honeywell 400, and Burroughs 5000 series.
Third Generation Computers – 1964 – 1971: Integrated Circuits
 The development of the integrated circuit was the hallmark of the third generation
of computers.

6.  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 interacted with an operating
system, which allowed the computer systems to run many different applications
simultaneously.
 Computers became smaller, faster, more reliable and cheaper. For the first time
they became accessible to mass audiences.
 Led to massive development of computer programs and application oriented
packages.
 Increased focus on aspects of data management.
 Development of Database Management Systems (DBMS).
 IBM 360, 370 series; Univac 1100, 9000 series.
Fourth Generation: 1971 – Present Microprocessors
 Technology based on VLSI
 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.
 Have massive memory capacity and still growing.
 PC computing became available to business community and home users since
1981 with the introduction of PC by IBM. Apple introduced the Macintosh in
1984.
 Microprocessors also entered several other areas of life as more and more
everyday products began to use them resulting in the convergence of computers
and telecommunications.
 Computer networks eventually led to the development of Internet.
 Development of GUIs, the mouse, and handheld devices.
 Web based software development for business and other applications
Fifth Generation – Present and Beyond: Artificial Intelligence
 Fifth generation computing devices, based on artificial intelligence, are still in
development.
 Some applications, such as, Voice Recognition, however, are being used today.
 The use of Parallel Processing and superconductors is helping to make artificial
intelligence a reality.
 The goal of fifth-generation computing is to develop devices that respond to
natural language input and are capable of learning and self-organization.
 Highly networked and parallel architecture based computers.
 Focus on Internet and Intranets.
 Technology based on VLSI.
 Speed reaching billions of instructions per second.
 Memory reaching billions of characters in capacity.

7.  Non-procedural programming environment.
Introduction to Computer Hardware
• Hardware vs Software
Hardware is everything you can touch and see
Examples: Monitor, hard drive, CD-ROM, computer cables, keyboard, mouse,
modem, printer, etc.
Software
• Software is a set of instructions that makes the computer perform tasks.
• A set of instructions that drive a computer to perform specific tasks is called a
program.
• These instructions tell the machine’s physical components what to do; without the
instructions, a computer could not do anything at all.
• When a computer uses a particular program, it is said to be running or executing
that program.
• Some programs exist primarily for the computer’s use to help it perform tasks and
manage its own resources.
• Other types of programs exist for the user, enabling him / her to perform tasks
such as creating documents or spreadsheets, etc.
• Thousands of different software programs are available for use on personal
computers.
• Most software falls into three major categories:
• System Software, Programming Software, and Application Software
System Software
System Software is the class of programs that control and support a computer system
and its information processing activities. It also facilitates the programming, testing
and debugging of computer programs. It includes Operating Systems, Compilers,
Device Drivers, Diagnostic Tools, Servers, etc.
• The purpose of systems software is to insulate the applications programmer as
much as possible from the details of the particular computer system being used.
There are three major categories of Systems Software:
Operating System: An OS supervises the overall operation of the host computer
system, including starting the computer, monitoring its status, scheduling operations,
and managing all its resources.
• An OS is essential for any computer, because it acts as an interpreter between the
hardware, application programs, and the user.
• Examples include Windows, Linux, Unix, Mac OS
A Network Operating System (NOS): It allows computers to communicate and
share data across a network while controlling network operations and overseeing the
network’s security.
Utility: A utility is a program that makes the computer system easier to use or
perform highly specialized functions.

8. • Utilities are used to manage disks, troubleshoot hardware problems, and perform
other tasks that the OS itself may not be able to do.
Programming Software
• It usually provides tools to assist a programmer in writing computer programs and
software using different programming languages in a more convenient way.
• The tools include – Text editors, Compilers, Interpreters, Linkers, Debuggers, and
so on.
• An Integrated Development Environment (IDE) merges these tools into a
software bundle. IDE generally provides an advanced Graphical User Interface
(GUI) facilitating a user to perform his tasks efficiently.
Application Software
• Application Software tells the computer how to accomplish specific tasks, such as
word processing or other applications.
• Thousands of applications are available for many purposes and for people of all
ages. Some major categories of these applications include:
– Word Processing: for creating text based documents.
– Spreadsheets: for creating numeric based documents such as budgets or
balance sheets.
– Database Management Software: for building and manipulating large
sets of data.
– Presentation Programs: for creating and presenting electronic slide
shows.
– Graphics Programs: for designing illustrations or manipulating
photographs, movies or animations.
– Multimedia authoring applications: for building digital movies that
incorporate sound, video, animation, and interaction features.
– Entertainment and Educational Software: many of which are
interactive multimedia events.
– Web Design Tools and Web Browsers and other Internet applications
such as e-mail programs.
– Games: some of which are for a single player and many of which can be
played by several people over a network or the Internet.
– Industrial Automation, Business Software and Medical Software
– Businesses are the biggest users of application software, but almost every
field of human activity now uses some form of application software.
Components of a Computer
• There are four components to a computer
– Input Devices
– Processor Unit
– Output Devices
– Auxiliary Storage Devices
Input Devices
• Input Devices enable the user to enter data into memory
• Examples of input devices:

9. – Keyboard
– Mouse
– Scanner
– Touch Screen Input
– OCR
The Processor Unit
• The Processor Unit is comprised of two components:
– Central Processing Unit (CPU)
– Memory
The Control Process Unit (CPU)
• Interprets instructions to the computer
• Performs logical and arithmetic operations
• Causes the input and output operations to occur
• A Pentium Pro Microprocessor can perform approximately 250 million
instructions per second (MIPS)
CPU TYPES
• Intel, Advanced Micro Devices (AMD), Motorola, Cyrix
• X86 family of processors: 8080, 8086, 8088, 80286, 80386, 80486, Pentium (P5),
Pentium Pro, Pentium II, Pentium IV
• MMX - additions to the CPU programming that allow for better and faster
multimedia tasks like graphics and sound.
Computer Memory
• RAM - Random Access Memory
– Computer’s primary storage of data to be processed
– Silicon chips that store data and instructions as electronic currents
– CPU can manipulate electrical currents
– Contents of RAM will be lost when power is turned off
• Usually measured in MB or KB (e.g.: 8 MB of RAM)
• 1000 KB approximately = 1 MB
• 1 MB contains approximately 500 pages of text information.
• More RAM = faster processing rate
• Applications determine how much RAM needed
ROM - Read Only Memory
– Instructions and data are hard coded on the silicon chips
– Examples: BIOS (Basic Input-Output System)
• Gives computer the initial instructions to get it started once
computer is turned on.
Cache
• Temporary holding area where the system stores frequently accessed information
• Allows the processor to operate faster
• Size measured in KB (e.g. 256K or 512 K)
• Cache associated with the terms L1 or L2

10. • L1 is internal to the microprocessor
• L2 is separate from the microprocessor
Output Devices
• Output Devices make the information resulting from processing available for use
• Examples of Output Devices:
– Printers
– Computer Screens
– Speakers
Computer Screens
• Also called monitor or Cathode Ray Tube (CRT)
• Flat panel screens - LCD (Liquid Crystal Display)
• Screen is made up of pixels
Auxiliary Devices
• Also know as Secondary Storage Devices
• Examples of Auxiliary Devices:
– Floppy Disks
– Hard Drives
– CD-ROM
– Tape Backup Drives
– ZIP Drives
Floppy Disks
• Two Types of floppy drives
– 1.2 MB 5.25”
– 1.44 MB 3.5”
• Advantages
– Inexpensive
– Portable
• Disadvantages
– Slow access time
– Low capacity
• Access time is measured in milliseconds (ms)
• Formatting and protecting floppy disks
Hard Disks
• Secondary Storage Device
• Able to store large amounts of data
• Internal vs External
• Storage measured in MB’s or GB’s
• Access time measured in milliseconds (9-28 ms)
• Compression programs are used to save storage space
CD-ROM

11. • Compact disk read-only memory disks are used to store large amounts of
prerecorded information
• Since programs are getting bigger, it is a good medium for storage of programs
• Drive Speeds: 4X, 6X, 8X, 10X, 16X, 20X, 24X
• Read-Write CD’s are now available
Monitor
• Measured diagonally in inches
• Actual viewable area is less
• Monochrome
– Black and white display
• Color Monitors
– SVGA, VGA, EGA, CGA:
• Image consists of small dots or pixels
• More pixels = clearer image
• Monitor needs monitor controller (Video/Monitor card) to function
– Memory on monitor controller accelerates display on image
– Accelerator chip speeds up display as well
End-user computing
End User Computing (EUC) is a group of approaches to computing that aim at better
integrating end users into the computing environment or that attempt to realize the
potential for high-end computing to perform in a trustworthy manner in problem solving
of the highest order.
The EUC Ranges section describes two types of approaches that are at different ends of
a spectrum. A simple example of these two extremes can use theSQL context. and php
The first approach would have canned queries and reports that for the most part
would be invoked with buttons and/or simple commands. In this approach, a
computing group would keep these canned routines up to date through the normal
development/maintenance methods.
For the second approach, SQL administration would allow for end-user
involvement at several levels including administration itself. Users would also
define queries though the supporting mechanism may be constrained in order to
reduce the likelihood of run-away conditions that would have negative influence
on other users. We see this already in some business intelligence methods which
build SQL, including new databases, on the fly. Rules might help dampen effects
that can occur with the open-ended environment. The process would expect, and
accommodate, the possibility of long run times, inconclusive results and such.
These types of unknowns are undecidable 'before the fact'; the need to do 'after
the fact' evaluation of results is a prime factor of many higher-order
computational situations but cannot (will not) be tolerated by an end user in the
normal production mode.

12. Structured Program Development
Introduction
• Before writing a program:
– Have a thorough understanding of the problem
– Carefully plan an approach for solving it
• While writing a program:
– Know what “building blocks” are available
– Use good programming principles
Algorithms
• Computing problems
– All can be solved by executing a series of actions in a specific order
• Algorithm: procedure in terms of
– Actions to be executed
– The order in which these actions are to be executed
• Program control
– Specify order in which statements are to executed
Pseudocode
• Pseudocode
– Artificial, informal language that helps us develop algorithms
– Similar to everyday English
– Not actually executed on computers
– Helps us “think out” a program before writing it
• Easy to convert into a corresponding C++ program
• Consists only of executable statements
Control Structures
• Sequential execution
– Statements executed one after the other in the order written
• Transfer of control
– When the next statement executed is not the next one in sequence
– Overuse of goto statements led to many problems
• Bohm and Jacopini
– All programs written in terms of 3 control structures
• Sequence structures: Built into C. Programs executed sequentially
by default
• Selection structures: C has three types: if, if/else, and switch
• Repetition structures: C has three types: while, do/while and for
• Flowchart
– Graphical representation of an algorithm
– Drawn using certain special-purpose symbols connected by arrows called
flowlines
– Rectangle symbol (action symbol):
• Indicates any type of action
– Oval symbol:
• Indicates the beginning or end of a program or a section of code

13. • Single-entry/single-exit control structures
– Connect exit point of one control structure to entry point of the next
(control-structure stacking)
– Makes programs easy to build
The if Selection Structure
• Selection structure:
– Used to choose among alternative courses of action
– Pseudocode:
If student’s grade is greater than or equal to 60
Print “Passed”
• If condition true
– Print statement executed and program goes on to next statement
– If false, print statement is ignored and the program goes onto the next
statement
– Indenting makes programs easier to read
• C ignores whitespace characters
• Pseudocode statement in C:
if ( grade >= 60 )
printf( "Passedn" );
– C code corresponds closely to the pseudocode
• Diamond symbol (decision symbol)
– Indicates decision is to be made
– Contains an expression that can be true or false
– Test the condition.
• if
– Only performs an action if the condition is true
• if/else
– Specifies an action to be performed both when the condition is true and
when it is false
• Psuedocode:
If student’s grade is greater than or equal to 60
Print “Passed”
else
Print “Failed”
– Note spacing/indentation conventions
• C code:
if ( grade >= 60 )
printf( "Passedn");
else
printf( "Failedn");
• Ternary conditional operator (?:)
– Takes three arguments (condition, value if true, value if false)
– Our pseudocode could be written:

14. printf( "%sn", grade >= 60 ? "Passed" : "Failed" );
– Or it could have been written:
grade >= 60 ? printf( “Passedn” ) : printf( “Failedn” );
The while Repetition Structure
• Repetition structure
– Programmer specifies an action to be repeated while some condition
remains true
– Psuedocode:
While there are more items on my shopping list
Purchase next item and cross it off my list
– while loop repeated until condition becomes false
• Counter-controlled repetition
– Loop repeated until counter reaches a certain value
– Definite repetition: number of repetitions is known
– Example: A class of ten students took a quiz. The grades (integers in the
range 0 to 100) for this quiz are available to you. Determine the class
average on the quiz
– Pseudocode:
Set total to zero
Set grade counter to one
While grade counter is less than or equal to ten
Input the next grade
Add the grade into the total
Add one to the grade counter
Set the class average to the total divided by ten
Print the class average
Problem becomes:
Develop a class-averaging program that will process an arbitrary number
of grades each time the program is run.
– Unknown number of students
– How will the program know to end?
Use sentinel value
– Also called signal value, dummy value, or flag value
– Indicates “end of data entry.”
– Loop ends when user inputs the sentinel value
– Sentinel value chosen so it cannot be confused with a regular input (such
as -1 in this case)
• Top-down, stepwise refinement
– Begin with a pseudocode representation of the top:
Determine the class average for the quiz
– Divide top into smaller tasks and list them in order:

15. Initialize variables
Input, sum and count the quiz grades
Calculate and print the class average
• Many programs have three phases:
– Initialization: initializes the program variables
– Processing: inputs data values and adjusts program variables accordingly
– Termination: calculates and prints the final results
• Refine the initialization phase from Initialize variables to:
Initialize total to zero
Initialize counter to zero
• Refine Input, sum and count the quiz grades to
Input the first grade (possibly the sentinel)
While the user has not as yet entered the sentinel
Add this grade into the running total
Add one to the grade counter
Input the next grade (possibly the sentinel)
• Refine Calculate and print the class average to
If the counter is not equal to zero
Set the average to the total divided by the counter
Print the average
else
Print “No grades were entered”
Nested control structures:
• Problem
– A college has a list of test results (1 = pass, 2 = fail) for 10 students
– Write a program that analyzes the results
• If more than 8 students pass, print "Raise Tuition"
• Notice that
– The program must process 10 test results
• Counter-controlled loop will be used
– Two counters can be used
• One for number of passes, one for number of fails
– Each test result is a number—either a 1 or a 2
• If the number is not a 1, we assume that it is a 2
• Top level outline
Analyze exam results and decide if tuition should be raised
• First Refinement
Initialize variables
Input the ten quiz grades and count passes and failures
Print a summary of the exam results and decide if tuition should be raised
• Refine Initialize variables to
Initialize passes to zero
Initialize failures to zero
Initialize student counter to one

16. • Refine Input the ten quiz grades and count passes and failures to
While student counter is less than or equal to ten
Input the next exam result
If the student passed
Add one to passes
else
Add one to failures
Add one to student counter
• Refine Print a summary of the exam results and decide if tuition should be raised
to
Print the number of passes
Print the number of failures
If more than eight students passed
Print “Raise tuition”
Assignment Operators:
• Assignment operators abbreviate assignment expressions
c = c + 3;
can be abbreviated as c += 3; using the addition assignment operator
• Statements of the form
variable = variable operator expression;
can be rewritten as
variable operator= expression;
• Examples of other assignment operators:
d -= 4 (d = d - 4)
e *= 5 (e = e * 5)
f /= 3 (f = f / 3)
g %= 9 (g = g % 9)
Increment and Decrement Operators:
• If c equals 5, then
printf( "%d", ++c );
– Prints 6
printf( "%d", c++ );
– Prints 5
– In either case, c now has the value of 6
• When variable not in an expression
– Preincrementing and postincrementing have the same effect
++c;
printf( “%d”, c );
– Has the same effect as
c++;

17. printf( “%d”, c );