tutorial 01 - introduction to computer
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TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
01. Draw the block diagram of computer and explain.
Ans :
Block diagram of a computer is as shown.
Input Units : Computers need
to receive data and
instruction in order to
solve any problem. Therefore
we need to input the data
and instructions into the
computers.
o The input unit
consists of one or
more input devices.
Keyboard is the one of
the most commonly used
input device. Other commonly used input devices are the mouse,
Scanners, Joystick, etc.
o All the input devices perform the following functions.
Accept the data and instructions from the outside world /
user.
Convert it to a form that the computer can understand (i.e.
Binary Language / low level language).
Supply the converted data to the computer system for
further processing.
Storage Unit: The storage unit of the computer holds data and
instructions that are entered through the input unit, before they are
processed.
o It preserves the intermediate and final results before these are
sent to the output devices. It also saves the data for the later
use.
o The various storage devices of a computer system are divided into
two categories :
Primary Storage:
Stores and provides very fast.
This memory is generally used to hold the program
being currently executed in the computer, the data
being received from the input unit, the intermediate
and final results of the program.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
The primary memory is temporary in nature.
The data is lost, when the computer is switched off
(i.e. volatile in nature).
In order to store the data permanently, the data has
to be transferred to the secondary memory.
E.g. RAM
Secondary Storage: It stores several programs, documents,
data bases etc.
The programs that you run on the computer are first
transferred to the primary memory before it is
actually run.
Whenever the results are saved, again they get stored
in the secondary memory.
The secondary memory is slower and cheaper than the
primary memory.
Some of the commonly used secondary memory devices
are Hard disk, CD, etc.,
Output Unit: The output unit of a computer provides the information and
results of a computation to outside world.
o Printers, Visual Display Unit (VDU / Monitor) are the commonly
used output devices.
Arithmetic Logical Unit: All calculations are performed in the
Arithmetic Logic Unit (ALU) of the computer.
o It also does comparison and takes decision.
o The ALU can perform basic operations such as addition,
subtraction, multiplication, division, etc and does logic
operations viz, >, <, =, „etc.
o Whenever calculations are required, the control unit transfers
the data from storage unit to ALU once the computations are done,
the results are transferred to the storage unit by the control
unit and then it is send to the output unit for displaying
results.
Control Unit: It controls all other units in the computer.
o The control unit instructs the input unit, where to store the
data after receiving it from the user.
o It controls the flow of data and instructions from the storage
unit to ALU.
o It also controls the flow of results from the ALU to the storage
unit.
o The control unit is generally referred as the central nervous
system of the computer that control and synchronizes its working.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
Central Processing Unit: The control unit and ALU of the computer are
together known as the Central Processing Unit (CPU).
o The CPU is like brain performs the following functions:
It performs all calculations.
It takes all decisions.
It controls all units of the computer.
02. Give applications of Computer.
Ans :
Mathematical Calculations :
Business : E.g. in Banks for online transactions and producing other
financial reports
Telecommunications : Internet, Fax, Email, Video Conferencing etc.
Entertainment : Watching movies, Playing Games
Medical Field : For different Cardiac and Xray application
Education : E-learning process, and information sharing on the
internet.
Space Technology :
Word Processing and Data Processing
* NOTE : Explain all the point yourselves with appropriate examples.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
03. Give characteristics of Computer
Ans : Speed :
o A computer is a very fast and accurate device.
o It can process thousands of instructions within a few seconds for
which a human being can take several days or months.
Accuracy
o Degree of accuracy of the computer is very high.
o Errors can occur in computerized system also but most of them
occur due to human mistakes rather than technical problems in the
computer.
Versatility
o We can perform many different tasks on the computer at a time.
o One moment it might be busy in calculating the statistical data
of a business organization for annual performance evaluation and
at next moment it is capable of working on inventory control.
Automation
o A machine is no sooner than done to be automatic if it, works by
itself without human intervention.
o Computers are automatic machines, because one started on a job,
they carry on, until the job is finished, without any human
assistance.
o However, computer being machines can not start them selves. They
cannot go out find their own problems and solutions.
o They have to be instructed.
Diligence
o A computer is free from dullness and lack of concentration.
o It can continuously work for hours without creating any error
human beings in doing regular types of jobs, which requires great
accuracy.
o Computer can perform the number of calculation with exactly the
same accuracy and speed as the first one.
No. I.Q.(Intelligence Quotient)
o A computer is not a magical device. It is no intelligence of it‟s
own.
o User can determine what tasks the computer will perform. So a
computer cannot take its own decision as you can.
o A computer can not take it own decision in this regard.
Large Storage :
o Computer is free from problems like exhaustion, lack of
concentration, confusion, etc., unlike human beings.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
04. Explain following giving examples :
a. Input Devices
Ans : An input device is any peripheral (piece of computer hardware
equipment) used to provide data and control signals to an information
processing system (such as a computer).
It is a Hardware Device.
The most common input devices are the mouse and keyboard.
However, joysticks, touch screens, webcams, and microphones are
considered input devices as well.
Types of Input Devices :
o Mice and other Pointing devices :
Other than the keyboard, mice are the most common
type of input device.
Nearly every computer has one, and they make
navigating the screen much easier than trying to use
just a keyboard.
Mice usually use a ball, light, or a laser to track
movement.
Similar peripherals, such as a touch screen or
laptop's touchpad, trackballs, graphics tablets, and
even joysticks are “pointing” input devices.
Touch screens are becoming an increasingly popular
pointing device, and someday may replace mice
altogether.
o Keyboards :
The keyboard is the most common input device.
It is almost unheard of for a computer to be without
some form of keyboard, be it a full QWERTY keyboard
or a smaller number pad.
It is possible to interact with most computers
solely through the keyboard, without even a mouse,
because they are usually the default input device.
Touch screens may eventually overcome the keyboard as
well, by providing an onscreen keyboard to save
space.
o Audio/Video Input.
Webcams and digital cameras can also be considered
input devices.
They provide visual data to the computer in the form
of images and video.
Some webcams can even be used as pointing devices by
tracking the location of a person's hands or face.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
Microphones and digital musical instruments, such as
midi keyboards, are audio input devices that provide
the computer with audio data.
b. Output Devices
Ans : Output devices are pieces of computer hardware that allow a
computer system to communicate information to a user or another system.
This information can be in any form, and includes sound, images,
and even tactile experiences.
Output devices can usually only be used to send data from the
computer; items called input devices allow users and other
systems to send data to the computer.
Some of the most common output devices allow computers to present
information visually.
E.G. Monitors, Printers, Plotters, Video projectors, Computer
Speakers etc.
Text, pictures, and other images are displayed on the monitor,
allowing users to interact with computer programs and receive
data.
They function in a way similar to monitors,
but display images over a much larger area.
Printers allow the computer to produce
documents, pictures, and images on paper
through the use of inks and other dyes.
c. Operating Systems
Ans : An operating system, or OS, is a software
program that enables the computer hardware to
communicate and operate with the computer software.
Without a computer operating system, a computer would be useless.
An OS takes care for all input and output in a computer system.
It manages users, processes, memory management, printing,
telecommunication, networking etc.
The operating system provides a layer of abstraction between the
user and the bare machine.
Users and applications do not see the hardware directly, but view
it through the operating system.
Operating systems provide a software platform on top of which
other programs, called application programs, can run.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
The application programs must be written to run on top of a
particular operating system.
For PCs, the most popular operating systems are DOS, OS/2, and
Windows, but others are available, such as Linux.
Graphical user interfaces allow you to enter commands by pointing
and clicking at objects that appear on the screen.
Operating systems can be classified as follows:
o multi-user : Allows two or more users to run programs at
the same time. Some operating systems permit hundreds or
even thousands of concurrent users.
o multiprocessing : Supports running a program on more than
one CPU.
o multitasking : Allows more than one program to run
concurrently.
o multithreading : Allows different parts of a single program
to run concurrently.
o real time: Responds to input instantly. General-purpose
operating systems, such as DOS and UNIX, are not real-time.
An operating system performs these services for applications:
o In a multitasking operating system where multiple programs
can be running at the same time, the operating system
determines which applications should run in what order and
how much time should be allowed for each application before
giving another application a turn.
o It manages the sharing of internal memory among multiple
applications.
o It handles input and output to and from attached hardware
devices, such as hard disks, printers, and dial-up ports.
o It sends messages to each application or interactive user
(or to a system operator) about the status of operation and
any errors that may have occurred.
o It can offload the management of what are called batch jobs
(for example, printing) so that the initiating application
is freed from this work.
o On computers that can provide parallel processing, an
operating system can manage how to divide the program so
that it runs on more than one processor at a time.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
05. Differentiate between Hardware and Software giving examples
Ans :
Hardware Software
Types: Motherboard, CPU, RAM,
BIOS, power supply, video
display controller,
computer bus, CD-ROM
drive, floppy disk, zip
drive.
System
software, Programming
software,
and Application
software.
Examples: CD-ROM, monitor, printer,
video card, scanners,
label makers, routers, and
modems.
Adobe Acrobat,
Internet Explorer ,
Microsoft Word ,
Microsoft Excel
Inter dependency: Hardware starts
functioning once software
is loaded.
To deliver its set of
instructions, Software
is installed on
hardware.
Definition: Devices required to store
and execute (or run) the
software.
Collection of
instructions that
enables a user to
interact with the
computer. Software is
a program that
enables a computer to
perform a specific
task, as opposed to
the physical
components of the
system (hardware).
Function: Hardware serve as the
delivery system for
software solutions. The
hardware of a computer is
infrequently changed,
incomparison with software
and data, which are “soft”
in the sense that they are
readily created, modified,
or erased on the computer
To perform the
specific task you need
to complete. Software
is generally not
needed to for the
hardware to perform
its basic level tasks
such as turning on and
responding to input.
Fault: Hardware faults are
physical.
Software faults are
not.
Lifetime: Hardware wears out over
time.
Software does not wear
out over time.
Failure: Hardware failure is
random. Hardware does have
increasing failure at the
last stage.
Software failure is
systematic. Software
does not have an
increasing failure
rate.
Reliability: Hardware stays at steady
reliability level in
useful life.
Software needs
constant testing after
upgrades.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
06. Explain Algorithms and Flowcharts by providing
a. Characteristics
b. Advantages
c. Disadvantages
d. Examples
06.A. Algorithms :
An Algorithm is just a detailed sequence of simple steps that are
needed to solve a problem.
An algorithm is a sequence of instructions, which are followed in
order to complete a task. An algorithm can be presented or written
in words, in a program (structured code) for a computer or as a
flowchart.
An algorithm is a sequence of unambiguous (having only one meaning )
instructions for solving a problem, i.e., for obtaining a required
output for any legitimate input in a finite amount of time.
Characteristics of Algorithm:
01. Finiteness : terminates after a finite number of steps
02. Definiteness : rigorously and unambiguously specified
03. Input : valid inputs are clearly specified
04. Output : can be proved to produce the correct output given a
valid input
05. Effectiveness : steps are sufficiently simple and basic.
Example of Algorithm: finding the average of two numbers
Algorithm:
Input: two numbers x and y
Output: the average of x and y
Steps:
1. input x 2. input y 3. sum = x + y 4. average = sum /2 5. output average
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
06.B. Flowchart :
A flowchart is a graphical representation of an algorithm.
These flowcharts play a vital role in the programming of a problem
and are quite helpful in understanding the logic of complicated and
lengthy problems.
Once the flowchart is drawn, it becomes easy to write the program in
any high level language.
Often we see how flowcharts are helpful in explaining the program to
others.
Hence, it is correct to say that a flowchart is a must for the
better documentation of a complex program.
Flowcharts are usually drawn using some standard symbols; however,
The following are some guidelines in flowcharting:
o In drawing a proper flowchart, all necessary requirements
should be listed out in logical order.
o The flowchart should be clear, neat and easy to follow. There
should not be any room for ambiguity in understanding the
flowchart.
o The usual direction of the flow of a procedure or system is
from left to right or top to bottom.
o Only one flow line should come out from a process symbol.
or
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
o Only one flow line should enter a decision symbol, but two or
three flow lines, one for each possible answer, should leave
the decision symbol.
o Only one flow line is used in conjunction with terminal
symbol.
o If the flowchart becomes complex, it is better to use
connector symbols to reduce the number of flow lines. Avoid
the intersection of flow lines if you want to make it more
effective and better way of communication.
o Ensure that the flowchart has a logical start and finish.
o It is useful to test the validity of the flowchart by passing
through it with a simple test data.
o Example of a simple Flowchart showing if a student is Pass or
fail based on marks.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
Read num
F T
grade = "pass"
End
Start
num >=60
grade = "Fail"
Print grade
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
Characteristics of Flowchart
Vertical Linear Design
The overall design of most flowcharts is a vertical pictorial of
various elements that flow downward until the user reaches a
decision or solution.
Certain parts of the chart move to the left or right horizontally
to accommodate additional decision making elements, but overall
the direction is vertical.
Inputs
The inputs of the flowchart are the questions asked of the user.
The answers will allow the user to move through the chart to the
ideal solution.
Outputs
The output of the flow chart is either the solution or the next
tier of a pattern of questions that will eventually lead to a
final output.
Directional Arrows
The arrows in a flow chart are key to its movement---they
represent the choices the user has in the flow between the inputs
and outputs. The arrows are commonly labeled with a simple "yes"
or "no" but can also have more specific answers.
The head of the one-way arrow shows the direction of movement for
the flow chart and helps the user move on to the next step of the
decision making process.
Start and End Boxes
A flowchart has a well-defined start and end. The start box is
usually either the first input question or the title of the
problem.
Even if the user cannot reach a solution by answering the
questions, there is a box that represents the termination of the
flow of inputs and outputs.
The box may be clearly labeled "End" or simply be a note stating
that a solution is impossible.
TUTORIAL : 01 – INTRODUCTION TO COMPUTER DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING
PREPARED BY : PROF. SOHIL VOHRA (ASST. PROFESSOR, DJMIT, MOGAR) CONTACT : [email protected]
The Advantages of flowcharts are as follows:
1. Communication: Flowcharts are better way of communicating the logic of a system to all concerned.
2. Effective analysis: With the help of flowchart, problem can be analyzed in more effective way.
3. Proper documentation: Program flowcharts serve as a good program documentation, which is needed for various purposes.
4. Efficient Coding: The flowcharts act as a guide or blueprint during the systems analysis and program development phase.
5. Proper Debugging: The flowchart helps in debugging process. 6. Efficient Program Maintenance: The maintenance of operating
program becomes easy with the help of flowchart. It helps the
programmer to put efforts more efficiently on that part
Disadvantages of Flowcharts:
1. Complex logic: Sometimes, the program logic is quite complicated. In that case, flowchart becomes complex and clumsy.
2. Alterations and Modifications: If alterations are required the flowchart may require re-drawing completely.
3. Reproduction: As the flowchart symbols cannot be typed, reproduction of flowchart becomes a problem.
4. The essentials of what is done can easily be lost in the technical details of how it is done.