The document provides an introduction to computer systems. It defines a system as interacting elements forming a complex whole or as a set of methods to carry out an activity. A computer system includes hardware, software, and peripheral devices. It defines types of computers such as analog, digital, and hybrid. It also describes the classification of computers by size, including microcomputers, minicomputers, mainframes, and supercomputers, and by function, such as servers, workstations, and embedded computers. The key components of a computer system are also outlined.

1. Lecture #1
Introduction to computer

2. System
Def #1:
A group of interacting, interrelated, or interdependent
elements forming a complex whole.
Def #2:
A set of detailed methods, procedures, and routines
established or formulated to carry out a specific activity,
perform a duty, or solve a problem.

3. Characteristics of System:
Structure
Behavior
Inter Connectivity

4. Sub-system
A major part of a system which itself has the characteristics
of a system, usually consisting of several components.
Set of elements, which is a system itself, and a component
of a larger system.

5. Computer System
A complete, working computer along with soft wares and
peripheral devices that are necessary to make the computer
function is called Computer system. Every computer system
requires an operating system to operate.

6. Computer System

7. Lets enter in the world of computers…..!!!!
Computer Literacy (Digital Literacy)

8. Why we use Computers ?
Why we need It ?

9. Computers are present in every aspect of daily living –in
the workplace, at home, in the classroom, and for
entertainment (ubiquitous computing/pervasive computing)

10. An electronic machine that
can accept data (input),
manipulate the data
according to specified rules
(process), produce results
(output), and stores the
results for future use.
What is a Computer?

11. What is a Computer?
An electronic device designed to accept data, perform
prescribed mathematical and logical operations at high speed,
and display the results of these operations.

12. Data VS Information
Data:
Collection of raw facts and figures.
Information:
Processed form of data which is meaningful.
Knowledge:
(i) Appropriate collection of information.
(ii) Combination of data, information and experience.

13. Information processing cycle
Series of input, processes, output and storage.
A computer often holds data, instructions and information
for future use.

14. The Components of a Computer
Input devices
Output devices
System unit
Storage devices
Communications devices

15. The Components of a Computer

16. Advantages
It helps you automate various tasks that you cannot do
manually.
It helps you organize and store your bulky data and
information in a better way.
It has much more computing and calculating power than an
ordinary human.
 It may help your work to be a lot easier.
 It may be the storage of your important data and files.

17. Advantages
It may be your handy book.
It may help you solve problems faster than an ordinary
human being can do.
It has speed, storage, reliability, consistency and
communications.
It helps you to find useful information using the Internet.
It helps in businesses, factories, offices, schools and homes.

18. Disadvantage
It destroys your social life and interactions with humans if
you do not maintain the balance.
It may effect to the destruction of your eye sight due to
radiation.
It may damage your studies and life.
Too much time in front of monitor may adverse effect your
eye sight and can also make you fat.

19. Disadvantage
The way it distracts and can deviate our thoughts and
activities towards unproductive activities.
 It could cause violation of privacy, impact on labor force,
health risks, impact on environment, distraction from work,
and antisocial influences.

20. Types of Computer
Computer types can be divided into 3 categories according to
electronic nature.
Analog Computer
Digital Computer
Hybrid Computer

21. Analogue Computer
Analogue types of Computer uses analogue signals that are
represented by a continuous set of varying voltages and are used
in scientific research centers.

22. Analogue Signal and Analogue Devices

23. Digital Computer
A computer that stores data in terms of digits (numbers) and
proceeds in discrete steps from one state to the next. The states
of a digital computer typically involves binary digits which may
take the form of the presence or absence of magnetic markers in
a storage medium. In digital computers, even letters, words and
whole texts are represented digitally.
0,1
False true
Low high

24. Digital Signal and Digital Devices

25. Hybrid Computers
Designed to display the features and characteristics of both
analog and the digital computers.
When the hybrid computers are used in the form of digital
computers then they are deigned to act as the controller for the
operations carried out in the system.
When analog is taken into account then in that case the
computer acts as a solution provider for different problems that
exit.
By depicting both the feature, it is found to be a beneficial
computer.

26. Examples of Hybrid Computer

27. Classification of Computer
There are two types of classes
Classes by size
Classes by Functions

28. Classes by size
Microcomputers (Personal computers)
Minicomputers (Midrange computers)
Mainframe computers
Supercomputer

29. Classes by functions
Servers
Workstations
Information appliances
Embedded computers

30. Microcomputers
Microcomputers are the most common type of computers used
by people today, whether in a workplace, at school or on the
desk at home. e.g.
Desktop computers
Game consoles Laptops
Notebook computers
Palmtop computers
Tablet PC
Programmable calculator

31. Palmtop Computers:
A small computer that literally fits in your palm. Compared to full-size
computers.
A computer that has a small screen and compressed keyboard and is small
enough to be held in the hand, often used as a personal organizer.

32. Tablet PC:
A tablet PC is a wireless,
portable personal computer with
a touch screen interface. The
tablet is typically smaller than a
notebook computer but larger
than a smart phone.

33. Notebook Computers
A notebook computer is a
battery- or AC-powered
personal computer generally
smaller than a briefcase that
can easily be transported and
conveniently used in
temporary spaces such as on
airplanes, in libraries,
temporary offices, and at
meetings. A notebook
computer, sometimes called
a laptop computer.

34. Programmable calculators
•A limited-function computer capable of working with only
numbers and not alphanumeric data.
•Programmable calculators allow the user to write and store
programs in the calculator in order to solve difficult problems or
automate an elaborate procedure.

35. Game Console Laptops
Console games are more commonly referred to as video games. They are played on
a device specially made for game play called a video game console. The player
interacts with the game through a controller, a hand-held device with buttons and
joysticks or pads.

36. Minicomputers
Contemporary term for this class of system is midrange
computer.
Midrange system is more powerful and larger than a work
station computer. Servers typically support several hundred
and some times up to a few thousand connected computers
at the same time.

37. Minicomputers
Used in smaller organizations.
Initially these had category between mainframe and personal
computers.
Now a days we use server machine instead of mini
computers.
such as the higher-end SPARC, POWER and Itanium -based
systems from Sun Microsystems, IBM and Hewlett-Packard.

38. Mini computers

39. Mainframe computers
Used in large organizations.
A very large and expensive computer capable of supporting
hundreds, or even thousands, of users simultaneously.
Also called enterprise servers.
There are multiple processors in these computers(2,4,12).
Banks and shopping marts are interconnected through
mainframe computers.

40. Main frame computers

41. Super Computers
 All of the resources to tackle one problem
 Used for very complex operations
i. Rocket launching
ii. Assembling
iii. Weather prediction
iv. Aeronautics
v. Testing of nuclear weapons
 Cray one 160 millions instructions /second
 160 trillion bytes storage
 6 trillion bytes memory

42. Super Computers

43. Comparison between Minicomputer,
Mainframe & Supercomputer
In some ways, mainframes are more powerful than
supercomputers as they support more simultaneous
programs. But supercomputers can execute a single program
faster than a mainframe.
The distinction between small mainframes and
minicomputers is vague, depending really on how the
manufacturer wants to market its machines.

44. Hierarchy:
A system or organization in which people or groups are
ranked one above the other according to status or authority.
In the hierarchy starting with a simple microprocessor
(watches) at the bottom supercomputers at the top,
mainframes are just below super computers.
Hierarchy of Computers:

45. Comparison Table
Category of
computer
Number of
simultaneous users
Size of computer
Personal computer
desktop)
Fits on a desk Usually one(more if
networkerd)
Mobile computer and
Mobile devices
Fits on your lap or in
hand
Usually one
Game console Small box or hand held
device
One to several
Server Small cabinet Two to thousands
Mainframe Partial room to full
room of equipment
Hundred to thousands
Super computer Full room of
equipment
Hundred to thousands
Embedded computer Miniature Usually one

46. Servers
 Server is a physical computer (a hardware system)
dedicated to running one or more such services (as a host)
to serve the needs of users of the other computers on the
network.
Types of Server:
1. Depending on the computing service that it offers it could be
2. Database server
3. File server
4. Mail server
5. Print server
6. Web server

47. Types of Server
Depending on the computing service that it offers it could be
1. Database server
2. File server
3. Mail server
4. Print server
5. Web server

48. Database Server
Provides database services to other computers as defined by the
client-server model.
DBMS provide database server functionality,
In a master-slave model, database master servers are central and
primary locations of data while database slave servers are
synchronized backups of the master acting as proxies.
e.g.
Oracle, DB2, SQL server

49. File Server
Computer attached to a network with primary purpose of
providing a location for shared disk access,
i.e. shared storage of computer files (such as documents,
sound files, photographs, movies, images, databases, etc.)
that can be accessed by the workstations that are attached to
the computer network

50. Mail Server
Every email that is sent passes through a series of mail
servers
A complex series of transfers takes place.
 Without this series of mail servers, email can be sent to the
email address of the same domain.

51. Server

52. Client Server Network

53. Workstations
In networking, workstation refers to any computer connected
to a local-area network. It could be a workstation or a
personal computer.

54. Information appliance
In information appliance or information device is any
machine or device that is usable for the purposes of
computing, telecommunicating, reproducing, and presenting
encoded information in innumerable forms and applications.

55. Information appliances

56. Embedded Computers
Embedded computers can be compared to "computers on a
chip". All in one , so to speak. You will find them in all kind of
devices surrounding us where you need to regulate something,
control or check something
e.g.
 Home automation devices e.g. Washing machines, Sewing
machines, Microwave
 Ticket machines at the subway,
 Cameras, clocks Cell phone, Video games, Global Positioning
System
 Automobiles, cars, motors (antilock brakes)

57. Mobile Devices
Handheld Computers
PDA
Smart Phones
GPS

58. Hand Held Computers

59. Personal Digital Assistant (PDA)

60. Smart phones

61. Global Positioning System