1.
Introduction to Computer
Systems
Course Code: IS228
Topic : Introduction to Computer
Instructor: Engr. Salman Muneer

2.
What is
Computer?
A computer is an electronic
machine that collects information,
stores it, processes it according to
user instructions, and then returns
the result.

3.
What is the importance of computer?
• Computers are important because they used in every field like
engineering, medical, science, agriculture, education, banking,
entertainment and business etc.
• Computer can do complex tasks and calculations fast,
effectively and accurately.
• Computers are mostly used to create books, posters,
magazines, and newspapers.
• For saving huge data for longer time.
• For security purpose.

4.
What is history of Computer?
• Father of computer is Charles Babbage.
• 1st Generation (1940 to 1956) Punch cards in Abacus
For example: Electronic Numerical Integrator and Computer(ENIAC), Universal Automatic
Computer I (UNIVAC-1), Electronic Discrete Variable Automatic Computer (EDVAC).
• 2nd Generation (1957-1963) Transistors
For example: IBM 1620, IBM 7094, CDC 1604, CDC 3600.
• 3rd Generation (1964-1971) Integrated Chips (IC)
For example: the IBM-360 series, the Honeywell-6000 series, and the IBM-370/168.
• 4th Generation (1971-1980) Microprocessor
For example: STAR 1000, PDP 11, CRAY-1, CRAY-X-MP, and Apple II.
• 5th Generation (1980- Now) ULSI (Ultra Large-Scale Integration) technology
For example: IBM, Pentium, Desktop, Laptop, Notebook.

5.
What are the
components
of
Computer?

6.
Computer Memory (RAM)

7.
Types of Computer
Computers can be classified in different ways as shown below:
1) Classification by processing
2) Classification by purpose
3) Classification by power and size/configuration/computing power
1) Classification by processing:
This is by how the computer represents and processes the data.
I) Digital Computers
II) Analog Computers
III) Hybrids Computers
I) Digital Computers: are computers which process data that is represented in the form of discrete values by
operating on it in steps. Digital computers process data represented in the form of discrete values like 0, 1, 2. They
are used for both business data processing and scientific purposes since digital computation results in greater
accuracy.
II) Analog Computers: are used for scientific, engineering, and process-controlled purposes. Outputs are represented
in the form of graphs. Analogue computers process data represented by continuous physical variables and output
physical magnitudes in the form of smooth graphs.
III) Hybrid Computers: are computers that have the combined features of digital and analog computers. They offer
an efficient and economical method of working out special problems in science and various areas of engineering.

8.
Types of Computer (Cont..)
2) Classification by purpose:
This is a classification by the use to
which the computer is put.
I) Special Purpose Computers
II) General Purpose Computers
I) Special purpose computers:
Special purpose computers are
used for a certain specific
function e.g. in medicine,
engineering, manufacturing.
II) General purpose computers:
General-purpose computers can be
used for a wide variety of tasks e.g.
accounting, word processing.

9.
Types of Computer (Cont..)
3) Classification by power and size/configuration/computing power:
Computers can be broadly classified by their speed and computing power.
I) Personal Computer (PC)
II) Workstation
III) Mini Computer
IV) Main Frame
V) Super Computer
I) Personal Computer: It is a single user computer system having moderately powerful microprocessor. For
example, Desktop computer, Laptop, Tablet.
II) Workstation: It is also a single user computer system which is similar to personal computer but have more
powerful microprocessor. For example, an average-powered computer connected to a larger network.
III) Mini Computer: It is a multi-user computer system which is capable of supporting hundreds of users
simultaneously.
IV) Main Frame: It is a multi-user computer system which is capable of supporting hundreds of users
simultaneously. Software technology is different from minicomputer.
V) Super Computer: It is an extremely fast computer which can execute hundreds of millions of instructions
per second.

10.
What are the advantages of computer?
1) High Speed
 Computer is a very fast device. The computer has units of speed in microsecond, nanosecond, and even
the picosecond.
 It is capable of performing calculation of very large amount of data.
2) Accuracy
 Computers perform all jobs with 100% accuracy provided that correct input has been given.
3) Connects you to the Internet
 Connecting a computer to the internet unlocks its full potential.
 Once connected, your choices and available options, as far as information goes, are almost limitless.
 It can do repeated work with same speed and accuracy.
4) Versatility
 A computer is very flexible in performing the jobs to be done.
 This machine can be used to solve the problems related to various fields.
 At one instance, it may be solving a complex scientific problem and the very next moment it may be
playing a card game.

11.
Advantages of computer (Cont..)
5) Reliability
A computer is a reliable machine.
Modern electronic components have long lives.
Computers are designed in such a way that maintenance is Easy.
6) Automation
Automation means ability to perform the given task automatically.
Once a program is given to a computer i.e. stored in computer memory, the
program and instruction can control the program execution without human
interaction.
7) Reduction in Paper Work
The use of computers for data processing in an organization leads to
reduction in paper work and results in speeding up a process.
As data in electronic files can be retrieved as and when required, the problem
of maintenance of large number of paper files gets reduced.

12.
Disadvantages of Computer
1) No I.Q
A computer is a machine that has no intelligence to perform any task.
Each instruction has to be given to a computer therefore a computer
cannot take any decision on its own.
2) Dependency
It functions as per a user’s instruction, so it is fully dependent on human
being.
3) Cost
Computer is expensive.
4) Health Issues
More Screen time may affect your eye eyesight.