This lecture include the following topics: Types of computer w.r.t working principal, Types of computers w.r.t size cost and speed,Types of computers w.r.t purpose

1. Introduction to Computer
Lecture # 3
Course Instructor : Sehrish Rafiq
Govt. Girls Degree College Maneri Swabi
Higher Education Department KP

2. Lecture overview

3. Types of computer w.r.t
working principal
• This classification is based on the way physical quantities are
represented in a computer.
• There are three basic types of computer w.r.t their working principal.
 Analog computers
 Digital computers
 Hybrid computers

4. Analog computers
• These computers are used to process analog data.
• Analog data is of continuous nature having an infinite variety of
values usually obtained from some measuring process.
• Such type of data includes temperature, pressure, speed ,weight,
voltage, depth etc.
• Analog computers measure continuous changes in some physical
quantity.
• They are ideal in situations where data can be accepted directly
from measuring instrument without having to convert it into numbers
or codes.

5. Continued…
• They do not require any storage capability because they measure
and compare quantities in a single operation.
• They are faster than digital computers.
• Output of an analog computer is generally in the form of readings on
a series of dial or a graph on strip chart.

6. Analog Computers

7. Applications of analog computers
• For measuring
Speed (Speedometer)
Temperature (Thermometer)
Weight (Weight machine)
• In specialized engineering and scientific applications for calculation
and measurement of analog quantities
• To control processes found in oil refinery where flow and
temperature measurements are important
• In paper making and in chemical industry

8. Digital Computers
• Digital computers operates on digital data such as numbers.
• They use binary number system in which there are only two digits 0
and 1 known as bits.
• They give more accurate and precise results than analog
computers.
• They provide long term storage and can store huge amount of
information.
• They are well suited for solving complex problems in engineering,
business and technology.

9. Digital computers

10. Hybrid Computers
• Hybrid computer utilize the best qualities of both analog and digital
computers.
• They have the speed of analog and accuracy of digital computers.
• They incorporate the measuring feature of analog and the counting
feature of digital computers.
• They are suited for situation where digital processing of data
collected in analog form is desirable.
• These computers are designed to perform special tasks where
measurements are converted to digits.

11. Hybrid Computers

12. Types of computer w.r.t purpose
• Computers can be divided into two types w.r.t purpose.
 General Purpose Computer
 Special Purpose Computer

13. General Purpose Computer
• These computers can store different programs and can thus be used
in countless applications.
• It can perform any kind of job with equal efficiency simply by
changing the application program stored in main memory.
Examples
• Personal computers, tablets, laptops, mini computer, super
computer, mainframe computer etc.

14. Special Purpose Computer
• A Special Purpose Computer is the one that is designed to perform
only one special task.
• The program or instructions set is permanently stored in such a
machine.
• They are very quick but cannot be used for any other purpose.
• They are also known as dedicated computers.
Examples :-
• Video game device, calculator, ATM Machine

15. Types of Computer w.r.t size, cost and
speed
• Size wise computers can be divided into four types w.r.t size, cost
and speed.
 Micro Computer
 Mini Computer
 Mainframe Computer
 Super computer

16. Micro Computer
• A microcomputer is a computer whose CPU is a microprocessor.
• A microprocessor is a processor all of whose components are built
on a single integrated circuit chip made of silicon.
• Micro computers are designed for personal use, therefore they are
also known as personal computers.
• They are smallest in size, least in price and small in memory as
compared to other types of computer.
• They are used for variety of applications like computer literacy, fun
and games, business applications, programming etc.

17. Continued…
• Due to their small size, they are easily accommodatable on table or
lap. Some of its types are handheld also.
• Some typical machines are:-
 DCM Tandy
 Apple- II
 BBC Acorn
 IBM-PC
 Pentium Series
 HP systems
 Dell Series

18. Types of Micro Computers

19. Mini computers
• Minicomputers are larger and more powerful than microcomputers but
smaller and less powerful than mainframes.
• They are cheaper in cost, smaller in size and small in memory as
compared to mainframe computers .
• They do not require air conditioning and can be operated in room
temperature.
• Generally they are used as servers on networks with personal
computers as nodes.
• Mini computer can serve up to 4000 connected users simultaneously.

20. Continued…
• It is normally accessed by users via personal computer or terminal.
• They can execute five million instructions per second.
• They cost somewhere between Rs.5 to 15 lac depending upon the
configuration.
• Mini computers are often used by small and medium-sized
companies to provide centralized store of information.
• Some typical machines are:-
 TDC 316
 PDP 11/70
 Honeywell (XPS-100)
 HCL-4

21. Minicomputers

22. Mainframe Computer
• They are very big in size and offer the maximum computing power.
• A large number of peripherals can be attached to them.
• They are generally used as servers in large networks.
• The original mainframes were housed in room-sized metal frames.
• Newer mainframes are about the same size as a large refrigerator.
• They are capable of handling data processing needs of head office
of a bank, or a big multinational company or may be a public utility
office.

23. Continued…
• They have larger storage and the speed of processing is also very
high.
• They can execute 10 to 100 millions of instructions per second
(MIPS), and cost somewhere between 1 to 5 million dollars.
• Some typical machines are:-
 Univac 1100/10
 Univac 1100/60
 Honeywell DSP 88/860
 IBM 270/168
 IBM 390

24. Mainframe Computers

25. Super computers
• They are most expensive of all the computers.
• These computers are big general purpose computers .
• They are capable of executing more than 10,000 millions
instruction per second and have largest storage capacities.
• These computers are used to solve complex mathematical
problems related to nuclear physics and plasma physics
,seismology and aerodynamics etc.
• They are quite expensive and cost somewhere around 10-30
million dollars depending upon the configuration

26. Continued…
• They are best for highly calculation- intensive tasks such as weather
forecasting, climate research, molecular modeling, physical
simulation.
• They are mostly used by military and scientific agencies.
• Some typical machines are
 Cray 1
 Cray 2
 Cray 3
 Param
 Cyber 810&830

27. Super Computers

28. Enough For Today!!!