Von Neumann Theory Types of Computer

1. Instructor : Muhammad Hammad Waseem
Email: m.hammad.wasim@gmail.com

2. Muhammad Hammad Waseem 2
• The Von Neumann Architecture and its
figure
• Important Features of the Von Neumann
Architecture

3. 
 The Von Neumann architecture is a design model for
a stored-program digital computer. Its main
characteristic is a single separate storage structure
(the memory) that holds both program and data.
 Von Neumann computer architecture, which is
illustrated in the following figure:
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The Von Neumann
Architecture
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4. 
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The Von Neumann
Architecture (cont…)

5. 
 both instructions (code) and data (variables and
input/output) are stored in memory;
 memory is a collection of binary digits (bits) that
have been organized into bytes, words, and regions
with addresses;
 the code instructions and all data have memory
addresses;
 to execute each instruction, it has to be moved to
registers;
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Important Features of Von
Neumann Architecture
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6. 
 only the registers have the “smarts” to do anything
with the instructions; memory locations have no
“smarts”;
 to save a result computed in the registers, it has to be
moved back to memory;
 operating systems and compilers keep the
instructions and data in memory organized so it
doesn't get mixed up together;
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Important Features
(Cont.)

7. 
TYPES OF
COMPUTERS
• Introduction
• Types based on Principle of operation
• Analog computers
• Digital computers
• Hybrid computers

8. 
 Computers can be classified based on their principles
of operation or on their configuration. By
configuration, we mean the size, speed of doing
computation and storage capacity of a computer.
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TYPES OF COMPUTERS
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9. 
 There are three different types of computers
according to the principles of operation.
 Those three types of computers are:
 Analog Computers
 Digital Computers
 Hybrid Computers
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Types based on
Principles of Operation
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10. 
 Analog Computer is a computing device that works
on continuous range of values.
 The results given by the analog computers will only
be approximate since they deal with quantities that
vary continuously.
 It generally deals with physical variables such as
voltage, pressure, temperature, speed, etc.
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Analog Computers
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Examples
• Speedometer
• Weight machine
• Thermometer
• Temperature
• Speed
Analog watch
Applications
• Engineering
• Scientific Work
• To control process
• Chemical industries
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Advantage & Disadvantages
Of Analog Computer
ADVANTAGE OF ANALOG COMPUTERS
• Analog computers are fast.
DISADVANTAGES OF ANALOG COMPUTERS
• Analog computers are not accurate.
• Analog computers lack memory.

13. 
 On the other hand a digital computer operates on
digital data such as numbers.
 It uses binary number system in which there are only
two digits 0 and 1. (a bit)
 Digital Computers can give more accurate and faster
results.
 Digital computer is well suited for solving complex
problems in engineering and technology.
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Digital Computers
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14. 
 Hence digital computers have an increasing use in
the field of design, research and data processing.
 Based on the purpose, Digital computers can be
further classified as:
 General Purpose Computers:
 Used for any type of applications.
 Special Purpose Computers:
 One that is built for a specific application.
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Digital Computers (Cont…)

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Examples
• Calculators
• Accounting machines
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Applications
• Scientific research
• Business
• Education
• Factories
• Market
• Art
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Advantage & Disadvantages
Of Digital Computer
ADVANTAGES OF DIGITAL COMPUTERS
• Digital computers are accurate.
• Store information.
DISADVANTAGES OF DIGITAL COMPUTERS
• Digital computers are slow as compared to
Analog computers.
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18. 
 A hybrid computer combines the desirable features
of analog and digital computers.
 It is mostly used for automatic operations of
complicated physical processes and machines.
 Now-a-days analog-to-digital and digital-to-analog
converters are used for transforming the data into
suitable form for either type of computation.
 Hybrid computers are mainly used for specialized
tasks.
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Hybrid Computers

19. 
 It combines the best features of both digital and analog.
 Hybrid computers have the accuracy of analog and speed
of digital computers
Applications
 In hospitals
 In Air Defence system
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Advantages Of Hybrid
Computers

20. 
Types of Computers
based on Configuration
/ Size
• Types of Computers based on Configuration / Size
• Super computers
• Mainframe computers
• Mini computers
• Micro computers
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21. 
 There are four different types of computers when we
classify them based on their performance and
capacity. The four types are
 Super Computers
 Mainframe Computers
 Mini Computers
 Micro Computers
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Types of Computers based
on Configuration / Size

22. 
 They are the best in terms of processing capacity and
also the most expensive ones.
 These computers can process billions of instructions
per second.
 Perhaps the best known super computer
manufacturer is Cray Research.
 Some of the "traditional" companies which produce
super computers are Cray, IBM and Hewlett-
Packard.
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Super Computers

23. 
 Weather forecasting
 Stock analysis
 Nuclear research
 Designing complex
machines
 Scientific simulations
 (animated) Graphics,
analysis of geological
data
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Applications & Uses

24. 
 Mainframe computers can also process data at very
high speeds i.e., hundreds of million instructions per
second and they are also quite expensive.
 They are large in size and occupy the space of a
room.
 Need cooling requirements as well.
 Perform multiple jobs and support hundred of users.
 Normally, they are used in banking, airlines and
railways etc. for their applications
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Mainframe Computers

25. 
 Mini computers are lower to mainframe computers
in terms of speed and storage capacity.
 They are also less expensive than mainframe
computers.
 Some of the features of mainframes will not be
available in mini computers. Hence, their
performance also will be less than that of
mainframes.
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Mini Computers

26. 
 The invention of microprocessor (single chip CPU)
gave birth to the much cheaper micro computers.
They are further classified into
 Desktop Computers
 Laptop Computers
 Handheld Computers(PDAs)
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Micro Computers

27. 
 Today the Desktop computers are the most popular
computer systems. These desktop computers are also
known as personal computers or simply PCs.
 They are usually easier to use and more affordable.
 They are normally intended for individual users for
their word processing and other small application
requirements.
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Desktop Computers

28. 
 Laptop computers are portable computers.
 They are lightweight computers with a thin screen.
 They are also called as notebook computers because
of their small size.
 They can operate on batteries and hence are very
popular with travellers.
 The screen folds down onto the keyboard when not
in use.
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Laptop Computers

29. 
 Handheld computers or Personal Digital Assistants
(PDAs) are pen-based and also battery-powered.
 They are small and can be carried anywhere.
 They use a pen like stylus and accept handwritten
input directly on the screen.
 They are not as powerful as desktops or laptops but
they are used for scheduling appointments, storing
addresses and playing games.
 They have touch screens which we use with a finger
or a stylus.
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Handheld Computers