History of
Computing
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Computers
A brief introduction
What is a computer?
● The original meaning of the word “computer” referred
to someone who carried out calculations rather than
an actual machine.
● A computer is a programmable electronic device that
can process, store and retrieve data.
● The data is processed by a set of instructions termed
a program.
● All computers consist of two basic parts, namely,
hardware and software.
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Mechanical Calculators
A device used to perform arithmetic operations
Pascaline Machine
● The first mechanical calculator was invented by
Blaise Pascal
● Could add or subtract two numbers
● Multiplication or division could be performed by
repeated addition or subtraction.
● The first calculator to be used in an office and the first
calculator to be commercialized.
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Pascaline Machine
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Step Reckoner
● Invented by Gottfried Wilhelm Leibniz, a German
mathematician and philosopher
● An advance on Pascal’s machine in that it was the
first calculator that could perform all four arithmetic
operations, that is addition, subtraction, multiplication
and division.
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Step Reckoner
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Difference Engine
● Designed by Charles Babbage
● This machine was the first to compute and print
mathematical tables mechanically
● The difference engine was designed to produce
mathematical tables and required human
intervention to perform the calculation.
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Difference Engine
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Analytical Engine
● A general-purpose programmable computing engine
which used punched cards
● Idea was borrowed from the Jacquard Loom
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Analytical Engine
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Jacquard Loom
● Used for weaving complex patterns in textiles
● First machine to use punch cards to control a
sequence of operations
● Did not perform computation, but it was able to
change the pattern of what was being weaved by
changing cards.
● Gave Babbage the idea to use punch cards to store
programs to perform the analysis and computation in
the analytic engine.
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Jacquard Loom
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Punched Cards
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Lady Ada Lovelace
● A mathematician and the first computer programmer
● Fascinated by the idea of the analytic engine
● predicted that such a machine could be used to
compose music, produce graphics as well as solving
mathematical and scientific problems.
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Lady Ada Lovelace
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Analog Computers
A brief introduction
Analog Computers
● The operations in an analog computer are performed
in parallel, and they are useful in simulating dynamic
systems.
● In analog technology, a wave is recorded or used in
its original form.
● They have been applied to flight simulation, nuclear
power plants and industrial chemical processes.
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Differential Analyser
● First very large scale general purpose mechanical
analog computer
● Developed by Vannevar Bush and others at the
Massachusetts Institute of Technology
● Data representation in an analog computer is
compact but may be subject to corruption with noise
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Differential Analyser
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Digital Computers
A brief introduction
Digital Computers
● It operates on data, including magnitudes, letters,
and symbols, that are expressed in binary code—i.e.,
using only the two digits 0 and 1.
● In digital technology, the analog wave is sampled at
some interval, and then turned into numbers that are
stored in the digital device.
● The recording does not degrade over time. As long
as the numbers can be read, you will always get
exactly the same wave.
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1st Generation of Computers:
Vacuum Tubes
● Used several thousand of these bulky vacuum tubes.
● A vacuum tube is a device that relies on the flow of
an electric current through a vacuum.
● The vacuum tube was used to represent one of two
binary states, that is the binary value ‘0’ or ‘1’.
● Widely used in electronic devices such as televisions,
radios and computers until they were replaced by
transistors from the late 1950s.
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Vacuum Tubes
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Electronic Numerical Integrator and Calculator (ENIAC)
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Universal Automatic Computer (UNIVAC)
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2nd Generation of Computers:
Transistors
● Can act as both an amplifier and a switch
● The transistor was invented by Shockley
● Put a few transistor switches together to make
something called a logic gate
● Logic gates let computers make very simple
decisions
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Traffic Lights Using Logic Gates
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Replica of the first working Transistors
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Transistors
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Transistorized
Digital Computer
(TRADIC)
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3rd Generation of Computers:
Integrated Circuits
● A massive amount of computational power may be
placed in a very small chip.
● They are small with little power consumed and may
be mass produced to very high quality standard.
● Difficult to modify or repair and nearly always need to
be replaced.
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Integrated Circuits
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Programmed Data Processor – 1 (PDP-1)
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PDP-6
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PDP-7
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PDP-8/E
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PDP-11/40
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PDP-12
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PDP-15
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PDP-15
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4th Generation of Computers:
Microprocessors
● It allowed a single chip to contain all of the
components of a computer from the CPU and
memory to input and output controls.
● The microprocessor could fit into the palm of the
hand whereas the early computers filled an entire
room
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Microprocessor
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Altair 8080
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Xerox Alto
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Apple I
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Apple II
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IBM PC
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IBM PS/2
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5th Generation of Computers:
Artificial Intelligence
● Its long-term goal is to create a thinking machine that:
○ Is Intelligent
○ Has consciousness
○ Has the ability to learn
○ Has free will
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Fields of
Artificial Intelligence
● Computing ● Robotics
● Logic and philosophy ● Expert systems
● Psychology ● Machine translation
● Linguistics ● Epistemology and
● Neuroscience and knowledge
neural networks representation
● Machine vision
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Done.
Any questions?
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