Considers various pioneers and their contribution to the Computing history. Their Concepts and Theories. How they became the basis of Computing

1. K. P de Silva
R.V Premabandu1

2. Introduction
 Considers various pioneers and their contribution to
the Computing history.
 Their Concepts and Theories.
 How they became the basis of Computing.
2

3. Content
 George Boole
 Boolean Algebra
 Charles Babbage
 Difference Engine
 Analytic Engine
 Formalism
 Alan Turing
 Turing Machines
 Enigma Codes
 Turing Test in AI
 Claude Shannon
 Boolean Algebra and Switching Circuits
 Information Theory
 Cryptography
 Von Neumann
 Von Neumann Architecture.
 Konrad Zuse
3

4. George Boole
 Nineteenth century mathematician,
 His calculus of logic is known as Boolean
Algebra.
 Introduced two quantities “0” and “1”.
 He then employed symbols such as x, y, z,
etc., to represent collections or Classes.
 Introduced three operators (+ , - , x).
 These symbols obeyed a rich collection of
algebraic laws such as Additive Identity,
Associativity, Commutativity and etc.
(1815–1864)
4

5. Boolean Algebra
 Foundation of all modern computers.
 Consists of propositions that are either true or false.
 Variables (e.g., A, B, etc.) are used to stand for
propositions.
 Propositions must be either true or false.
E.g. 2 + 2 = 4 is true.
2 ∗ 5 = 11 is false.
 Propositions may be combined using logical connectives to
form new propositions.
5

6. Logical Connectives
 The standard logical connectives are…
AND - ∧
OR - ∨
NOT - ￢
 These connectives may be expressed using the other
logical connectives
Implication (⇒)
Equivalence (⇔)
E.g. A ⇒ B is equivalent to ￢A∨B
E.g. A ⇔ B is equivalent to (A ⇒ B) ∧ (B ⇒ A)
6

7. AND, OR and NOT Gates
 Boolean logical operations are implemented by
electronic AND, OR and NOT gates.
 Fundamental building blocks for more complex
circuits.
7

8. Charles Babbage
 Charles Babbage is considered to be one of the fathers
of computing.
 He was interested in a method that calculation could
be done mechanically.
 Introduced a design concept for Difference Engine and
Analytic Engine.
(1791) 8

9. Difference Engine
 Built in 1853.
 Compute polynomials of degree 4 on 15-digit numbers.
 Compute and print mathematical tables mechanically.
 The only operation that the Difference Engine can
perform is the addition.
 Finite differences was the concept of calculating the
answers.
 A key weakness is that it requires the intervention of
humans to perform the calculation.
9

10. Difference Engine
Difference Engine is on display in the Science Museum
in London. 10

11. Analytic Engine
 Babbage proposed a revolutionary idea for analytic
engine to resolve weaknesses of difference engine.
 Built in 1978.
 Included a processor, memory.
 Way to input information and output results.
 Capable of executing all possible tasks that may be
expressed in algebraic notation.
 Used punched cards to store programs to perform the
analysis and computation in the Analytic Engine.
11

12. Analytic Engine
 Punched cards in the design was extremely powerful.
 Two types
 Operation Cards
 Variable Cards
 Operation cards are used to define the operations.
 Variable cards define the variables.
 Ada Lovelace suggested to a method write a program
in Analytic Engine.
 Over 100 years before Von Neumann’s architecture.
12

13. Analytic Engine
13

14. Formalism
 Formalism was proposed by David Hilbert.
 This formal system is the basis of modern predicate
logic.
 A formal system consists of a formal language.
 Included axioms, definitions, universal and existential
quantification, and formalization of proof.
 Determines the truth or falsity of any mathematical
statement based on a Algorithm with set of rules.
14

15. Formalism
 E.g.1 x = y;
this returns true if x is the same as y, and false
otherwise.
 E.g.2 More complex expression such as
f (x, y, z) = w is true
if f (x, y, z) is identical with w, and false otherwise.
 E.g.3 P(x) returns true if x is prime. where P() is
termed a concept.
“P(5) = true”
15

16. Alan Turing
 Was a British mathematician who was highly influential
in the development of Computer Science.
 Engaged in the Design work in the development of first
stored program computer.(ACE)
 Introduced the concept of Turing machine.
 Designed a electromechanical machine known has
bombe to break in to Enigma Codes.
(1912-1954)16

17. Turing Machine
 Turing machine is very simple machine.
 Equivalent to an actual physical Computer.
 The machine may read from and write to the tape.
 Has an associated set of rules that defines its behavior.
 Programmed to solve any problem for which there is
an algorithm.
 It was used to determine the solvability of certain
problem.
17

18. Concept of Turing Machine
18

19. Enigma Machine & Enigma Codes
The Enigma machine 19

20. Bombe Machine
 Turing was able brake Enigma codes by his Bombe
machine.
Cardboard replica of bombe. 20

21. Automated Computer Engine(ACE)
Pilot ACE
21

22. Turing Test
 Turing devised a famous
experiment that would allow a
computer to be judged as a
conscious and thinking machine.
 The concept of this Turing test
was the foundation of Artificial
Intelligence.
22

23. Claude Shannon
 Shannon found that Boolean algebra could be
employed to simplify the design of circuits and
telephone routing switches.
 He laid the foundation of modern Information Theory.
 Shannon proposed the idea of converting any kind of
data to binary digits.
23

24. Boolean Algebra & Switching Circuits
 Switching circuit “Xab” between two terminals a and b
Xab = 0 if open
Xab = 1 if closed
24

25. Information Theory
 Sending information rapidly and reliably from the
source point to the destination point without any
distraction.
25

26. Cryptography
 Secure way of communication between two parties.
 Messages are encrypted according to a Mathematical
function.
26

27. John von Neumann
 Hungarian mathematician.
 Made fundamental contributions to a vast number of
fields including computer science.
 His work on Quantum Mechanics was very influential.
 He introduced an Architecture during his work on
ENIAC & EDVAC.
27

28. Von Neumann Architecture
 The early machines could perform only a particular
task.
 This architecture uses a single store for both machine
instructions and programs.
 Much simpler to reconfigure the computer for a
different task.
28

29. Von Neumann Architecture
29

30.  Manchester Mark I was the first computer with Von
Neumann architecture.
 Ferranti produced the world’s first commercial
computer in 1951.
Von Neumann Architecture
30

31. Manchester Mark I
31

32. Konrad Zuse
 Was a German Engineer.
 Pioneered in building first functional tape stored,
program-controlled computer.( Z3)
 He designed the first high-level programming
language Plankalkül.
32

33. Summary
 Considered the contributions of important people in
the history of computing including Boole, Babbage,
Shannon, Turing and von Neumann.
 Boole was an English mathematician who developed
Boolean Algebra which is the foundation of all modern
computers.
 Charles Babbage did pioneering work on the
Difference Engine and Analytic Engine.
 Turing is famous for his work on a theoretical
mathematical machine termed the “Turing Machine”.
33

34. Summary
 He also made contributions to the cryptography and to
Artificial Intelligence.
 Claude Shannon was the first person to see the
applicability of Boolean Algebra to simplify the design
of circuits and telephone routing switches.
 Von Neumann was a mathematician gave his name to
the Von Neumann architecture that is used in almost
all computers.
 Zuse was a German engineer who developed the Z3
machine in 1941. He also developed the Plankalkul
high-level programming language in 1946.
34

35. References
 A Brief History of Computing by Gerard O’Regan.
 www.wikipedia.com
35

36. Any Questions.. ??
36

37. 37