History of Computing

1
History of Computing

• Define a computer before 1935?
• What is the definition after 1945?

2
History of Computing

• Define a computer before 1935?
• A person that computes or performs arithmetic
  calculations
• What is the definition after 1945?
• An electronic device for performing arithmetic
  calculations

3
History of Computing

• What motivated the need for computing machines?

4
History of Computing

• What motivated the need for computing machines?
• Complex and tedious arithmetic calculations

5
History of Computing

• What are some example tedious calculations that
  were performed that motivated the need for
  computing machines?

6
History of Computing

• What are some example tedious calculations that
  were performed that motivated the need for
  computing machines?
• Basic arithmetic (abacus)
• Navigation and Mathematical tables (Babbage)
• Flight trajectory tables (WWII)
• Census (Eckert and Mauchley, UNIVAC)
• Inventory and budget (J. Lyons)

7
History of Computing

• What are some examples of early computing
  machines (mechanical computers)?

8
History of Computing

• What are some examples of early computing
  machines (mechanical computers)?
• Abacus (5000 yrs ago)
• Slide rule (Outred, 1600s)
• Pascaline (Blaise Pascal, 1600s)
• Difference engine (Charles Babbage, 1822)
• Tabulating machine (Herman Hollerith, 1890)

9
History of Computing

• What was the purpose of Babbages Difference
  Engine?

10
History of Computing

• What was the purpose of Babbages Difference
  Engine?
• Calculation of mathematical tables evaluating
  mathematical functions for sequences of values
  using the method of finite differences

11
History of Computing

• What was the purpose of Babbages Difference
  Engine?
• Calculation of mathematical tables evaluating
  mathematical functions for sequences of values
  using the method of finite differences

12
History of Computing

• Why did Babbage want to create the Analytical
  Engine even after having increasing demand for
  his Difference Engine?

13
History of Computing

• Why did Babbage want to create the Analytical
  Engine even after having increasing demand for
  his Difference Engine?
• The Difference Engine was still fixed in purpose.
  He wanted to design a programmable machine.

14
History of Computing

• What was a major significance of the Analytical
  Engine towards the progress of computing?

15
History of Computing

• What was a major significance of the Analytical
  Engine towards the progress of computing?
• First time someone designed a machine independent
  of its ultimate purpose.
• Birth of distinction between software and
  hardware

16
History of Computing

• Who worked closely with Babbage during the
  development of the Analytical Engine and is
  credited as the first computer programmer?

17
History of Computing

• Who worked closely with Babbage during the
  development of the Analytical Engine and is
  credited as the first computer programmer?
• Ada Lovelace, daughter of the poet Lord Byron
• Programming language Ada is named after her.

18
History of Computing

• How were numbers represented and stored in the
  mechanical computers?

19
History of Computing

• How were numbers represented and stored in the
  mechanical computers?
• Positions of beads abacus (5000 years ago)

20
History of Computing

• How were numbers represented and stored in the
  mechanical computers?
• Orientation of number wheels Pascals Pascaline
  (1600s)

21
History of Computing

• How were numbers represented and stored in the
  mechanical computers?
• Orientation of gears
• Babbages difference engine
• (1822)

22
History of Computing

• How were numbers represented and stored in the
  mechanical computers?
• Arrangements of holes in a punch card Herman
  Hollerith (1890)

23
History of Computing

• How were numbers represented in modern computers?

24
History of Computing

• How were numbers represented in modern computers?
• A series of 2-way switch settings
• Binary representation, streams of 0s and 1s

25
History of Computing

• How were numbers represented in modern computers?
• A series of 2-way switch settings
• Binary representation, streams of 0s and 1s
• Why binary?

26
History of Computing

• How were numbers represented in modern computers?
• A series of 2-way switch settings
• Binary representation, streams of 0s and 1s
• Why binary?
• Because binary digit (bit) easier to represent
• Only 2 states On/off, high/low, in/out,
  up/down,

27
History of Computing

• Why were binary digits fundamental to electronic
  computers?

28
History of Computing

• Why were binary digits fundamental to electronic
  computers?
• Engineering simplicity!
• Used on/off switches to represent binary digits
  (bits)
• Relays, vacuum tubes, transistors, integrated
  circuits

29
History of Computing

• Why didnt mechanical computers need binary
  numbers?

30
History of Computing

• Why didnt mechanical computers need binary
  numbers?
• Unnecessary to perform number conversion
• They were able to easily distinguish more than 2
  states per digit

31
History of Computing

• Why was the vacuum tube so important to computer
  development?

32
History of Computing

• Why was the vacuum tube so important to computer
  development?
• SPEED!
• Fast switching between binary states
• 1000 times faster than relay (Colossus)
• For what tradeoffs?

33
History of Computing

• Why was the vacuum tube so important to computer
  development?
• SPEED!
• Fast switching between binary states
• 1000 times faster than a relay (Colossus)
• For what tradeoffs?
• Reliability and cost!

34
History of Computing

• What replaced the vacuum tube and completely
  revolutionized computers in 10 years?

35
History of Computing

• What replaced the vacuum tube and completely
  revolutionized computers in 10 years?
• Transistors

36
History of Computing

• What eventually replaced transistors?
• Integrated circuits (ICs)

37
History of Computing

• What did relays, vacuum tubes, transistors, and
  integrated circuits all have in common for their
  use in computers?

38
History of Computing

• What did relays, vacuum tubes, transistors, and
  integrated circuits all have in common for their
  use in computers?
• All acted as a 2-way switch that represented a
  single bit of information

39
History of Computing

• Most early computers were constructed only to
  perform tedious arithmetic calculations. What was
  special about the machine Colossus that Alan
  Turing helped design? What was its purpose?

40
History of Computing

• Most early computers were constructed only to
  perform tedious arithmetic calculations. What was
  special about the machine Colossus that Alan
  Turing helped design? What was its purpose?
• Manipulated language symbols not just numbers
• Breaking German codes (U-boat attacks on British)

41
History of Computing

• Describe Turings vision of what a computer is or
  should be?

42
History of Computing

• Describe Turings vision of what a computer is or
  should be?
• Symbol manipulator not just numerical machine
• A learning machine
• A machine that exhibits some intelligence

43
History of Computing

• What is the Turing test?

44
History of Computing

• What is the Turing test?
• A test devised by Alan Turing to determine if a
  machine could be considered to possess some
  intelligence.
• After 5 minutes, if a person asking a remote
  entity questions was not sure if the entity was
  human or machine, then the computer could be said
  to possess some intelligence.

45
History of Computing

• Your thoughts
• Do you think this test was sufficient?
• What would make you believe that a machine had
  intelligence?
• Do you consider this to be a danger? Why?

46
History of Computing

• What were computers intended to replace?

47
History of Computing

• What were computers intended to replace?
• Large groups of people performing tedious,
  repetitive tasks such as arithmetic calculations
  and various bookkeeping.
• Your thoughts Was this really a bad thing? Were
  peoples fears justified? Will this replacement
  of humans by machines continue?

48
History of Computing

• Your thoughts
• How were computers portrayed in the early years
  of computing (think UNIVAC times)?
• How are they portrayed now?
• Are there as many misconceptions and fears today?
  Why or why not?