ECM 1407 The History of Computing

Question 1

What are the 2 root classes of machines?

Answer 1

Mechanical
Electronic

Question 2

What are the 2 root classes of computers?

Answer 2

Analogue
Digital

Question 3

Give the timeline of the pre-history of computing:

Answer 3

• Abacus
  ○ 1000 - 500 BC
• Antikythera mechanism
  ○ - 100 BC
  ○ The oldest example of an analogue computer
• First automatic mechanical calculator
  ○ 1623: Wilhem Schickard
  ○ It could add and subtract 6-digit numbers
• Leibniz’s calculating machine
  -1640s

Question 4

Significance of Antikythera mechanism from Leibniz’s calculating machine

Answer 4

The Antikythera mechanism was analogue, while the Leibniz calculating machine was digital

Question 5

The prelude and invention of the Difference Machine:

Answer 5

• London, 1821
  ○ Charles Babbage - Wishing to create a mechanical computer via a steam engine
• 1822
  ○ Charles Babbage announces the difference engine to the public
• 1823
  ○ Babbage receives funding from the British government to start working on his project
  ○ £1700 (approx £200,000 now)
  ○ Babbage hires an exceptional toolmaker named Joseph Clement
  § Just adding plus and minus
• 1832
  ○ Babbage and Clement built a working prototype of the Difference Engine

Question 6

Outcome of the Difference Machine?

Answer 6

• 1834
  ○ The machine construction is halted, Joseph Clement and Babbage dispute over compensation as government funding ceases
  ○ Clement melts the existing machine just to gain money
  ○ Was the difference engine just a calculator? Yes, a great one
  ○ It mechanised not just a single calculation but a whole series of calculations on a number of variables
  It had storage that can be used for later processing

Question 7

How did Babbage describe the ‘Analytical Engine’ in 1837?

Answer 7

1) Input
2) Store -> Memory
3) Mill -> Central Processing Unit (CPU)
4) Output
○ Never built when Babbage was alive due to fund shortages

Question 8

What did Babbage develop in 1847-1849?

Answer 8

The Difference Engine No. 2

This Engine calculates with numbers thirty-one digits long and can tabulate any polynomial up to the seventh order. The design was elegantly simple and required only approximately a third of the parts called for in Difference Engine No. 1

Question 9

What was the name of the first program developed by the first programmer, Ada Lovelace?

Answer 9

Note-G
Holds a legacy as a visionary

Question 10

Wilhem Gottfried Leibniz

Answer 10

• In 1703, Leibniz described how binary numbers may be added, subtracted, multiplied and divided
• He also developed the concept of formal symbolic logic, considered to be ahead of his time when not many advancements were made back then

Question 11

Charles Boole

Answer 11

• 1847, algebra of Boole: the foundation for modern computing.

Question 12

Claude Shannon

Answer 12

• 1936: Boolean algebra + circuit design
• Shannon provided mathematical techniques for building a network of switches to realize a specific logical function
  ○ An electrical circuit that works if, and only if, the right combination of buttons is pressed.

Question 13

What controversy surrounds Lovelace’s title as the first programmer?

Answer 13

Deemed the first computer programmer by many, despite many of the findings being handed to her by Babbage.
She did, however, discover bugs in Babbage’s code.