1. INTRODUCTION TO INFORMATION TECHNOLOGY history of computers BGEC1O7

2. History of computers
Pre-Mechanical Computing: From Counting on fingers to pebbles to hash marks on walls to hash marks on bone to hash marks in sand
Interesting thought:
Do any species, other than homo sapiens, count?

3. Before humans invented “machines” to help them count or do math, they used whatever was at hand.
It’s possible the human facility in math is the most significant difference between us and other species. The capability is a two-edged sword. We’re able to dream up and implement advances in technology which have led to all kinds of wonderful improvements in our lives. But we’re also the one species which, because of this capability, has the power to destroy our world.
Now that’s a scary thought that should give us all pause…..

4. In the early days of mankind, man used to count the head of cattle by putting lines on tree.
Slowly these lines changed to numbers. To do calculation on numbers he started inventing machines.
COUNTING

5. Mechanical computers: From The Abacus to Charles Babbage and his Difference Engine The Abacus
Abacus was probably the earliest of counting devices.
It consists of rectangular wooden frame with two compartments and beads sliding along the steel wires for counting.
Multiplications and divisions are done using repeated additions and subtractions.
Even today in which cross strings are fixed, beads are inserted on to the strings. There are a number of rows of beads.

6. The abacus is often wrongly attributed to China
The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. The abacus is still in use today, principally in the far east (eg. Japan, Indonesia, China, North Korea, south Korea etc.)
Its only value is that it aids the memory of the human performing the calculation. A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator (multiplication and division are slower).

7. (Chinese) Abacus
Used for performing arithmetic operations

8. Napier’s Logarithms and Bones (1617)

9. NAPIER’S LOGS AND BONES
John Napier, a Scottish mathematician invented logarithms. The use of logarithms enabled him to transform multiplications and divisions problems of addition and subtractions.
In the beginning he called logarithms as artificial numbers. But later, he named them logarithms.
Napier also invented a computing device consisting of sticks with numbers carved on them.
These sticks are called bones as they were made of bones (later also made with wood). These bones helped a lot in multiplication involving large numbers.

10. Napier’s Bones
In the early 1600s, the Scottish mathematician named John Napier invented a tool called Napier's Bones.
These were multiplication tables inscribed on strips of bone or wood.

11. Napier’s logarithms
John Napier’s logarithms that took advantage of the fact that addition is easier than multiplication: log (a * b) = log a + log b
Logarithms are inverse of power function: log2 8 = because 23 = 8
His logarithms used lookup tables to find the solution to otherwise tedious and error-prone mathematical calculations.
To quote Napier himself: Seeing there is nothing (right well-beloved Students of the Mathematics) that is so troublesome to mathematical practice, nor that doth more molest and hinder calculators, than the multiplications, divisions, square and cubical extractions of great numbers, which besides the tedious expense of time are for the most part subject to many slippery errors, I began therefore to consider in my mind by what certain and ready art I might remove those hindrances.

12. And having thought upon many things to this purpose, I found at length some excellent brief rules to be treated of (perhaps) hereafter. But amongst all, none more profitable than this which together with the hard and tedious multiplications, divisions, and extractions of roots, doth also cast away from the work itself even the very numbers themselves that are to be multiplied, divided and resolved into roots, and putteth other numbers in their place which perform as much as they can do, only by addition and subtraction, division by two or division by three.

13. What was an important contribution of John Napier (1550-1617) ?
Logarithms were also the basis for the invention of the slide rule by William Oughtred ( ), of England, in 1633.
John Napier
QUESTION
What was an important contribution of John Napier ( ) ?
Do you know what a slide rule is?

14. Slide Rule
Napier's invention led directly to the slide rule, first built in England in 1600s and still in use in the 1960's by the National Aeronautics and Space Administration (NASA) engineers of the Mercury, Gemini, and Apollo programs which landed men on the moon.
The actual size was hand-held with a middle sliding edge.

15. Oughtred’s (1621) and Schickard‘s (1623] slide rule
Here’s Robby the Robot holding a giant-sized slide rule:

16. Slide Calculators

17. Slide rule is ruler-like device marked with logarithmic scales used to perform mathematical calculations.
Slide rule was used extensively for mathematical calculations by students, engineers, scientists, military, and others until largely replaced by hand-held calculators, starting with HP models in 1970’s.
As the name indicates, the slide rule has one scale within the other.
Suppose you want to add two numbers 3 and 5, set 3 on the fixed scale and slide the moving scale. So that its “0” coincides with “5” of sliding scale. This is the sum of 3 and 5. The process of reading could be quick if you are trained in the use of slide rule.

18. Blaise Pascal’s Pascaline (1645)

19. Blaise Pascal was the son of tax collector who had to do lot of calculations as part of his job.
He wanted to make his job easier by inventing a calculator.
He invented the first digital calculator to help his father with his work of collecting taxes.
The user would dial the numbers he wanted to add together and the machine would automatically add them. The result would be shown through six small windows at the top of the machine.
Computer scientist honoured Pascal by naming a programming language Pascal after him.

21. 8-digit Pascaline

22. 6-digit Pascaline ( Cheaper )

23. Pascaline Insides

24. Charles Babbage (1791-1871) The Father of Computers
BABBAGE DIFFERENCE AND ANALYTICAL ENGINES
Who was Charles Babbage ( ) ?

25. A founding member of the British Royal Astronomical Society.
A British National and the son of a wealthy banker who wanted to correct the errors in the logarithm tables being used during his time.
In 1822, he made a machine which calculated the successive difference of expressions (X2 +ax + b is an example of an expression) and prepared table which helped him in his calculations.
The royal Astronomical society awarded a gold medal to him for his invention and granted a large sum of money to carry out further work.
He wanted to make an accurate calculating machine called “Babbage’s Analytical Engine” which was similar in concept to modern computers or general device for any kind of calculation and symbol manipulation.
The Analytical Engine was designed to use punch cards.

26. The analytical engine was supposed to be very accurate
The analytical engine was supposed to be very accurate. So it needed lot of parts made with precision.
Babbage could not make such parts. He conceived that his machine would use input devices, would have a processing part called “mill” where you can perform calculations and output devices.
Since he was 100 years ahead in his ideas, he could not get parts needed for his machine.
This is because there were no tools to make such precision parts.
He did a lot of work related to making precision parts and spend all the grants but failed in his attempt to make a machine. He ultimately died as a frustrated man.
The Analytical Engine was eventually built completely in the latter half of the 19th century, by Georg and Edvard Scheutz as per Babbage’s blueprints.

27. Charles Babbage’s proposed steam driven calculating machine the size of a room, called the Difference Engine.
This machine would be able to compute tables of numbers, such as logarithm tables.
Babbage drew up the blueprints for it while still an undergrad at Cambridge University in England.
The device was never finished.

28. Charles Babbage’s Difference Engine [1822-1842]

29. The latest working model of Babbage’s Difference Engine [1989-1991]

30. Actual working model of Babbage’s Difference Engine; exhibit at the London Science Museum. It was built ( ) to commemorate the 200th anniversary of Charles Babbage’s birth. “During the 1980s, Allan Bromley, an associate professor at the University of Sydney, Australia, studied Babbage's original drawings for the Difference and Analytical Engines at the Science Museum library in London. 
This work led the Science Museum to construct a working difference engine No. 2 from 1989 to 1991, under Doron Swade, the then Curator of Computing. This was to celebrate the 200th anniversary of Babbage's birth. In 2000, the printer which Babbage originally designed for the difference engine was also completed.

31. Charles Babbage’s Analytical Engine [1837-1871—never completed by him]

32. World’s first programmer- Lovelace 1700’s and 1800’s

33. LADY ADA LOVELACE
Ada Byron or Ada Lovelace, the daughter of the famous English poet, Lord Byron and trained in mathematics and science became colleague of Babbage after hearing about his ideas for “Analytic Engine” at a dinner party.
Babbage befriended her and though she was only 19, she was fascinated by Babbage's ideas.
She studied the works of Babbage and wrote about them.
She began fashioning programs for the Analytic Engine, although still unbuilt.
The Analytical Engine remained unbuilt (the British government refused to get involved with this one) but Ada earned her spot in history as the first computer programmer.

34. Ada invented the subroutine and was the first to recognize the importance of looping.
From her account only, we can see the close resemblance of the modern day computers and Babbage’s work.
Lady Ada Lovelace’s contributions are very important. Since she predicted that computers can be programmed, a language, Ada used widely in America’s Department of Defence Computers was name after her.
This was done to honor her since she was the first computer programmer and Predicted in 1843 many uses for engine and developed first “programs” for it.
Why did the U.S. DOD name the new programming language it developed in “Ada” ?

35. Electro-mechanical computers
Herman Hollerith’s
1890
Census Counting Machine to
Howard Aiken
and the Harvard Mark I (1944)
Electricity was discovered long before it was actually named as such. One Sir Thomas Browne is supposed to have come up with the term “electricity”. It was a while before electricity was used to power computing machines.

36. Herman Hollerith's machine
Governments all over the world collect details about the number of people living in their countries.
This information helps the government in planning for the future, sometimes you find enumerators (people taking such details) coming to your house with forms to collect such details.
This operation is called “census” which is normally done once in 10years.

37. In the United States a census was carried in and the US Government was processing the census data. Even as this was going on, the next census was due in To process the census in fast, the Government announced a competition.
Dr. Herman Hollerith produced cards out of special paper pulp, designed punching machines to punch holes in the card to count census figures and invented sorting machines to read such punched card and collect data.
He could complete the job within three years, achieving a speedup of about three times.

38. Hollerith Desk

39. Hollerith Desk
Hollerith's technique was successful and the census was completed in only 3 years at a savings of 5 million dollars.

40. IBM
Hollerith built a company, the Tabulating Machine Company which, after a few buyouts, eventually became International Business Machines, known today as IBM.

41. Hollerith’s Innovation
By using punch cards, Hollerith created a way to store and retrieve information.
This was the first type of read and write technology

42. Examples of Punch Cards
Punch cards were used to store information

43. The Atanasoff-Berry Computer (ABC)
THE ABC WAS THE FIRST ELECTRONIC DIGITAL COMPUTER , INVENTED BY JOHN VINCENT ATANASOFF
QUESTION:
In the 1900’s the first fully electronic digital computer was named “ABC.” Why?

44. ABC
One of the earliest attempts to build an all-electronic (that is, no gears, cams, belts, shafts, etc.) digital computer occurred in by J. V. Atanasoff,
John V. Atanasoff, was a professor at Iowa State University and graduate Student at Clifford E. Berry
This machine was the first to store data as a charge on a capacitor, which is how today's computers store information in their main memory (DRAM or dynamic RAM). As far as its inventors were aware, it was also the first to employ binary arithmetic.

45. The ABC was a digital computer, so-called because it processed data in discrete, digital units (the digits 1 and 0). It also used the binary (base 2) number system in computation, the results being converted to and from decimal (base 10) for the purposes of human consumption. Being binary, the data could easily be represented electronically since switches natural have two states—on and off—which lend themselves to representing the numbers or values 1 and 0.
The ABC used vacuum tubes, punched cards and a memory device that looked like a drum.

46. Using 18,000-19,000 vacuum tubes, 70,000 resistors and 5 million soldered joints this massive instrument required the output of a small power station to operate it.
It could do nuclear physics calculations (in two hours) which it would have taken 100 engineers a year to do by hand.
The system's program could be changed by rewiring a panel.
Influenced design of ENIAC

47. Exercise 2 What does ABC stands for?
Who was the first computer programmer?
What was his/her contribution?
Discuss the contribution of John Napier
Discuss the contribution of Herman Hollerith

48. The ENIAC
What is ENIAC ?
Electronic Numerical Integrator and Computer, world’s first electronic digital computer, developed by Army Ordnance to compute WWII ballistic firing tables.
It served as prototype for development of most other modern computers .
Weighed over 30 tons, and stored a maximum of twenty 10-digit decimal numbers.
Included logic circuitry design now standard in computers
John Presper Eckert (at right)
( ) and John Mauchly (at left) ( ) were professors in the
University of Pennsylvania Moore School of Engineering

49. Mauchly invited himself to Atanasoff’s home for a long weekend in order to check out the ABC.
Atanasoff made him welcome, showed him his machine, and gave him a copy of the paper describing the workings of the machine that already had been filed with the Iowa State College’s patent lawyer.
Mauchly returned to Pennsylvania and, together with Eckert, designed and built the ENIAC (Electronic Numerical Integrator and Computer) which was commissioned by the U.S. Department of Defense and delivered in 1946.
ENIAC filled a 20 by 40 foot room, weighed 30 tons, and used more than 18,000 vacuum tubes that act as switches.

50. Eckert and Mauchly successfully filed for the patent as inventors of the electronic digital computer, ignoring Atanasoff’s work.
Some thirty years later, in 1972, this injustice was rectified when Honeywell (for Atanasoff) successfully challenged Sperry Rand (the company that acquired Eckert and Mauchly’s patent), and Atanasoff and Berry were duly credited as being the inventors of the electronic digital computer.
Mauchly died in Eckert died in 1995, one week before the nonogenarian Atanasoff. You might say that Atanasoff had the last laugh.

51. eniac

52. The ENIAC: Electronic Numerical Integrator and Computer
The ENIAC: 30 tons, 18,000 vacuum tubes (act as switch or amplifier), with the computing power of little more than the modern calculator…..

53. Programming the eniac

54. The ENIAC was programmed by rewiring the machine, instruction by instruction, tedious work carried out mostly by women working for the U.S. Ordnance Office. The machine was intended for use in the calculation of ballistics trajectories for the big guns of World War II.
It was ready a bit late for that, but nonetheless was an immensely significant achievement on Eckert and Mauchly’s part. Such a shame they neglected to recognize Atanasoff’s contribution to their endeavors.

55. Eniac wiring John Von Neumann
John Von Neumann came up with the bright idea of using part of the computer’s internal memory (called Primary Memory) to “store” the program inside the computer and have the computer go get the instructions from its own memory, just as we do with our human brain.

56. Eniac wiring
Like all the earliest electronic digital computers, the ENIAC was programmed manually; that is to say, the programmers wrote the programs out on paper, then literally set the program for the computer to perform by rewiring it or hard-wiring it—plugging and unplugging the wires on the outside of the machine. Hence all those external wires in the picture above and on the previous slide.

57. Then along came John Von Neumann, who worked at Princeton’s Institute for Advanced Study and who collaborated with Eckert and Mauchly. He came up with the bright idea of using part of the computer’s internal memory (called Primary Memory) to “store” the program inside the computer and have the computer go get the instructions from its own memory, just as we do with our human brain. Neato! No more intricate, complex, cumbersome external wiring. Much faster; much more efficient.

58. Unfortunately, it didn’t solve the problem of the possibility of error
Unfortunately, it didn’t solve the problem of the possibility of error. As long as humans are around, we’ll always have that!
It’s ironic that Eckert and Mauchly were upset when Von Neumann was given credit for this “stored program concept,” because they thought they deserved it, too. Now why didn’t they think the same about Atanasoff? Go figure!

59. Problems with eniac
The ENIAC used 18,000 vacuum tubes to hold a charge
Vacuum tubes were so notoriously unreliable that even twenty years later many neighborhood drug stores provided a "tube tester"

60. Replacing the vacuum tube

61. The Stored Program Computer
The EDVAC, EDSAC and UNIVAC were the first computers to use the stored program concept
They used vacuum tubes so they were too expensive and too large for households to own and afford

62. UNIVAC Universal Automatic Calculator
In 1947, after ENIAC became operational Mauchly and Eckert formed their own Company – “The Eckert- Mauchly Computer Corporation”.
Immediately after this they started the design of UNIVAC-1. This was purchased by US bureau of Census. Univac was the first computer dedicated to business applications.

63. Universal automatic computer (univac)
The Universal Automatic Computer or UNIVAC was a computer milestone achieved by Dr. J. Presper Eckert and Dr. John W. Mauchly, the team which invented the ENIAC computer. In 1946, Eckert and Mauchly were contracted by the United States Census Bureau to build a computer to help with the increase in population. They were given $300,000 to build the machine. In 1951, the machine was finally built at a final cost of over one million dollars.
UNIVAC was the world's first electronic general purpose data processing computer.

64. univac
In the 1950's, UNIVAC was the household word for "computer" just as "Kleenex" is for "tissue".
UNIVAC was also the first computer to employ magnetic tape.

65. Read on the following
EDVAC (Electronic Discrete Variable Automatic Computers)
EDSAC (Electronic Delay Storage Automatic Calculator)