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## A Brief History of the Computer

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Title: A Brief History of the Computer

1
A Brief History of the Computer
• Presented by
• Trisha Cummings

2
What is a Computer?
• A computer is a machine which can take
instructions, and perform computations based on
those instructions
• It is the ability to take instructions often
known as programs in computer speak and
execute them, is what distinguishes a computer
from a mechanical calculator.

3
Numbers, Calculating and Us
• The first known use of numbers dates back to
around 30000 BC when tally marks were used by
Paleolithic peoples.
• It is safe to assume that humans begin counting -
and that fingers and thumbs provide nature's
abacus.
• The decimal system is no accident.
• Ten has been the basis of most counting systems
in history. When any sort of record is needed,
notches in a stick or a stone are the natural
solution.
• This system had no concept of place-value (such
as in the currently used decimal notation), which
limited its representation of large numbers.
• Egyptian numbers 3000-1600 BC
• In Egypt, from about 3000 BC, records survive in
which 1 is represented by a vertical line and 10
is shown as .
• The Egyptians write from right to left, so the
number 23 becomes lll

4
Babylonian numbers 1750 BC
• The Babylonians use a numerical system with 60 as
its base.
• This is extremely unwieldy, since it should
logically require a different sign for every
number up to 59 (.
• Instead, numbers below 60 are expressed in
clusters of ten - making the written figures
awkward for any arithmetical computation.
• Through the Babylonian pre-eminence in astronomy,
their base of 60 survives even today in the 60
seconds and minutes of angular measurement, in
the 180 degrees of a triangle and and in the 360
degrees of a circle.
• Much later, when time can be accurately measured,
the same system is adopted for the subdivisions
of an hour.
• The Babylonians take one crucial step towards a
more effective numerical system.
• They introduce the place-value concept, by which
the same digit has a different value according to
its place in the sequence.
• We now take for granted the strange fact that in
the number 222 the digit '2' means three quite
different things - 200, 20 and 2 - but this idea
is new and bold in Babylon.

5
Zero, decimal system, Arabic numerals from 300 BC
• The digits now used internationally make their
appearance gradually from about the 3rd century
BC, when some of them feature in the inscriptions
of Asoka.
• The Indians use a dot or small circle when the
place in a number has no value, and they give
this dot a Sanskrit name - sunya, meaning
'empty'.
• The system has fully evolved by about AD 800,
when it is adopted also in Baghdad.
• The Arabs use the same 'empty' symbol of dot or
circle, and they give it the equivalent Arabic
name, sifr.
• About two centuries later the Indian digits reach
Europe in Arabic manuscripts, becoming known as
Arabic numerals.
• And the Arabic sifr is transformed into the
'zero' of modern European languages.
• But several more centuries must pass before the
ten Arabic numerals gradually replace the system
inherited in Europe from the Roman empire.

6
The abacus 1st millennium BC
• In practical arithmetic the merchants have been
far ahead of the scribes, for the idea of zero is
in use in the market place long before its
adoption in written systems.
• It is an essential element in humanity's most
basic counting machine, the abacus.
• This method of calculation - originally simple
furrows drawn on the ground, in which pebbles can
be placed - is believed to have been used by
Babylonians and Phoenicians from perhaps as early
as 1000 BC.
• In a later and more convenient form, still seen
in many parts of the world today, the abacus
consists of a frame in which the pebbles are kept
in clear rows by being threaded on rods.
• Zero is represented by any row with no pebble at
the active end of the rod.

7
Roman numerals from the 3rd century BC
• The completed decimal system is so effective that
it becomes, eventually, the first example of a
fully international method of communication.
• But its progress towards this dominance is slow.
• For more than a millennium the numerals most
commonly used in Europe are those evolved in Rome
from about the 3rd century BC.
• They remain the standard system throughout the
Middle Ages, reinforced by Rome's continuing
position at the centre of western civilization
and by the use of Latin as the scholarly and
legal language.

8
Binary numbers 20th century AD/CE
• Our own century has introduced another
international language, which most of us use but
few are aware of.
• This is the binary language of computers.
• When interpreting coded material by means of
electricity, speed in tackling a simple task is
easy to achieve and complexity merely
complicates.
• So the simplest possible counting system is best,
and this means one with the lowest possible base
- 2 rather than 10.
• Instead of zero and 9 digits in the decimal
system, the binary system only has zero and 1.
• So the binary equivalent of 1, 2, 3, 4, 5, 6, 7,
8, 9, 10 is 1, 10, 11, 100, 101, 111, 1000, 1001,
1011, 1111 and so ad infinitum

9
Ancient Computer
• A bronze Greek device constructed in around 80BC
could be the world's oldest computer.
• The "Antikythera Mechanism" - consisting more
than 30 bronze dials and wheels - was recovered
from the wreck of a cargo ship off the Greek
island of Antikythera in 1900.
• Its exact purpose was unknown, although a theory
centers on it being used to calculate the
movement of the planets then known to the Greeks
Mercury, Venus, Mars, Jupiter and Saturn.

10
'Antikythera Mechanism'
11
Adding Machines
• Adding machines date back to the 17th century.
• They started with simple machines that could only
add (and sometimes subtract.)
• Many were rather tricky to use and could produce
erroneous results with untrained users.
• Apparently, Wilhelm Schickard produced the first
adding machine in 1623.

12
• Unfortunately, this one-of-kind machine was
destroyed in a fire and its existence remained
unknown until recently.
• Blaise Pascal (re)invented an adding/subtracting
machine in 1642 with no knowledge of Shickard's
machine.
• Pascal made many of his machines and is therefore
often thought of as the original inventor.
• His first machine was 14" x 5" x 3" and had 8
digits.

13
Jacquard Loom
• Basile Bouchon was a textile worker in Lyon who
invented a way to control a loom with a
perforated paper tape in 1725.
• The son of an organ maker, Bouchon adapted the
concept of music automata controlled by pegged
cylinders to the repetitive task of weaving.
• Further refinements by others eventually lead to
the wildly successful Jacquard loom.

14
• Jacques de Vaucanson (February 24, 1709November
21, 1782) was a French engineer and inventor who
is credited with creating the world's first true
robots, as well as for creating the first
completely automated loom.
• His proposals for the automation of the weaving
process, although ignored during his lifetime,
were later perfected and implemented by Joseph
Marie Jacquard, the creator of the Jacquard loom.

15
• The Jacquard Loom is a mechanical loom, invented
by Joseph Marie Jacquard in 1801, that has holes
punched in pasteboard, each row of which
corresponds to one row of the design.
• Multiple rows of holes are punched on each card
and the many cards that compose the design of the
textile are strung together in order.

16
• Uses punch card technology
• on a treadle driven loom

17
Charles Babbage
• Perhaps the most famous mechanical computer was
Charles Babbage's Analytical Engine, first
proposed in the 1830's.
• He originated the idea of a programmable
computer.
• Considered the "father of computing."
• Invents Analytical machine an automatic
calculator which never makes it off the ground
due to its complexity (1823 1842)

18
• Nine years later, the Science Museum completed
the printer Babbage had designed for the
difference engine, an astonishingly complex
device for the 19th century.
• Parts of his uncompleted mechanisms are on
display in the London Science Museum.
• In 1991 a perfectly functioning difference
engine was constructed from Babbage's original
plans.
• Built to tolerances achievable in the 19th
century, the success of the finished engine
indicated that Babbage's machine would have
worked.

19
Difference Engine
• Charles Babbage

20
Herman Hollerith
• Is widely regarded as the father of modern
automatic computation.
• He chose the punched card as the basis for
storing and processing information and he built
the first punched-card tabulating and sorting
machines as well as the first key punch, and he
founded Tabulating Machine Company.
• Which later becomes IBM.
• Hollerith's designs dominated the computing
landscape for almost 100 years.

21
• Hollerith's ideas for automation of the census
are expressed succinctly in Patent No. 395,782 of
Jan. 8, 1889
• "The herein described method of compiling
statistics which consists in recording separate
statistical items pertaining to the individual by
holes or combinations of holed punched in sheets
of electrically non-conducting material, and
bearing a specific relation to each other and to
a standard, and then counting or tallying such
statistical items separately or in combination by
means of mechanical counters operated by
electro-magnets the circuits through which are
controlled by the perforated sheets,
substantially as and for the purpose set forth."

22
• Had the idea to use Jacquard's punched cards to
represent the census data, and to then read and
collate this data using an automatic tabulating
machine.

23
How it works
• The results of a tabulation are displayed on the
clock-like dials.
• A sorter is on the right.
• On the tabletop below the dials are a
Pantographic card punch on left and the card
reading station on the right, in which metal pins
pass through the holes, making contact with
little wells of mercury, completing an electrical
circuit.
• When workers wanted some time off, they would
suck the mercury out of the wells with medicine
droppers and squirt it into the spittoon).
• All of these devices are fed manually, one card
at a time, but the tabulator and sorter are
electrically coupled.

24
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25
• He did not stop at his original 1890 tabulating
machine and sorter, but produced many other
innovative new models.
• He also invented the first automatic card-feed
mechanism, the first key punch, and took what was
perhaps the first step towards programming by
introducing a wiring panel in his 1906 Type I
Tabulator, allowing it to do different jobs
without having to be rebuilt!
• The 1890 Tabulator was hardwired to operate only
on 1890 Census cards.
• These inventions were the foundation of the
modern information processing industry.

26
Hollerith Automatic Feed Tabulator
• After the 1890 census, the US population
continued to grow and the original
tabulator-sorters were not fast enough to handle
the 1900 census so Hollerith devised another
machine to stave off another data processing
crisis.
• Towards the end of the 1900 Census, Hollerith
sped up the processing of information by adding
an automatic feed to his tabulator.
• It fed cards downward into the unit through a
circuit-closing press.
• Later, the pins of the sensing unit were replaced
by brushes to further speed the flow of
information and information punched in the cards
began to control the operation of the units.
• Hollerith had begun to put information on the
assembly line.

27
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28
Pantographic Card Punch
• Developed for the 1890 US census.
• Prior to 1890, cards were punched using a train
conductor's ticket punch that allowed holes to be
placed only around the edge of the card, and was
not terribly accurate, and which tended to induce
strain injuries.
• The Pantographic punch allowed accurate placement
of holes with minimum physical strain, one hole
at a time, and also provided access to the
interior of the card, allowing more information
per card.

29
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30
Our First Real Computer Eniac
• ENIAC, short for Electronic Numerical Integrator
And Computer
• It was the first high-speed, purely electronic,
digital computer capable of being reprogrammed to
solve a full range of computing problems
• ENIAC was conceived and designed by John Mauchly
and J. Presper Eckert of the University of
Pennsylvania.
• ENIAC was designed and built to calculate
artillery firing tables for the U.S. Army's
Ballistic Research Laboratory

31
• The contract was signed on June 5, 1943.
• In July, 1943 was constructed by the University
of Pennsylvania's Moore School of Electrical
Engineering.
• It was unveiled on February 14, 1946, having cost
almost 500,000.
• ENIAC was shut down on November 9, 1946 for a
refurbishment and a memory upgrade, and was
transferred to Aberdeen Proving Ground, Maryland
in 1947.
• There, on July 29 of that year, it was turned on
and ran continuous until 1145 p.m. October 2,
1955.

32
• ENIAC's physical size was massive compared to
modern PC standards.
• It weighed 30 short tons, was roughly 8.5 feet by
3 feet by 80 feet, took up 680 square feet
• Basically, it filled an entire room.
• It used vacuum tube technology
• It contained 17,468 vacuum tubes, 7,200 crystal
diodes, 1,500 relays, 70,000 resistors, 10,000
capacitors

33
Six women did most of the programming of
ENIAC by manipulating its switches and cables
Two women wiring the right side of the ENIAC with
a new program. "U.S. Army Photo" from the
archives of the ARL Technical Library. Standing
Ester Gerston Crouching Gloria Ruth Gorden
34
Cpl. Irwin Goldstein (sets the switches on one of
the ENIAC's function tables at the Moore School
of Electrical Engineering. (U.S. Army photo)
foreground)
• Programmers Betty Jean Jennings (left) and Fran
Bilas (right) operate the ENIAC's main control
panel at the Moore School of Electrical
Engineering. (U.S. Army photo from the archives
of the ARL Technical Library)

J. Presper Eckert and John W. Mauchly examine a
printout of ENIAC results in a newsreel from
February 1946.
Glen Beck (background) and Betty Snyder
(foreground) program the ENIAC in BRL building
328. (U.S. Army photo)
35
Evolution
• UNIVAC I of 1951 was the first business computer
made in the U.S. "Many people saw a computer for
the first time on television when UNIVAC I
predicted the outcome of the 1952 presidential
elections.
• Bendix G-15 of 1956, inexpensive at 60,000, for
science and industry but could also be used by a
single user several hundred were built - used
magnetic tape drive and key punch terminal

36
• IBM 650 that "became the most popular
medium-sized computer in America in the 1950's" -
rental cost was 5000 per month - 1500 were
installed - able to read punched cards or
magnetic tape - used rotating magnetic drum main
memory unit that could store 4000 words,
• Jack Kilby of Texas Instruments patented the
first integrated circuit in Feb. 1959
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