Transcript A Brief History of the computer

A Brief History of the Computer
Presented by
Trisha Cummings
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.
Numbers, Calculating and Us
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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.
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The decimal system is no accident.
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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.
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Egyptian numbers: 3000-1600 BC
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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^^
Babylonian numbers: 1750 BC
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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.
Zero, decimal system, Arabic numerals:
from 300 BC
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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.
The abacus: 1st millennium BC
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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.
Roman numerals: from the 3rd century BC
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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.
Binary numbers: 20th century AD/CE
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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
Ancient Computer
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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.
'Antikythera Mechanism'
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.
 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.
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.
 Jacques
de Vaucanson (February 24,
1709–November 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.
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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.
Uses punch card technology
on a treadle driven loom
Charles Babbage
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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)
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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.
Difference Engine
Charles Babbage
Herman Hollerith
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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.
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Hollerith's ideas for automation of the
census are expressed succinctly in Patent
No. 395,782 of Jan. 8, 1889:
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"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."
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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.
How it works
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The results of a tabulation are displayed on the clocklike 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.
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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.
Hollerith Automatic Feed Tabulator
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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.
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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.
Pantographic Card Punch
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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.
Our First Real Computer Eniac
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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
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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 11:45 p.m. October 2, 1955.
 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
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
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)
Glen Beck (background) and Betty Snyder (foreground)
program the ENIAC in BRL building 328. (U.S. Army
photo)
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.
Evolution
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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.“
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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
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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,
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Jack Kilby of Texas Instruments
patented the first integrated circuit in
Feb. 1959