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

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^^

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.

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.

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.

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.

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

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.

'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.

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.

Uses punch card technology

on a treadle driven loom

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)

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.

Charles Babbage

Difference Engine

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.

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."

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 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.

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 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.

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.

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

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 technologyIt 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

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)

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)

J. Presper Eckert and John W. Mauchly examine a printout of ENIAC results in a newsreel from February 1946.

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

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