Computer History 2011 Part 1 - Early Devices

8/12/2019 Computer History 2011 Part 1 - Early Devices

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COMPUTER HISTORY


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Early Devices

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TheAbacusis a compu-tational tool that was

used to quickly add andsubtract numbers. Theabacus, the first knowncalculator, wasinvented by the Babyloniansas an aid tosimple arithmetic around this date.This laidthe foundations for positional notationandlater computing developments.

The ABACUS (c.2400 BC)


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It has been in use in Chinafor thousandsof years and still used in everydaytransactions throughout the Far East.

Early Devices


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The earliest form of abacus, the dust abacus,has been used in Babylonia and perhapsearlier times.

The ancient Egyptian bead and wire abacusdates from 500 BC.


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Early Devices

NAPIERS BONES (c. 1614)

Napier's bones is anabacus created by John

Napier for calculation ofproducts and quotientsof numbers that wasbased on Arabmathematics and latticemultiplication used byFibonacci writing in theLiber Abaci.


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Early Devices

Napiers Bones is also called Rabdology(fromGreek o [rabdos], rodand o

[logos], word). The abacus consists of aboard with a rim; the user places Napier'srods in the rim to conduct multiplication ordivision.


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The board's left edge is divided into 9squares, holding the numbers 1 to 9. TheNapier's rods consist of strips of wood, metalor heavy cardboard. Napier's bones are three

dimensional, square in cross section, withfour different rods engraved on each one. Aset of such bones might be enclosed in aconvenient carrying case.

Early Devices


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SLIDE RULE (c. 1620s)

Early Devices

Since real numbers can be representedas distances or intervals on a line, the

slide rule was invented in the 1620s toallow multiplication and divisionoperations to be carried out significantlyfaster than was previously possible.


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Blaise Pascal inventedThe second mechanical

calculator, called alter-natively the PascalinaortheArithmetique, in1642, the first being thatof Wilhelm Schickard in1623.

Early Devices

PASCALINE (c. 1642)


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A 6-digit model for those who couldnot afford the 8 digit model

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A Pascaline opened up to observe the gears and cylinderswhich rotated to display the numerical result

Early Devices


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Step Reckoner (c. 1671)

A four-function (addition, subtraction,multiplication, and division) calculatoremployed fluted drumshaving ten flutesarranged around their circumference in astair-step fashion

This was developed byGottfried WilhelmLeibniz (co-inventorwith Newton ofcalculus).

Early Devices


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Punch Card (c. 1725)

Punched card system of

a music machine. Alsoreferred to as Bookmusic, a one-stopEuropean medium fororgans

Early Devices


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As early as 1725, Basile Bouchon useda perforated paper loop in a loom toestablish the pattern to be reproduced oncloth, and in 1726 his co-worker Jean-Baptiste Falcon improved on his design byusing perforated paper cards attached toone another for efficiency in adapting andchanging the program.

The Bouchon-Falcon loom was semi-automaticand required manual feedof theprogram

Early Devices


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Jacquards Loom(c. 1801)

In 1801, Joseph-

Marie Jacquarddeveloped a loom inwhich the patternbeing woven was

controlled bypunched cards.

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The series of cards could be changedwithout changing the mechanical design ofthe loom. This was a landmark point inprogrammability.

Early Devices


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By selectingparticular cards

for Jacquard'sloom, the wovenpatternwill bedefined.

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In 1835 Charles Babbage described hisanalytical engine. It was the plan of ageneral-purpose programmable computer,employing punch cards for input and asteam enginefor power.

One crucial invention was to use gearsfor the function served by the beadsof an

abacus. In a real sense, computers allcontain automatic abacuses (technicallycalled the arithmetic logic unit or floating-point unit).

Early Devices


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His initial idea was to use punch-cards tocontrol a machine that could calculate and printlogarithmic tables with huge precision (a

specific purpose machine).Babbage's idea soon

developed into a general-purposeprogrammable computer, his analytical engine.

While his design was sound and the plans

were probably correct, or at least debuggable,

the project was slowed by various problems.Babbage was a difficult man to work with andargued with anyone who didn't respect hisideas.

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All the parts for his machine had to bemade by hand. Small errors in each itemcan sometimes sum up to largediscrepanciesin a machine with thousands

of parts, which required these parts to bemuch better than the usual tolerancesneeded at the time.

The project dissolved in disputes withthe artisan who built parts and was endedwith the depletion of government funding.

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A reconstruction of the Difference EngineII by Dr. Doron Swade, an earlier, morelimited design, has been operational since1991at the London Science Museum. With a

few trivial changes, it works as Babbagedesigned it and shows that Babbage wasright in theory.

The museum used computer-operated

machine tools to construct the necessaryparts, following tolerances which amachinist of the period would have beenable to achieve.

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Some feel that the technology of the timewas unable to produce parts of sufficientprecision, though this appears to be false.The failure of Babbage to complete theengine can be chiefly attributed to difficulties

not only related to politics and financing, butalso to his desire to develop an increasinglysophisticated computer.

Today, many in the computer field term

this sort of obsession creeping featuritis.

Early Devices


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Ada Lovelace, Lord Byron'sdaughter, translated andadded notes to the "Sketch ofthe Analytical Engine" byFederico Luigi, Conte

Menabrea.She has become closely

associated with Babbage.Some claim she is the world'sfirst computer programmer,

however this claim and thevalue of her othercontributions are disputed bymany.

Early Devices

Computer History 2011 Part 1 - Early Devices

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