Computer HistoryHow did we get here?

The First "Computers"

• People– Navigation tables, planetary positions, artillery tables

http://www.computerhistory.org/revolution/calculators/1/65/2209First 3:00

Calculation Aides

• Tools to calculate with:– Abacus– Napier’s bones– Slide rule

Calculating Machines

• Pascaline – 1642 mechanical calculator– Gear driven

Binary

• Gottfried Leibniz– Four function calculator– Advocated calculating with binary numbers

Weaving

• Joseph Jacquard– 1801 : power loom– Punch card driven patterns

Difference Engine

• Charles Babbage– 1822 – Difference engine : Steam powered calculator• Set the stage for IT overruns

– Analytical Engine• Punch card programmable• Memory & Processing separate

• Ada Byron– First programmer

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Changing Society

• Herman Hollerith : Hollerith Desk– Built for 1890 Census– Read/Write storage– Census complete in 3 years– Founded company now known

as IBM

Mark I

• 1944– First digital programmable computer• Mechanical

– WWII Firing tables

First Bug

• Grace Hopper– Programmer for Mark I– Designed first compiler

Electric Calculator

• Bombe & Colossus– Built by Great Britain– Code breaking calculator

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Electrical Computer

• ENIAC: Electronic Numerical Integrator and Calculator– 20x40 foot room– Programmed with patch cords and dials

Stored Programs

• What differentiates a calculator from a computer?

Modern Era Starts

• 1st generation modern computers– General purpose– Electronically stored program– Vacuum tube switches

• Manchester Baby– First working stored

program computer

• EDVAC

Von Neumann

• The Non Nuemann architecture:

Transistors

• Electronic switches– Invented 1947

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Modern Era

• Second Gen : 1950’s & 60’s– Transistor based– Mainframe era

Modern Era

• Third Gen : 1960’s-1970– Integrated circuits

• Monitors / Keyboards / Operating Systems

Apple

• Fourth Gen 1971+– Microprocessor

• PC as hobby – late 1970s– Altair & Apple I

PC Era

• 1981 - IBM PC – Highly successful personal computer– MS-DOS

Ubiquitous Computing

• Computers everywhere– Phones, cars, DVRs, toys, etc…

• Highly Integrated Circuits– Multiple parts of a computer on one chip

So Who Invented It?

http://www.computerhistory.org/revolution/birth-of-the-computer/4/91/2214