History of Computers

“Necessity Is the Mother of Invention”

Counting

Man started off by counting on his digits

◦ Needed ways to measure months and seasons in order to perform festivals and ceremonies

Primitive Calendar

Stonehenge Home for thousands of years to ceremonial

and religious events involving the summer solstice

The Abacus:

The First “Automatic” Computer◦The abacus◦First attempt at automating the

counting process. ◦The abacus is not really an automatic

machine; it is more a machine which allows the user to remember his current state of calculations while performing more complex mathematical operation.

Forefathers of ComputingForefathers of Modern Computers

Blaise Pascal

Charles Babbage

Gottfried Wilhelm

And Before That . . . .

On February 13, 1967 an amazing discovery was made by American scientists working in the National Library of Spain, Madrid. They had chanced upon 2 unknown works of Leonardo da Vinci, known as the "Codex Madrid". There was much excitement regarding this discovery and public officials stated that the manuscripts "weren't lost, but just misplaced".

Did Pascal plagiarize DaVinci’s work?

The First MechanicalCalculator (1653)

Pascal’s Gear System◦A one tooth gear engages its single tooth with

a ten-tooth gear once every time it revolves; the result will be that it must make ten revolutions in order to rotate then ten-teeth gear once.

◦This is the way that an odometer works for counting kilometers. The one tooth gear is large enough so that it only engages the next size gear after 1km has passed.

Fully automatic

Computing ForefathersGottfried Wilhelm Leibniz (1646-

1716)◦invented the Leibniz wheel, used in

the arithmometer, the first mass-produced mechanical calculator.

◦ He also refined the binary number system, which is at the foundation of virtually all digital computers

Joseph Marie Jacquard

• First mechanical loom (1801)

•Used punched cards to create patterns in fabric

Computing ForefathersCharles Babbage “invented” the

idea of the Difference Engine (mid-1800s)

Went on to develop the prototype of the Analytical Engine, but only a portion of it was completed at the

time of his death.

What About the Women??!Ada Byron Lovelace considered

to be the first “computer programmer.

Protégé of Charles BabbageAda Byron saw the Analytical

Engine as a “general-purpose computer.”

Herman Hollerith’s Tabulating MachineTabulating Machine for U S

Census Bureau.Started company to market

machine.

IBMHollerith sold his Tabulating

Machine Company, which then merged with several other businesses

Thomas Watson became president of merged companies in 1920s and changed name to International Business Machines.

Alan TuringTuring first described the Turing machine in

an article published in 1936, “On Computable Numbers.”

A Turing machine is an idealized computing device consisting of a read/write head (or 'scanner') with a paper tape passing through it.

The tape is divided into squares, each square bearing a single symbol--'0' or '1', for example. This tape is the machine's general purpose storage medium, serving both as the vehicle for input and output

Konrad Zuse--Binary Representations

Numbers can be converted to decimal to adding together the values of the holes, given that the first hole = 1 and the second 2, etc.

For example, 26=2^5+2^3+2^1+2^0

Holes represent an “on” signal.With 6 holes permissible, 2^6

numbers possible.

Harvard Mark I

Grace M. Hopper working on the Harvard Mark-I, developed by IBM and Howard Aiken. The Mark-I remained in use at Harvard until 1959, even though other machines had surpassed it in performance, providing vital calculations for the navy in World War II.

ENIAC

John Von NeumannThe Von Neumann Machine

◦ Data and program can be stored in the same space. Thus, the machine itself can alter either its program or its internal data.

◦ Conditional goto’s to other points in the code◦ Von Neumann worked with Mauchly and Eckert

on the design for EDVAC◦ Also a contributor to the fields of game theory

and cellular automata

John Von Neumann

EDVAC

Miniaturization (1950s)Transistors

◦Freedom from vacuum tubes, which were extremely bulky

◦Integrated Circuits

Computers in the 1960s

MicroprocessorIn November, 1971, a company called

Intel publicly introduced the world's first single chip microprocessor, the Intel

Invented by Intel engineers Frederico Faggan, Ted Hoff, and Stanley Mazor.

Intel 4004 took the integrated circuit down one step further by placing all the parts that made a computer think (i.e. central processing unit, memory, input and output controls) on one small chip.

The AltairIn 1975 Bill Gates and Paul Allen

approached Ed Roberts if MITS, the company who developed the Altair, and promised to deliver the BASIC complier.

They did so, and from that sale, Microsoft was born

The Best & The Brightest!?!?!?

Machine Language!?!?!?BASIC- Beginner’s All-Purpose

Symbolic Instruction Code◦Developed by Kemeny and Kurtz in

1964, two mathematicians at Dartmouth

◦Simple, easy-to-understand syntax allowed students to quickly learn it.

◦Provided ease of programming and easier debugging than machine code or assembly

Other Languages FORTRAN

◦ FORmula Translator◦ Used for science, math, & engineering

PASCAL◦ Developed by Niklaus Wirth in the 60’s◦ Disciplined approach to structure and data description

COBOL◦ Common Business Oriented Language

Data description stored separately from the pgram.◦ C

Derivative of ALGOL It and its decendant’s very popular today for system

programming

Apple’s Steve & Steve

The PC Explosion!

PCs in the 20th CenturyFastGraphical User Interfaces (GUI)

◦Allows you to use a mouse to control the computer

◦Can run thousands of different sets of instructions (programs)

Internet

SputnikARPAARPANETInternetWWW!

The WebThe Web can be used for:

◦ Looking up information on publications◦ Shopping for books, computers, or CD’s◦ Investigating staff or research at

universities◦ Downloading pictures, games, or other

files/The Web (World Wide Web) was

developed at CERN lab in Zurich, Switzerland

…And On to the 21st Century!