Augusta Ada King,Countess of Lovelace

● Charles Babbage’s patron, assistant, and chronicler

● Daughter of Lord Byron, the poet

● Wrote sets of instructions for the Analytical Engine

● World’s first computer programmer

● U.S. Department of Defense named itsprogramming langauge Ada after her

1815-1852

”The Analytical Engine weaves algebraic patterns just as the Jacquard loom

weaves flowers and leaves”

Jacquard loom

Herman Hollerith

● Developed a tabulating machine for the U.S. census of 1890

● Stacks of punched cards served as a permanent memory

● Cut census time from 10+years to 6 weeks

● Not programmable

● Started a company to markethis machine which merged with others to form the Computing-Tabulating-Recording Company (eventually known as... )

Herman Hollerith

John Atanasoff and Clifford Berry

● American physicists at Iowa State College

● Berry was Atanasoff’s grad student

● Built ABC machine in late 1930s

● Special-purpose calculator for finding solutions to systems of equations

● All-electronic design using vacuum tubes for switching elements

● Never completed, due to insufficient funding

The Atanasoff-Berry Computer (replica)

Konrad Zuse

● German engineer under the Third Reich

● Built Z1, Z2, Z3, and Z4 in late 1930s and early 1940s with Helmut Schreyer

● Electromechanical design with relays for switching elements

● General-purpose computing device

● Controlled by perforated celluloid strips(like punched cards)

● First machine to use binary number system

● Never completed, due to insufficient funding from the Nazi government

1100101011000100011011111000010110010010111101010

Howard Aiken

● American physicist and applied mathematician

● Built Mark I at Harvard in collaboration withGrace Hopper and IBM engineers in 1944

● Inspired by Babbage’s Analytical Engine

● Electromechanical design with relays for switching elements

Rear Admiral Grace Hopper

Howard Aiken

● Handled 23-digit numbers, logarithms, trigonometric functions

● Controlled by punched paper tape

● Fully automatic but slow(3-5 seconds per multiplication)

● Remained in use at Harvard until 1959

Rear Admiral Grace Hopper

The First Bug

● Grace Hopper found the first actual computer bug while working on the Mark II in 1945

Alan Turing

● English mathematician and first true computer scientist

● Invented a mathematical model of a computer called a Turing Machine

● Proved fundamental theorems about the limitations of computers

● Wrote groundbreaking papers in many different fields

– Theory of computation (1936)

– Artificial intelligence (1950)

– Self-organizing chemical reactions (1952)

Alan Turing

● During World War II, he secretly worked for the British government to crack German Enigma codes

● Helped develop the British electronic code-breaking computer called Colossus

● Enabled Allies to read German military transmissions from 1942 on

● Persecuted by British government after the war for being homosexual

● Forced to undergo hormone “therapy”

● Committed suicide in 1954 at the age of 41

ENIAC● Electronic Numerical Integrator And Calculator

● Developed by John Mauchly and J. Presper Eckert at the University of Pennsylvania in1945

● First general-purpose all-electronic digital computer

● Filled a 30 x 50 ft. room

● Weighed 30 tons

● Dissipated 150,000 wattsof energy

● Performed calculations forthe atomic bomb projectat Los Alamos

ENIAC● Used 19,000 vacuum tubes

ENIAC● ...which tended to burn out frequently

Hmm...maybe it’sthis one? Nope...

How about this one?Nope...

ENIAC● Reprogramming required physically rewiring the machine

ENIAC● ...which was a tedious and error-prone process

Hold on... I think theblue one and the redone are supposed to

be reversed...

ENIAC

ENIAC

ENIAC

ENIAC

John von Neumann● Hungarian mathematician, computer

scientist, cyberneticist, all-around genius

● Worked on atomic bomb project in WW II

● Invented game theory and developed theory of self-replicating automata

● Originated key concept ofstored-program computerin 1945

● Program instructions = data

● Easily reprogrammable

● Von Neumann architectureis still the universal standard

EDVAC● Electronic Discrete Variable Automatic Computer

● Designed by Mauchly, Eckert, and Von Neumann

● Stored-program design

● Used binary instead ofdecimal to representinformation

● Version called UNIVAC Iwas the first commerciallyavailable computer system

● Sold to the U.S. CensusBureau in 1951

First Generation Computers● Mid 1940s to late 1950s

● Stored-program design with ~ 1000 words of RAM

● Used vacuum tubes, but required less space than ENIAC

● Punched cards for input and output

● Vacuum tube or magnetic core memoryfor data storage

● Programmed directlyin binary machinelanguage

● Included EDVAC andUNIVAC

First Generation Computers

Transistors

● Invented at Bell Labs in 1947 byWilliam Shockley, John Bardeen,and Walter Brattain

● Generated far less heat thanvacuum tubes

● Required far less power

● Much faster, smaller, cheaper,and more reliable

Transistors● Incorporated into Second Generation computers in the late

1950s and early 1960s

Integrated Circuits● Invented in the late 1950s by Jack Kilby of Texas

Instruments

● Many transistors etched on a single silicon chip as a single electronic circuit

● Faster due to decreased distance between transistors Incorporated into Third Generation computers in the mid 1960s to early 1970s

VLSI Technology● Very Large Scale Integration

● Thousands or millions of transistors per chip

● First microprocessor chip: Intel 4004 (1971)

● Designed by Ted Hoff for Japanese calculator company

● Followed by Intel 8008 and 4040 (1972) and 8080 (1974)

● Entire computer packaged as a single integrated circuit chip

● Like having an Analytical Engine the size of a shirt button

VLSI Technology● Incorporated into Fourth Generation computers from the

mid 1970s to the present

VAX minicomputer from Digital Equipment Corporation (early 1980s)

MITS Altair 8800 (1975)● First popular and affordable microcomputer ($375)

● Based on Intel 8080 chip

● 256 bytes of RAM (that’s bytes, not kilobytes or megabytes)

● Programmed by manually flipping switches on front panel

● Output in the form of blinking lights

● No softwareavailable

● MITS couldn’tsell them fastenough!

MITS Altair 8800 (1975)● Some assembly required

MITS Altair 8800 (1975)● Some assembly required

● Bill Gates and Paul Allenpromised MITS a BASICinterpreter for the Altair,leading to the creation ofMicrosoft in 1975

Ha, ha, I’m richer than you!

Other Early Developments

● IMSAI 8080 microcomputerwas similar to the Altair 8800

● Doug Engelbart invented the mouse at SRI in 1964

● Xerox PARC Alto computer (1974) used mouse, graphics, menus, and icons

Apple Computer, Inc.

Steve Jobs and Steve Wozniak The original Apple I

Apple II (1977)● color graphics● BASIC, 4K RAM● cassette tape data storage● $1300● VisiCalc released in 1979

Apple Computer, Inc.● Sales went from $2.5 million to $583 million in six years

● Fortune 500 by 1982

● Steve Jobs visits Xerox PARC in 1979

● Apple Macintosh introduced in 1984

● First widely available microcomputer with GUI

The Personal Computing Era is Born

TRS-80 Model II

Radio ShackTRS-80 Model I

affectionatelyknown as the“Trash 80”

Commodore PET (1977)

IBM PC (1981)

reverse-engineered by Compaq in 1985

The Internet and the World Wide Web● ARPANET created in 1969 by connecting together 4

computers at UCSB, UCLA, Utah, and SRI

● World Wide Web conceived at CERN in Switzerland in late 1980s by Tim Berners-Lee

● First Web browser written in 1990by Tim Berners-Lee using a NeXTcomputer

The Internet and the World Wide Web● Marc Andreesen and Eric Bina at the University of Illinois

develop Mosaic Web browser

● Marc Andreesen and Jim Clark found Netscape Communications, Inc. in 1994

● Netscape goes public on August 9, 1995 andis worth $3 billion by the end of the day

Marc Andreesen

The Future . . . ?

● “I think there is a world market for maybe five computers” —Thomas J. Watson Chairman of IBM, 1943

● “If automotive technology had progressed as fast as computer technology between 1960 and today, the car today would have an engine less than a tenth of an inch across, would get 120,000 miles per gallon, have a top speed of 240,000 miles per hour, and would cost $4”

—Rick Decker and Stuart Hirshfield The Analytical Engine

● Other predictions, anyone?

For Further Reading

One of the best available historiesof the personal computer revolution is

Fire in the Valley: the Making of the Personal Computerby Paul Freiberger and Michael Swaine