A Brief History of Computers

The ENIAC was notoriously unreliable.

- vacuum tubes were much better than the relay switches, but still unreliable - consumed a lot of POWER - were to BIG

Transistors

- Like vacuum tubes, transistors could be used as amplifiers or as switches. - Advantages: much smaller (pea-sized), used no power, 100% reliable - one of the most important BREAKTHROUGHS in the history of computing - 1956 Nobel Prize in Physics. -

John von Neumann

- Mauchly and Eckert worked w/ him - they designed a better machine called EDVAC (Electronic Discrete Variable Automatic Computer) - Neumann helpe define how the machine stored and processed its PROGRAMS, laying the foundations for how all modern computers operate

Bill Gates and GUI

- Saw how Macintosh worked (easy to use) - launched WINDOWS, an upgraded version of his MS-DOS software. - Apple saw this as blatant plagiarism but case collapsed => Microsoft effectively secured right to use the Macintosh "look and feel" in all present and future versions of Windows. - MICROSOFT WINDOWS 95 system launched three years later

- Howard Aiken (1900-1973).

- Sponsored by IBM - FIRST LARGE SCALE DIGITAL COMPUTER OF THIS KIND (ELECTRICAL) - variously known as the HARVARD MARK I or the IBM Automatic Sequence Controlled Calculator (ASCC)

Alan Turing (1912-1954)

- THEORY of how computers processed information. - described a theoretical computer now known as a TURING MACHINE - "father of MODERN COMPUTING"—the 20th-century's equivalent of Babbage.

Steve Wozniak

- The Altair inspired him to make his own computer - "Woz": the hacker's "hacker"—technically brilliant and highly creative engineer who pushed the boundaries of computing largely for his own amusement. - used an INTEL processor to build the APPLE I

Vannevar Bush (1890-1974).

- US government scientist - Developed world's most powerful calculators - ultimate calculator: Rockefeller DIFFERENTIAL ANALYZER 1935) from 320 km (200 miles) of wire and 150 electric motor - known as ANALOG CALCULATORS

Bush's accomplishments

- WWII: Roosevelt appointed him US National Defense Research Committee, and then director of the Office of Scientific Research and Development (OSRD) - => in charge of the Manhattan Project - 1945: sketched out an idea for memory-storing and sharing device called MEMEX that would later inspire Tim Berners-Lee to INVENT the World Wide Web.

John Atanasoff (1903-1995) and Clifford Berry

- built a more elaborate binary machine that they named the Atanasoff Berry Computer (ABC). - 1000 times more accurate than Bush's Differential Analyzer

MITS Altair 8800

- built by Ed Roberts - first home computer - far cray from moderns PC's and laptops

"monolithic" integrated circuit (IC)

- collection of transistors and other components that could be manufactured all at once, in a block, on the surface of a semiconductor. - BUT components on IC still had to be connected by hand - At the same time, Robert Noyce was perfecting almost the same idea (at Fairchild) => Found a way to INCLUDE CONNECTIONS between components in an integrated circuit, thus AUTOMATING the entire process.

Bob Metcalfe

- developed a new way of LINKING COMPUTERS "through the ether" (empty space) that he called ETHERNET - left Xerox to form his own company, 3Com

Bill Gates

-Rapidly put together an operating system called DOS, based on a product called QDOS (Quick and Dirty Operating System - Some believe Microsoft and IBM cheated Kildall out of his place in computer history; Kildall himself accused them of copying his ideas. - Th IBM PC, powered by Microsoft's operating system, was a runaway success.

APPLE COMPUTER CORPORATION

-Steve Jobs persuaded Woz that they should go into business making the APPLE I - They set up in a garage belonging to Jobs' parents - Built the APPLE II, world's first easy-to-use home "MICROCOMPUTER"

Konrad Zuse (1910-1995)

constructed his Z1, the WORLD'S FIRST PROGRAMMABLE BINARY COMPUTER

World War II

crucial period in the history of computing, when powerful gargantuan computers began to appear

"Metcalfe's Law"

Computers become useful the more closely connected they are to other people's computers - Companies explored the power of local area networks (LANs) => became clear that there were great benefits to be gained by connecting computers over even greater distances—into wide area networks (WANs).

Ouptut

a printing mechanism

Input

a way of feeding in numbers

Binary Code

a way of representing any decimal number using only the two digits zero and one

The user revolution - Apple

- "user-friendliness." - Jobs went to PARC and saw the Xerox Alto

Colossus

- 1943 - Colossus was the first fully electronic computer - used the VACUUM TUBE instead of the relay system -

Gary Kildall

- 1976 - wrote an operating system called CP/M that acted as an intermediary between the user's programs and the machine's hardware - realized that all he had to do was REWRITE CP/M so it worked on each different machine. Then all those machines could run identical user programs—without any modification at all—inside CP/M. - Made all the different microcomputers compatible at a stroke. - first PC OPERATING SYSTEM - became billionaire

analog calculators

- ANALOG because they stored numbers in a PHYSICAL form (as so many turns on a wheel or twists of a belt) rather than as digits. - Could carry out incredibly complex calculations but it took several days of wheel cranking and belt turning before the results finally emerged.

Herman Hollerith (1860-1929)

- American statistician - built one of the world's first PRACTICAL CALCULATING MACHINE => TABULATOR - to help compile census data (was occurring every 7 1/2 yrs). Full analysis done in 2 1/2 yrs - TABULATING MACHINE COMPANY in 1896 to manufacture it commercially - Tabulating Machine Company => Computing Tabulating Recording (C-T-R) =>INTERNATIONAL BUSINESS MACHINES (IBM) in 1924

IBM fights back

- Apple's success selling to businesses was a shock to IBM and the other big companies - released the IBM PERSONAL COMPUTER (PC) - Won the market back

Tim Berners-Lee

- BIG IDEA: combine the power of computer networks with the information-sharing idea Vannevar Bush had proposed in 1945. - World Wide Web was invented —an easy way of sharing information over a computer network

Claude Shannon (1916-2001)

- Bush's student - brilliant mathematician - figured out how ELECTRICAL CIRCUITS could be linked together to process BINARY CODE with Boolean algebra (a way of comparing binary numbers using logic) and thus make SIMPLE DECISIONS

Calculators vs Computers

- Calculator: a device that makes it quicker and easier for people to do sums—but it needs a human operator. - Computer: on the other hand, is a machine that can operate automatically, without any human help, by following a series of stored instructions called a program (a kind of mathematical recipe). - Calculators EVOLVED into computers when people devised ways of making entirely automatic, programmable calculators. - Pascal and Lebiniz's inventions weren't computers

Augusta Ada Byron (1815-1852)

- Countess of Lovelace, daughter of poet LORD BYRON - enthusiastic mathematician - helped to refine Babbage's ideas for making his machine programmable - => this is why she is still, sometimes, referred to as the world's first COMPUTER PROGRAMMER - little survived after his death

John Mauchly (1907-1980) and J. Presper Eckert (1919-1995)

- ENIAC's inventors, - Electronic Numerical Integrator And Calculator (ENIAC). - first time public saw the vacuum - world's first FULLY ELECTRONIC, GENERAL-PURPOSE, DIGITAL COMPUTER. - Colossus might have qualified for this title too, but it was designed purely for one job (code-breaking) - Formed the Eckert Mauchly Computer Corporation in the 40s

Blaise Pascal (1623-1666)

- French scientist and philosopher - in 1642, age 18 - first practical mechanical calculator, the PASCALINE - to help his tax-collector father do his sums. - series of interlocking COGS (gear wheels with teeth around their outer edges) - could add and subtract decimal numbers

Gottfried Wilhelm Leibniz (1646-1716)

- German mathematician and philosopher - similar but more advanced machine (like the Pascaline) - instead of cogs, it had a "STEPPED DURM" (a cylinder with teeth of increasing length around its edge), an innovation that survived in mechanical calculators for 300 hundred years. - The LEBINIZ MACHINE could do much more than Pascal's: - add, subtract, multiply, divide, square roots - Another pioneering feature was the first memory store or "REGISTER" - also invented BINARY CODE

IBM vs the CP/M

- IBM wanted to buy CP/M for much less than it was worth - IBM turned to BILL GATES, Microsoft owner and programmer

Integrated Electronics

- INTEL for short - founded by Robert Noyce and Gordon Moore who had left Fairchild - Made a UNIVERSAL CHIP that could be programmed to work in computers and calcs - The general-purpose, single chip computer or MICROPROCESSOR WAS BORN - the next phase of the computer revolution.

Apple Lisa

- Jobs launched his own version of the Alto project to develop an easy-to-use computer called PITS (Person In The Street). - became the Apple Lisa (1983)—the first widely available computer with a GUI DESKTOP - was too expensive but cheaper machine called the MACINTOSH (1984)

The Manhattan Project

secret $2-billion initiative that led to the creation of the atomic bomb

Turing machine

simple information processor that works through a series of instructions, reading data, writing results, and then moving on to the next instruction

Turing test

simple way to find out whether a computer can be considered intelligent => sees if it can sustain a plausible conversation with a real human being.

Memory

something to store these numbers while complex calculations were taking place)

Processor

the number-cruncher that carried out the calculations

More on Turing

- development of code-breaking machinery that played a key part in Britain's wartime victory - played a lesser role in the creation of several large-scale experimental computers including ACE (Automatic Computing Engine), Colossus, and the Manchester/Ferranti Mark I (described below). - Best known for conceiving what's become known as the TURING TEST , a simple way to find out whether a computer can be considered intelligent by seeing whether it can sustain a plausible conversation with a real human being.

William Shockley

- formed a corporation to continue working on trasistor - hired best brains - employees like Noyce and Moore left the company due to Shockley's management style

Charles Babbage (1791-1871)

- grumpy English mathematician - "father of the computer" because his machines had an INPUT , a MEMORY, a PROCESSOR, and an OUPUT—the same basic components shared by all modern computers.

Xerox Alto

- had a desktop-like screen with little picture icons that could be moved around with a mouse - was the very first graphical user interface (GUI, pronounced "gooey") - idea conceived by Alan Kay (1940-) and now used in virtually every modern computer.

The beginning...

- history of computers dates back 2500 yrs ago - the abacus - became great inventions in last 2 decades of 20th century

Apple II

- home users, schools, and small businesses were buying it - a disk drive unit: made it easy to store data; - spreadsheet program called VisiCalc: gave Apple users the ability to analyze that data.

Jack Kilby (1923-2005)

- how to improve the transistor in Dallas - transistors were a great advance on vacuum tubes BUT => Machines that used thousands of transistors still had to be HAND WIRED to connect everything - so he invented the "MONOLITHIC" INTEGRATED CIRCUIT (IC)

integrated circuits

- increasingly sophisticated and compact. - engineers were speaking of large-scale integration (LSI), in which hundreds of components could be crammed onto a single chip, and then very large-scale integrated (VLSI), when the same chip could contain thousands of components.

"Bug"

- modern term for a problem that holds up a computer program - 1950s - MOTHS, attracted by the glowing lights of vacuum tubes, flew inside machines like the ENIAC, caused a SHORT CIRCUIT, and brought work to a juddering halt.

Lee de Forest (1873-1961)

- named the AUDION - invented the vacuum tube - better form of a switch - each one about as big as a person's thumb and glowing red hot like a tiny electric light bulb - 1906 - the FATHER OF THE RADIO" because their first major use was in radio receivers

Babbage's results

- never completed a single one of the hugely ambitious machines that he tried to build. - no surprise => each engine had tens of thousands of precision-made gears - British gov't financed 17,000 pounds then pulled out - Augusta Ada Byron helped him more

The abacus

- simple calculator made from beads and wires - still used in some parts of the world today. - the principle—making repeated calculations more quickly than the human brain—is exactly the same in modern computers and the abacus - invented circa 500 BC in the Middle East - fastest form of calculator until mid 17th CENTURY

John Bardeen, Walter Brattain, and William Shockley

- solution for size of the ENIAC - created a new form of amplifier => the POINT-CONTACT TRANSISTOR - Shockley then invented the JUNCTION TRANSISTOR, which has formed the BASIS of most transistors ever since.

The PC

- successful essentially for one reason - all other microcomputers were INCOMPATIBLE, used different hardware and worked in different way s

INTEL and MICROSOFT succeed

- supplying the software and hardware for almost every PC on the planet.

George Boole (1815-1864)

- used the idea of BINARY CODE to invent a new branch of mathematics called BOOLEAN ALGEBRA - binary code and Boolean algebra => allow computers to make simple decisions by comparing long strings of zeros and ones

First machines that used ELECTRICAL SWITCHES to store numbers

- when a switch was "off", stored the number zero - flipped over to its other, "on", position, stored the number one - Hundreds or thousands of switches could store a great many binary digits. These machines were DIGITAL COMPUTERS: unlike analog machines, which stored numbers using the positions of wheels and rods, they STORED NUMBERS AS DIGITS.

The Internet

-, the best known WAN today - a global network of individual computers and LANs that links up hundreds of millions of people. - began in 60s - when 4 universities made the first WAN

So Bush was...

1) Father of the digital computer 2) Overseer of the atom bomb 3) Inspiration for the Web Bush played a pivotal role in three of the 20th-century's most far-reaching technologies.

Fairchild Semiconductor,

1956 - eight of them—including Noyce and Moore—left Shockley Transistor to found their own company (Fairchild Semiconductor) - Thus began the growth of "SILICON VALLEY," the part of California centered on Palo Alto