The History of Computers

How did this all get started?

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Learning Goals

• By the end of this unit, you should be able to...

• Recognize and state the trends that led to current day computers

• Be able to list examples of early computers and their contributions

• Be able to list some of the major players (e.g. who was Charles Babbage?)

• To gain a sense of the rapid development and huge distances that have been traveled, particularly in the last 30 years

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The Abacus

The oldest surviving abacus was used in 300 BC by the Babylonians.

300 BC

The word “calculus” comes from the Latin word for pebble

There are typically 4 or 5 markers for each finger, and 1 or 2 markers for each hand

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A More Modern Abacus

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Slide Rules

• Our parents / grandparents used slide rules...

• First build in England in 1632

• Used up until the 60s

• NASA used these for their calculations for Apollo

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The Calculating Clock

• First gear-driven calculating machine actually built

• Invented by Wilhelm Schickard

• Sadly, Schickard died of the plague not long after...

1623

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The Pascaline

• Blaise Pascal (19) invented this tool to help his father, a tax collector

• 50 were built, though suffered from inaccurate gears

1642

Up until the digital age, cars used the same mechanism in the odometer to increment a subsequent wheel after a full revolution of the first

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The Pascaline

• Blaise Pascal (19) invented this tool to help his father, a tax collector

• 50 were built, though suffered from inaccurate gears

1642

Up until the digital age, cars used the same mechanism in the odometer to increment a subsequent wheel after a full revolution of the first

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Stepped Reckoner

• Gears were unfortunately inaccurate

• In response, Gottfried Wilhelm Leibnitz invented the stepped reckoner

• It used a fluted cylinder with teeth of varying lengths

• Depending on the position, a sliding gear would meet with some or all of these teeth to get different results

1673

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The Jacquard Loom

• Invented by Joseph Marie Jacquard

• Powered loom that used punched wooden cards to automatically read in a pattern

• Needles pushed the threads through the holes to achieve different designs

1801

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Making cards

1801

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Jacquard’s own pattern

1801

• To demonstrate the coolness factor, Jacquard wove this self portrait

• It required 10,000 punch cards!

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Not a popular guy...

• The loom was able to replace workers due to its efficiency

• Consequently there was much unrest and many looms were smashed, and Jacquard even attacked

• Interestingly... history has shown that technology, in the long run, always seems to increase the number of jobs available....

1801

Today

Charles Babbage

1820s

• An English mathematician, he proposed a steam-driven calculating machine (the size of a room)

• He called this little device the Difference Engine

• The government funded him for their use in ocean navigation tables

• At that time, the British gov’t published a 7 vol. set of nag. tables which came with a companion volume of over 1000 corrections

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Charles Babbage

1820s

• The device was never completed

• But it did gain the dubious honour of the most expensive government-funded project in English history (up to that point)

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Analytic(al) Engine

1820s

• Instead, he went on to envision the Analytic Engine

• Large as a house, with 6 steam engines required...

• This device broke ground for its plan to use punch-card technology... i.e. it could be programmed!

• What’s more, it could hold data.. it had a rudimentary memory via the punch cards

• The “Store” held the numbers; the “Mill” wove them into new results

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Analytic(al) Engine

1820s

• Instead, he went on to envision the Analytic Engine

• Large as a house, with 6 steam engines required...

• This device broke ground for its plan to use punch-card technology... i.e. it could be programmed!

• What’s more, it could hold data.. it had a rudimentary memory via the punch cards

• The “Store” held the numbers; the “Mill” wove them into new results

Memory! CPU!

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Analytic(al) Engine

1820s

• It also had a fancy new feature: the conditional statement!

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Charles Babbage & Ada Byron

1820s

• During this time, Babbage became friends with 19-year-old Ada Byron

• She later married (someone else) and because Countess Lady Lovelace

• He wrote letters describing his work and met with her

• She wrote back and described her “Notes”

• Detailed sequences of instructions she had prepared for the Analytic Engine

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Charles Babbage & Ada Byron

1820s

• It was through these interactions that Byron because the first computer programmer in history

• She invented the subrountine (function), and recognized the importance of loops

• The programming language Ada was named in recognition of her work

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(Oh, and the Analytic Engine.. it wasn’t built either... but Babbage did dabble in things here and there... such as inventing the modern postal service, and the opthalmoscope)

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Census Taking

• In 1790 the first census took 9 months

• The 1880 census took almost 8 years

• A prize offered to the inventor of a better census system went to Herman Hollerith for the 1890 census

• He adopted (finally) the loom punch cards for computation

1890s

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Hollerith Desk

• Hollerith’s invention was a desk with...

• A card reader could sense holes in the card, which indicated numbers

• Gears that turned to add this count to the total

• A wall of dials to display the total

1890s

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Hollerith Desk

• The 1890 census?

• Took 3 years to complete

• Saved over 5 million dollars

1890s

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Hollerith

• The original punch cards could not be changed

• Hollerith observed that it would be useful to read one set of cards, and then have a device punch new cards in response

• This allowed for more complicated analyses

• This was the same idea that Babbage had....

1890s - 1900s

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The Tabulating Machine Company

• Hollerith started a company called the Tabulating Machine Company

• It leased tabulating machines (punch card machines) to companies

• Early adopters include department store sales analysis

• Pennsylvania Steel Co. for cost accounting based on labour and manufacturing

• And of course the census (though there was later competition from the Powers company)

1901

Today1920

Today

The Tabulating Machine Company• After a name change to Computing Tabulating

Recording Co...

• The company, in 1924, changed it’s name to International Business Machines Corp. (IBM)

...you may have heard of it!

1924

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Punch Cards

• ...became the staple

• Gas bill... punched card you had to return

• Government issued cheques

• Tolls on highways

• Library books

• Employee time cards

1900s - 1980s

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Mark I

• The original IBM inventions didn’t require negative numbers of multiplication since there uses were limited to accounting and inventory

• But the US military wished a system that was more scientific...

• They wanted to calculate shell trajectories based on physicists formulas -- called “firing tables”

• Hired people to do this job (the origin of the term “computer”!)

• An early success in automation was the Mark I1944

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Mark I

• Built as a partnership between Harvard and IBM in 1944

• The first programmable digital computer ever!

• It contained switches, relays, rotating shafts, and clutches

...Oh, and it filled a large room

It used 500 miles of wire, was 8 feet tall and 51 feet long!

1944

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Mark I

1944

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One of Mark’s tape readers:

1944

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Mark I

• It operated on numbers 23-digits wide

• Could add/subtract in 3/10ths of a second

• Could multiply in 4 seconds

• Could divide in 10 seconds

• Today computers require less than a billionth of a second to add

• It could store 72 numbers

• Today’s computers can store nearly a billion numbers in RAM, and 10s of billions on the hard drive

1944

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Mark I

• The principle designer, Howard Aiken (Harvard), is perhaps best known for his estimate that six electronic digital computers would be enough to satisfy the computing needs of the entire US

• IBM asked him to figure this out to determine if it was worth developing this invention as a standard product

• Luckily IBM didn’t give up...

• But no one foresaw the micro-electronics revolution1947

Today

Grace Hopper

• Remember the computer “bug”? It was the Mark I that Grace Hopper “debugged”!

• She went on to develop the first high-level language (i.e. not 1’s and 0’s!) called “Flow-matic”

• It eventually became COBOL

• A high-level language requires an intermediary program to translate it back to binary... this is called a compiler

• Hopper thus wrote the first compiler, too

1953

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Alan Turing’s Bombe

• The second world war also saw another use for computers: codebreaking

• Alan Turing developed an electromechanical machine for breaking Enigma codes

1930s

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Colossus

• This later led to the Colossus...

...both Colossus Mark I and Colossus Mark II

• Unlike the Harvard Mark machines, this relied on vacuum tubes

1943

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ENIAC: General Purpose Computing• Although still funded by military money, this time the

goal was an all-purpose machine that could replace all the “computers”

• ENIAC filled a 20 x 40 foot room, weight 30 tonnes, and used nearly 20,000 vacuum tubes

• Like Mark I it used paper card readers

• ENIAC was silent, but HOT! About 174,000 watts of heat, in fact

• To program, patch cords were rearranged

1945

Today

ENIAC

• ENIAC could only hold 20 numbers at a time

• But without moving parts it was much faster than the Mark I

• Multiplication took 2.8 thousandths of a second

• It’s clock speed was 100,000 cycles per second (ours today are about 2.5 billion per second)

• The first sample problem solved took 20 seconds (compared to the human answer obtained after 40 hours of work with a mechanical calculator)

1945

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ENIAC

• ENIAC’s first task?

• To determine if the hydrogen bomb was possible

• Sadly, 500,000 punch cards later, it’s answer was yes

1945

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ENIAC

1945

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ENIAC

1945

Today

ENIAC

1945

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UNIVAC

• By the end of the 50s, computers were no longer one-of-a-kind hand-built devices only for government and universities

• The inventors of ENIAC, Eckert and Mauchly went on to start a company called UNIVAC (“UNIVersal Automatic Computer”)

• This became the household word for computer in the 50s

• This was the first computer to use magnetic tape

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Micro-electronics Revolution

• Computers remained enormous for a long stretch of time....

• The micro electronics rev. saw the hand-wiring of the past mass-produced as integrated circuits

• These are fast to produce... and small

1959

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IBM 7030 (Stretch)

1959

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PDP-12 the mini- computer!

1969

An entire industry segment was devoted to “mini”

computers

The PDP-12 was a dual processor, 12-bit minicomputer intended for interactive lab use

(721 were built)

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Mainframe computers

1970s

• Large-scale, general purpose computers

• Two ways to interact:

• Time sharing (everyone got a short turn: realtime interaction)

• Batch mode (have your program ready before hand: non-realtime interaction)

• E.g. IBM 7090, IBM 360, IBM 370

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Mainframe computers (IBM 7090)

1970s

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Teletype

1970s

• Simultaneous, time-share interaction was achieved with a teletype

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Key Punch Machine

1970s

• To write your program to be run in batch mode, you needed a key punch machine to prepare your punch cards

Today

CDC 7600 (Early Cray Supercomp.)

1970s

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Microcomputing

• True micro computing did not become possible until the invention of the microprocessor

• Industry giant, Intel, invented the microprocessor in 1971 (20 years after the first computer)

• These general purpose chips could be used for anything

• Instead users supplied a program, stored in memory, to generate the desired behaviour

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Altair 8800 (8080 microprocessor)

• The first personal computer (PC)

• Developed by MITS

• Hand to built from a mail-order kit!

1975

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Altair 8800 (8080 microprocessor)

• In it’s original form, you could only make the lights blink

• It was programmed by flipping switches, then a special switch that loaded it all into memory-- this was repeated until the entire program was loaded, at which point it was run

• It later included a tape reader, additional RAM cards and a teletype terminal

1975

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Back to BASICs

• Around this time the Altair designers received a letter asking if they were interested, and to contact a Seattle-based company, called “Micro-soft”

• They contacted them only to realize there was no BASIC (yet), or company for that matter

• They were intrigued, though...

• Micro-soft (then Bill Gates and Paul Allen) wrote their own 8080 simulator (since they couldn’t afford an Altair) and ran it on a PDP-10

1975

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Back to BASICs

• Altair BASIC was then delivered to the company by Allen

• It was written on paper tape (with a bug)

• The next day the bug was corrected and the very first program typed in was “2+2”

...luckily, it returned 4

• Micro-soft was born!

• The language proved incredibly popular.. today there are more dialects of BASIC than any other language

1975

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Enter Apple...

• About this time Apple started on the scene, inspired by the Altair

• Steve Wozniak and Steve Jobs built their own computer and released it April 1st, 1976

• The original Apple was the first single circuit board computer

• It had a video interface, 8k of RAM and a keyboard

1976

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Enter Apple...

• About 200 units were built over 10 months and sold for $666.66!

1976

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Today

Now things start taking off...

• In 1977 we see the Apple II (sometimes written Apple ][)

• This was the first mass-produced Apple machine

1977

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Now things start taking off...

• By 1981 we have the IBM PC Home Computer

• As well as MS-DOS

1977

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Apple Macintosh

• “Never trust a computer you cannot lift!”

• One of the most famous TV commercials ever made...

1984

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Microsoft Windows

• Although far from the originators of the idea (Xerox gets that distinction for its STAR interface), undeniably the introduction of Windows changed the face of computers forever

• Released to the public in 1985, it was the first mass produced HCI that used the Desktop metaphor extensively, as well as the mouse

• The Desktop revolution had truly begun!

1985