a history of computers - st monica's college · 2012-11-27 · 1937 ad george robert...

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History ofComputers!

350 Million Years BC The first tetrapods leave the oceans

30,000 BC to 20,000 BC Carving notches into bones

8500 BC Bone carved with prime numbers discovered

1900 BC to 1800 BC The first place-value number system

1000 BC to 500 BC The invention of the abacus

383 BC to 322 BC Aristotle and the Tree of Porphyry

300 BC to 600 AD The first use of zero and negative numbers

1274 AD Ramon Lull's Ars Magna

1285 AD to 1349 AD William of Ockham's logical transformations

1434 AD The first self-striking water clock

1500 AD Leonardo da Vinci's mechanical calculator

1600 AD John Napier and Napier's Bones

1621 AD The invention of the slide rule

1625 AD Wilhelm Schickard's mechanical calculator

1640 AD Blaise Pascal's Arithmetic Machine

1658 AD Pascal creates a scandle

1670 AD Gottfried von Leibniz's Step Reckoner

1714 AD The first English typewriter patent

1726 AD Jonathan Swift writes Gulliver's Travels

1735 AD The Billiard cue is invented

1761 AD Leonhard Euler's geometric system for problems in class logic

1800 AD Jacquard's punched cards

Circa 1800 AD Charles Stanhope invents the Stanhope Demonstrator

1822 AD Charles Babbage's Difference Engine

1829 AD Sir Charles Wheatstone invents the accordion

1829 AD The first American typewriter patent

1830 AD Charles Babbage's Analytical Engine

1834 AD Georg and Edward Scheutz's Difference Engine

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1834 AD Tally sticks: The hidden dangers

1837 AD Samuel Morse invents the electric telegraph

1847 AD to 1854 AD George Boole invents Boolean Algebra

1857 AD Sir Charles Wheatstone uses paper tape to store data

1860 AD Sir Joseph Wilson Swan's first experimental light bulb

1865 AD Lewis Carroll writes Alice's Adventures in Wonderland

1867 AD The first commercial typewriter

1868 AD First skeletons of Cro-Magnon man discovered

1869 AD William Stanley Jevons invents the Jevons' Logic Machine

1872 AD Lewis Carroll writes Through the Looking-Glass

Circa 1874 AD The Sholes keyboard

1876 AD Lewis Carroll writes The Hunting of the Snark

1876 AD George Barnard Grant's Difference Engine

1878 AD The first true incandescent light bulb

1878 AD The first shift-key typewriter

1879 AD Robert Harley publishes article on the Stanhope Demonstrator

1880 AD The invention of the Baudot Code

1881 AD Allan Marquand's rectangular logic diagrams

1881 AD Allan Marquand invents the Marquand Logic Machine

1883 AD Thomas Alva Edison discovers the Edison Effect

1886 AD Lewis Carroll writes The game of Logic

1886 AD Charles Pierce links Boolean algebra to circuits based on switches

1890 AD John Venn invents Venn Diagrams

1890 AD Herman Hollerith's tabulating machines

Circa 1900 AD John Ambrose Fleming invents the vacuum tube

1902 AD The first teleprinters

1906 AD Lee de Forest invents the Triode

1921 AD Karel Capek's R.U.R. (Rossum's Universal Robots)

1926 AD First patent for a semiconductor transistor

1927 AD Vannevar Bush's Differential Analyser

Circa 1936 AD The Dvorak keyboard

1936 AD Benjamin Burack constructs the first electrical logic machine



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1937 AD George Robert Stibitz's Complex Number Calculator

1937 AD Alan Turing invents the Turing Machine

1938 AD Claude Shannon's master's Thesis

1939 AD John Vincent Atanasoff's special-purpose electronic digital computer

1939 AD to 1944 AD Howard Aiken's Harvard Mark I (the IBM ASCC)

1940 AD The first example of remote computing

1941 AD Konrad Zuse and his Z1, Z3, and Z4

1943 AD Alan Turing and COLOSSUS

1943 AD to 1946 AD The first general-purpose electronic computer -- ENIAC

1944 AD to 1952 AD The first stored program computer -- EDVAC

1945 AD The "first" computer bug

1945 AD Johann (John) Von Neumann writes the "First Draft"

1947 AD First point-contact transistor

1948 AD to 1951 AD The first commercial computer -- UNIVAC

1949 AD EDSAC performs it's first calculation

1949 AD The first assembler -- "Initial Orders"

Circa 1950 AD Maurice Karnaugh invents Karnaugh Maps

1950 AD First bipolar junction transistor

1952 AD G.W.A. Dummer conceives integrated circuits

1953 AD First TV Dinner

1957 AD IBM 610 Auto-Point Computer

1958 AD First integrated circuit

1962 AD First field-effect transistor

1962 AD The "worst" computer bug

1963 AD MIT's LINC Computer

1970 AD First static and dynamic RAMs

1971 AD CTC's Datapoint 2200 Computer

1971 AD The Kenbak-1 Computer

1971 AD The first microprocessor: the 4004

1972 AD The 8008 microprocessor

1973 AD The Xerox Alto Computer

1973 AD The Micral microcomputer









1973 AD The Scelbi-8H microcomputer



1974 AD The Mark-8 microcomputer


1975 AD The Altair 8800 microcomputer

1975 AD Bill Gates and Paul Allen found Microsoft

1975 AD The KIM-1 microcomputer

1975 AD The Sphere 1 microcomputer

1976 AD The Z80 microprocessor

1976 AD The Apple I and Apple II microcomputers

1977 AD The Commodore PET microcomputer

1977 AD The TRS-80 microcomputer

1979 AD The VisiCalc spreadsheet program

1979 AD ADA programming language is named after Ada Lovelace

1980 AD Danny Cohen writes "On Holy Wars and a Plea for Peace"

1981 AD The first IBM PC

1997 AD The first Beboputer Virtual Computer

Further Reading



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350 Million Years BCThe First Tetrapods Leave the Oceans

The number system we use on a day-to-day basis is the decimal system, which isbased on ten digits: zero through nine. The name decimal comes from the Latin decemmeaning ten, while the symbols we use to represent these digits arrived in Europearound the thirteenth century from the Arabs who, in turn, acquired them from theHindus.a

As the decimal system isbased on ten digits, it is said to bebase-10 or radix-10, where theterm radix comes from the Latinword meaning "root" . Outside ofspecialist requirements such ascomputing, base-10 numberingsystems have been adoptedalmost universally.

This is almost certainly due tothe fact that we happen to haveten fingers (including our thumbs).If mother nature had decreed sixfingers on each hand we wouldprobably be using a base-twelvenumbering system.

In fact this isn't as far-fetched as it may atfirst seem. The term "tetrapod" refers to ananimal which has four limbs, along with hipsand shoulders and fingers and toes. In themid-1980s, paleontologists discoveredAcanthostega who, at approximately 350 millionyears old, is the most primitive tetrapod known-- so primitive in fact that these creatures stilllived exclusively in water and had not yetventured onto land.

The first tetrapod had 8 fingers on each handCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

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After the dinosaurs (who were also tetrapods) exited the stage, humans were onebranch of the tetrapod tree that eventually inherited the earth (along with hippopotami,hedgehogs, aardvarks, frogs, ...... and all of the other vertebrates). Ultimately, we're alldescended from Acanthostega or one of her cousins. The point is that Acanthostegahad eight fully evolved fingers on each hand (see the figure above), so if evolutionhadn't taken a slight detour, we'd probably have ended up using a base-sixteennumbering system, which would have been jolly handy when we finally got around toinventing computers, let me tell you! (As a point of interest, the Irish hero Cuchulain wasreported as having seven fingers on each hand, but this would have been no help incomputing whatsoever.)

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These notes are abstracted from the book Bebop BYTES Back(An Unconventional Guide to Computers) Copyright Information

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30,000 BC to 20,000 BCCarving Notches Into Bones

The first tools used asaids to calculation werealmost certainly man's ownfingers, and it is not simply acoincidence that the word"digit" is used to refer to afinger (or toe) as well as anumerical quantity.

As the need to represent larger numbers grew,early man employed readily available materials for thepurpose. Small stones or pebbles could be used torepresent larger numbers than fingers and toes, andhad the added advantage of being able to easily storeintermediate results for later use. Thus, it is also nocoincidence that the word "calculate" is derived fromthe Latin word for pebble.

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The oldest known objects used to represent numbers are bones with notches carvedinto them. These bones, which were discovered in western Europe, date from theAurignacian period 20,000 to 30,000 years ago and correspond to the first appearanceof Cro-Magnon man. (The term "Cro-Magnon" comes from caves of the same name inSouthern France, in which the first skeletons of this race were discovered in 1868.)

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Of special interest is a wolf's jawbonemore than 20,000 years old with fifty-fivenotches in groups of five. This bone, whichwas discovered in Czechoslovakia in 1937,is the first evidence of the tally system.

The tally system is still used to thepresent day, and could therefore qualify asone of the most enduring of humaninventions (see also Tally Sticks: TheHidden Dangers).

The first evidence of the tally system.Copyright (c) 1997. Maxfield & Montrose Interactive Inc.

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Carving Notches Into Bones

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Also of interest is a piece of bone dating from around 8,500 BC, which wasdiscovered in Africa, and which appears to have notches representing the primenumbers 11, 13, 17, and 19. Prime numbers are those that are only wholly divisible bythe number one and themselves, so it is not surprising that early man would haveattributed them with a special significance. What is surprising is that someone of thatera had the mathematical sophistication to recognize this quite advanced concept andtook the trouble to write it down -- not the least that prime numbers had little relevanceto everyday problems of gathering food and staying alive.

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Carving Notches Into Bones





1900 BCThe First Place-Value Number System

The decimal system with which weare fated is a place-value system,which means that the value of aparticular digit depends both on thedigit itself and on its position within thenumber. For example, a four in theright-hand column simply means four...... in the next column it means forty...... one more column over meansfour-hundred ...... then four thousand,and so on.

For many arithmetic operations, theuse of a number system whose base iswholly divisible by many numbers,especially the smaller values, conveyscertain advantages. And so we come tothe Babylonians, who were famous fortheir astrological observations andcalculations, and who used asexagesimal (base-60) numbering system(see also The invention of the abacus).

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Although sixty may appear to be a large value to have as a base, it does conveycertain advantages. Sixty is the smallest number that can be wholly divided by two,three, four, five, and six ...... and of course it can also be divided by ten, fifteen, twenty,and thirty. In addition to using base sixty, the Babylonians also made use six and ten assub-bases.a

The Babylonian's sexagesimal system, whichfirst appeared around 1900 to 1800 BC, is alsocredited as being the first known place-valuenumber system, in which the value of a particulardigit depends both on the digit itself and its positionwithin the number. This was an extremely importantdevelopment, because prior to place-value systemspeople were obliged to use different symbols torepresent different powers of a base, and havingunique symbols for ten, one-hundred, onethousand, and so forth makes even rudimentarycalculations very difficult to perform (see also TheAncient Egyptians).

Finally, although theBabylonian's sexagesimalsystem may seem unwieldy tous, one cannot help but feel thatit was an improvement on theSumerians who came beforethem. The Sumerians had threedistinct counting systems to keeptrack of land, produce, andanimals, and they used acompletely different set ofsymbols for each system!

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The First Place-Value Number System



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The First Place-Value Number System





1000 BC to 500 BCThe Invention of the Abacus

The first actual calculating mechanismknown to us is the abacus, which is thoughtto have been invented by the Babylonianssometime between 1,000 BC and 500 BC,although some pundits are of the opinion thatit was actually invented by the Chinese (seealso The first place-value number system).

The word abacus comes to us byway of Latin as a mutation of theGreek word abax. In turn, the Greeksmay have adopted the Phoenicianword abak, meaning "sand", althoughsome authorities lean toward theHebrew word abhaq, meaning "dust."

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Irrespective of the source, the original concept referred to a flat stone covered withsand (or dust) into which numeric symbols were drawn. The first abacus was almostcertainly based on such a stone, with pebbles being placed on lines drawn in the sand.Over time the stone was replaced by a wooden frame supporting thin sticks, braidedhair, or leather thongs, onto which clay beads or pebbles with holes were threaded.a

A variety of different types ofabacus were developed, but themost popular became those basedon the bi-quinary system, whichutilizes a combination of two bases(base-2 and base-5) to representdecimal numbers. Although theabacus does not qualify as amechanical calculator, it certainlystands proud as one of firstmechanical aids to calculation.

See also:Leonardo da Vinci's mechanical calculator

John Napier and Napier's Bones

The invention of the slide rule

Wilhelm Schickard's mechanical calculator

Blaise Pascal's Arithmetic Machine

Gottfried von Libniz's Step Reckoner

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The Invention of the Abacus





The Invention of the Abacus




Logic Diagrams

As we may or may not have previously discused (depending on the way in whichyou're bouncing around our web pages), these days we are predominantly concernedwith computers, but it's worth noting that there has historically been a great deal offascination in logic in general. This fascination was initially expressed in the form oflogic diagrams, and later in the construction of special-purpose logic machines formanipulating logical expressions and representations.a

Diagrams used to representlogical concepts have been aroundin one form or another for a verylong time. For example, the Greekphilosopher and scientist Aristotle(384 BC to 322 BC) was certainlyfamiliar with the idea of using astylized tree figure to represent therelationships between (andsuccessive sub-divisions of) suchthings as different species.Diagrams of this type, which areknown as the Tree of Porphyry,are often to be found in medievalpictures.

Following the Tree of Porphyry, thereseems to have been a dearth of activity on thelogic diagram front until 1761, when the brilliantSwiss mathematician Leonhard Eulerintroduced a geometric system that couldgenerate solutions for problems in class logic.

Euler's work in this area didn't really catchon, however, because it was somewhatawkward to use, and it was eventuallysupplanted in the 1890s by a more polishedscheme proposed by the English logician JohnVenn. Venn was heavily influenced by the workof George Boole, and his Venn Diagrams verymuch complemented Boolean Algebra.

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Venn Diagrams were strongly based on the interrelationships between overlappingcircles or ellipses. The first logic diagrams based on squares or rectangles wereintroduced in 1881 by Allan Marquand, a lecturer in logic and ethics at John HopkinsUniversity.

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Logic Diagrams



Marquand's diagrams spurredinterest by a number of othercontenders, including one offering byan English logician and author, theReverend Charles LutwidgeDodgson.

Dodgson's diagrammatictechnique first appeared in his bookThe game of Logic, which waspublished in 1886, but he is betterknown to us by his pen-name, LewisCarroll, and as being the author ofAlice's Adventures in Wonderland.

Lewis CarrollCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

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Leaping from one topic to another with the agility of a mountain goat, we might alsonote that Lewis Carroll enjoyed posing logical conundrums in many of his books, suchas Alice's Adventures in Wonderland (1865), Through the Looking-Glass (1872), andThe Hunting of the Snark (1876). For example, consider this scene from the MadHatter's tea party in Chapter 7 of Alice's Adventures in Wonderland:a

"Take some more tea," the March Hare said to Alice, very earnestly.a

"I've had nothing yet," Alice replied in an offended tone: "so I can't take more."a

"You mean you can't take less," said the hatter:"it's very easy to take more than nothing."

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And we would have to chastise ourselves soundly if we neglected the sceneinvolving Tweedledum and Tweedledee in Chapter 4 of Through the Looking-Glass:a

"I know what you're thinking about," said Tweedledum; "but it isn't so, nohow."a

"Contrariwise," continued Tweedledee, "if it was so, it might be; and if it were so, itwould be; but as it isn't, it ain't. That's logic."

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Logic Diagrams


You have to admit, thesegems of information aren't tobe found in your averagehistory of computers, arethey? But once again we'vewandered off the beaten path("No," you cry, "tell me it isn'tso!").

Apart from anything else, rectangular logicdiagrams as espoused by Allan Marquand and LewisCarroll are of interest to us because they were theforerunners of a more modern form known asKarnaugh Maps. Karnaugh Maps, which wereinvented by Maurice Karnaugh, in the 1950s, quicklybecame one of the mainstays of the digital logic andcomputer designer's tool-chest.

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Logic Diagrams





300 BC to 600 ADThe First Use of Zero and Negative Numbers

Interestingly enough, the idea of numbers like one, two, and three developed along time before the concept of zero. This was largely because the requirement for anumber "zero" was less than obvious in the context of the calculations that early manwas trying to perform.a

For example, suppose that a young man'sfather had instructed him to stroll up to the topfield to count their herd of goats and, onarriving, the lad discovered the gate wideopen and no goats to be seen. First, his taskon the counting front had effectively beendone for him. Second, on returning to hisaged parent, he probably wouldn't feel theneed to say: "Oh revered one, I regret toinform you that the result of my calculationslead me to believe that we are the proudpossessors of zero goats."

Instead, he would be far more inclined toproclaim something along the lines of:"Father, some drongo left the gate open andall of our goats have wandered off."

In the case of the originalBabylonian system (see also The firstplace-value number system), a zerowas simply represented by a space.Imagine if, in our decimal system,instead of writing 104(one-hundred-and-four) we were towrite 1 4 (one-space-four).

It's easy to see how this can lead toa certain amount of confusion,especially when there are multiplezeros next to each other. Theproblems can only be exacerbated if,like the Babylonians, one is using abase-sixty system and writing on claytablets in a thunderstorm.

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After more than 1,500 years of potentially inaccurate calculations, the Babyloniansfinally began to use a special sign for zero. Many historians believe that this sign, whichfirst appeared around 300 BC, was one of the most significant inventions in the historyof mathematics. However, the Babylonians only used their symbol as a place holderand they didn't have the concept of zero as an actual value. Thus, clay tablet accountingrecords of the time couldn't say something like "0 fish," but instead they had to write outin full: "We don't have any fish left."a

The First Use of Zero and Negative Numbers



The use of zero as an actual value, along with the concept of negative numbers,first appeared in India around 600 AD. Although negative numbers appear reasonablyobvious to us today, they were not well-understood until modern times. As recently asthe eighteenth century, the great Swiss mathematician Leonhard Euler (pronounced"Oiler" in America) believed that negative numbers were greater than infinity, and it wascommon practice to ignore any negative results returned by equations on theassumption that they were meaningless!

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The First Use of Zero and Negative Numbers





1274 ADRamon Lull's Ars Magna

Possibly the first person in the history of formal logic to use a mechanical device togenerate (so-called) logical proofs was the Spanish theologian Ramon Lull (see alsologic diagrams and logic machines). In 1274, Lull climbed Mount Randa in Majorca insearch of spiritual sustenance.a

After fasting and contemplating his navelfor several days, Lull experienced what hebelieved to be a divine revelation, and hepromptly rushed back down the mountain topen his famous Ars Magna. This magnumopus described a number of eccentric logicaltechniques, but the one of which Lull wasmost proud (and which received the mostattention) was based on concentric disks ofcard, wood, or metal mounted on a centralaxis.

Ramon Lull's disks.a

Lull's idea was that each disk should contain a number of different words or symbols,which could be combined in different ways by rotating the disks. In the case of oursomewhat jocular example shown above, we can achieve 4 x 4 x 4 = 64 differentsentences along the lines of "I love mice," "You hate cats," and "They eat frogs."a

Ramon Lull's Ars Magna

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Of course, Lull had amore serious purpose inmind, which was to provethe truth of everythingcontained within theBible. For example, heused his disks to showthat "God's mercy isinfinite," "God's mercy ismysterious," "God'smercy is just," and soforth.

Lull's devices were far more complex than our simpleexample might suggest, with several containing as manyas sixteen different words or symbols on each disk. Hismasterpiece was the figura universalis, which consistedof fourteen concentric circles (the mind boggles at therange of combinations that could be generated by thisdevice).

Strange as it may seem to us, Lull's followers (calledLullists) flourished in the late middle ages and therenaissance, and Lullism spread far and wide acrossEurope.

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Why is all of this of interest to us? Well by some strange quirk of fate, Lull's work firedthe imagination of several characters with whom we are already familiar, such asGottfried von Leibniz who invented the mechanical calculator called the Step Reckoner.(See also Jonathan Swift and Gulliver's Travels.)a

Although Leibniz had little regard for Lull'swork in general, he believed there was a chance itcould be extended to apply to formal logic. In a rareflight of fancy, Leibniz conjectured that it might bepossible to create a universal algebra that couldrepresent just about everything under the sun,including (but not limited to) moral andmetaphysical truths.

In 1666, at the age of 19,Leibniz wrote his Dissertio deArte Combinatoria, from whichcomes a famous quotedescribing the way in which hebelieved the world could be inthe future:

a"If controversies were to arise," said Leibniz, "there would be no more need ofdisputation between two philosophers than between two accountants. For it

would suffice to take their pencils in their hands, and say to each other: Let uscalculate."

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1285 AD to 1349 ADWilliam of Ockham's Logical Transformations

William of Ockham (also known as William of Occam) was born in 1285 in Surrey,England, and lived until sometime around 1349. Ockham (who entered the Franciscanorder and studied and taught at the University of Oxford from 1309 to 1319) was knownas Doctor Invincibilis (from the Latin, meaning "unconquerable doctor") and VenerabilisInceptor (meaning "worthy initiator").a

Ockham was a philosopher and Scholastictheologian, and also won fame as a logician.During the course of his logical investigations,Ockham discovered the foundations for whatwere to become known as DeMorganTransformations, which were described byAugustus DeMorgan some 500 years later.

To celebrate Ockham's positionin history, the OCCAM computerprogramming language was namedin his honor. (OCCAM is the nativeprogramming language for theBritish-developed INMOStransputer.)

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William of Ockham's Logical Transformations

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1434 ADThe First Self-Striking Water Clock

In addition to the Egyptians (seealso The ancient egyptians), manyother people experimented withwater clocks and some interestingvariations sprouted forth. Forexample, in some cases a float wasconnected to a wheel and, as thefloat changed its level, the wheelturned to indicate the hour on a dial.

Water clocks were also a standard meansof keeping time in Korea as early as the "ThreeKingdoms" period, and it was here that one ofthe first known automatic water clocks wasdevised in 1434. This clock was calledChagyongnu, which literally translates as"self-striking water clock." When the waterreached a certain level, a trigger devicereleased a metal ball which rolled down achute into a metal drum to "gong the hour."

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The First Self-Striking Water Clock







1500 ADLeonardo da Vinci's Mechanical Calculator

Many references cite the Frenchmathematician, physicist, and theologian,Blaise Pascal as being credited with theinvention of the first operationalcalculating machine called the ArithmeticMachine.

However, it now appears that the firstmechanical calculator may have beenconceived by Leonardo da Vinci almostone hundred and fifty years earlier thanPascal's machine.

Leonardo da Vinci.Copyright (c) 1997. Maxfield & Montrose Interactive Inc.

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One of da Vinci's original sketches.Courtesy of IBM

Da Vinci was a genius:painter, musician, sculptor,architect, engineer, and so on.However, his contributions tomechanical calculation remainedhidden until the rediscovery oftwo of his notebooks in 1967.

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These notebooks, which datefrom sometime around the 1500s,contained drawings of a mechanicalcalculator, and working models of daVinci's device have since beenconstructed. Working model of da Vinci's device.

Courtesy of IBM

Leonardo da Vinci's Mechanical Calculator



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See also:The invention of the abacus






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Leonardo da Vinci's Mechanical Calculator





1600 ADJohn Napier and Napier's Bones

In the early 1600s, a Scottishmathematician called John Napierinvented a tool called Napier's Bones,which were multiplication tablesinscribed on strips of wood or bone.

Napier, who was the Laird ofMerchiston, also invented logarithms,which greatly assisted in arithmeticcalculations.

Napier's Bones.Courtesy of IBM

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John Napier.Copyright (c) 1997. Maxfield & Montrose Interactive Inc.

In 1621, an English mathematicianand clergyman called William Oughtredused Napier's logarithms as the basis forthe slide rule (Oughtred invented boththe standard rectilinear slide rule and theless commonly used circular slide rule).However, although the slide rule was anexceptionally effective tool that remainedin common use for over three hundredyears, like the abacus it also does notqualify as a mechanical calculator.

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See also:




Leonardo da Vinci's mechanical calculator




The invention of the abacus


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1625 ADWilhelm Schickard's Mechanical Calculator

As was previously noted,determining who invented the firstmechanical calculator is somewhatproblematical. Many references citethe French mathematician,physicist, and theologian, BlaisePascal as being credited with theinvention of the first operationalcalculating machine called theArithmetic Machine.

However, Pascal's claim to famenotwithstanding, the German astronomer andmathematician Wilhelm Schickard wrote aletter to his friend Johannes Kepler aboutfifteen years before Pascal started developinghis Arithmetic Machine. (Kepler, a Germanastronomer and natural philosopher, was thefirst person to realize (and prove) that theplanets travel around the sun in ellipticalorbits.)

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In his letter, Schickard wrote that he had built a machine that "...immediatelycomputes the given numbers automatically; adds, subtracts, multiplies, and divides".Unfortunately, no original copies of Schickard's machine exist, but working models havebeen constructed from his notes.a







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Wilhelm Schickard's Mechanical Calculator






Wilhelm Schickard's Mechanical Calculator


1640 ADBlaise Pascal's Arithmetic Machine

As fate would have it,determining who invented the firstmechanical calculator is somewhatproblematical. Many references citethe French mathematician, physicist,and theologian, Blaise Pascal asbeing credited with the invention ofthe first operational calculatingmachine.

Blaise Pascal.Copyright (c) 1997. Maxfield & Montrose Interactive Inc.

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Pascal's Arithmetic Machine.Courtesy of IBM

In 1640, Pascal started developing adevice to help his father add sums ofmoney. The first operating model, theArithmetic Machine, was introduced in1642, and Pascal created fifty more devicesover the next ten years. (In 1658, Pascalcreated a scandal when, under thepseudonym of Amos Dettonville, hechallenged other mathematicians to acontest and then awarded the prize tohimself!)

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However, Pascal's device could only add and subtract, while multiplication anddivision operations were implemented by performing a series of additions orsubtractions. In fact the Arithmetic Machine could really only add, because subtractionswere performed using complement techniques, in which the number to be subtracted isfirst converted into its complement, which is then added to the first number. Interestinglyenough, modern computers employ similar complement techniques.a







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1670 ADGottfried von Leibniz's Step Reckoner

In the 1670s, a German Baroncalled Gottfried von Leibniz(sometimes von Leibnitz) tookmechanical calculation a step beyondhis predecessors.

Leibniz, who entered university atfifteen years of age and received hisbachelor's degree at seventeen, oncesaid: "It is unworthy of excellent mento lose hours like slaves in the labor ofcalculation, which could be safelyrelegated to anyone else if machineswere used."

Gottfried von Leibniz.Copyright (c) 1997. Maxfield & Montrose Interactive Inc.

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Leibniz's Step Reckoner.Courtesy of IBM

Leibniz developed Pascal's ideasand, in 1671, introduced the StepReckoner, a device which, as wellas performing additions andsubtractions, could multiply, divide,and evaluate square roots byseries of stepped additions.

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Gottfried von Leibniz's Step Reckoner



Leibniz also stronglyadvocated the use of thebinary number system, whichis fundamental to theoperation of moderncomputers.

Pascal's and Leibniz's devices were the forebearsof today's desk-top computers, and derivations ofthese machines continued to be produced until theirelectronic equivalents finally became readily availableand affordable in the early 1970s.

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Gottfried von Leibniz's Step Reckoner





1714 ADThe First English Typewriter Patent

One of the most ubiquitous techniques for interactively entering data into a computeris by means of a keyboard. However, although the fingers of an expert typist leap fromkey to key with the agility of a mountain goat and the dexterity of a concert pianist,newcomers usually spend the vast bulk of their time desperately trying to locate the nextkey they wish to press.a

It is actually not uncommon forstrong words to ensue describingthe way in which the keys are laidout, including the assertion thatwhoever came up with the schemewe employ must have been ablithering idiot. So why is it that adevice we use so much isconstructed in such a way thatanyone who lays their hands onone is immediately reduced touttering expletives and bangingtheir heads against the nearestwall? Ah, there's the question and,as with so many things, the answeris shrouded in the mists of time ....

The first references to what we wouldcall a typewriter are buried in the records ofthe British patent office. In 1714, by thegrace of Queen Anne, a patent was grantedto the English engineer Henry Mill. In abrave attempt towards the longest sentencein the English language with the minimumuse of punctuation, the wording of thispatent's title was:

"An artificial machine or method for theimpressing or transcribing of letters singly or

progressively one after another, as inwriting, whereby all writing whatever may be

engrossed in paper or parchment so neatand exact as not to be distinguished from

print." a

Unfortunately, after all the labors of the long-suffering patent clerk (a man whocould have benefited from access to a typewriter if ever there was one), Mill never gotaround to actually manufacturing his machine. (See also The first American typewriterpatent and The first commercial typewriter.)

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The First English Typewriter Patent





The First English Typewriter Patent




1726 ADJonathan Swift writes Gulliver's Travels

In 1274, the Spanish theologian Ramon Lull experienced what he believed to be adivine revelation, in which he invented an eccentric logical technique based onconcentric disks mounted on a central axis. Strange as it may seem to us, Lull'sfollowers (called Lullists) flourished in the late middle ages and the renaissance, andLullism spread far and wide across Europe.a

Of course, Lull also has his detractors(which is a kind way of saying that manypeople considered him to be a ravinglunatic). In 1726, the Anglo-Irish satiristJonathan Swift wrote Gulliver's Travels.

(On the off chance you were wondering,Swift penned his great work nine yearsbefore the billiard cue was invented. Priorto this, players used to strike the ballswith a small mace.)

Johnathan Swift.Copyright (c) 1997. Maxfield & Montrose Interactive Inc.

a

Gulliver's Travels was originally intended as an attack on the hypocrisy of theestablishment, including the government, the courts, and the clergy (Swift didn't like torestrict himself unduly), but it was so well written that it immediately became a children'sfavorite.a

In part III, chapter 5 of the tale, a professor of Laputa shows Gulliver a machine thatgenerates random sequences of words. This device was based on a 20 foot squareframe supporting wires threaded through wooden cubes, where each face of every cubehad a piece of paper bearing a word pasted onto it.a

Jonathan Swift writes Gulliver's Travels



Students randomly changed thewords using forty handles mountedaround the frame. The students thenexamined the cubes, and if three orfour adjacent words formed part of asentence that made any sense, theywere immediately written down byscribes. The professor told Gulliverthat by means of this technique:

"The most ignorant person at a reasonablecharge, and with little bodily labor, may write

books in philosophy, poetry, law, mathematics,and theology, without the least assistance

from genius or study."

a

The point is that Swift is believed to have been mocking Lull's art when he pennedthis part of his story. (Having said this, computer programs have been used to createrandom poetry and music ...... which makes you wonder what Swift would have writtenabout us).a

In fact Swift continues to affect us instrange and wondrous ways to this day. Whena computer uses multiple bytes to represent anumber, there are two main techniques forstoring those bytes in memory: either themost-significant byte is stored in the locationwith the lowest address (in which case wemight say it's stored "big-end-first), or theleast-significant byte is stored in the lowestaddress (in which case we might say it's stored"little-end-first).

Not surprisingly, somecomputer designers favor one stylewhile others take the opposite tack.This didn't really matter until peoplebecame interested in creatingheterogeneous computingenvironments in which multiplediverse machines were connectedtogether, at which point manyacrimonious arguments ensued.

a

In 1980, a famous paper written by Danny Cohen entitled "On Holy Wars and aPlea for Peace" used the terms big-endian and little-endian to refer to the twotechniques for storing data. These terms, which are still in use today, were derived fromthat part of Gulliver's tale whereby two countries go to war over which end of ahard-boiled egg should be eaten first -- the little end or the big end!

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Jonathan Swift writes Gulliver's Travels





1800 ADJacquard's Punched Cards

In the early 1800s, a French silk weaver called Joseph-Marie Jacquard invented away of automatically controlling the warp and weft threads on a silk loom by recordingpatterns of holes in a string of cards.a

In the years to come, variations onJacquard's punched cards would find avariety of uses, including representingthe music to be played by automatedpianos and the storing of programs forcomputers

IBM 80-column punched card format.a

See also:Charles Babbage's Analytical Engine & Herman Hollerith's tabulating machines

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Jacquard's Punched Cards





Logic Machines

As we may or may not have previously discused (depending on the way in whichyou're bouncing around our web pages), these days we are predominantly concernedwith computers, but it's worth noting that there has historically been a great deal offascination in logic in general. This fascination was initially expressed in the form oflogic diagrams, and later in the construction of special-purpose logic machines formanipulating logical expressions and representations.a

The world's first real logic machine, in thesense that it could actually be used to solveformal logic problems (as opposed to thosedescribed in Ramon Lull's Ars Magna, whichtended to create more problems than theysolved), was invented in the early 1800s bythe British scientist and statesman CharlesStanhope (third Earl of Stanhope). A man ofmany talents, the Earl designed a devicecalled the Stanhope Demonstrator, which wasa small box with a window in the top, alongwith two different colored slides that the userpushed into slots in the sides.

Although Stanhope's brainchilddoesn't sound like much it was a start(and there was more to it than we'vecovered here), but Stanhope wouldn'tpublish any details and instructed hisfriends not to say anything aboutwhat he was doing. In fact it wasn'tuntil around sixty years after hisdeath that the Earl's notes and one ofhis devices fell into the hands of theReverend Robert Harley, whosubsequently published an article onthe Stanhope Demonstrator in 1879.

a

Working on a somewhat different approach was the British logician and economistWilliam Stanley Jevons, who, in 1869, produced the earliest model of his famousJevons' Logic Machine.a

Logic Machines



The Jevons' Logic Machine was notablebecause it was the first machine that couldsolve a logical problem faster than thatproblem could be solved without using themachine! Jevons was an aficionado ofBoolean logic, and his solution wassomething of a cross between a logicalabacus and a piano (in fact it wassometimes referred to as a "Logic Piano").

This device, which was about 3 feet tall,consisted of keys, levers, and pulleys, alongwith letters that could be either visible orhidden. When the operator pressed keysrepresenting logical operations, theappropriate letters appeared to reveal theresult.

The next real advance in logicmachines was made by AllanMarquand, whom we previously met inconnection with his work on logicdiagrams. In 1881, by means of theingenious use of rods, levers, andsprings, Marquand extended Jevons'work to produce the Marquand LogicMachine. Like Jevons' device,Marquand's machine could only handlefour variables, but it was smaller andsignificantly more intuitive to use.(Following the invention of his logicmachine, Marquand abandoned logicalpursuits to become a professor of artand archeology at PrincetonUniversity.)

a

Things continued to develop apace. In 1936, the American psychologist BenjaminBurack from Chicago constructed what was probably the world's first electrical logicmachine. Burack's device used light bulbs to display the logical relationships between acollection of switches, but for some reason he didn't publish anything about his workuntil 1949.a

In fact the connection betweenBoolean algebra and circuits basedon switches had been recognized asearly as 1886 by an educator calledCharles Pierce, but nothingsubstantial happened in this area untilClaude E. Shannon published his1938 paper (as is discussedelsewhere in this history).

Following Shannon's paper, a substantialamount of attention was focused ondeveloping electronic logic machines.Unfortunately, interest in special-purposelogic machines waned in the 1940s with theadvent of general-purpose computers, whichproved to be much more powerful and forwhich programs could be written to handleformal logic.

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Logic Machines





1822 ADCharles Babbage's Difference Engine

The first device that might be considered to be a computer in the modern sense ofthe word was conceived in 1822 by the eccentric British mathematician and inventorCharles Babbage.a

In Babbage's time, mathematical tables,such as logarithmic and trigonometricfunctions, were generated by teams ofmathematicians working day and night onprimitive calculators. Due to the fact thatthese people performed computations theywere referred to as "computers." In fact theterm "computer" was used as a jobdescription (rather than referring to themachines themselves) well into the 1940s,but over the course of time this term becameassociated with machines that could performthe computations on their own.

Charles BabbageCopyright (c) 1997. Maxfield & Montrose Interactive Inc

a

In 1822, Babbage proposed building a machine called the Difference Engine toautomatically calculate these tables. The Difference Engine was only partiallycompleted when Babbage conceived the idea of another, more sophisticated machinecalled an Analytical Engine.

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Charles Babbage's Difference Engine



Interestingly enough, morethan one hundred and fifty yearsafter its conception, one ofBabbage's earlier Difference Engineswas eventually constructed fromoriginal drawings by a team atLondon's Science Museum. The finalmachine, which was constructedfrom cast iron, bronze and steel,consisted of 4,000 components,weighed three tons, and was 10 feetwide and 6½ feet tall.

The device performed its first sequenceof calculations in the early 1990's andreturned results to 31 digits of accuracy,which is far more accurate than thestandard pocket calculator. However, eachcalculation requires the user to turn acrank hundreds, sometimes thousands oftimes, so anyone employing it for anythingmore than the most rudimentarycalculations is destined to become one ofthe fittest computer operators on the faceof the planet!

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Charles Babbage's Difference Engine





1837 ADSamuel Morse Invents the Electric Telegraph

In 1837, the British physicist and inventor Sir Charles Wheatstone and the British electricalengineer Sir William Fothergill Cooke invented the first British electric telegraph. (Sir Charles wasa busy man. Amongst other things, he also invented the accordion in 1829 and three-dimensionalphotographs in the form of his stereoscope in 1838.)a

Wheatstone's telegraph made use of five wires,each of which was used to drive a pointer at thereceiver to indicate different letters. In the same year,the American inventor Samuel Finley Breese Morsedeveloped the first American telegraph, which wasbased on simple patterns of "dots" and "dashes"called Morse Code being transmitted over a singlewire (the duration of a "dash" is three times theduration of a "dot").

Subset of International Morse Codea

Morse's system was eventually adopted as the standard technique, because it was easier toconstruct and more reliable than Wheatstone's. Note that the figure above only shows a subset ofthe code (although it's quite a large subset), but it's enough to give the general idea. Also notethat this table shows International Morse Code, which is a slightly different flavor to AmericanMorse Code.a

The Morse Telegraph and Morse code are of interest, because they sparked the firstapplication of paper tapes as a medium for the preparation, storage, and transmission of data,and this technique would eventually be used be the designers of computers.

a

Samuel Morse Invents the Electric Telegraph





Samuel Morse Invents the Electric Telegraph




1829 ADThe First American Typewriter Patent

Following the first English typewriter patent in 1714 and a few sporadic attemptsfrom different parts of the globe, the first American patent for a typewriter was granted in1829 to William Austin Burt from Detroit. However, the path of the inventor is rarely asmooth one as Burt was to discover. We may only picture the scene in the patent office:a

Clark: "Hello there, Mr. Burt, I have both good news and bad news. Which wouldyou like first sir?"

a

Burt: "I think I'll take the good news, if it's all the same to you."a

Clark: "Well the good news is that you've been granted a patent for the devicewhich you are pleased to call your Typographer."

a

Burt: "Good grief, I'm tickled pink, and the bad news?"a

Clark: "Sad to relate, the only existing model of your machine was destroyed in afire at our Washington patent office!"

a

To be perfectly honest, the patentoffice (along with the Typographer) burneddown in 1836, seven years after Burtreceived his patent. But as we all learn atour mother's knee, one should never allowawkward facts to get in the way of a goodstory.

As fate would have it, the fireprobably caused no great loss tocivilization as we know it. Burt's firstTypographer was notably ungainly, somuch so that it was possible to writemuch faster than one could type withthis device.

a

Undaunted, Burt produced a second model the size of a present-day pinballmachine, which, if nothing else, would have made an interesting conversation piece ifgiven to a friend as a Christmas stocking-filler. Perhaps not surprisingly, no one wasinterested, and Burt eventually exited the stage to make room for younger contenders.(See also The first commercial typewriter.)

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The First American Typewriter Patent




The First American Typewriter Patent





1830 ADCharles Babbage's Analytical Engine

As was previously noted, the first device that might be considered to be acomputer in the modern sense of the word was conceived by the eccentric Britishmathematician and inventor Charles Babbage.a

In 1822, Babbage proposedbuilding a machine called theDifference Engine to automaticallycalculate mathematical tables. TheDifference Engine was only partiallycompleted when Babbage conceivedthe idea of another, more sophisticatedmachine called an Analytical Engine.

(Some texts refer to this machine asan "Analytical Steam Engine," becauseBabbage intended that it would bepowered by steam).

Charles BabbageCopyright (c) 1997. Maxfield & Montrose Interactive Inc

a

The Analytical Engine was intended to use loops of Jacquard's punched cards tocontrol an automatic calculator, which could make decisions based on the results ofprevious computations. This machine was also intended to employ several featuressubsequently used in modern computers, including sequential control, branching, andlooping.

a

Charles Babbage's Analytical Engine



Ada LovelaceCopyright (c) 1997. Maxfield & Montrose Interactive Inc

Working with Babbage was AugustaAda Lovelace, the daughter of the Englishpoet Lord Byron. Ada, who was a splendidmathematician and one of the few peoplewho fully understood Babbage's vision,created a program for the Analytical Engine.

Had the Analytical Engine ever actuallyworked, Ada's program would have beenable to compute a mathematical sequenceknown as Bernoulli numbers. Based on thiswork, Ada is now credited as being the firstcomputer programmer and, in 1979, amodern programming language was namedADA in her honor.

a

Babbage worked on his Analytical Engine from around 1830 until he died, but sadlyit was never completed. It is often said that Babbage was a hundred years ahead of histime and that the technology of the day was inadequate for the task. Refuting this is thefact that, in 1834, two Swedish engineers called Georg and Edward Scheutz built asmall Difference Engine based on Babbage's description. In his book, Engines of theMind, Joel Shurkin stated:a

"One of Babbage's most serious flaws was his inability to stop tinkering.No sooner would he send a drawing to the machine shop than hewould find a better way to perform the task and would order workstopped until he had finished pursuing the new line. By and large

this flaw kept Babbage from ever finishing anything."

a

Further supporting this theory is the factthat, in 1876, only five years after Babbage'sdeath, an obscure inventor called GeorgeBarnard Grant exhibited a full-sized differenceengine of his own devising at the PhiladelphiaCentennial Fair. Grant's machine was 8 feetwide, 5 feet tall, and contained over 15,000moving parts.

The point is that, althoughBabbage's Analytical Engine wasintellectually far more sophisticatedthan his Difference Engine,constructing an Analytical Enginewould not have been beyond thetechnology of the day.

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1834 ADTally Sticks: The Hidden Dangers

The practice of makingmarks on, or cutting notchesinto, things to represent numbershas survived to the present day,especially among schoolchildren making tally marks ontheir desks to signify the days oftheir captivity (see also Carvingnotches into bones).

In the not-so-distant past, storekeepers, whooften could not read or write, used a similartechnique to keep track of their customer's debts.For example, a baker might make cuts across astick of wood equal to the number of loaves in theshopper's basket. This stick was then splitlengthwise, with the baker and the customerkeeping half each, so that both could rememberhow many loaves were owed and neither of themcould cheat.

a

Similarly, the British government used wooden tally sticks until the early 1780s.These sticks had notches cut into them to record financial transactions and to act asreceipts. Over the course of time these tally sticks were replaced by paper records,leaving the cellars of the Houses of Parliament full to the brim with pieces of old wood.a

Rising to the challenge with theinertia common to governmentsaround the world, Parliament ditheredaround until 1834 before finallygetting around to ordering thedestruction of the tally sticks. Therewas some discussion about donatingthe sticks to the poor as firewood, butwiser heads prevailed, pointing outthat the sticks actually represented"top secret" government transactions.

The fact that the majority of the poorcouldn't read or write and often couldn'tcount was obviously of no great significance,and it was finally decreed that the sticksshould be burned in the courtyard of theHouses of Parliament. However, fate isusually more than willing to enter the stagewith a pointed jape -- gusting winds causedthe fire to break out of control and burn theHouse of Commons to the ground (althoughthey did manage to save the foundations)!

a

Tally Sticks: The Hidden Dangers





Tally Sticks: The Hidden Dangers




1847 AD to 1854 ADGeorge Boole Invents Boolean Algebra

Around the same timethat Charles Babbage wasstruggling with his AnalyticalEngine, one of hiscontemporaries, a Britishmathematician calledGeorge Boole, was busilyinventing a new and rathercunning form ofmathematics.

Boole made significant contributions in severalareas of mathematics, but was immortalized for twoworks in 1847 and 1854, in which he representedlogical expressions in a mathematical form now knownas Boolean Algebra. Boole's work was all the moreimpressive because, with the exception of elementaryschool and a short time in a commercial school, hewas almost completely self-educated.

a

In conjunction with Boole, another British mathematician, Augustus DeMorgan,formalized a set of logical operations now known as DeMorgan transformations. As theEncyclopedia Britannica says: "A renascence of logical studies came about almostentirely because of Boole and DeMorgan."a

In fact the rules we now attribute toDeMorgan were known in a more primitiveform by William of Ockham (also known asWilliam of Occam) in the 14th Century. Inorder to celebrate Ockham's position inhistory, the OCCAM computer programminglanguage was named in his honor. (In fact,OCCAM is the native programming languagefor the British- developed INMOS transputer.)

Unfortunately, with theexception of students of philosophyand symbolic logic, BooleanAlgebra was destined to remainlargely unknown and unused forthe better part of a century, until ayoung student called Claude E.Shannon recognized its relevanceto electronics design.

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George Boole Invents Boolean Algebra





George Boole Invents Boolean Algebra




1857 ADWheatstone Uses Paper Tape to Store Data

In 1837, the Americaninventor Samuel Finley BreeseMorse developed the firstAmerican electric telegraph,which was based on simplepatterns of "dots" and "dashes"called Morse Code beingtransmitted over a single wire.

The telegraph quickly proliferated thanks to therelative simplicity of Morse's system. However, aproblem soon arose in that operators could onlytransmit around ten words a minute, which meantthat they couldn't keep up with the public'sseemingly insatiable desire to send messages toeach other. This was a classic example of acommunications bottleneck.

a

Thus, in 1857, only twenty years after the invention of the telegraph, Sir CharlesWheatstone (the inventor of the accordion) introduced the first application of papertapes as a medium for the preparation, storage, and transmission of data.a

Sir Charles' paper tape used two rowsof holes to represent Morse's dots anddashes. Outgoing messages could beprepared off-line on paper tape andtransmitted later. Wheatstone's perforated paper tape

a

By 1858, a Morse paper tape transmitter could operate at 100 words a minute.Unsuspectingly, Sir Charles had also provided the American public with a way to honortheir heroes and generally have a jolly good time, because used paper tapes were toeventually become a key feature of so-called ticker-tape parades.a

Sir Charles Wheatstone Uses Paper Tape to Store Data



In a similar manner to Sir Charles' telegraphtape, the designers of the early computersrealized that they could record their data on apaper tape by punching rows of holes acrossthe width of the tape. The pattern of the holes ineach data row represented a single data valueor character. The individual hole positionsforming the data rows were referred to as"channels" or "tracks," and the number ofdifferent characters that could be representedby each row depended on the number ofchannels forming the rows.

The original computer tapes hadfive channels, so each data rowcould represent one of thirty-twodifferent characters. However, asusers began to demand morecomplex character sets, includingthe ability to use both uppercasecharacters ('A', 'B', 'C', ...) and theirlowercase equivalents ('a', 'b', 'c',...), the number of channels rapidlyincreased, first to six and later toeight.

a

1-inch computer paper tape

This illustration represents one of the more popularIBM standards -- a one-inch wide tape supporting eightchannels (numbered from 0 to 7) with 0.1 inchesbetween the punched holes.

The first paper tape readers accessed the data bymeans of springy wires (one per channel), which couldmake electrical connections to conducting plates underthe tape wherever a hole was present. These readerswere relatively slow and could only operate at aroundfifty characters per second.

a

Later models used opto-electronic techniques, in which a light source was placed on one sideof the tape and optical cells located on the other side were used to detect the light and therebyrecognize the presence or absence of any holes.a

In the original slower-speedreaders, the small sprocket holesrunning along the length of the tapebetween channels 2 and 3 wereengaged by a toothed wheel toadvance the tape. Thehigher-speed opto-electronicmodels used rubber rollers to drivethe tape, but the sprocket holesremained, because light passingthrough them could be detected andused to generate synchronizationpulses.

On the off-chance that you werewondering, the reason the sprocket holeswere located off-center between channels 2and 3 (as opposed to being centeredbetween channels 3 and 4) was to enablethe operator to know which side of the tapewas which. Of course, it was still necessaryto be able to differentiate between the twoends of the tape, so the operators usedscissors to shape the front-end into atriangular point, thereby indicating that thiswas the end to be stuck into the tape reader.

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1867 ADThe First Commercial Typewriter

Following William Austin Burt's attemptat a typewriter, numerous other innovatorsleapt into the fray with truly Heath Robinsonofferings. Some of these weird andwonderful contraptions were as difficult touse as a Church organ, while others printedby keeping the paper stationary and hurlingthe rest of the machine against it ...... themind boggles.

The first practical typewritingmachine was conceived by threeAmerican inventors and friends whospent their evenings tinkeringtogether. In 1867, Christopher LathamSholes, Carlos Glidden, and SamualW. Soule invented what they calledthe Type-Writer (the hyphen wasdiscarded some years later).

a

Soulé eventually dropped out, but the others kept at it, producing close to thirtyexperimental models over the next five years. Unfortunately, Sholes and Glidden neverreally capitalized on their invention, but instead sold the rights to a smooth-talkingentrepreneur called James Densmore, who, in 1873, entered into a contract with a gunand sewing machine manufacturer to produce the device.

a

Strangely, the manufacturers, E.Remington and Sons from the stateof New York, had no experiencebuilding typewriters. This wasprimarily because no one had everproduced a typewriter before, butthere's also the fact that (let's faceit) Remington and Sons made gunsand sewing machines.The first thing they did was to huntfor the best artist-mechanic theycould find, and they eventuallysettled on a man called William K.Jenne.

However, Jenne's expertise was in thedesign of sewing machines, with the result thatthe world's first commercial typewriter, releasedin 1874, ended up with a foot pedal to advancethe paper and sweet little flowers on the sides!

See also:The Sholes keyboard

The Dvorak keyboard

The first printing telegraphs

The first teleprinters

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The First Commercial Typewriter






The First Commercial Typewriter






1878 ADThe First True Incandescent Light Bulb

Now here's a bit of a poser for you -- who invented the first electric light bulb? If yourimmediate response was "The legendary American inventor, Thomas Alva Edison," thenyou'd certainly be in the majority, but being in the majority doesn't necessarily mean thatyou're right.a

Thomas Alva EdisonCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

It's certainly true that Edison didinvent the light bulb (or at least "a" lightbulb), but he wasn't the first. In 1860, anEnglish physicist and electrician, SirJoseph Wilson Swan, produced his firstexperimental light bulb using carbonizedpaper as a filament. Unfortunately, Swandidn't have a strong enough vacuum orsufficiently powerful batteries and hisprototype didn't achieve completeincandescence, so he turned hisattentions to other pursuits.

a

Fifteen years later, in 1875, Swan returned to consider the problem of the light bulband, with the aid of a better vacuum and a carbonized thread as a filament (the samematerial Edison eventually decided upon), he successfully demonstrated a trueincandescent bulb in 1878 (a year earlier than Edison). Furthermore, in 1880, Swangave the world's first large-scale public exhibition of electric lamps at Newcastle,England.

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The First True Incandescent Light Bulb



So it's reasonable to wonderwhy Edison received all of thecredit, while Swan wascondemned to obscurity. Themore cynical among us maysuggest that Edison was thrustinto the limelight (see notebelow) because many amongus learn their history throughfilms, and the vast majority ofearly films were made inAmerica by patriotic Americans.

However, none of this should detract fromEdison who, working independently,experimented with thousands of filamentmaterials and expended tremendous amounts ofeffort before discovering carbonized thread. It isalso probably fair to say that Edison did producethe first commercially viable light bulb.

The reason why this is of interest to us hereis that Edison's experiments with light bulbs ledhim to discover the Edison Effect, whichultimately led to the invention of the vacuumtube.

a

As one final nugget of trivia, the term "limelight" comes from the incandescent lightproduced by a rod of lime bathed in a flame of oxygen and hydrogen. At the time it wasinvented, limelight was the brightest source of artificial light known. One of it's first useswas for lighting theater stages, and actors and actresses were keen to positionthemselves "in the limelight" so as to be seen to their best effect.

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The First True Incandescent Light Bulb






1890 ADHerman Hollerith's Tabulating Machines

It is often said that necessity isthe mother of invention, and thiswas certainly true in the case ofthe American census. Followingthe population trends establishedby previous surveys, it wasestimated that the census of 1890would be required to handle datafrom more than 62 millionAmericans.

In addition to being prohibitively expensive,the existing system of making tally marks in smallsquares on rolls of paper and then adding themarks together by hand was extremely timeconsuming. In fact it was determined that, if thesystem remained unchanged, there was nochance of collating the data from the 1890 censusinto any useful form until well after the 1900census had taken place, by which time the 1890data would be of little value.

a

The solution to this problem was developed during the 1880s by an Americaninventor called Herman Hollerith, whose idea it was to use Jacquard's punched cards torepresent the census data, and to then read and collate this data using an automaticmachine.a

While he was a lecturer at MIT,Hollerith developed a simple prototypewhich employed cards he punchedusing a tram conductor's ticket punch,where each card was intended tocontain the data associated with aparticular individual.

From this prototype, he evolved amechanism that could read thepresence or absence of holes in thecards by using spring-mounted nailsthat passed through the holes to makeelectrical connections.

Herman Hollerith

Herman Hollerith's Tabulating Machines



Copyright (c) 1997. Maxfield & Montrose Interactive Inc.a

Hollerith's final system included an automatic electrical tabulating machine with alarge number of clock-like counters that accumulated the results. By means of switches,operators could instruct the machine to examine each card for certain characteristics,such as profession, marital status, number of children, and so on.

a

When a card was detected that met thespecified criteria, an electrically controlledsorting mechanism could gather those cardsinto a separate container. Thus, for the firsttime it was possible to extract informationsuch as the number of engineers living in aparticular state who owned their own houseand were married with two children. Althoughthis may not tickle your fancy, having thiscapability was sufficient to drive thestatisticians of the time into a frenzy ofexcitement and data collation.

In addition to solving the censusproblem, Hollerith's machines provedthemselves to be extremely useful fora wide variety of statisticalapplications, and some of thetechniques they used were to besignificant in the development of thedigital computer. In February 1924,Hollerith's company changed its nameto International Business Machines,or IBM. (See also Hollerith's punchedcards.)

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Herman Hollerith's Tabulating Machines


http://www.maxmon.com/punch1.htm





1883 AD to 1906 ADThe Invention of the Vacuum Tube

In 1879, the legendaryAmerican inventor Thomas AlvaEdison publicly exhibited hisincandescent electric light bulb forthe first time.

(If you ever happen to be inDearborn, Michigan, you shouldtake the time to visit the HenryFord Museum, which happens tocontain the world's largest andmost spectacular collection of lightbulbs.)

Thomas Alva EdisonCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

a

Edison's light bulbs employed a conducting filament mounted in a glass bulb fromwhich the air was evacuated leaving a vacuum. Passing electricity through the filamentcaused it to heat up enough to become incandescent and radiate light, while thevacuum prevented the filament from oxidizing and burning up.a

The Invention of the Vacuum Tube



Edison continued to experimentwith his light bulbs and, in 1883, foundthat he could detect electrons flowingthrough the vacuum from the lightedfilament to a metal plate mounted insidethe bulb. This discovery subsequentlybecame known as the Edison Effect.

Edison did not develop thisparticular finding any further, but anEnglish physicist, John AmbroseFleming, discovered that the EdisonEffect could also be used to detect radiowaves and to convert them to electricity.Fleming went on to develop atwo-element vacuum tube known asdiode.

In 1906, the American inventor Lee deForest introduced a third electrode calledthe grid into the vacuum tube. Theresulting triode could be used as both anamplifier and a switch, and many of theearly radio transmitters were built by deForest using these triodes (he alsopresented the first live opera broadcastand the first news report on radio).

De Forest's triodes revolutionized thefield of broadcasting and were destined todo much more, because their ability to actas switches was to have a tremendousimpact on digital computing.

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The Invention of the Vacuum Tube





1902 ADThe First Teleprinters

In 1902, a young electrical engineer called Frank Pearne approached Mr. JoyMorton, the president of the well-known Morton Salt Company. Pearne had beenexperimenting with printing telegraphs and needed a sponsor. Morton discussed thesituation with his friend, the distinguished mechanical engineer Charles L. Krum, andthey eventually decided they were interested in pursuing this project.a

After a year of unsuccessful experiments,Pearne lost interest and wandered off intothe sunset to become a teacher. Krumcontinued to investigate the problem and, in1906, was joined by his son Howard, whohad recently graduated as an electricalengineer. The mechanical and electricaltalents of the Krums Senior and Juniorcomplemented each other. After solving theproblem of synchronizing the transmitter andreceiver, they oversaw their first installationon postal lines between New York City andBoston in the summer of 1910.

These devices, calledteleprinters, had a typewriter-stylekeyboard for entering outgoingmessages and a roll of paper forprinting incoming messages. TheKrums continued to improve thereliability of their systems over theyears. By 1914, teleprinters werebeing used by the Associated Pressto deliver copy to newspaper officesthroughout America, and by theearly 1920s they were in generaluse around the world.

a

Meanwhile, toward the end of the 1920s and the early 1930s, scientists andengineers began to focus their attentions on the issue of computing. The first devices,such as Vannevar Bush's Differential Analyzer, were predominantly analog, but noteveryone was a devotee of analog computing. At a meeting in New Hampshire inSeptember 1940 George Robert Stibitz used a digital machine to perform the firstdemonstration of remote computing. Leaving his computer in New York City, he took ateleprinter to the meeting which he connected to the computer using a telephone line.Stibitz then proceeded to astound the attendees by allowing them to pose problemswhich were entered on the teleprinter; within a minute, the teleprinter printed theanswers generated by the computer.a

The First Teleprinters



By the 1950s, computers were becomingmuch more complex, but operators were stilllargely limited to entering programs using a switchpanel or loading them from paper tapes orpunched cards. Due to the fact that the only wayfor early computers to be cost-effective was forthem to operate twenty-four hours a day, thetime-consuming task of writing programs had tobe performed off-line using teleprinters withintegrated paper tape writers or card punches.

As computers increased in power, teleprintersbegan to be connected directly to them. Thisallowed the operators and the computer tocommunicate directly with each other, which wasone of the first steps along the path toward theinteractive way in which we use computers today.

By the middle of the 1960s,computers had become sopowerful that many operatorscould use the same machinesimultaneously, and a newconcept called time-sharing wasborn. The computer could switchbetween users so quickly thateach user had the illusion theyhad sole access to the machine.(Strangely enough, time-sharingis now only practiced in largecomputing installations, becausecomputers have become sopowerful and so cheap thateveryone can have a dedicatedprocessor for themselves).

a

However, the days of the teleprinter in the computing industry were numbered;they were eventually supplanted by the combination of computer keyboards and videodisplays, and the sound of teleprinters chuntering away in the back of computer roomsis now little more than a nostalgic memory. (See also The first commercial typewriterand The first printing telegraphs.)

a


The First Teleprinters







1921 ADKarel Capek's R.U.R.

In 1921, the Czech authorKarel Capek produced hisbest known work, the playR.U.R. (Rossum's UniversalRobots), which featuredmachines created to simulatehuman beings.

Some references state that term "robot" wasderived from the Czech word robota, meaning"work", while others propose that robota actuallymeans "forced workers" or "slaves." This latter viewwould certainly fit the point that Capek was trying tomake, because his robots eventually rebelledagainst their creators, ran amok, and tried to wipeout the human race.

a

However, as is usually the case with words, the truth of the matter is a little moreconvoluted. In the days when Czechoslovakia was a feudal society, "robota" referred tothe two or three days of the week that peasants were obliged to leave their own fields towork without remuneration on the lands of noblemen. For a long time after the feudalsystem had passed away, robota continued to be used to describe work that one wasn'texactly doing voluntarily or for fun, while today's younger Czechs and Slovaks tend touse robota to refer to work that's boring or uninteresting.

a


Karel Capek's R.U.R. (Rossum's Universal Robots)






1926 AD to 1962 ADThe First Transistors

The transistor and subsequently the integrated circuit must certainly qualify as twoof the greatest inventions of the twentieth century. These devices are formed frommaterials known as semiconductors, whose properties were not well-understood untilthe 1950s. However, as far back as 1926, Dr. Julius Edgar Lilienfield from New Yorkfiled for a patent on what we would now recognize as an NPN junction transistor beingused in the role of an amplifier (the patent title was "Method and apparatus forcontrolling electric currents").a

Unfortunately, seriousresearch on semiconductors didn'treally commence until World WarII.

At that time it was recognizedthat devices formed fromsemiconductors had potential asamplifiers and switches, andcould therefore be used to replacethe prevailing technology ofvacuum tubes, but that they wouldbe much smaller, lighter, andwould require less power.

All of these factors were ofinterest to the designers of theradar systems which were to playa large role in the war.

Bell Laboratories in the United Statesbegan research into semiconductors in 1945,and physicists William Shockley, WalterBrattain and John Bardeen succeeded increating the first point- contact germaniumtransistor on the 23rd December, 1947 (theytook a break for the Christmas holidays beforepublishing their achievement, which is whysome reference books state that the firsttransistor was created in 1948).

In 1950, Shockley invented a new devicecalled a bipolar junction transistor, which wasmore reliable, easier and cheaper to build,and gave more consistent results thanpoint-contact devices. (Apropos of nothing atall, the first TV dinner was marketed by theC.A. Swanson company three years later.)

a

The First Transistors




By the late 1950s, bipolar transistors were being manufactured out of silicon ratherthan germanium (although germanium had certain electrical advantages, silicon wascheaper and easier to work with). Bipolar junction transistors are formed from thejunction of three pieces of doped silicon called the collector, base, and emitter. Theoriginal bipolar transistors were manufactured using the mesa process, in which adoped piece of silicon called the mesa (or base) was mounted on top of a larger pieceof silicon forming the collector, while the emitter was created from a smaller piece ofsilicon embedded in the base.a

In 1959, the Swiss physicist JeanHoerni invented the planar process, inwhich optical lithographic techniqueswere used to diffuse the base into thecollector and then diffuse the emitter intothe base. One of Hoerni's colleagues,Robert Noyce, invented a technique forgrowing an insulating layer of silicondioxide over the transistor, leaving smallareas over the base and emitter exposedand diffusing thin layers of aluminum intothese areas to create wires. Theprocesses developed by Hoerni andNoyce led directly to modern integratedcircuits.

In 1962, Steven Hofstein and FredricHeiman at the RCA research laboratory inPrinceton, New Jersey, invented a newfamily of devices called metal-oxidesemiconductor field-effect transistors(MOS FETs for short).

Although these transistors weresomewhat slower than bipolar transistors,they were cheaper, smaller and used lesspower. Also of interest was the fact thatmodified metal-oxide semiconductorstructures could be made to act ascapacitors or resistors.

a


The First Transistors








1927 ADVannevar Bush's Differential Analyser

In 1927, with the assistance of two colleagues at MIT, the American scientist,engineer, and politician Vannevar Bush designed an analog computer that could solvesimple equations. This device, which Bush dubbed a Product Intergraph, wassubsequently built by one of his students.a

Bush continued to develop hisideas and, in 1930, built a biggerversion which he called aDifferential Analyzer. TheDifferential Analyzer was based onthe use of mechanical integratorsthat could be interconnected inany desired manner. To provideamplification, Bush employedtorque amplifiers which werebased on the same principle as aship's capstan. The final deviceused its integrators, torqueamplifiers, drive belts, shafts, andgears to measure movements anddistances (not dissimilar inconcept to an automatic sliderule).

Although Bush's first Differential Analyzerwas driven by electric motors, its internaloperations were purely mechanical. In 1935Bush developed a second version, in which thegears were shifted electro-mechanically andwhich employed paper tapes to carryinstructions and to set up the gears.

In our age, when computers can beconstructed the size of postage stamps, it isdifficult to visualize the scale of the problemsthat these early pioneers faced. To providesome sense of perspective, Bush's secondDifferential Analyzer weighed in at a whopping100 tons! In addition to all of the mechanicalelements, it contained 2000 vacuum tubes,thousands of relays, 150 motors, andapproximately 200 miles of wire.

a

As well as being a major achievement in its own right, the Differential Analyzer wasalso significant because it focused attention on analog computing techniques, andtherefore detracted from the investigation and development of digital solutions for quitesome time.

a

Vannevar Bush's Analog Computer -- The Differential Analyser




Vannevar Bush's Analog Computer -- The Differential Analyser





Circa 1936 ADThe Dvorak Keyboard

Almost anyone who spends more than a few seconds working with a QWERTYkeyboard quickly becomes convinced that they could do a better job of laying out thekeys. Many brave souls have attempted the task, but few came closer than efficiencyexpert August Dvorak in the 1930s.a

When he turned his attention tothe typewriter, Dvorak spent manytortuous months analyzing theusage model of the QWERTYkeyboard (now there's a man whoknew how to have a good time).The results of his investigationwere that, although the majority ofusers were right-handed, theexisting layout forced the weakerleft hand (and the weaker fingerson both hands) to perform most ofthe work. Also, thanks to Sholes'main goal of physically separatingletters that are commonly typedtogether, the typist's fingers wereobliged to move in awkwardpatterns and only ended upspending 32% of their time on thehome row.

Dvorak took the opposite tack to Sholes, andattempted to find the optimal placement for thekeys based on letter frequency and humananatomy. That is, he tried to ensure that letterswhich are commonly typed together would bephysically close to each other, and also that the(usually) stronger right hand would perform thebulk of the work, while the left hand would havecontrol of the vowels and the lesser-usedcharacters. The result of these labors was theDvorak Keyboard, which he patented in 1936.

The Dvorak keyboard (circa 1936)a

The Dvorak Keyboard





Note that Dvorak's keyboard had shiftkeys, but they are omitted from the abovefigure for reasons of clarity. The results ofDvorak's innovations were tremendouslyeffective. Using his layout, the typist'sfingers spend 70% of their time on the homerow and 80% of this time on their homekeys. Thus, as compared to theapproximately 120 words that can beconstructed from the home row keys of theQWERTY keyboard, it is possible toconstruct more than 3,000 words onDvorak's home row (or 10,000 words ifyou're talking to someone who's trying tosell you one). Also, Dvorak's schemereduces the motion of the hands by a factorof three, and improves typing accuracy andspeed by approximately 50%, and 20%,respectively.

Unfortunately, Dvorak didn't reallystand a chance trying to selltypewriters based on his newkeyboard layout in the 1930s. Apartfrom the fact that existing typists didn'twish to re-learn their trade, Americawas in the heart of the depressionyears, which meant that the last thinganyone wanted to do was to spendmoney on a new typewriter.

In fact, the Dvorak keyboard mighthave faded away forever, except thatenthusiasts in Oregon, USA, formed aclub in 1978, and they've beenactively promoting Dvorak's techniqueever since. (See also The Sholes(QWERTY) keyboard.)

a


The Dvorak Keyboard







1937 ADGeorge Stibitz's Complex Number Calculator

In 1927, the American scientist, engineer,and politician Vannevar Bush designed ananalog computer that could solve simpleequations. Bush's work was extremelysignificant, because (quite apart from anythingelse) it focused attention on analog computingtechniques, and therefore detracted from theinvestigation and development of digitalsolutions for quite some time.

But not everyone wasenamored by analog computing.

In 1937, George Robert Stibitz,a scientist at Bell Laboratoriesbuilt a digital machine based onrelays, flashlight bulbs, and metalstrips cut from tin-cans.

a

Stibitz's machine, which he called the "Model K" (because most of it wasconstructed on his kitchen table), worked on the principle that if two relays wereactivated they caused a third relay to become active, where this third relay representedthe sum of the operation. For example, if the two relays representing the numbers 3 and6 were activated, this would activate another relay representing the number 9. (A replicaof the Model K is on display at the Smithsonian).a

Stibitz later went on tocreate a machine called theComplex NumberCalculator.

Although this device was not sophisticated bytoday's standards, it was animportant step along theway.

In 1940, Stibitz performed a spectaculardemonstration at a meeting in New Hampshire. Leavinghis computer in New York City, he took a teleprinter tothe meeting and proceeded to connect it to his computervia telephone. In the first example of remote computing,Stibitz astounded the attendees by allowing them topose problems which were entered on the teleprinter;within a short time the teleprinter presented the answersgenerated by the computer.

a

George Robert Stibitz's Complex Number Calculator



http://www.maxmon.com/relay1.htm



George Robert Stibitz's Complex Number Calculator




1937 ADAlan Turing invents the Turing Machine

Many of the people who designed the earlycomputers were both geniuses and eccentricsof the first order, and the English mathematicianAlan Turing was first among equals.

In 1937, while a graduate student, Turingwrote his ground-breaking paper "OnComputable Numbers with an Application to theEntscheidungsproblem." One of the premises ofTuring's paper was that some classes ofmathematical problems do not lend themselvesto algorithmic representations and are notamenable to solution by automatic computers.

Alan TuringCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

a

Since Turing did not have access to a real computer (not unreasonably as they didn'texist at the time), he invented his own as an abstract "paper exercise." This theoreticalmodel, which became known as a Turing Machine, was both simple and elegant, andsubsequently inspired many "thought experiments." A few years later Turing wasdestined to be a key player in the design and creation of COLOSSUS, which was one ofthe world's earliest working programmable electronic digital computers.

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Alan Turing invents the Turing Machine

http://www.maxmon.com/1937bad.htm [7/16/2003 4:16:47 PM]





1938 ADClaude Shannon's master's Thesis

Around the 1850s, the British mathematician George Boole was busily inventing anew form of mathematics, in which he represented logical expressions in amathematical form now known as Boolean Algebra.a

Unfortunately, with the exceptionof students of philosophy andsymbolic logic, Boolean Algebra wasdestined to remain largely unknownand unused for the better part of acentury. In fact it was not until 1938that Claude E. Shannon published anarticle based on his master's thesis atMIT. (Shannon's thesis has sincebeen described as: "Possibly the mostimportant master's thesis of thetwentieth century.")

In his paper, which was widelycirculated, Shannon showed how Boole'sconcepts of TRUE and FALSE could beused to represent the functions ofswitches in electronic circuits. It is difficultto convey just how important this conceptwas; suffice it to say that Shannon hadprovided electronics engineers with themathematical tool they needed to designdigital electronic circuits, and thesetechniques remain the cornerstone ofdigital electronic design to this day.

a

Apropos of nothing at all, Shannon is also credited with the invention of therocket-powered Frisbee, and is famous for riding down the corridors at Bell Laboratorieson a unicycle while simultaneously juggling four balls.

a


Claude Shannon's master's Thesis






1939 ADJohn Vincent Atanasoff's Special-Purpose

Electronic Digital Computer

It is said that history is written by thevictors. (It is also said that those whofail to learn the lessons of history aredoomed to repeat them -- this isparticularly true in the case of historycourses at high school.)

When one is considering events thatoccurred only a few decades in thepast, however, it would not beunreasonable to expect s aid events tobe fairly well-documented, therebyallowing one to report: "This persondefinitely invented this thing at thistime."

Sad to relate, this is not always thecase as we shall see.....

We now turn our attention to anAmerican mathematician and physicist,John Vincent Atanasoff, who has thedubious honor of being known as the manwho either did or did not construct the firsttruly electronic special-purpose digitalcomputer.

A lecturer at Iowa State College (nowIowa State University), Atanasoff wasdisgruntled with the cumbersome andtime-consuming process of solvingcomplex equations by hand. Workingalongside one of his graduate students(the brilliant Clifford Berry), Atanasoffcommenced work on an electroniccomputer in early 1939, and had aprototype machine by the autumn of thatyear.

a

In the process of creating the device, Atanasoff and Berry evolved a number ofingenious and unique features. For example, one of the biggest problems for computerdesigners of the time was to be able to store numbers for use in the machine'scalculations. Atanasoff's design utilized capacitors to store electrical charge that couldrepresent numbers in the form of logic 0s and logic 1s. The capacitors were mounted inrotating bakelite cylinders, which had metal bands on their outer surface. Thesecylinders, each approximately 12 inches tall and 8 inches in diameter, could store thirtybinary numbers, which could be read off the metal bands as the cylinders rotated.

a

John Vincent Atanasoff's Special-Purpose Electronic Digital Computer

http://www.maxmon.com/1939bad.htm (1 of 2) [7/16/2003 4:17:33 PM]


Input data was presented to themachine in the form of punched cards,while intermediate results could bestored on other cards. Once again,Atanasoff's solution to storingintermediate results was quiteinteresting -- he used sparks to burnsmall spots onto the cards. Thepresence or absence of these spotscould be automatically determined bythe machine later, because the electricalresistance of a carbonized spot variedfrom that of the blank card.

Some references report thatAtanasoff and Berry had a fully workingmodel of their machine by 1942.However, while some observers agreedthat the machine was completed and didwork, others reported that it was almostcompleted and would have worked, whilestill others stated that it was just acollection of parts that never worked. Sounless more definitive evidence comesto light, it's a case of: "You pays yourmoney and you takes your choice."

a


John Vincent Atanasoff's Special-Purpose Electronic Digital Computer






1939 AD to 1944 ADHoward Aiken's Harvard Mark I (the IBM ASCC)

Many consider that the moderncomputer era commenced with thefirst large-scale automatic digitalcomputer, which was developedbetween 1939 and 1944 (see alsoKonrad Zuse and his Z3 computer).

This device, the brainchild of aHarvard graduate, Howard H. Aiken,was officially known as the IBMautomatic sequence controlledcalculator (ASCC), but is morecommonly referred to as the HarvardMark I.

Howard AikenCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

a

The Mark I was constructed out of switches, relays, rotating shafts, and clutches, andwas described as sounding like a "roomful of ladies knitting." The machine containedmore than 750,000 components, was 50 feet long, 8 feet tall, and weighedapproximately 5 tons!a

Howard Aiken's Harvard Mark I (the IBM ASCC)




IBM automatic sequence controlledcalculator (ASCC) (Courtesy of IBM)

Although the Mark I is considered to be the firstdigital computer, its architecture was significantlydifferent from modern machines. The device consistedof many calculators which worked on parts of the sameproblem under the guidance of a single control unit.Instructions were read in on paper tape, data wasprovided on punched cards, and the device could onlyperform operations in the sequence in which they werereceived.

a

This machine was based on numbers that were 23 digits wide -- it could add orsubtract two of these numbers in three-tenths of a second, multiply them in fourseconds, and divide them in ten seconds.a

Aiken was tremendouslyenthused by computers, butlike so many others he didn'tanticipate the dramaticchanges that were to come.For example, in 1947 hepredicted that only sixelectronic digital computerswould be required to satisfythe computing needs of theentire United States.

Although this may cause a wry chuckle today, itis instructive because it accurately reflects thegeneral perception of computers in that era. Inthose days computers were typically onlyconsidered in the context of scientific calculationsand data processing for governments, largeindustries, research establishments, andeducational institutions. It was also widely believedthat computers would only ever be programmed andused by experts and intellectual heroes (if only theycould see us now). (Don't forget to check outKonrad Zuse and his Z3 computer.)

a


Howard Aiken's Harvard Mark I (the IBM ASCC)





1941 ADKonrad Zuse and his Z1, Z3, and Z4

In the aftermath of World War II, it was discovered that a program controlledcalculator called the Z3 had been completed in Germany in 1941, which means that theZ3 pre-dated Howard Aiken's Harvard Mark I.a

The Z3's architect was a German engineercalled Konrad Zuse, who developed his firstmachine, the Z1, in his parents' living room inBerlin in 1938. Although based on relays, the Z3was very sophisticated for its time; for example, itutilized the binary number system and couldhandle floating-point arithmetic. (Zuse hadconsidered employing vacuum tubes, but hedecided to use relays because they were morereadily available, and also because he fearedthat tubes were somewhat unreliable).

In 1943, Zuse started work on ageneral-purpose relay computercalled the Z4. Sadly, the originalZ3 was destroyed by bombing in1944 and therefore didn't survivethe war (although a new Z3 wasreconstructed in the 1960s).However, the Z4 did survive (in acave in the Bavarian Alps) and by1950 it was up and running in aZurich bank.

a

It is interesting to note that paper was in short supply in Germany during to the war,so instead of using paper tape or punched cards, Zuse was obliged to punch holes inold movie film to store his programs and data. We may only speculate as to the filmsZuse used for his hole-punching activities; for example, were any first-edition MarleneDietrich classics on the list? (Marlene Dietrich fell out of favor with the Hitler regimewhen she emigrated to America in the early 1930s, but copies of her films would stillhave been around during the war.)a

Konrad Zuse and his Z1, Z3, and Z4





Zuse was an amazing man, who, inmany respects, was well ahead of histime. For example, in 1958 heproposed a parallel processor called afield computer, years before parallelcomputing became well understood.He also wrote (but neverimplemented) Pkankalkül, which is astrong contender as the first high-levelprogramming language.

To fully appreciate Zuse's achievements, itis necessary to understand that hisbackground was in construction engineering.Also, Zuse was completely unaware of anycomputer-related developments in Germanyor in other countries until a very late stage. In1957, Zuse received the honorary degree ofDr.techn. in Berlin, and he was subsequentlyshowered with many other honors andawards.

aNEW! Discover much more about Konrad Zuse in an Extensive Article written by hiseldest son, Horst Zuse, featuring many pictures from Horst's private collection that havenever been published before!


Konrad Zuse and his Z1, Z3, and Z4


http://www.gottaglow.com/zuse




1943 ADAlan Turing and COLOSSUS

During World War II, Alan Turing (inventor of the Turing Machine) worked as acryptographer, decoding codes and ciphers at one of the British government'stop-secret establishments located at Bletchley Park.a

During this time, Turing was a keyplayer in the breaking of the German'snow-famous ENIGMA Code. However, inaddition to ENIGMA, the Germans hadanother cipher that was employed for theirultra-top-secret communications.

This cipher, which was vastly morecomplicated that ENIGMA, was generatedby a machine called a Geheimfernschreiber(secret telegraph), which the allies referredto as the "Fish."

Alan TuringCopyright (c) 1997. Maxfield & Montrose Interactive Inc.

a

In January 1943, along with a number of colleagues, Turing began to construct anelectronic machine to decode the Geheimfernschreiber cipher. This machine, whichthey dubbed COLOSSUS, comprised 1,800 vacuum tubes and was completed andworking by December of the same year!a

By any standards COLOSSUS was one of the world's earliest workingprogrammable electronic digital computers. But it was a special-purpose machine thatwas really only suited to a narrow range of tasks (for example, it was not capable ofperforming decimal multiplications). Having said this, although COLOSSUS was built asa special-purpose computer, it did prove flexible enough to be programmed to execute avariety of different routines.

Alan Turing and COLOSSUS



a


Alan Turing and COLOSSUS





1943 AD to 1946 ADThe first general-purpose electronic computer

By the mid-1940s, the majority ofcomputers were being built out of vacuumtubes rather than switches and relays.Although vacuum tubes were fragile,expensive, and used a lot of power, theywere much faster than relays (and muchquieter).

If we ignore Atanasoff's machine andCOLOSSUS, then the first truegeneral-purpose electronic computer wasthe electronic numerical integrator andcomputer (ENIAC), which was constructedat the University of Pennsylvania between1943 and 1946.

ENIAC, which was the brainchildof John William Mauchly and J.Presper Eckert Jr., was a monster.

It was 10 feet tall, occupied 1,000square feet of floor- space, weighedin at approximately 30 tons, andused more than 70,000 resistors,10,000 capacitors, 6,000 switches,and 18,000 vacuum tubes. The finalmachine required 150 kilowatts ofpower, which was enough to light asmall town.

a

One of the greatest problems with computers built from vacuum t ubes was reliability;90% of ENIAC's down-time was attributed to locating and replacing burnt-out tubes.Records from 1952 show that approximately 19,000 vacuum tubes had to be replacedin that year alone, which averages out to about 50 tubes a day!a

During the course of developingENIAC, Mauchly and Eckert recognizeda variety of improvements and newtechniques, which they determined touse in any subsequent machines. Forexample, one of the main problems withENIAC was that it was hard-wired; thatis, it did not have any internal memoryas such, but needed to be physicallyprogrammed by means of switches anddials.

Around the summer of 1943, Mauchlyand Eckert discussed the concept ofcreating a stored-program computer, inwhich an internal read-write memorywould be used to store both instructionsand data. This technique would allow theprogram to branch to alternateinstruction sequences based on theresults of previous calculations, asopposed to blindly following apre-determined sequence of instructions.

a

The first general-purpose electronic computer -- ENIAC




Eckert's idea was to use mercury delay lines (which he already knew a great dealabout) for the memory. Around the beginning of 1944, Eckert wrote an internal memoon the subject and, in August 1944, Mauchly and Eckert proposed the building ofanother machine called the electronic discrete variable automatic computer (EDVAC).

a


The first general-purpose electronic computer -- ENIAC


http://www.maxmon.com/delay1.htm




1944 AD to 1952 ADThe First Stored Program Computer -- EDVAC

As was previously discussed, If we ignoreboth Atanasoff's machine and COLOSSUS,then the first true general- purpose electroniccomputer was the ENIAC, which wasconstructed at the University of Pennsylvaniabetween 1943 and 1946. However, ENIAC'sunderlying architecture was very different tothat of modern computers. During the courseof designing ENIAC, it's creators, John WilliamMauchly and J. Presper Eckert Jr., conceivedthe concept of stored program computing.

This concept was subsequentlydocumented by Johann (John) vonNeumann in his paper which is nowknown as the First Draft.

(The computer structure resultingfrom the criteria presented in the "FirstDraft" is popularly known as a vonNeumann Machine, and virtually alldigital computers from that timeforward have been based on thisarchitecture.)

a

In August 1944, Mauchly and Eckert proposed the building of a new machine calledthe electronic discrete variable automatic computer (EDVAC). Unfortunately, althoughthe conceptual design for EDVAC was completed by 1946, several key members leftthe project to pursue their own careers, and the machine did not become fullyoperational until 1952. When it was finally completed, EDVAC contained approximately4,000 vacuum tubes and 10,000 crystal diodes. A 1956 report shows that EDVAC'saverage error-free up-time was approximately 8 hours.a

The First Stored Program Computer -- EDVAC






In light of its late completion,some would dispute EDVAC'sclaim-to-fame as the firststored-program computer.

A small experimental machine(which was based on the EDVACconcept) consisting of 32 words ofmemory and a 5-instructioninstruction set was operating atManchester University, England,by June 1948.

Another machine called the electronic delaystorage automatic calculator (EDSAC) performedits first calculation at Cambridge University,England, in May 1949.

EDSAC contained 3,000 vacuum tubes andused mercury delay lines for memory. Programswere input using paper tape and output resultswere passed to a teleprinter. Additionally, EDSACis credited as using one of the first assemblerscalled "Initial Orders," which allowed it to beprogrammed symbolically instead of usingmachine code.

a

Last but not least, the first commercially available computer, the universal automaticcomputer (UNIVAC I), was also based on the EDVAC design. Work started on UNIVACI in 1948, and the first unit was delivered in 1951, which therefore predates EDVAC'sbecoming fully operational.

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The First Stored Program Computer -- EDVAC


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1971 AD to 1976 ADThe First Microprocessors

With the benefit of hindsight (the one exact science), the advent of themicroprocessor appears to have been an obvious development. But this was less thanself-evident at the time for a number of reasons, not the least that computers of the daywere big, expensive, and a complete pain to use. Although these arguments wouldappear to support the development of the microprocessor, by some strange quirk of fatethey actually managed to work to its disfavor.a

Due to the fact thatcomputers were so big andexpensive, only largeinstitutions could affordthem and they were onlyused for computationallyintensive tasks. Thus,following a somewhatcircular argument, popularopinion held that only largeinstitutions neededcomputers in the firstplace. Similarly, due to thefact that computers werefew and far between, onlythe chosen few had anyaccess to them, whichmeant that only a handfulof people had the faintestclue as to how theyworked.

Coupled with the fact that the early computerswere difficult to use in the first place, this engenderedthe belief that only heroes (and heroines) with size-16turbo-charged brains had any chance of being capableof using them at all. Last but not least, computers ofthe day required many thousands of transistors andthe thrust was toward yet more powerful computers interms of raw number-crunching capability, butintegrated circuit technology was in its infancy and itwasn't possible to construct even a few thousandtransistors on a single integrated circuit until the late1960s.

The end result was that the (potential) future of the(hypothetical) microprocessor looked somewhat bleak,but fortunately other forces were afoot. Althoughcomputers were somewhat scarce in the 1960s, therewas a large and growing market for electronic desktopcalculators. In 1970, the Japanese calculator companyBusicom approached Intel with a request to design aset of twelve integrated circuits for use in a newcalculator.

a

The First Microprocessors




The task was presented to one Marcian "Ted" Hoff, a man who could foresee asomewhat bleak and never-ending role for himself designing sets of special-purposeintegrated circuits for one-of-a-kind tasks. However, during his early ruminations on theproject, Hoff realized that rather than design the special-purpose devices requested byBusicom, he could create a single integrated circuit with the attributes of asimple-minded, stripped-down, general-purpose computer processor.a

The result of Hoff's inspirationwas the world's first microprocessor,the 4004, where the '4's were usedto indicate that the device had a 4-bitdata path. The 4004 was part of afour-chip system which alsoconsisted of a 256-byte ROM, a32-bit RAM, and a 10-bit shiftregister. The 4004 itself containedapproximately 2,300 transistors andcould execute 60,000 operations persecond. The advantage (as far asHoff was concerned) was that bysimply changing the externalprogram, the same device could beused for a multitude of futureprojects.

Knowing how pervasive micro- processorswere to become, you might be tempted toimagine that there was a fanfare of trumpetsand Hoff was immediately acclaimed to be themaster of the known universe, but such wasnot to be the case.

The 4004 was so radically different fromwhat Busicom had requested that they didn'timmediately recognize its implications (muchas if they'd ordered a Chevy Cavalier, whichhad suddenly transmogrified itself into anAston Martin), so they politely said that theyweren't really interested and could theyplease have the twelve-chip set they'doriginally requested (they did eventually agreeto use the fruits of Hoff's labors).

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In November 1972, Intel introduced the 8008, which was essentially an 8-bitversion of the 4004. The 8008 contained approximately 3,300 transistors and was thefirst microprocessor to be supported by a high-level language compiler called PL/M. The8008 was followed by the 4040, which extended the 4004's capabilities by addinglogical and compare instructions, and by supporting subroutine nesting using a smallinternal stack.a



However, the 4004, 4040,and 8008 were all designedfor specific applications, and itwas not until April 1974 thatIntel presented the first truegeneral-purposemicroprocessor, the 8080.This 8-bit device, whichcontained around 4,500transistors and could perform200,000 operations persecond, was destined forfame as the central processorof many of the early homecomputers.

Following the 8080, the microprocessor fieldexploded with devices such as the 6800 fromMotorola in August 1974, the 6502 from MOSTechnology in 1975, and the Z80 from Zilog in 1976(to name but a few).

Unfortunately, documenting all of the differentmicroprocessors would require an entire web site, sowe won't even attempt the task here. Instead, we'llcreate a cunning diversion that will allow us to leapgracefully into the next topic ......

Good grief! Did you see what just flew past yourwindow?

See also The first personal computers (PCs).

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1973 AD to 1981 ADThe First Personal Computers (PCs)

As is true of many facets incomputing, the phrase "PersonalComputer" can be something of aslippery customer. For example, the IBM610 Auto-Point Computer (1957) wasdescribed as being "IBM's first personalcomputer" on the premise that it wasintended for use by a single operator, butthis machine was not based on thestored program concept and it cost$55,000! Other contenders include MIT'sLINC (1963), CTC's Datapoint 2200(1971), the Kenbak-1 (1971), and theXerox Alto (1973), but all of thesemachines were either cripplinglyexpensive, relatively unusable, or onlyintended as experimental projects. So,for our purposes here, we will understand"Personal Computer" to refer to anaffordable, general-purpose,microprocessor- based computerintended for the consumer market.

Given that the 8008 microprocessor wasnot introduced until November 1972, theresulting flurry of activity was quiteimpressive. Only six months later, in May1973, the first computer based on amicroprocessor was designed and built inFrance. Unfortunately the 8008-basedMicral, as this device was known, did notprove tremendously successful in America.However, in June of that year, the term"microcomputer" first appeared in print inreference to the Micral.

In the same mid-1973 time-frame, theScelbi Computer Consulting Companypresented the 8008-based Scelbi-8Hmicrocomputer, which was the firstmicroprocessor-based computer kit to hitthe market (the Micral wasn't a kit -- it wasonly available in fully assembled form). TheScelbi-8H was advertised at $565 andcame equipped with 1 K-byte of RAM.

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In June 1974, Radio Electronics magazine published an article by Jonathan Titus onbuilding a microcomputer called the Mark-8, which, like the Micral and the Scelbi-8H,was based on the 8008 microprocessor. The Mark-8 received a lot of attention fromhobbyists, and a number of user groups sprang up around the US to share hints andtips and disseminate information.

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The First Personal Computers (PCs)



Around the same time that JonathanTitus was penning his article on theMark-8, a man called Ed Roberts waspondering the future of his failingcalculator company known as MITS(which was located next to a laundromatin Albuquerque, New Mexico). Robertsdecided to take a gamble with what littlefunds remained available to him, and hestarted to design a computer called theAltair 8800 (the name "Altair" originatedin one of the early episodes of Star Trek).(The authors don't have the faintest cluewhy the Altair 8800 wasn't named theAltair 8080, but we would be delighted tolearn the answer to this conundrum ifanyone out there knows -- feel free toemail us at [email protected].)

Roberts based his Altair 8800 systemon the newly-released 8080microprocessor, and the resultingdo-it-yourself kit was advertised inPopular Electronics magazine in January1975 for the then unheard-of price of$439. In fact, when the first unit shippedin April of that year, the price had fallen toan amazingly low $375. Even though itonly contained a miserly 256 bytes ofRAM and the only way to program it wasby means of a switch panel, the Altair8800 proved to be a tremendous success.(These kits were supplied with a steelcabinet sufficient to withstand mostnatural disasters, which is why aremarkable number of them continue tolurk in their owner's garages to this day).

aAlso in April 1975, Bill Gates and Paul Allen founded Microsoft (which was to achieve acertain notoriety over the coming years), and in July of that year, MITS announced theavailability of BASIC 2.0 on the Altair 8800. This BASIC interpreter, which was writtenby Gates and Allen, was the first reasonably high-level computer language program tobe made available on a home computer. MITS sold 2,000 systems that year, whichcertainly made Ed Roberts a happy camper, while Microsoft had taken its first tentativestep on the path toward world domination.

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In June 1975, MOS Technologyintroduced their 6502 microprocessorfor only $25 (an Intel 8080 woulddeplete your bank account by about$150 at that time). A short time later,MOS Technology announced their6502-based KIM-1 microcomputer,which boasted 2 K-bytes of ROM (forthe monitor program), 1 K-byte ofRAM, an octal keypad, a flashingLED display, and a cassette recorderfor storing programs. This unit, whichwas only available in fully-assembledform, was initially priced at $245, butthis soon fell to an astoundingly$170.

The introduction of new microcomputersproceeded apace. Sometime after the KIM-1became available, the Sphere Corporationintroduced its Sphere 1 kit, which compriseda 6800 microprocessor, 4 K-bytes of RAM, aQWERTY keyboard, and a video interface(but no monitor) for $650.

In March 1976, two guys called SteveWozniak and Steve Jobs (who had beenfired with enthusiasm by the Altair 8800)finished work on a home-grown 6502-basedcomputer which they called the Apple 1 (afew weeks later they formed the AppleComputer Company on April Fools day).

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mailto:[email protected]

Although it was not tremendously sophisticated, the Apple 1 attracted sufficientinterest for them to create the Apple II, which many believe to be the first personalcomputer that was both affordable and usable. The Apple II, which became available inApril 1977 for $1,300, comprised 16 K-bytes of ROM, 4 K-bytes of RAM, a keyboard,and a color display. Apple was one of the great early success stories. In 1977 they hadan income of $700,000 (which was quite a lot of money in those days), and just oneyear later this had soared tenfold to $7 million! (which was a great deal of money inthose days).

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Also in April 1977, CommodoreBusiness Machines presented their6502-based Commodore PET, whichcontained 14 K-bytes of ROM, 4K-bytes of RAM, a keyboard, a display,and a cassette tape drive for only $600.Similarly, in August of that year,Tandy/Radio Shack announced theirZ80-based TRS-80, comprising 4K-bytes of ROM, 4 K-bytes of RAM, akeyboard, and a cassette tape drive for$600.

One point that may seem strange todayis that there were practically no programsavailable for the early microcomputers(apart from the programs written by theusers themselves). In fact it wasn't untillate in 1978 that commercial softwarebegan to appear. Possibly the mostsignificant tool of that time was theVisiCalc spreadsheet program, which waswritten for the Apple II by a student at theHarvard Business School and whichappeared in 1979.

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It is difficult to overstate the impact of this VisiCalc, but it is estimated that over aquarter of the Apple machines sold in 1979 were purchased by businesses solely for thepurpose of running this program. In addition to making Apple very happy, the success ofVisiCalc spurred the development of other applications such as wordprocessors.a

When home computers first beganto appear, existing manufacturers oflarge computers tended to regard themwith disdain ("It's just a fad ..... it willnever catch on"). However, it wasn't toolong before the sound of moneychanging hands began to awaken theirinterest. In 1981, IBM launched theirfirst PC for $1,365, which, if nothingelse, sent a very powerful signal to theworld that personal computers werehere to stay.

Unfortunately, we've only been able totouch on a few systems here, but hopefullywe've managed to illustrate both thepublic's interest in, and the incredible paceof development of, the personal computer.The advent of the general-purposemicroprocessor heralded a new era incomputing -- microcomputer systems smallenough to fit on a desk could be endowedwith more processing power than monstersweighing tens of tons only a decadebefore.

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The effects of these developments are stillunfolding, but it is not excessive to say thatdigital computing and the personal computerhave changed the world more significantlythan almost any other human invention, andmany observers believe that we've only justbegun our journey into the unknown!

See also Further Reading.

For your interest ...... In 1975, anIBM mainframe computer that couldperform 10,000,000 instructions persecond cost around $10,000,000. In1995 (only twenty years later), acomputer video game capable ofperforming 500,000,000 millioninstructions per second was availablefor approximately $500!

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http://www.maxmon.com/chac.htm




1997 ADThe First Beboputer Virtual Computer

In 1997, Maxfield & Montrose Interactive Inc. introduced the Beboputer(TM). TheBeboputer (pronounced "bee-bop-you-ter") is a fully-functional virtual computer whichaccompanies the book Bebop BYTES Back (An Unconventional Guide to Computers).a

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The First Beboputer Virtual Computer

http://www.maxmon.com/1997cad.htm (1 of 3) [7/16/2003 4:21:20 PM]


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The screenshot above shows thehexadecimal keypad in the upper-left.This device can be used to enter andrun programs. Also shown are a set of8 switches, which are plugged into oneof the Beboputer's input ports, and adual 7-segment LED display, which isplugged into one of the Beboputer'soutput ports

Also shown are a typewriter-stylekeyboard and the Beboputer's virtualcomputer screen.

In fact the screen shows a maze, andsolving this maze is one of thecompetitions that are posted on a set ofspecial Beboputer Web pages (that youaccess from the Beboputer).

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In addition to creating your own experiments, the Beboputer comes equipped with aseries of interactive laboratories. Building on simple concepts, these educationallaboratories will guide you through a unique learning experience, providing you with anin-depth understanding of how computers work.a

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As is illustrated above, each laboratory comes equipped with a multimediaintroduction to reinforce your educational experience. In fact, the Beboputer comesequipped with more than 200 megabytes of multimedia content, including archivevideos of early computers.



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a history of computers - st monica's college · 2012-11-27 · 1937 ad george robert...

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