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Introduction to Computer

History of Computer

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History of Computer

The first computers were people!

Electronic computers and the earlier mechanical computers were given this name because they performed the work that had previously been assigned to people.

"Computer" was originally a job title: it was used to describe those human beings whose job was to perform the repetitive calculations required to compute such things as

navigational tables, tide charts, and planetary positions for astronomical almanacs.

Calculating-Table by Gregor Reisch: Margarita Philosophica, 1503

A typical computer operation back when computers were people.

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The abacus was an early aid for mathematical computations.
A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator.
The oldest surviving abacus was used in 300 B.C. by the Babylonians.

A modern abacus consists of rings that slide over rods.

This older abacus dates from the time when pebbles were used for counting. The word "calculus" comes from the Latin word for pebble.

History of Computer

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A more modern abacus

Note how the abacus is really just a representation of the human fingers:

the 5 lower rings on each rod represent the 5 fingers and

the 2 upper rings represent the 2 hands.

History of Computer

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1617

A Scotsman named John Napier invented logarithms,

a technology that allows multiplication via addition.

Napier also invented an alternative to tables, where the logarithm values were carved on ivory sticks which are now called Napier's Bones.

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Slide rule, first built in England in 1621 and used till 1970s. It was a mechanical analog computer used for calculations.

History of Computer

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1452-1519

Leonardo da Vinci

made drawings of gear-driven calculating machines but apparently never built any.

A Leonardo da Vinci drawing showing gears arranged for computing

History of Computer

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The first gear-driven calculating machine to actually be built was probably the Calculating Clock, so named by its inventor, the German professor Wilhelm Schickard in 1623.

This device got little publicity because Schickard died soon afterward in the bubonic plague.

Schickard's Calculating Clock

History of Computer

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1642

Blaise Pascal invented the Pascaline . It was a mechanical calculator that could perform additions and subtraction.

History of Computer

Shown below is an 8 digit version of the Pascaline

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A Pascaline opened up so you can observe the gears and cylinders which rotated to display the numerical result

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1801

the Frenchman Joseph Marie Jacquard invented a power loom that could read from punched wooden cards, held together in a long row by rope.

Descendents of these punched cards have been in use ever since.

Jacquard's Loom showing the threads and the punched cards

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History of Computer

A close-up of a Jacquard card

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This tapestry was woven by a Jacquard loom

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1822

the English mathematician Charles Babbage proposed a steam driven calculating machine, the size of a room, which he called the Difference Engine.

Analytic Engine

General-purpose computer, included features such as arithmetic logic unit, control flow, and memory. Considered as conceptual predecessor of modern computers.

Ada Byron, first programmer

For more details on Charles Babbage work visit http://www.computersciencelab.com/ComputerHistory/HistoryPt2.htm

History of Computer

By 1822 the English mathematician Charles Babbage was proposing a steam driven calculating machine the size of a room, which he called the Difference Engine. This machine would be able to compute tables of numbers, such as logarithm tables. He obtained government funding for this project due to the importance of numeric tables in ocean navigation. By promoting their commercial and military navies, the British government had managed to become the earth's greatest empire. But in that time frame the British government was publishing a seven volume set of navigation tables which came with a companion volume of corrections which showed that the set had over 1000 numerical errors. It was hoped that Babbage's machine could eliminate errors in these types of tables. But construction of Babbage's Difference Engine proved exceedingly difficult and the project soon became the most expensive government funded project up to that point in English history. Ten years later the device was still nowhere near complete, acrimony abounded between all involved, and funding dried up. The device was never finished.

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Hollerith's invention, known as the Hollerith desk, consisted of

a card reader which sensed the holes in the cards,

a gear driven mechanism which could count, and

a large wall of dial indicators to display the results of the count.

An operator working at a Hollerith Desk

History of Computer

The next breakthrough occurred in America. The U.S. Constitution states that a census should be taken of all U.S. citizens every 10 years in order to determine the representation of the states in Congress. While the very first census of 1790 had only required 9 months, by 1880 the U.S. population had grown so much that the count for the 1880 census took 7.5 years. Automation was clearly needed for the next census. The census bureau offered a prize for an inventor to help with the 1890 census and this prize was won by Herman Hollerith, who proposed and then successfully adopted Jacquard's punched cards for the purpose of computation.

Hollerith's invention, known as the Hollerith desk, consisted of a card reader which sensed the holes in the cards, a gear driven mechanism which could count (using Pascal's mechanism which we still see in car odometers), and a large wall of dial indicators (a car speedometer is a dial indicator) to display the results of the count.

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History of Computer

A few Hollerith desks still exist today [photo courtesy The Computer Museum]

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Two types of computer punch cards

History of Computer

Hollerith built a company, the Tabulating Machine Company which, after a few buyouts, eventually became International Business Machines, known today as IBM. IBM grew rapidly and punched cards became ubiquitous. Your gas bill would arrive each month with a punch card you had to return with your payment. This punch card recorded the particulars of your account: your name, address, gas usage, etc. (I imagine there were some "hackers" in these days who would alter the punch cards to change their bill). As another example, when you entered a toll way (a highway that collects a fee from each driver) you were given a punch card that recorded where you started and then when you exited from the toll way your fee was computed based upon the miles you drove. When you voted in an election the ballot you were handed was a punch card. The little pieces of paper that are punched out of the card are called "chad" and were thrown as confetti at weddings. Until recently all Social Security and other checks issued by the Federal government were actually punch cards. The check-out slip inside a library book was a punch card. Written on all these cards was a phrase as common as "close cover before striking": "do not fold, spindle, or mutilate". A spindle was an upright spike on the desk of an accounting clerk. As he completed processing each receipt he would impale it on this spike. When the spindle was full, he'd run a piece of string through the holes, tie up the bundle, and ship it off to the archives. You occasionally still see spindles at restaurant cash registers.

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1941

All-electronic digital computer built by J. V. Atanasoff, and Clifford Berry
J. V. Atanasoff was a professor of physics and mathematics at Iowa State University.
The machine could solve 29 simultaneous equations with 29 unknowns.
Its design was appropriate for only one type of mathematical problem, and it was not further pursued after world War II.

The Atanasoff-Berry Computer

History of Computer

One of the earliest attempts to build an all-electronic (that is, no gears, cams, belts, shafts, etc.) digital computer occurred in 1937 by J. V. Atanasoff, a professor of physics and mathematics at Iowa State University. By 1941 he and his graduate student, Clifford Berry, had succeeded in building a machine that could solve 29 simultaneous equations with 29 unknowns. This machine was the first to store data as a charge on a capacitor, which is how today's computers store information in their main memory (DRAM or dynamic RAM). As far as its inventors were aware, it was also the first to employ binary arithmetic. However, the machine was not programmable, it lacked a conditional branch, its design was appropriate for only one type of mathematical problem, and it was not further pursued after World War II. It's inventors didn't even bother to preserve the machine and it was dismantled by those who moved into the room where it lay abandoned.

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Colossus computers were built during World War II by Britain. Among firs digital electronic computers, used to break German codes.

History of Computer

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In 1965 the work of the German Konrad Zuse was published for the first time in English.
Zuse had built a sequence of general purpose computers in Nazi Germany.
The first, the Z1, was built between 1936 and 1938 in the parlor of his parent's home.
The Z3, built in 1941, was probably the first operational, general-purpose, programmable (that is software controlled) digital computer.

The Zuse Z1 in its residential setting

History of Computer

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ENIAC, one of the first electronic general-purpose computer
ENIAC stood for Electronic Numerical Integrator and Calculator.
built at the University of Pennsylvania between 1943 and 1946
by two professors, John Mauchly and the 24 year old J. Presper Eckert.
ENIAC filled a 20 by 40 foot room,
weighed 30 tons, and
used more than 18,000 vacuum tubes.

ENIAC: the "Electronic Numerical Integrator and Calculator” [U.S. Army photo]

History of Computer

The title of forefather of today's all-electronic digital computers is usually awarded to ENIAC, which stood for Electronic Numerical Integrator and Calculator. ENIAC was built at the University of Pennsylvania between 1943 and 1945 by two professors, John Mauchly and the 24 year old J. Presper Eckert, who got funding from the war department after promising they could build a machine that would replace all the "computers", meaning the women who were employed calculating the firing tables for the army's artillery guns. The day that Mauchly and Eckert saw the first small piece of ENIAC work, the persons they ran to bring to their lab to show off their progress were some of these female computers (one of whom remarked, "I was astounded that it took all this equipment to multiply 5 by 1000").

ENIAC filled a 20 by 40 foot room, weighed 30 tons, and used more than 18,000 vacuum tubes. Like the Mark I, ENIAC employed paper card readers obtained from IBM (these were a regular product for IBM, as they were a long established part of business accounting machines, IBM's forte). When operating, the ENIAC was silent but you knew it was on as the 18,000 vacuum tubes each generated waste heat like a light bulb and all this heat (174,000 watts of heat) meant that the computer could only be operated in a specially designed room with its own heavy duty air conditioning system. Only the left half of ENIAC is visible in the first picture, the right half was basically a mirror image of what's visible.

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To reprogram the ENIAC you had to rearrange the patch cords and the settings of 3000 switches

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Eckert, Mauchly and John von Neumann teamed to design EDVAC
which pioneered the stored program
After ENIAC and EDVAC came other computers with humorous names such as ILLIAC, JOHNNIAC, MANIAC ☺

ILLIAC II built at the University of Illinois

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Eckert and Mauchly set up their own company.
Their first product was the famous UNIVAC computer.
"Universal Automatic Computer"
first commercial computer.
The first UNIVAC was sold to the Census bureau.
UNIVAC was also the first computer to employ magnetic tape.

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A reel-to-reel tape drive [photo courtesy of The Computer Museum]

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1944

Harvard Mark I computer was built as a partnership between Harvard and IBM
first programmable digital computer made in U.S
The machine weighed 5 tons
incorporated 500 miles of wire
8 feet tall and 51 feet long
had a 50 ft rotating shaft running its length, turned by a 5 horsepower electric motor.
The Mark I ran non-stop for 15 years.

The Harvard Mark I: an electro-mechanical computer

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One of the primary programmers for the Mark I was Grace Hopper.
Hopper found the first computer "bug":
a dead moth that had gotten into the Mark I and whose wings were blocking the reading of the holes in the paper tape.
The word "bug" had been used to describe a defect since at least 1889
but Hopper is credited with coining the word "debugging" to describe the work to eliminate program faults.

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The IBM 7094, a typical mainframe computer [photo courtesy of IBM]

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The Teletype was the standard mechanism used to interact with a time-sharing computer.

A teletype was a motorized typewriter that could transmit your keystrokes to the mainframe and then print the computer's response on its roll of paper.

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A close-up of paper tape

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An IBM Key Punch machine which operates like a typewriter except it produces punched cards rather than a printed sheet of paper

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Transistors, 1947
Integrated Circuits, 1960

History of Computer

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The first microprocessor was developed at Intel in 1971.
A microprocessor (uP) is a computer that is fabricated on an integrated circuit (IC).
The Intel 4004 was the first microprocessor (uP).
The 4004 consisted of 2300 transistors and was clocked at 108 kHz (i.e., 108,000 times per second)
Intel was started in 1968
Intel invented both the DRAM and the EPROM, two memory technologies that are still going strong today.

History of Computer

This transformation was a result of the invention of the microprocessor. A microprocessor (uP) is a computer that is fabricated on an integrated circuit (IC). Computers had been around for 20 years before the first microprocessor was developed at Intel in 1971. The micro in the name microprocessor refers to the physical size. Intel didn't invent the electronic computer. But they were the first to succeed in cramming an entire computer on a single chip (IC). Intel was started in 1968 and initially produced only semiconductor memory (Intel invented both the DRAM and the EPROM, two memory technologies that are still going strong today). In 1969 they were approached by Busicom, a Japanese manufacturer of high performance calculators (these were typewriter sized units, the first shirt-pocket sized scientific calculator was the Hewlett-Packard HP35 introduced in 1972). Busicom wanted Intel to produce 12 custom calculator chips: one chip dedicated to the keyboard, another chip dedicated to the display, another for the printer, etc. But integrated circuits were (and are) expensive to design and this approach would have required Busicom to bear the full expense of developing 12 new chips since these 12 chips would only be of use to them.

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The original IBM Personal Computer (PC)

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References

http://www.computersciencelab.com/ComputerHistory/History.htm

http://www.computersciencelab.com/ComputerHistory/HistoryPt2.htm

http://www.computersciencelab.com/ComputerHistory/HistoryPt3.htm

http://www.computersciencelab.com/ComputerHistory/HistoryPt4.htm

https://en.wikipedia.org/wiki/Abacus