Computer history timeline By Sherry Yuan

mid-1600’s: Blaise Pascal Blaise Pascal’s father was a tax officer. The two of them would spent hours together trying to figure out the taxes each French citizen owes the government. Pascal decided to invent a machine to do the math for them. This resulted in La Pascaline, which could add and subtract with a set of eight gears. This machine was never very popular, because it often broke and was slow. There is a computer language named Pascal in his honour.

1676: Gottfried Wilhelm von Leibniz This German mathematician built the Leibniz Calculator a few years after La Pascaline. It could add, substract, multiply, divide and even find square roots. Although this machine was never manufactured, almost every mechanical calculator in the next 150 years was made similar to it

1801: Joseph Marie Jacquard This Frenchman built a machine for the weaving industry that could be programmed through sets of heavy cardboard punched cards. The cards for one weaving design were linked together. When they passed through the loom, a set of rods in the machine were guided by the cards to make the design. Even though other weavers were already using punched cards for their looms, the Jacquard Loom refined the ideas.

1822: Charles Babbage Charles Babbage was a mathematics professor at Cambridge University. The tables he had to use for his classes were full of mistakes, so Babbage decided to build a machine that could make exact copies of the tables. He soon lost interest in his first attempt, the Difference Engine. Charles Babbage planned the Analytical Engine instead, a machine amazingly similar to a computer. It read programs from punched cards, figured and stored the answers to problems, and printed the answers on paper. He died before he could complete it and his son made a model from his father’s notes and drawings. Babbage is called the Father of Computers.

1887: Herman Hollerith The U.S. Census Bureau held a contest to find better ways to count and record the census. The contest winner, Herman Hollerith came up with the Tabulating Machine. It used punched cards to read and sort data. The punched cards were made to match each person’s answers to questions, and were read by the Tabulator as they passed over tiny brushes. Each time a brush found a hole, it completed an electric circuit and special counting dials would record the new data for that answer.

1944: Howard Aiken Punched card machines were beginning to be used by scientist and they underwent big changes. Howard Aiken of Harvard University started working on a general-purpose machine similar to the Analytical Engine. The Mark I, completed in 1944 could be programmed to do many computing jobs and was the first automatic calculator. It was not a true computer because it was operated through mechanical methods instead of electronic methods.

1939: John Vincent Atanasoff John Vincent Atanasoff and his helper, Clifford Berry, were working on the first electronic computer at Iowa State University before the Mark I was even finished. Atanasoff were doing complex math research that couldn’t be done by any calculating machines of his time, so he invented the ABC. It stood for “Atanasoff-Berry Computer”. The ABC used vacuum tubes for counting and storing data, which was unusual for computers at that time. All the data fed into the ABC were coded using binary notation, meaning any number or letter were written in a series of zeros and ones. They stood for two states of electricity: “on” and “off”.

1940’s: John Mauchly and J. Presper Eckert, Jr. Mauchly These two had met Atanoff earlier and learned about the vacuum tubes. They also planned to build a computer at the University of Pennsylvania Moore School of Engineering. The U.S. Army heard about their ideas and, since it was during WWII, they asked them to build the computer in the hopes that it could help the soldiers figure their gunnery tables fast. The machine was called the Electronic Numerical Integrator And Calculator, ENIAC for short. It was huge and could do a math problem that would take one person 40 hours to do in 20 seconds.

1950: John Von Neumann There was an inconvenience about the ENIAC: It took operators several hours to rewire and reset its switches when needed to be reprogrammed. John Von Neumann outlined a way to overcome the problem, called the stored- program concept. He said that instructions could be stored in the computer’s primary memory. The computer would read the holes in a new set of paper to change what was held in memory. This idea resulted in a new computer, called the EDVAC. It was short for Electronic Discrete Variable Automatic Computer.

The Computer Generations: 1st and 2nd Computers had truly begun when vacuum tubes were used for counting and storing data. There are four generation for computers. The First Generation was 1951-1958. UNIVAC computers were invented by Mauchly and Eckert, who had also built the ENIAC. These computers were large, slow and produced lots of heat. The Second Generation was 1959-1964. Transistors began to replace vacuum tubes in computers. They were smaller and gave off less heat. Second generation machines had a better form of primary memory. They led to real-time computing, so that events could be input and processed as they happened.

The Computer Generations: 3rd 3rd and 4th The Third Generation, 1965-1970, saw the creation of integrated circuits. Jack S. Kilby of Texas Instruments found a way to put several circuits onto a tiny chip. His first integrated circuit didn’t work very well, but soon silicon chips were being used. They were tiny and could hold 64 circuits. The Fourth Generation is 1971- today. Engineers are finding new ways to put even more circuits onto single chips. These are called large-scale integration. This makes computer much faster, smaller and increases memory. Ted Hoff made a microprocessor, leading to the invention of personal computers. They were in DIY kits. Soon, they were being sold in stores. A lot more programs were created.