Computer History

Notes:

Computer Literacy- implies an ability to use a computer.

Definition of a Computer- A computer is a data processing machine. It accepts input (information), processes it according to a set of instructions (a program) and produces the results as output. It is an electronic machine that accepts data, processes it according to instructions, and provides the results as new data.

A computer can not think. It can make comparisons and simple decisions. A calculator can not.

Definition of a Program - list of instructions, in a particular language that the computer understands, on how to do something detailed and specific. 

Computer History

Major Inventors and Inventions in the History of Computers

The abacus- The abacus is the earliest known invention to allow the manipulation of data. It can be dated back to 3000 B.C. Ancient civilizations in India, China, Egypt, and Mesopotamia were using calculating devices such as the abacus. 

John Napier - A Scottish mathematician who invented Napier's Rods or Bones in 1617. This device which looked like a multiplication table allowed the user was able to multiply large numbers by manipulating these rods. 

Blaise Pascal - In 1642 this frenchman built the first operating model of a calculating machine, which he called the Pascaline. During the next 10 years he made 50 more of these machines. The machine could add and subtract and is considered the first mechanical calculator. It was the size of a shoe box and operated through a series of gears and wheels. Because of how expensive it was to build and because people feared it would put them out of work, the Pascaline was not a commercial success. Blaise Pascal also has a programming language named after him.

Baron Gottfried Wilhelm Von Leibniz - A German mathematician who designed an instrument called the Stepped Reckoner in 1694. It was more versatile than the Pascaline because it could add, subtract, multiply and divide. It used cylinders to do its calculations. Leibniz's most important contribution was not the machine itself, but the use of binary code. Binary code is a system of counting using two digits 0 and 1. The 1 would represent existence and 0 nonexistence. The binary system is the standard internal language of today's computers.

Joseph Marie Jacquard - Although not a calculating device, Jacquard's loom was important to the development of the computer. In 1790, Jacquard used punched cards to create patterns on fabric woven on a loom. In a sense, each punchcard served as a small program telling the loom what to do. 

Charles Babbage - Known as the father of computers. In 1835, Babbage designed a system which included a control unit, information storage unit, and could produce printed output. He called it the Analytical Engine. The machine however could not be completed because the precision tools needed to make it were not available at that time. Historians say that all modern computers descend directly from Babbage's Analytical Engine. Ironically when Babbage died he was considered a failure.

Augusta Ada Byron - Tried to help Babbage by raising money for his invention. She also wrote a demonstration program for the Analytical Engine. Because of this program she is considered the first computer programmer. The programming language Ada was named after her.

Herman Hollerith - Hollerith worked at the census bureau in the 1880s and became interested in finding an easier way to tabulate the population. Hollerith went to work on a tabulating machine which relied heavily on Jacquard's punchcard idea. He designed a machine which pressed pins against cards the size of dollar bills. Each hole represented characteristics of the population such as sex, birthplace, and number of children. If a pin went through a hole and made contact with a metal surface below a circuit would be completed. The item was counted and added to the total. Hollerith sold 56 of his tabulating machines to the census bureau and the census was completed in 2 years instead of 7. Hollerith was very successful and formed his own company which later became known as International Business Machines or IBM in 1924. 

The Modern Computer

Howard Aiken - Aiken, with the help of IBM, built the modern equivalent of Babbage's Analytical Engine in 1943. It was called the Mark I. It was 51 feet long, 8 feet high, 2 feet thick and had 500 miles of wire. It weighed 5 tons. It accepted information through punched cards, stored, and processed this information. It was noisy and could make 3 calculations per second. The Mark I was the first electromechanical computer. After the Mark I and Mark II computers became faster because they were no longer electromechanical.

John Atanasoff and Clifford Berry - In 1939 Atanasoff and Berry built the first semielectonic digital computer called the ABC, Atanasoff - Berry Computer. 

John Mauchly and J. Presper Eckert - used some of Atanasoff and Berry's ideas to build the electronic digital computer called the ENIAC (Electronic Numerator Integrator and Calculator) in 1946. The ENIAC was built chiefly because of the emergence of Worl War II. The military needed extremely fast computers to calculate the ballistics table for new Naval guns and missiles. The ENIAC was the size of a room and weighed 30 tons. It used 18000 vacuum tubes instead of the relays and switches which had been used on earlier computers. It performed 5000 calculations per second. The biggest problem with the ENIAC was that in order to run another program, wires had to be rewired differently.

John Von Neumann - Was the main reason the EDVAC ( Electronic Discrete Variable Automatic Computer) was built in 1949. It was the first stored program digital computer. 

UNIVAC - In 1951, the builders of the ENIAC developed this more advanced digital computer. It could handle numbers and alphabetic characters equally well. Within a few years it was mass produced and became commercially available. During the 1950's computer manufacturers began selling computers to the public.

Generations of Computers

First Generation
The first generation of computers began in the 1940s and into the 1950s. During this period computers used vacuum tubes to conduct electricity. Tubes were continually burning out and had to be replaced. This made computers very expensive. During the first generation, data was stored on magnetic tapes and magnetic drums. 

Second Generation
The second generation of computers began when the transistor replaced the vacuum tube in the late 1950s. The transistor conducts energy more efficiently, consumes less energy, needs less space, and generates less heat. They also don't burn out like vacuum tubes did. Computers became smaller, more reliable and less expensive. Small and medium sized businesses could now afford to buy computers. 

Third Generation
The third generation of computers began in 1964 with the introduction of integrated circuits. In that year scientists developed tiny integrated circuits and installed hundreds of these transistors on a single silicon chip. Computers became better and less expensive.

Fourth Generation
The fourth generation of computers came about because of the development of microprocessors. These microprocessors were made possible because of the development of large-scale integration. Large scale integration has made it possible for computers to become very small. During this generation Apple Computers came into being. Steve Wozniak and Steve Jobs began making Apple computers in 1970. In 1977 they enjoyed enormous success with their introduction of the Apple II personal computer. In 1981, IBM entered the market with their own IBM PC. Because of IBM's success other companies developed clones which were able to run the same programs. They were IBM compatible. Personal computers were beginning to be used widely.

The Fifth Generation
The fifth generation of computers is now in process and goes on into the future. It is characterized by superfast computer chips. Computer chips are capable of over 8 billion calculations per second. It is and will be characterized by developments in artificial intelligence, greater capacity of information, improvements in communication, improvements in speed, and decrease in size and price. 

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