2. What are the advantages of the portable computer? Name as many as you can.

Text 8 C

1. Skim the text and get ready to discuss the main stages of the development of the computer:

The development of the Computer

The ideas and inventions of many engineers, mathematicians, and scientists led to the development of the computer. The ancient abacus served as the earliest sort of calculating device. But its use was limited by the need to move each counter individually.

Early calculating devices. The first true calculating machines were developed in the 1600’s. In 1642, the French mathematician, scientist, and philosopher Blaise Pascal invented the first automatic calculator.

During the early 1670's, the German mathematician Gottfried Wilhelm von Leibniz extended the usefulness of the calculator that Pascal had invented.

Leibniz sought a counting system that would be easier for a machine to handle than the decimal system He developed the binary system of mathematics in the late 1600's. Binary mathematics uses only the 0 and the 1 arranging them to represent all numbers.

The first successful computer. In 1888, American inventor and businessman Herman Hollerith devised a punched card system, including the punching equipment, for tabulating the results of the United State census. Hollerith's machines used electrically charged nails that, when passed through a hole punched in a card, created a circuit. The circuits registered on another part of the machine, where they were read and recorded.

The first analog computer. Vannevar Bush, an American electrical engineer, worked to develop a computer that would help scientists. In 1930, he built a device called a differential analyzer to solve differential equations. This machine was the first reliable analog computer. It derived measurements from the movements of its gears and shafts.

The first electronic computers. Some scientists and engineers saw greater computing potential in electronics. The first special-purpose electronic digital computer was constructed in 1939 by John V. Atanasoff, an American mathematician and physicist. In 1944, Howard Alken, a Harvard University professor, built another early form of digital computer, which he called the Mark l. The operations of this machine were controlled chiefly by electromechanical relays (switching devices).

In 1946, two engineers at the University of Pennsylva­nia, I. Presper Eckert, Jr., and John William Mauchly, built the first general-purpose electronic digital computer. They called it ENIAC (Electronic Numencal Integrator And Computer). ENIAC contained about 18,000 vacuum tubes, which replaced the relays that had controlled the operation of Mark I. The machine weighed more than 30 tons (27 metric tons), occupied more than 1,5000 square (140 square meters) of floor space, and consumed 150 kilowatts of electricity during operation. ENIAC operated about 1,000 times as fast as the Mark I. It could perform about 5,000 additions and 1,000 multiplications per second. ENIAC also could store parts of its programming.

The miniaturization of computer components. The invention of the transistor in 1947 led to the produc­tion of faster and more reliable electronic computers. Transistors control the flow of electric current in elec­tronic equipment. They soon replaced the bulkier, less reliable vacuum tubes. In 1958, Control Data Corpora­tion introduced the first fully transistorised computer, designed by American engineer Seymour Cray. IBM introduced its first transistorised computers in 1959.

During the 1960's, computer technology improved rapidly. Different kinds of circuits were placed on silicon chips. Some of the circuits contained the computer's logic. Other chips held memory. By the early 1970's, the entire workings of a computer could be placed on a handful of chips. As a result, smaller computers became possible. The central chip that controlled the computer became known as a microprocessor.

The personal computer. The first personal com­puter, the Altair, was introduced in 1975. Only electron­ics hobbyists bought these computers.

In 1977, two American students, Steven P. Jobs and Stephen G. Wozniak, founded the Apple Computer Company and introduced the Apple II personal com­puter. The Apple II was much less expensive than main­frames. As a result, computers became available to peo­ple other than computer specialists and technicians. Personal computers were purchased by small and medium-sized businesses that could not afford main­frames or did not need the immense computing power that mainframes provided. Millions of individuals, families, and schools also bought them.

In 1981, IBM entered the personal computer market with its PC. The machine was even more successful than the Apple II. Apple scored another success in 1984 with the introduction of its Macintosh, a powerful, easy-to-use desktop computer.

Computers of the future. Tomorrow's computers will be increasingly powerful. Computer researchers continue to seek ways to develop faster and more powerful machines and software. For example, experimental computers called optical processors use beams of laser light, rather than electric current, to process data. Many scientists believe that optical computers will someday work much faster than electronic ones. Much software research focuses on the development of new virtual-reality programs to provide increasingly realistic simulated experiences. Computer experts predict that virtual-reality will play a large role in education and training as well as offer dramatic possibilities for entertainment. Much software research also focuses on the further development of artificial intelligence, which is intended to help computers make decisions rather than simply to manipulate.

2. Continue the list of inventions which have resulted in the development of the modern computer:

(a) abacus (рахівниця)

(b) automatic calculator

(c) ………

3. Match the names with the things they are associated with. See the list from ex.2:

1. Seymour Cray

2. Gottfried Wilhelm von Leibniz

3. John V.Atanasoff

4. Steven P.Jobs and Stephen G.Wozniak

5. Blaise Pascal

6. Vannevar Bush

7. J.Presper Eckert, Jr., and John William Mauchly

8. Herman Hollerith

9. Howard Alken

e.g. 5b; …

4. Explain which events the following dates refer to:

1981; 1947; 1946; 1975; 1959; 1888; 1642.