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Unit 7
Computers
Start-up
I. Discuss the following questions.
1. In what ways are computers used at home or at work?
2. How powerful are modern computers?
3. What are the possible spheres of improvement of computers?
4. How are computers likely to change our life?
II. The following text comes from "Basic English for Computing" by Eric H. Glendinning and J. Mc. Ewan printed in 1999. Look through these predictions and say which:
have already happened and when they happened;
have not happened yet but are going to or will happen to your mind;
will never happen.
2000 Artificial ears.
Videophone which will dial automatically when you tell it the name of the person you wish to call.
2002 Electronic implants to stimulate the muscles of disabled people.
2004 Three-dimensional fax.
Computer touch screens which unfold from your wristwatch.
2005 Computers which write their own software.
2007 Smart clothes which alter their thermal properties according to the weather.
2010 Robotic pets.
2015 Artificial lungs.
2020 Regular manned flights to Mars.
2030 Direct connections between brain and computer.
2035 Artificial brain.
II. Below there is the text about the history of computers. Read it carefully and be ready for a comprehension check-up.
History of Computers
The idea that number systems do not necessarily have to be based on 10 is not a recent one. Gottfried Leibnitz, working in the 1600s, developed theories of logic and binary numbers. A century later, George Boole, a British mathematician, devised a branch of logic that is still applied to binary systems in computing.
The principle of the abacus was first translated into a mechanical calculator in 1642 by the great French scientist Blaise Pascal. Numbers were fed into his machine by turning dials similar to those on a telephone, and the result appeared in a window. The machine added or subtracted numbers with total accuracy, but was a financial flop.
In 1694, Gottfried Liebnitz in Germany improved the mechanical calculator so that it could also multiply and divide. He devised a way of making it automatically perform repeated additions or subtractions. Mechanical calculators then advanced rapidly over the following two centuries, until they were gradually displaced by much faster electronic calculators from the late 1950s and on.
Early calculators only did arithmetic; unlike a computer, they could not store results and they could not be given instructions. However, the idea that such a machine could be built occurred to the British inventor Charles Babbage. Babbage at that time was working on a machine called the Difference Engine capable of accurate calculation of logarithms using the method of differences. He wanted to make a successor that could be programmed to perform different kinds of calculations and that could store results. The machine was called the Analytical Engine. It was to be given instructions on punched cards.
The electronic computer, like many inventions, was called in by the pressure of war. It was built on Babbage's principles but used electronic valves or vacuum tubes. The first computer, called Colossus, was built in Britain in 1943 to break German codes.
Colossus was in fact only used for code-cracking, and the first general-purpose computer was ENIAC, an American machine completed in 1946. ENIAC was hot and huge, with 18,000 vacuum tubes. Computers only got smaller with the invention of the transistor and the microchip.
Electronics really goes back to the turn of the century, when the first devices that could produce and process electric signals were invented. These were electronic valves or vacuum tubes in which a beam of electrons produced by a glowing filament carried a current between electrodes. The diode valve came first, invented by the British scientist John Ambrose Fleming in 1904, followed in America by Lee de Forest's three-electrode mode valve in 1906. The diode changed alternating current to a direct-current signal, and the mode amplified a signal. These valves were crucial to the development of radio and television, and sound recording.
However, valves were large and unreliable as the filament sooner or later burned out, making the development of small electronic machines impossible. The solution was found in 1948 by American scientists William Shockley, John Bardeen and Walter Brattain. Their research led to the discovery of the semiconductor diode and transistor. Pieces of semiconductor replaced the filament and electrodes, and made electronic components small and fully reliable.
The next important development was to fabricate several components in a single piece of semiconductor — the integrated circuit. This was invented by the American engineer Jack Kilby in 1958 and it led to a microchip, into which many thousands of components are packed. The first microprocessor was produced in 1970.
The first generation of computers used vacuum tubes and came out in 1950. These computers could perform thousands of calculations per second. In I960, the second generation of computers was developed and these could perform work ten times faster than their predecessors. The reason for this was the use of transistors instead of vacuum tubes. Second-generation computers were smaller, faster and more dependable. The third-generation computers appeared on the market in 1965. They could do a million calculations a second, which is 1,000 times as many as first-generation computers. Unlike second-generation computers, these are controlled by tiny integrated circuits and are smaller and more dependable. Fourth-generation computers arrived with the integrated circuits that have greatly reduced size. As many as 1,000 tiny circuits now fit onto a single chip. A chip is a square or rectangular piece of silicon, usually from 1/2 to 1/4 inch, upon which several layers of an integrated circuit are imprinted, after which the circuit is encapsulated in plastic, ceramic or metal. Fourth-generation computers are 50 times faster than third-generation computers and can complete approximately 1,000,000 instructions per second.
Check up for Comprehension
I. Answer the following questions.
1. Is the binary code a recent invention?
2. Were the early calculators based on a decimal or a binary system?
3. The mechanical calculator invented by Pascal could perform practically all mathematical calculations, couldn't it?
4. In what way did the mechanical computer differ from calculators?
5. What are the principles of work of the electronic computer?
6. How does a vacuum tube work?
7. Why was it impossible to make computers smaller and more reliable until 1948?
8. What was the invention of the microprocessor preceded by?
9. How is the latest generation computer different from the first one?
II. Read the text again, divide it into logical parts and find a suitable title for each part from the list below.
Mechanical computers
Diodes, transistors and microchips
Binary code
Calculators
Generations of computers
Electronic computers
II. Look through the text once again and choose the best answers to complete the following statements.
1. The improved mechanical calculator could do
a) addition and subtraction;
b) multiplication and division;
c) all four mathematical functions.
2. The first general-purpose computer was
a) Colossus;
b) ENIAC;
c) Analytical Engine.
3. The first-generation computers used
a) semiconductor diodes;
b) vacuum tubes;
c) microchips.
4. The third-generation computers could do
a) 1,000 calculations a second;
b) 100,000 calculations a second;
c) 1,000,000 calculations a second.
5. Modern computers are to be given instructions on
a) punched cards;
b) magnetic tapes;
c) input devices directly.
III. Summarise the main stages of computer development using the diagram below.
IV. Match the characteristics of each generation of computers given on the right-hand side with the sequence on the left:
|
A. First generation |
a. Used transistors. Data stored internally on magnetic disks. |
|
B. Second generation |
b. Used integrated circuits, electronic solid-state memory. External memory stored on magnetic disks. |
|
C. Third generation |
c. Vacuum-tube based machines. Magnetic drums used for internal storage and magnetic tape for external storage. |
|
D. Fourth generation |
d. Used microchips. Have greatly reduced size. Perform operations very fast. |
Word Study
I. Form nouns from the following verbs.
|
Verb |
Noun |
|
calculate add subtract divide multiply |
|
|
store invent perform integrate appear |
II. Match the words in A with the statements in B.
|
A |
B |
|
1. Abacus |
a. was developed by Leibnitz in the 1600s. |
|
2. Vacuum Tubes |
b. enabled electronic compo nents to be small and fully re liable. |
|
3. Transistors |
c. contains several components in a single piece of a semicon ductor. |
|
4. A chip |
d. is a piece of silicon with several layers of integrated circuits imprinted. |
|
5. An integrated circuit |
e. were crucial in the develop ment of radio, television and sound recording. |
|
6. The binary system |
f. is an instrument used for counting. |
|
7. Microminiaturization |
g. is the reduction of circuiting onto a chip. |
III. Replace the words in bold type with the synonyms used in the text.
1. The Difference Engine was capable of precise calculation of logarithms.
2. The branch of logic developed by George Boole is still used in binary systems in computing.
3. The Analytical Engine was to be able to keep the results.
4. Transistors made computers smaller and more reliable.
5. The piece of chip with several layers of integrated circuits is then put into a plastic, ceramic or metal capsule.