1.26 Say if these statements are true or false (correct the false ones).
1. A computer can store or handle any data even if it hasn’t received instruction to do it. 2. All computers accept and process information in the form of instructions and characters. 3. The information necessary for solving problems is found in the memory of the computer. 4. All computers can perform arithmetic operations, make decisions, and communicate in some way with the user. 5. A computer can do everything without any person’s interference. 6. Electric pulses moving at the speed of light a computer can carry out vast number of arithmetic-logical operations almost instantaneously. 7. A person cannot do the same, because his life is too short. 8. Computers have circuits, which can make decisions. 9. The kinds of decisions which computer circuits can make are not of the type: Is one number less than another?, Are two numbers equal? and Is one number greater than another?; but of the type: 'Who would win a war between two countries?' or 'Who is the richest person in the world?'. 10. A computer is a machine with an intricate network of electronic circuits that operate switches or magnetize tiny metal cores. 11. The switches are capable of being in one possible magnetized state. 13. The digital machine is capable of storing and manipulating numbers, letters, voltages and characters. 14. The basic idea of a computer is that we can make the machine do what we want by outputting signals that turn certain switches on and turn others off. 15. The basic job of computers is the processing of information. 16. The program provides the information needed to solve the problem and the data tells the computers what to do. 17. They are kept inside the computer in a place called memory. 18. Computers are thought to have many remarkable powers.
1.27 Prepare reports on the topics of Unit 1 or retell one of the texts.
Unit Two
Development of Computers
Topics for Essays, Oral or Written Reports
From the abacus to the computer.
Computer — a God's gift or a Devil's toy?
If I were the inventor of a computer ...
Text 2A analogue & digital computers
find the answers to the questions below in the text underneath:
Into what two main classes were computing machines at first divided?
What does the essential difference between digital and analogue computers lie in?
Why are digital computers used more widely?
What are digital computers used for?
How many problems can these machines solve at the same time?
What kind of machine may a digital computer be?
Computing machines were at first divided into two main classes: digital and analogue. The essential difference between digital and analogue computers does not lie in the machines themselves, but in the way their signals are interpreted.
An analogue computer is a device that simulates the behaviour of a physical system. The computer variables may, for example, be voltages, currents or shaft rotations.
The digital computer differs from the analogue one in that it handles numbers. The simplest digital computer is the human hand, from which the decimal system was derived. The first digital computer was probably the abacus, which is still used in many countries.
Digital computers are used more widely because of the following advantages over the analogue computers: a) a digital system is capable of greater accuracy than the analogue system and operates more efficiently b) a digital system is more reliable and easier in maintenance than an analogue system.
Digital computers are used for handling problems, which require a great volume of calculations with high speed and accuracy. These machines are characterized by the ability to solve several problems of different types at the same time. A digital computer or a data-processing system may be either a general-purpose or a special-purpose machine. The former is the "big brains" that solves the most difficult problems of science and engineering. The latter does only one job over and over again. It is built for only one purpose and cannot do anything else.