Exercises. 4. Memorize the following definitions:

4. Memorize the following definitions:

1. FORTRAN is a problem oriented high level programming language for scientific and mathematical use. It is a compiler language. 2. PL/I is a general-purpose high level programming language for scientific and commercial applications.

5. Answer the following questions:

1. What is FORTRAN? 2. What are low level languages oriented to? 3. What are high level languages oriented to? 4. When was FORTRAN developed? 5. What does a FORTRAN program consist of? 6. Who assigns alphanumeric names to data items? 7. Which forms may data items in FORT-RAN take? 8. By means of what are the actual operations expressed in FORTRAN? 9. How is a program in FORTRAN structured? 10. What do segments in a FORTRAN program consist of? 11. When was PL/I introduced? 12. What is PL/1? 13. What does PL/1 aim at? 14. What are the more important features of PL/1? 15. How many symbols does PL/1 use? 16. What logical statements does PL/1 use?

6. Compare FORTRAN and PL/I.

7. Speak on:

a) arithmetic and logical assignment statements in FORTRAN;

b) the features of the general-purpose PL/1.

8. Translate the following sentences paying attention to the meaning of the words given below:

a) structure – структура, конструкция, строение

to structure – строить, конструировать, создавать

1. The structure of this device is very complex. 2. The block structure of ALGOL is of great value because it permits the parts of a program to be written by different programmers. 3. The words of a language are structured directly from the characters which are usually the smallest units that have meaning by themselves. 4. The program of FORTRAN is structured in segments.

b) master – главный, основной

to master – управлять, руководить, совершенствовать

1. A master card is a punched card-holding any fixed information about a group of cards. 2. Master data are data elements of a record which seldom change. 3. We have to master our knowledge in mathematics and English. 4. The CPU masters the actual calculations inside the computer.

c) to state – устанавливать

state – государство, штат, состояние

1. Programming languages offer various ways for a programmer to state precisely the order of instructions which is often known as the " sequence of control". 2. Scientists of the Soviet State take an important part in international conferences and symposiums. 3. Lights and signals on the control panel show the electrical state of the computer.

d) aim – цель, намерение

to aim – иметь целью

1. The aim of this paper is to show the organization of a memory made on thin films. 2. PL/1 aims at mathematical and economical use. 3. This equipment aims at printing results on cards and displaying them on screens.

e) only – только

the only – единственный

1. In computers only two electrical states are used, 1 for one state, and 0 for the other. 2. The idea of an automatic computer that would not only add, multiply, subtract, and divide but perform a sequence of reasonable operations automatically was given by the English scientist Charles Babbage. 3. It was the only way to solve this problem. 4. Petrov is the only student in our group who had worked at the computing centre before entering the Institute. 5. The access time is only a few millionth of a second for magnetic cores. 6. The printers are used only for output unit.

9. Read Text В without a dictionary. Render the main points of the text in Russian:

TEXT B

ALGOL

ALGOL was developed as an international language for the expression of the algorithms between individuals, as well as a programming language. It was introduced in the early 1960s and gained popularity in Europe more than in the United States.

ALGOL is an acronym for ALGOrithmic Language. It is a problem oriented high level programming language for mathematical and scientific use, in which the source program provides a means of defining algorithms as a series of statements and declarations having a general resemblance to algebraic formulae and English sentences.

An ALGOL program consists of data items, statements and declarations, organized in a program structure in which statements are combined to form compound statements and blocks. Ingredients of the ALGOL, namely, characters, words, expressions (data items), statements, and declarations are really the hierarchical ingredients, because words are made from combination of characters, expressions are composed of groups of words, and statements consist of combinations of expressions.

Declarations used in ALGOL provide the compiler with information about quantities appearing in the program. The 'type declaration' is used to specify whether a variable is an integer, a real number or a Boolean variable.

ALGOL was originally known as IAL or International Algebraic Language. Improvements and modifications are still being offered. There were some versions of ALGOL, the most known of them being ALGOL 60 and ALGOL 68.

Notes:

declaration – описание (в алгоритмическом языке АЛГОЛ); объявление (в алгоритмическом языке ПЛ./1)

whether a variable is an integer – является ли переменная целым числом

10. Read Text В' and translate it without a dictionary. Write a short summary:

TEXT B'

COBOL

COBOL is an acronym for Common Business Oriented Language. It is internationally accepted programming language developed for general commercial use. COBOL is a problem oriented high-level language in which the source program is written using statements in English.

A COBOL program is written in four divisions: Identification Division, Environment Division, Data Division, and Procedure Division. The Identification Division contains descriptive information that identifies the program being compiled. The Environment Division deals with the specification of the computer to be used for operating the object program, including such information as the size of memory, the number of tape decks, printers and other peripheral devices that will be used; a description of the computer to be used for compiling the source program is also given here. The Data Division is used to allocate labels to all units of data on which operations are to be performed. All input and output files are defined and associated with the peripheral units to be used for input and output. The Procedure Division gives the step-by-step instructions necessary to solve the problem. These steps are specified by means of instructions expressed in English statements which can be recognized (распознавать; узнавать) by the compiler and translated into a sequence of machine code instructions capable of being used by the computer to solve the problem.

The advantages of using COBOL are that it is relatively simple to learn, and programs can be quickly written and tested; programmers can easily understand programs not written by them, and thus associated documentation can be simplified; and programs can be used on other machines, within the limitations noted above.

The disadvantages are: (1) the relative inefficiency of the resulting object program as compared with a program written in machine code or a machine oriented language and (2) the lack of flexibility (гибкость) imposed by the restrictions (ограничение) on the type of instructions and methods for performing operations in a highly standardized language.

Notes:

Identification Division – раздел идентификации

Environment Division – раздел оборудования

to deal with – иметь дело с

tape decks – комплекты (наборы) перфолент

step-by-step instructions – поэтапные команды