SOFTWARE

All information is transmitted across the Internet in small units of data called packets. Software on the sending computer divides a large document into many packets for transmission; software on the receiving computer regroups incoming packets into the original document. Similar to a postcard, each packet has two parts: a packet header specifying the computer to which the packet should be delivered, and a packet payload containing the data being sent. The header also specifies how the data in the packet should be combined with the data in other packets by recording which piece of a document is contained in the packet.

A series of rules known as computer communication protocols specify how packet headers are formed and how packets are processed. The set of protocols used for the Internet are named TCP/IP after the two most important protocols in the set: the Transmission Control Protocol and the Internet Protocol. Hardware devices that connect networks in the Internet are called IP routers because they follow the IP protocol when forwarding packets. A router examines the header in each packet that arrives to determine the packet’s destination. The router either delivers the packet to the computer destination across a local network or forwards the packet to another router that is closer to the final destination. Thus, a packet travels from router to router as it passes through the Internet.

TCP/IP protocols enable the Internet to automatically detect and correct transmission problems. For example, if any network or device malfunctions, protocols detect the failure and automatically find an alternative path for packets to avoid the malfunction. Protocol software also ensures that data arrive complete and intact. If any packets are missing or damaged, protocol software on the receiving computer requests that the source resend them. Only when the data has arrived correctly the protocol software makes these data available to the receiving application program, and therefore to the user.

TASKS

1. Transcribe the words and give their Russian equivalents

1. transmission (n.)

2. specify (v.)

3. deliver (v.)

4. protocol (n.)

5. router (n.)

6. forward (v.)

7. examine (v.)

8. determine (v.)

9. malfunction (n.),(v.)

2. Translate the following word combinations

1. packet header

2. packet payload

3. computer communication protocol

4. Transmission Control Protocol

5. the Internet Protocol

6. IP routers

4. Choose the words which are close in meaning to the underlines ones.

1. Hardware devices that connect networks in the Internet are called IP routers.

· are referred to

· are referred to as

· are known as

· are famous as

· are named

2. A router examines the header in each packet that arrives to determine the packet’s destination.

· investigates

· finds

· receives

· transmits

· studies

3. The router either delivers the packet to the computer destination across a local network or forwards the packet to another router that is closer to the final destination.

· transmits

· determines

· refers to

· sends

· inputs

5. Define the following

1. The Internet

2. A packet

3. A packet header

4. A packet payload

5. Software

6. A sending computer

7. A receiving computer

8. Computer communication protocols

9. TCP/IP

10. IP routers

6. Read and translate the text

SOFTWARE

TEXT 1

SOFTWARE

The physical components of a computer – the hardware – are not useful by themselves. Before they can function, computers need programs to coordinate the activities of these physical components. In addition, they need programs designed to perform specific tasks, such as word processing, payroll calculations, budget analysis, data manipulation, or the presentation of information to students. All such programs are known as software.

You may recall that one of the major breakthroughs in computing occurred when Von Neumann and his colleagues suggested that the instructions of a program must be stored in the memory of the computer. This stored-program concept essentially changed the first computers, which had fixed functions, into general purpose machines, with functions that the programmer could define and change. With this capability of exchanging one set of instructions for another, the computer became the remarkably versatile device we know today.

A program, then, is a series of instructions that tells the computer what to do. When the computer actually follows the instructions, we say that it executes the program. In our own lives, we create "programs" every day, although they are not usually intended for a computer. A set of directions enabling friends to find your house is a program. These directions, although simple at first glance, may be quite complicated, and include decision making. For example, you may say: "Drive east on Maple Street. When you reach the red-brick house just after the church, turn left to get to the house”.

In the same way, you must instruct the computer what functions to perform, what decisions to make, how to make them. It is safe to assume that computers will do only what they are told. Consequently, every detail must be provided, because with missing steps or details the program will fail to perform as desired.

Programs of all types share one common feature. They consist of a list of instructions that the central processor can recognize. In reality, we rarely write the instructions that the processor itself needs. We write instruc­tions that are later translated into these by a special program called either a compiler, condenser, or an interpreter, depending on how it performs the transla­tion. At the processor level, instructions are very primitive, consisting of short sequences of bits representing numbers, which makes them difficult to use. Fortunately, instructions have been developed that are more meaningful to people, such as PRINT or GO TO that have meanings similar to their English-language counterparts. These are far easier to use and are called high-level. A whole set of instructions is called a language.

Programs fall into three broad categories: operating systems, programming languages, and application programs. The term “software” applies to all of these. Just as hardware includes printers, VDU's, card readers, and a host of other devices, so software includes all the various types of programs that exist. Oper­ating systems control and coordinate the activities or operations of the com­puter; programming languages enable people to write programs; and applica­tion programs consist of the instructions necessary to perform specific tasks. For example, a system program would enable the computer to send the results of a payroll program to a printer. The payroll program, which is an example of an application program, would be written in a programming language like COBOL.

TASKS

1. Give equivalents of the following words and transcribe them:

1. coordinate (v.)

2. design (v.)

3. breakthrough (n.)

4. occur (v.)

5. colleague (n.)

6. essentially (adv.)

7. purpose (n.)

8. capability (n.)

9. versatile (adj.)

10. execute (v.)

11. consequently (adv.)

12. recognize (v.)

13. compiler (n.)

14. condenser (n.)

15. interpreter (n.)

16. various (adj.)

2. Give equivalents of the following words:

1. word processing

2. payroll calculations

3. payroll program

4. budget analysis

5. data manipulation

6. stored-program concept

7. application program

8. card reader

3. Give English equivalents of:

4. From the sentences given below write out the sentences where the Infinitive performs the function of:

a) a part of a compound predicate;

b) an adverbial modifier of purpose.

1. Computers need programs to coordinate the activities of these physical components.

2. In addition, they need programs designed to perform specific tasks.

3. Von Neumann and his colleagues suggested that the instructions of a program must be stored in the memory of the computer.

4. Every detail must be provided.

5. They consist of a list of instructions that the central processor can recognize.

6. At the processor level, instructions are very primitive, consisting of short sequences of bits representing numbers, which makes them difficult to use.

7. Applica­tion programs consist of the instructions necessary to perform specific tasks.

5. Read and translate the text.

TEXT 2

Date: 2015-01-02; view: 1177