Systems. Information. Codes

A computer is a system. It is a set of parts or subsystems. The main sub­systems are input, output, processor, and storage. Each subsystem performs a specific subfunction, and the sub­systems work together to perform infor­mation processing — acquiring, storing, and manipulating information and com­municating the results.

Information is data that has a context. This concept is useful because the context helps us to make decisions and solve problems us­ing data and information. Data are simply facts, numbers, let­ters, or symbols, whereas information always has a context. A simple example illustrates this. If I were to hand you a piece of paper with the letter A written on it, what have I given you? A piece of data—and rather raw data at that. If I hand you the same piece of paper and tell you that it is your grade for this course, that is information.

As a practical matter, the speed, reli­ability, and usefulness of computers par­tially stem from the fact that data and information can easily be represented as electrical signals. This was first demon­strated by the early telegraph. At the transmitter end, a telegrapher would transform a series of letters in the alphabet into pulses of electric current by a pattern of long and short switch clos­ings. At the receiving end, the pulses of electric current were converted into a series of clicks that a human receiver could translate back into letters of the alphabet.

One of the key concepts in this pro­cess is the idea of a code. A code is a set of symbols, such as the dots and dashes of the Morse code, that repre­sents another set of symbols, such as the letters of the alphabet.

A circuit is required for electricity to work as a carrier of information.. A circuit is an interconnected set of electronic components that performs a function. A circuit can be as simply as a switch, a light bulb, and some wire, but computers need far more complex cir­cuits. The circuits used in computers are called integrated circuits—combina­tions of millions circuits built on tiny pieces of silicon that are called chips.

The porch light as a signal can dem­onstrate the idea of a binary signal. Ei­ther there is current flowing and the light is on, or there is no current flowing and the light is off. In a computer circuit, the on-and-off combinations are repre­sented by two different levels of voltage. The first (usually the higher) level of voltage is said to be on, whereas the second level of voltage is said to be off.

This on-and-off pattern is the basic building block for the coding of all pat­terns of information used in computer and communication systems. The pat­tern is often referred to as the binary system. By combining binary and digit(for the digits 0 and 1 used in the binary system), we derive the term bit. A bit is the smallest possible unit of information because one bit is enough to tell the difference between two alternatives, such as on or off. Bits are the means by which the data that flow through the circuits of a com­puter are represented. Groups of bits can be arranged to represent numbers, letters, and special symbols in the form of a code.

3.4 Find antonyms.

Input, transmitter, useful, receiver, early, coded, familiar, different, together, difficult, more, late, output, separately, similar, simple, unfamiliar, complex, useless, less, give, encoded, take, easy.

3.5 Find synonyms.

Main, speak, convey, demonstrate, transform, chief, sender, send, use, perform, tell, do, complex, convert, remember, unite, show, recollect, sophisticated, combine, transmitter, apply.

3.6 Give the definition of the following terms.

Bit, data, code, circuit, integrated circuit, information

3.7 Find the equivalents of the following words and phrases in the text.

Мовою даних, вирішувати проблеми, виходити з (факту), ключове поняття, набір символів, носій інформації, складна схема, двійкова система, закодована інформація, в ширшому розумінні, імпульси електроструму, представляти набір символів, набір електронних складових, незалежно від, прискорити спілкування, фізичний розмір, розширювати можливості (потенціал), електричний сигнал, рівень напруги, передавати, приймач, можливості комп’ютера.

3.8 Answer the questions.

1. What is the difference between data and information?

2. What do the speed, reliability and usefulness of computers stem from?

3. What is a code?

4. What is a circuit?

5. What do we call the circuits used in computers?

6. What is a chip?

7. Explain the idea of a binary signal.

4.1 Read the text and translate it. Write out the computer terms and learn them.

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