Presentation of the principles of organizing internal and external memory. The principles of organizing the internal and external memory of a computer. Purpose and device of the computer

Description of the presentation for individual slides:

1 slide

Slide Description:

Purpose and device of the computer. The principles of organizing internal and external memory.

2 slide

Slide Description:

3 slide

Slide Description:

MEMORY CHARACTERISTICS: Capacity - the maximum amount of information "fit" in various devices memory; The speed of access to information; The way of accessing information is direct or sequential; Write-read principle - magnetic or optical

4 slide

Slide Description:

TYPES OF MEMORY External Internal VCU (external storage devices) is designed for long-term storage of user information. It can be updated, deleted unnecessary. This type of memory is not intended to store user information. It is used by the system itself and ensures its functioning Floppy disks Hard disks Compact disks Flash-based devices Random access memory (RAM) Cache memory Persistent memory

5 slide

Slide Description:

EXTERNAL MEMORY The main function of a computer's external memory is the ability to store a large amount of information (programs, documents, audio and video clips, etc.) for a long time. A device that records / reads information is called a drive or drive, and information is stored on media (for example, floppy disks). Information on external media has a file organization. A file is information stored on an external medium and having its own name.

6 slide

Slide Description:

FLEXIBLE MAGNETIC DISKS A floppy disk - also called a floppy disk or a floppy disk - is a round flexible plate with a magnetized layer inserted into a plastic case. The floppy disk rotates in a plastic case, protected by two spacers to reduce friction. The principle of recording on floppy disks is magnetic. Access to information is direct. In floppy disks (3.5 inches) there is a mode of information protection against erasure and writing, which is carried out by switching the appropriate switch on the plastic envelope. A standard floppy disk contains 1.44 MB of information. Floppy disks need very careful storage. They cannot be wet, hit, or carelessly handled.

7 slide

Slide Description:

HARD DISKS The hard disk drive (HDD - Hard Disk Drive) refers to non-removable magnetic disk drives. Hard magnetic disks are several dozen disks located on one axis, enclosed in metal case and rotating at high angular velocity. The speed of writing and reading information with hard drives quite large (about 133 MB / s) due to the fast rotation of the disks (7200 rpm). V hard drives rather fragile and miniature elements are used. To preserve the information and performance of hard drives, it is necessary to protect them from impacts and sudden changes in spatial orientation during operation.

8 slide

Slide Description:

LASER DRIVES AND DISCS Laser drives use the optical principle of reading information. On laser discs CD (CD - Compact Disk, compact disc) and DVD (DVD - Digital Video Disk, digital video disc) information is recorded on one spiral-left track (like on a gramophone record), containing alternating areas with different reflectivity. The laser beam hits the surface of the rotating disk, and the intensity of the reflected beam depends on the reflectivity of the track section and becomes 0 or 1.

9 slide

Slide Description:

DEVICES BASED ON FLASH-MEMORY Flash-memory is a non-volatile type of memory that allows you to write and store data in microcircuits. Devices based on flash memory do not have any moving parts, which ensures high data security when used in mobile devices... Flash memory is a microcircuit housed in a miniature package. To write or read information, drives are connected to a computer via a USB port. The information capacity of memory cards reaches 16 GB. Memory cards

10 slide

Slide Description:

INTERNAL MEMORY The devices that make up the internal memory are located on the "motherboard" in system unit... This type of memory is not intended to store user information. It is used computer system... Properties internal memory: Discreteness; Discrete objects are made up of individual particles. The memory consists of separate cells - bits. Addressability. Entering information into memory, as well as retrieving it from memory, is carried out by addresses.

11 slide

Slide Description:

RAM RAM RAM (RAM, Random Access Memory - random access memory) - this is a fast storage device not very large volume directly connected to the processor and designed to write, read and store executable programs and data processed by these programs.

Bits Bytes Internal memory information structure - bit-byte

Properties of internal memory 1. Discreteness (lat. Discretus) - intermittent, consisting of separate parts) A memory cell that stores one binary character is called BIT. BIT 0 or 1 Binary encoding 2. Addressability Memory byte - the smallest addressable part of the internal memory The processor accesses the internal memory by addresses Internal memory structure Bytes Bits Serial number byte is called its ADDRESS

File - a named space on a disk for storing information Information on external media has a file organization Information structure of external memory Information structure of external memory - file Types of information: text, numerical, graphic, sound

LMD magnetic tape drives (streamers) Cassette drives Magnetic disc drives LMD (floppy drives) CD drive Optical (laser) drives Floppy disk drives (floppy disks) Hard disk drives (hard drives) CD-R, CD-RW DVD drives -ROM

The device for writing and reading information from floppy disks is a floppy disk drive (FDD - Floppy Disk Drive). The information capacity of the floppy disk is small and amounts to only 1.44 MB. The speed of writing and reading information is also low (about 50 KB / s) due to the slow rotation of the disk (360 rpm). Floppy disks (floppy disk, floppy disk)

In order to store information on a disk, the disk must be formatted, i.e. the physical and logical structure of the disk must be created. In the process of formatting, concentric tracks are formed on the disk, which, in turn, are divided into sectors; for this, the magnetic head of the drive places marks of tracks and sectors in certain places on the disk.

After formatting a 3.5 "floppy disk, its parameters will be as follows:

First HDD was developed by IBM in 1973 and had a capacity of 16 KB. Hard magnetic disks are several disks placed on one axis, enclosed in a metal case and rotating at a high angular velocity. Due to the many tracks on each side and the large number of disks, the information capacity of hard disks can be tens of thousands of times larger than the information capacity of floppy disks and reach hundreds of GB. The speed of writing and reading information from hard disks is quite high (about 133 MB / s) due to the fast rotation of the disks (7200 rpm).

Magnetic tapes A device for recording and reading information from flexible magnetic tapes is called a streamer. Magnetic tapes are: Cassette Reel is designed to create data archives, Reserve copy; is a flexible plastic tape covered with a thin magnetic layer; information is recorded by means of magnetic recording; the capacity of the tape can be up to several gigabytes.

Used to store a large amount of information in a small area; the disc is made of polycarbonate, which is covered with a reflective layer on one side; information is recorded by means of optical recording; optical disk capacity - 640 MB and more Laser (optical) disks

The MAGNETO-OPTICAL DISK is used in the construction of optical libraries; is a polycarbonate substrate 1.2 mm thick, on which several thin-film layers are applied; information is recorded both by magnetic and optical recording; the capacity of the magneto-optical disk is up to 9.1 GB.

Flash - disks (cards) Flash memory is a non-volatile type of memory that allows recording and storing data in microcircuits. Flash-based devices have no moving parts, which ensures high data security when used in mobile devices. Flash memory is a microcircuit housed in a miniature package. To write or read information, drives are connected to a computer via a USB port. Information capacity of memory cards from 256 MB - 4 GB. Reading devices - Card reader.

The first samples of flash memory were developed by Toshiba back in 1984, but its mass use began only a few years ago with the advent of digital cameras. Flash memory is increasingly used for storing and transferring data. Manufacturers today produce several types of cards and USB drives, which first appeared in 2001.

| Purpose and device of the computer. Computer memory

Lesson 6
Purpose and device of the computer. The principles of organizing internal and external memory

§5. Purpose and device of the computer
§6. Computer memory

Purpose and device of the computer

The main topics of the paragraph:

What is common between a computer and a human;
- what devices are included in the computer;
- what is data and program;
- von Neumann principles.

Issues under study:

What do a computer and a person have in common

With this lesson, we begin our acquaintance with the computer. For informatics, a computer is not only a tool for working with information, but also an object of study. You will learn how a computer is arranged, what work can be done with it, what exist for this software.

Since ancient times, people have tried to make their work easier. For this purpose, various machines and mechanisms were created that enhance the physical capabilities of a person. An electronic computing machine (in modern terminology - a computer) (Fig. 2.1) was invented in the middle of the 20th century to enhance the capabilities of human mental work, that is, work with information.

It is known from the history of science and technology that the ideas of many of his inventions were "peeped" in nature.

For example, back in the 15th century, the great Italian scientist and artist Leonardo da Vinci studied the structure of the bodies of birds and used this knowledge to design aircraft.

The Russian scientist N. Ye. Zhukovsky, the founder of aerodynamics, also investigated the mechanism of flight of birds. The results of these studies are used in the design of aircraft structures.

Does a computer have a prototype in nature? Yes! Such a prototype is the person himself. Only the inventors tried to transfer not the physical, but the intellectual capabilities of a person to the computer.

By its purpose, a computer is a universal technical tool for a person to work with information.

According to the principles of the device, a computer is a model of a person working with information..

What devices are included in the computer

Human information activity is divided into components:

Reception (input) of information;
storing information (storing in memory);
thinking process (information processing);
transmission (output) of information.

The computer includes devices that perform similar functions:

Input Devices;
storage devices - memory;
processing device - processor;
output devices.

During the operation of the computer, information through the input devices enters the memory; the processor retrieves the processed information from the memory, works with it and places the processing results into the memory; the results obtained are communicated to the person through the output devices.

Most often, the input device is a keyboard, and the output device is a monitor or printer (printing device).

What is data and program

And yet, one cannot equate the "computer mind" with the human mind. The most important difference is that the work of a computer is strictly subordinate to the program laid down in it, while a person controls his own actions.

Computer memory stores data and programs.

Data is processed information presented in the computer memory in a special form.

Program- This is a description of the sequence of actions that a computer must perform to solve the task of data processing.

If information for a person is knowledge that he possesses, then information for a computer is data and programs stored in memory. Data is "declarative knowledge", programs are "procedural knowledge" of a computer.

Von Neumann principles

In 1946, the American scientist John von Neumann formulated the basic principles of the structure and operation of computers. The composition of computer devices described above and the interaction between them is called the von Neumann architecture. The Neumann architecture is characterized by the presence of one processor, which controls the operation of all other devices. You have yet to become familiar with other von Neumann principles.

Briefly about the main

A computer is a software-controlled device for performing any kind of work with information.

The computer includes: processor, memory, input devices, output devices.

Computer memory stores data and programs.

A computer works according to programs created by man.

Questions and tasks

1. What human capabilities does the computer reproduce?

2. List the main devices included in the computer. What is the purpose of each of them?

3. Describe the process of exchanging information between computer devices.

4. What is a computer program?

5. How does the data differ from the program?

6. Prepare a paper on the principles formulated by von Neumann.

Computer memory

The main topics of the paragraph:

Internal and external memory;
- the structure of the internal memory of the computer;
- a program in the computer's memory;
- media and external memory devices.

Issues under study:

Computer as a model of a person working with information.
- Scheme of information exchange in a computer.
- Difference between program and data.
- Difference between internal and external computer memory.
- The principle of binary coding of information.
- The structure of the computer's internal memory, its properties.
- Media and external memory devices.

Internal and external memory

Working with information, a person uses not only his own knowledge, but also books, reference books and other external sources. In Chapter I "Man and Information" it was noted that information can be stored in the memory of a person and on external media. A person can forget the memorized information, and the records are saved more reliably.

A computer also has two types of memory: internal (operative) and external (long-term) memory.

Inner memory is an electronic device that stores information while powered by electricity. When the computer is disconnected from the network, information from random access memory disappears. During its execution, the program is stored in the internal memory of the computer.

The formulated rule refers to the principles of Neumann. This rule is called the stored program principle.

External memory- these are various magnetic media (tapes, disks), optical discs, flash memory cards. Saving information on external media does not require constant power supply.

V modern computers there is another type of internal memory, which is called read-only memory - ROM... This is a non-volatile memory, information from which can only be read.

Figure 2.2 shows the composition of computer devices. Arrows indicate the directions of information exchange.

The structure of the computer's internal memory

Computer devices perform certain work with information (data and programs). But how is the information itself represented in the computer? To answer this question, let's "look" inside the machine memory. The structure of the computer's internal memory can be conventionally depicted as shown in Fig. 2.3.

The smallest unit of memory in a computer is called a memory bit. In Figure 2.3, each cell represents a bit. You can see that the word "bit" has two meanings: a unit for measuring the amount of information and a particle of computer memory. Let us show how these concepts are related to each other.

Each bit of memory can be stored in this moment one of two values: zero or one. The use of two characters to represent information is called binary encoding.

Data and programs are stored in computer memory as binary code.

One character of a two-letter alphabet carries 1 bit of information.

One bit of memory contains one bit of information.

The bit structure defines the first property of the computer's internal memory - discreteness... Discrete objects are made up of individual particles. For example, sand is discrete because it consists of grains of sand. "Grains of sand" computer memory are the bits.

The second property of the computer's internal memory is addressability... Eight consecutive memory bits form a byte. You know that this word also denotes a unit of information equal to eight bits. Therefore, one byte of memory stores one byte of information.

In the internal memory of the computer, all bytes are numbered. Numbering starts at zero.

The ordinal number of a byte is called its address.

The principle of addressability means that:

Writing information to memory, as well as reading it from memory, is performed by addresses.

Program in computer memory

Several consecutive bytes of memory form a memory cell, the address of which is the address of the least significant byte, that is, the byte with the lowest number. Figure 2.4 shows the principle of addressing using 4-byte memory locations as an example.

One memory location can store one program instruction or data item processed by the program (for example, a number). A machine program is a set of instructions located in sequential memory locations (Figure 2.5).

Program command consists of the operational part - the operation code and the address part - the addresses of the location in the memory of the processed data. The opcode defines the action the processor takes on command. The processor's job is automatic execution sequence of program commands until its completion (stop commands).

External storage media and devices

External memory devices are devices for reading and writing information to external media. Information on external media is stored in the form of files. You will learn more about what files are later.

The most important external memory devices in modern computers are magnetic disk drives(NMD), or floppy drives.

The principle of magnetic recording was invented in the 1920s. Then acoustic tape recorders appeared, which made it possible to record speech, music on a magnetic tape, and then play the recorded sounds. The first type of external memory devices on a computer was tape drives - analogs of acoustic tape recorders.

Modern NMD works similarly to a tape recorder. On the disk surface, covered with a thin ferromagnetic layer, a binary code is written: the magnetized section is one, the non-magnetized one is zero. When read from disk, this record is converted to zeros and ones in the bits of the internal memory.

A recording head is brought to the magnetic surface of the disk (Fig. 2.6), which can move along a radius. During the operation of the LMD, the disk rotates. In each fixed position, the head interacts with a circular track. Binary information is recorded on these concentric tracks.

Another type of external media is optical discs (their other name is laser discs). They use not a magnetic, but an optical-mechanical method of recording and reading information.

First, there were laser discs, on which information is recorded only once. You cannot erase or overwrite it. Such disks are called CD-ROMs - Compact Disk-Read Only Memory, which means "compact disk - read only". Later, rewritable laser discs - CD-RW were invented. On them, like on magnetic media, the stored information can be erased and rewritten.

Media that the user can remove from the drive is called removable media.

The largest information capacity among removable media is possessed by laser disks of the DVD type (Digital Versatile Disk - universal digital disk). They are sometimes referred to as video discs. The amount of information stored on a DVD is measured in gigabytes. Movies recorded on DVD can be viewed using a computer just like on a TV.

Flash memory is a relatively new type of external memory device. The flash memory device is connected to the computer via a universal USB connector.

Briefly about the main

The computer includes internal and external memory.

The executable program is stored in internal memory (stored program principle).

Information in the computer's memory is in binary form.

The smallest element in a computer's internal memory is a bit. One bit of memory stores one bit of information: the value O or 1.

Eight consecutive bits form a byte of memory. The bytes are numbered starting from zero. The sequence number of a byte is called its address.

In the internal memory, information is written and read by addresses.

A machine program is a set of instructions located in sequential memory locations.

External memory: magnetic disks; optical (laser) discs - CD, DVD; flash memory.

Questions and tasks

1. Try to explain why a computer needs two types of memory: internal and external. Prepare your message.

2. What is the principle of a stored program?

3. What is the property of discreteness of the internal memory of a computer?

4. What are the two meanings of the word "bit"? How are they related?

5. What is the addressability property of the computer's internal memory?

6. What is a machine program? What information does the program command contain?

7. Name the external memory devices of the computer and take their photos.

8. What types optical discs you know?

Electronic attachment to the lesson

Download lesson materials

Lesson objectives: Studying new material on the topic "Principles of organizing the internal and external memory of a computer."

Lesson Objectives:

Educational:

to acquaint students with the information structure of internal and external memory;
to acquaint with the basic concepts of the topic, the classification and purpose of external memory devices.

Developing:

to carry out propaedeutics of the formation of intellectual and informational skills;
develop independence in thinking and learning activities.

Educational:

foster interest in the subject;
foster a culture of working at a computer - “user culture”;
foster responsibility, independence, respect for each other.

Lesson type: combined - a lesson in explaining new material

Forms, educational work, students: frontal work, work in pairs, individual work at the computer.

Means of education:

textbooks: Semakin I. G., Zalogova L. A., Rusakov S. V., Shestakova L. V. Informatics: Basic course for 7 - 9 grades. - M .: Laboratory of Basic Knowledge, 1998.
Semakin I. G., Varaksin G. S. Structured synopsis basic course... - M .: Laboratory of Basic Knowledge, 2001.

CDs: Anatomy of a Computer - 2

hardware and software:

Personal computers;
MS Windows OS application - PowerPoint program;
presentation on the topic of the lesson "Internal and external memory of a computer";
projector.

Lesson steps:

I. Organizational part.

II. Communication of the topic and objectives of the lesson. Explanation of the work on the score sheet.

III. Homework check. Programmed control of the studied material (test).

IV. Updating basic knowledge.

V. Explanation of the new material.