RAM. Long-term memory. External computer memory Long-term computer memory table
Lesson "Random and long-term memory" in 8th grade. The lesson lasts 1 hour. According to the program by N.D. Ugrinovich (34 hours). Appendix: test on the topic at the end of the lesson for mastery of the material plus presentation.
According to the new Federal State Educational Standards, this is a seventh grade topic.
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Computer RAM and long-term memory
RAM Cell number Information in cell 1 073 741 823 11111111 …… .. …… .. 4 00000000 3 11110000 2 00001111 1 10101010 0 01010101 RAM is a sequence of numbers, starting from zero, cells Each cell can store a binary code eight characters long.
RAM The volume of computer RAM can be determined by the formula: I op = I cell * N where: I cell is the amount of information stored in the cell N is the number of cells Example: In a computer, the number of memory cells is 1,073,741,824 The amount of information in each cell , I cell = 8 bits = 1 byte Then the information volume of the RAM of this computer is equal to: I op = I cell * N = 1 byte * 1,073,741,824 = 1,073,741,824 bytes/1024 = 1,048,576 KB/1024 = 1024 MB = 1 GB
RAM RAM is manufactured in the form of Memory modules are installed in special connectors on the computer motherboard of memory modules
Long-term memory hard disk optical disk Memory card (flash memory) Flash disk floppy disk
Long-term memory Hard magnetic disk
Long-term memory Optical disc The surface of an optical disc has areas of varying reflectivity. The disk drive laser beam falls on the surface of the disk, is reflected and converted into digital computer code (reflects - 1, does not reflect - 0).
Long-term memory Non-volatile memory Flash disk from the inside: 1. USB connector. 2. Microcontroller. 3. Checkpoints. 4. Flash memory chip. 5. Quartz resonator. 6. LED. 7. Write-protect switch. 8. Space for an additional memory chip.
Long-term memory Non-volatile memory A flash memory card is a large integrated circuit (LSI) housed in a miniature flat package. Special adapters are used to read information from memory cards.
Homework Textbook, §§ 2.2.4, 2.2.5, test questions orally, tasks 2.1, 2.2 written in a notebook.
http://great.az/index.php?newsid=8153 http://lib.rus.ec/b/331980/read http://www.ru.all.biz/g672155/ Resources:
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Lesson on the topic: “Random and long-term memory. 8th grade"
Lesson type: familiarization with new material.
Type of lesson: mixed.
At the time of the lesson, students must
know:
The main components of a computer, the composition of the system unit;
Backbone-modular principle of computer construction;
Input and output devices;
Purpose and main characteristics of the processor;
Purpose and design of the system board.
be able to :
Determine the characteristics of the main computer devices;
Briefly outline the main points of the lesson;
State your answer clearly.
Lesson objectives:
- repeat the topic “Processor and motherboard”;
- give the concept of operational and long-term memory;
Learn to use the acquired knowledge in practice.
Lesson objectives:
educational:introduce students to the types of computer memory; introduce the concepts of “random access memory”, “long-term memory”, “non-volatile memory”, expand the understanding of computer devices.
educational: formation of information culture.
developing: development of thinking, memory, attentiveness.
As a result of studying this topic, students should
know:
Purpose of computer RAM and long-term memory;
Features of different types of computer memory;
The device of RAM and long-term memory of a computer.
be able to:
Calculate the information volume of RAM;
Compare the information volume of different media.
During the classes:
1.Organizational point:
- greeting, report from the duty officer about absentees.
2.Updating knowledge, checking homework:
- Frontal survey:
1. What is the purpose of the processor in a computer?
(answer: Processor is a device that performs all arithmetic and logical operations and controls other computer devices).
2. What processor characteristics affect its performance?
(answer: Processor performance depends on clock frequency and bit depth).
3. What is the purpose of the motherboard?
(answer: The motherboard is a computer hardware device. It contains all the main computer systems).
4. What is installed on the system board?
(answer: processor, random access memory (RAM) boards, read-only memory (ROM), buses - a set of conductors through which signals are exchanged between the internal devices of the computer)
5. What connectors are on the system board?
(answer: connectors for installing a processor and RAM modules, connectors for connecting additional devices (slots), connectors for connecting external devices).
Visual check of homework.
3. Studying new material.
Lesson motto: “Don’t be afraid when you don’t know: it’s scary when you don’t want to know”
Guys, today in lesson we will get acquainted with the types of computer memory(slide 1). The very concept of “memory” is associated with human memory. That's right - computer memory is similar to human memory. A person is able to remember some events throughout his life, but he does not remember some information for long, only as long as there is a need for it.(you can ask students to give 2-3 examples of information that a person stores in his memory for a long time and information that is needed for a very short time).
The computer also has long-term memory, where information is stored permanently until the user deletes it as unnecessary. And there is RAM, where information is stored as long as the computer is turned on. When the computer is turned off, all information from RAM is deleted.
And yet, the difference between human memory and computer memory is colossal - the work of a computer is subordinated to the program embedded in it, and a person controls his own actions.
So, let's figure out how computer RAM works.(slide 2).
RAMis a sequence of cells numbered starting from zero. Each RAM cell can store a binary code eight characters long.
(slide 3) Volume I op computer RAM can be determined if the amount of information I yach , stored in each cell, multiplied by N - the number of cells.
I op = I cell * N
The amount of information stored in each cell, I yach = 8 bits = 1 byte. Knowing the number of RAM cells, you can calculate the amount of RAM on your computer. For example, the number of cells is 1,073,741,824. Then:
I op = I cell * N = 1 byte * 1,073,741,824 = 1,073,741,824 bytes/1024 = 1,048,576 KB/1024 = 1024 MB = 1 GB
(slide 4) RAM is manufactured in the form of memory modules, which are plates with electrical contacts, on the sides of which large integrated circuits (LSI) are placed. Memory modules are installed in special slots on the computer motherboard.
Used for long-term storage of informationlong-term (external) memory.On such media, information is stored in the form of binary code,those. in the form of sequences of zeros and ones.
Long-term memory devices include:(slide 5)
Hard magnetic disk (hard drive);
Optical discs (CD, DVD);
Flash memory, flash disks;
Until recently, flexible magnetic disks (floppy disks) were used, but due to their small information volume (1.44 MB), they are a thing of the past.
Let's take a closer look at these devices.
(slide 6)
Hard magnetic disk- several thin metal disks rotating very quickly on one axis are enclosed in a metal casing. Information on disks is stored on concentric tracks on which magnetized and non-magnetized areas alternate. The magnetized section stores computer unit 1, and the non-magnetized section stores computer zero 0. To write or read information, the magnetic head of the drive is installed on a specific concentric track of the disk and information is written or read.
(slide 7)
Optical discs.Information on an optical disk is stored on a single spiral-shaped track running from the center of the disk to the periphery and containing alternating areas of poor and good reflectivity.
In the process of reading information from an optical disk, a laser beam installed in the disk drive falls on the surface of the rotating disk and is reflected. Since the surface of the optical disk has areas with different reflectivity, the reflected beam also changes its intensity and is converted into digital computer code (reflects - 1, does not reflect - 0).
There are several types of optical discs:
CDs and CD-RW discs. They can store up to 700 MB of information;
DVD and DVD-RW discs. The capacity of such disks is 4.7 GB.
CDs and DVDs are not rewritable. Information is recorded on them once. Information can be written to CD-RW and DVD-RW discs multiple times (but a limited number of times).
(slide 8)
Non-volatile memory - cards flash memory and flash disks. They do not require connection to an electrical voltage source and have no moving parts, therefore they ensure high data security.
Flash memory card is a large integrated circuit (LSI) housed in a miniature flat package. To write and read information from memory cards, special adapters are used (built into portable devices or connected to computers using a USB connector).
(slide 9)
Flash disk It is a memory LSI, placed in a miniature case and connected to the USB connector of a computer.
4. Fixing the material.
We got acquainted with the types of computer memory. Now let's consolidate the knowledge that you gained in class with the help of a test. We sit down at the computers, open the “Sign Test”, the “Random and Long-Term Memory” test.(They take the test on a computer. Testing in the “Sign” program saves time and students receive grades immediately. In addition, after completing the test, they see all the correct answers and can check themselves).
Annex 1 .
5. Lesson summary.
Recording homework, grading.
Grades are given based on the test results, taking into account the work of individual students in the lesson.
(slide 10) Homework: Textbook N.D. Ugrinovich. Computer Science and ICT. 8th grade. §§ 2.2.4, 2.2.5, test questions orally, tasks 2.1, 2.2 written in a notebook.
(slide 11) Thanks for the lesson!
Used literature: N.D. Ugrinovich. Computer Science and ICT. 8th grade
Smart electronic machines have long been firmly established in human everyday life. But, despite this, their device still raises basic questions among many users. For example, not everyone knows what types of memory there are. But here everything is not so complicated, although not entirely simple. There are two main types - internal memory and external, which, in turn, have their own gradation.
Types of internal computer memory
Internal memory is so called because it is built into the main units of the computer and is an integral element of the system, ensuring its functionality. It is impossible to remove or extract it without negative consequences. The following types are distinguished:
- operational – is a set of programs and algorithms necessary for the operation of the microprocessor;
- cache memory – this is a kind of buffer between the RAM and the processor, which ensures optimal execution speed of system programs;
- constant – laid down when the computer is manufactured at the factory, it includes tools for monitoring the state of the PC at each boot; programs responsible for starting the system and performing basic actions; system setup programs;
- semi-permanent – contains data about the settings of a specific PC;
- video memory – it stores video fragments that should be displayed on the screen; it is part of the video controller.
Types of computer RAM
The performance and “intellectual level” of a computer are largely determined by its RAM. It stores data used during active operation of the electronic machine. It can also be of different types, but the most commonly used blocks are DDR, DDR2, DDR3. They differ in the number of contacts and speed characteristics.
Types of external computer memory
External computer memory is represented by various types of removable storage media. Today, the main ones are hard drives, USB drives, or flash drives and memory cards. Laserdiscs and floppy disks are considered obsolete. But, although it is removable, it is still used as a storage unit for permanent memory and the computer will not work without it. However, it can be freely removed and moved to another system unit, which is why it is classified as an external memory device.
A person stores information in memory. On a computer, information is stored in operational(internal) memory. RAM (OP or RAM)- random access memory (RAM), fast memory, which consists of cells that have their own address.
To quickly work with data that should always be at hand, the processor needs faster memory than a hard drive. In principle, such memory is already built into it itself - we are talking about cache memory. But the volume is extremely small - a maximum of 512 kb, and many megabytes are needed to work with modern programs.
This is why a computer needs RAM—memory with high access speed. It is impossible to store information in it permanently - when the power is turned off, all information from the RAM disappears. But for all kinds of intermediate operations and calculations, you can’t imagine anything better!
The fundamental feature of RAM is its ability to store information only while the machine is running.
However, when you turn on the computer, all information from RAM is erased.
The capabilities of a computer largely depend on the amount of RAM: the larger the memory, the greater the ability of the computer to work with information.
Used for long-term storage of information external memory. VZU- (external storage devices) are designed for permanent storage of large amounts of information (programs, documents, video clips, etc.). A device that provides recording/reading of information is called a drive or disk drive, and information is stored on media (for example, floppy disks).
In floppy magnetic disk drives (FMD) and hard magnetic disk drives (HDD) or “hard drives”, the recording, storage and reading of information is based on the magnetic principle, and in laser CD-ROM and DVD-ROM drives, the optical principle is used.
- floppy magnetic disk drives (FMD)) Flexible magnetic disks are placed in a plastic case. This storage medium is called a floppy disk. The floppy disk is inserted into the disk drive, which is installed in a special compartment for the disk drive of the system unit. Currently, the most common floppy disks are 5.25 and 3.5 inches.
Probably every person has already held in their hands this small 3.5-inch flat rectangular thing, inside of which there is a polymer disk (film) with a magnetic layer of protection applied to it (from mechanical influences). If necessary, access to it can be obtained by moving the metal flap blocking it, which a spring located inside the floppy disk seeks to return to its original position. A round metal piece is fixed in the center of the polymer disk, which can be easily seen from one side of the disk. Through this part, the drive motor transmits rotation to the polymer film disk.
Due to its simplicity and low cost, the floppy disk gained unprecedented popularity, and until recently, drives for 3.5-inch floppy disks were installed in almost every personal computer.
The total volume of the floppy disk is 1440 KB.
ZIP, or rather, Iomega ZIP is one of the magnetic drives that was very popular some time ago. In its design, ZIP resembles a regular 3.5-inch floppy drive. There are internal and external modifications of this drive with different interfaces on the market. The advantage of external drives is the ability to connect to almost any computer, the advantage of internal drives is a slightly higher transfer speed. The volume of ZIP floppy disks can be 100 and 250 MB.
Hard disk drives (HDD) or simply HDD (hard drive) - designed for permanent storage of information used when operating a computer: operating system, documents, games, etc. The main characteristics of a hard drive are its capacity, measured in gigabytes (GB), data read speed, average access time, cache memory size. It is located inside the system unit and is not visible. Hard drive bays are similar to floppy drive bays. The hard drive cannot be disassembled and the magnetic media cannot be removed from it. Therefore, there is no need for the hard drive to protrude from the front panel. Even when the hard drive is installed in the floppy drive bay, it is covered with a plastic panel.
Hard magnetic disks are several dozen disks placed on one axis, enclosed in a metal case and rotating at high speed.
Optical storage devices (CD-ROM and DVD-ROM) use the optical principle of reading information. Information on a laser disc is recorded on one spiral-shaped track (like on a gramophone record), containing alternating sections with different reflectivity.
Flash. This is a relatively young type of memory. It is based on microcircuits from which information is not erased when the power is turned off. These storage media can be externally designed in different ways: as flash cards, which are used to record information in digital cameras, and as external flash drives, connected to a computer via a USB port and displayed on the computer as a separate logical drive.
Flash cards are used to record information on them in various devices, such as digital cameras. The advantage of these cards is that they can be changed (just like photographic films: you took a certain number of photographs, filled the card’s memory, replaced this card with another and you can continue taking photographs).
There are a large number of different Flash cards, which differ from each other in the volume of stored information (16-512 MB), size and shape of the case.
Flash drives. A relatively young and very promising type of information carrier. Being small in size, these discs look like a short marker or pencil.
Drives are available in capacities of 8, 16, 32, 64, 128, 256, 512 MB, 1 and 2 GB.
Hybrid and solid state drives. Hybrid Hard Drive (HHD) In fact, HHD is a new type of drive that combines a high-speed flash memory module and a traditional hard drive with rotating magnetic platters. According to the creators, the flash memory built into the drive, thanks to this division of labor, allows the hybrid drive to increase the boot speed of the computer and at least halve the level of energy consumption (which is especially important for laptop PCs).
Modern computers have an open architecture principle.
Open Architecture Principle means that it is possible to easily replace outdated computer parts; the new part (unit) will be compatible with all the equipment that was used previously.
Connecting your computer to the network. A computer can exchange information (transmit and receive) with other computers using local and global computer networks. For this purpose it includes network card and modem. The ability to exchange data between computers via regular telephone communication is provided by modems, fax modems
Modem (modulator - demodulator ) – a device for transmitting computer data over long distances over telephone lines.
Digital signals generated by a computer cannot be transmitted directly over the telephone network because it is designed to carry human speech—continuous audio frequency signals.
The modem converts the computer's digital signals into alternating current of the audio frequency range - this process is called modulation, as well as the reverse conversion, which is called demodulation. Hence the name modem - modulator/demodulator.
To communicate, one modem calls another by phone number, and the latter answers the call. Then the modems send signals to each other, agree on a communication mode suitable for both of them. The transmitting modem then begins sending simulated data at the agreed upon rate (bits per minute) and format. The modem at the other end converts the received information into digital form and transmits it to its computer. Having completed the communication session, the modem disconnects from the line.
Based on their appearance and installation location, modems are divided into internal and external. Internal modems are an electronic board installed directly into the computer, while external modems are a stand-alone device connected to one of the ports. An external modem costs more than an internal modem of the same type due to its visual appeal and easier installation. The main parameter in modem operation is the data transfer speed. It is measured in bits per second. Also important indicators in modern modems are the presence of an error correction mode and a data compression mode.
The first mode provides additional signals through which modems check data at both ends of the line and discard untagged information, while the second mode compresses the information for faster and clearer transmission, and then restores it to the receiving modem. Both of these modes significantly increase the speed and purity of information transmission, especially in Russian telephone lines.
Highway . Information is exchanged between individual computer devices using highways, connecting all computer devices.
We can present all of the above in the form of a general diagram.
GENERAL DIAGRAM OF COMPUTER (PC)
Long-term (external) memory is non-volatile memory designed for long-term storage of information.
The processor does not have direct access to the contents of external memory. In order for the processor to process data from long-term memory, it must first be loaded into RAM. Currently, the main long-term memory devices include hard magnetic disks, optical disk drives, and flash memory devices. Previously, magnetic tapes, floppy disks, and magneto-optical disks were also used for long-term storage of information.
The main external memory device is hard magnetic disk(picture 1). Inside the hard drive there are one or more platters mounted on a common spindle. Data is usually written on both sides of each platter, although in some hard drives manufacturers may use single-sided platters in addition to double-sided platters. Writing and reading information is carried out using read/write heads. Under the plates there is a motor that rotates them at a fairly high speed. The rotation speed of the plates is measured in revolutions per minute (rpm). The first hard drives had a rotation speed of 3600 rpm. In modern hard drives, rotation speeds have increased to 7200, 10,000 and 15,000 rpm.
Figure 1 - Hard drive
During the recording process, digital information stored in RAM is converted into alternating electric current, which is supplied to the magnetic head and then transmitted to the magnetic disk, but in the form of a magnetic field. After the termination of the external field, zones of residual magnetization are formed on the surface of the disk. Before using the hard disk, you must format it.
Formatting involves three steps.
1. Low-level disk formatting. During this process, physical structures are created on the hard drive: tracks, sectors, control information. This process is performed by the manufacturer on plates that do not yet contain any information.
2. Partitioning. This process splits the hard drive into logical drives (C:, D:, etc.). This function is performed by the operating system.
3. High-level formatting. This process is also performed by the operating system and depends on its type. High-level formatting creates logical structures responsible for storing files correctly, as well as, in some cases, system boot files at the beginning of the disk.
Hard drives were originally created as internal devices and were not intended for backing up or transferring information from one computer to another. About 20 years ago, the most common device used for this purpose was floppy disks (floppy disks). However, their capacity by modern standards was very small (1.44 MB), so they were replaced by optical discs CDs (compact discs), which allow you to store fairly large amounts of information (650-800 MB) and are much more reliable than floppy disks. To work with CDs on your computer, you need a special drive (optical drive).
An overview of the hard drive is presented in video 1:
Hard drive review.MTS
Video 1 - Hard drive overview
There are commercially produced read-only (CD-ROM) disks, write-once (CD-R) and write-once (CD-RW) disks. The last two types of discs are designed for recording on special recording optical drives. All types of disks have the same information storage structure. Data is written using a red laser beam onto a spiral track running from the center of the disk to its periphery. Along the path there are depressions called pits (pit - “deepening”). On recorded discs, pits are imitated by dark spots of a special recording layer, resulting from heating the desired area with a laser. Any information is encoded by alternating recesses and spaces between them.
DVDs have a higher data density than CDs. There are discs on which information is recorded in two layers. Depending on the above parameters, DVDs can have a capacity of 4.7 GB or 8.5 GB. All compact discs (both CDs and DVDs) have the same information storage structure. The read/write speed of optical drives is measured in units of multiples of the base speed (denoted by 16x, 24x, 48x, etc.). For CD drives the base speed is 150 Kb/s, for DVD - 1.385 MB/s.
Blu-ray (Blu-ray Disc) is the name of the next generation optical disc format. In Blu-Ray, instead of the red laser used in DVDs and CD-ROMs, a blue laser is used to write and read data. The blue laser has a wavelength much shorter than the red laser. This allows the data track to be thinner, resulting in a significant increase in storage capacity. The format was developed to enable recording, dubbing and playback of high-definition video (HD-video), as well as to store large amounts of data. The capacity of the new format is from 25 to 50 GB.
By device flash memory(flash memory) resembles a dynamic volatile memory chip in which transistors are installed in the memory cells instead of capacitors. When voltage is applied, the transistor takes one of the fixed positions - closed or open. It remains in this position until a new electrical charge is applied to it, changing its state. Thus, a sequence of logical zeros and ones is formed in this type of memory similar to static memory: cells closed to the passage of electric current are recognized as logical ones, open ones - as logical zeros.
USB flash drive (flash drive, Figure 2) is a flash memory-based device for storing and transferring data from one computer to another.
Figure 2 - Flash drive
Flash memory is enclosed in a housing that resembles a keychain in appearance. The interface for connecting to a computer is USB. The capacity of modern flash drives reaches 128-256GB and continues to grow at a rapid pace.
The main characteristics of any type of memory are:
- Memory capacity is the maximum amount of information that can be placed in this memory. (measured in kilobytes, megabytes, gigabytes)..
- Memory access time- this is the minimum time sufficient to store a unit of information in memory (usually measured in nanoseconds).
- Information recording density is the amount of information recorded on a unit of media surface.
Computer internal memory
Read Only Memory- non-volatile read-only memory (ROM).
This type of memory is located on the motherboard and is used to store information that usually does not change during the operation of the computer, for example, the firmware for testing computer components and the first stage of booting the operating system (BIOS). Of all types of internal memory it is the slowest
Random Access Memory- volatile memory used for temporary storage of commands and data necessary for the processor to perform current operations.
Physically, RAM is built on DRAM (Dynamic Random Access Memory) chips. The access speed of DRAM is lower than that of chip-based static memory SRAM (Static Random Access Memory).
After turning off the computer, the contents of RAM are “zeroed”.
Cache memory
Cache memory is an element of the processor. This is ultra-fast memory physically built on SRAM (Static Random Access Memory) chips. The cache stores the contents of the most frequently used RAM cells, as well as parts of the program that the processor is most likely to access
Long-term (external) computer memory
External memory is a non-volatile memory designed for long-term storage of information.
The processor does not have direct access to the contents of external memory. In order for the processor to process data from long-term memory, it must first be loaded into RAM.
The main devices of long-term memory include:
Magnetic disk- main external memory device
Before using the hard drive, you must format it. The formatting operation includes three stages:
- low-level disk formatting(physical structures are created: tracks, sectors, control information);
- partitioning(the process of dividing a hard drive into logical drives (C:, D:, etc.);
- high level formatting(logical structures are created that are responsible for storing files, as well as, in some cases, system boot files at the beginning of the disk).
To increase the reliability of data storage, as well as to increase the speed of reading/writing information when working with large volumes of data, arrays of several disks - RAID arrays - are used.
Optical discs
- CD(English Compact Disc, CD) is an optical storage medium, the process of recording and reading information is carried out using a laser.
- DVD(English: Digital Versatile Disc - digital multi-purpose disk) - an optical storage medium that has a denser working surface structure than a CD.
- Blu-ray(Blu-ray Disc) is the name of the next generation optical disc format.
Flash memory
The operating principle of flash memory is based on semiconductor technology. A change in charge ("write" and "erase") of an isolated region ("pocket") occurs when a voltage is applied between the gate and source of this region. Flash memory allows you to write and read data relatively quickly and retains it after the power is turned off.
