At present, it is already difficult to surprise someone with a flash drive. These miniature products have become so firmly established in our daily lives that it is now very difficult to do without them. This is especially true for students who simply need such devices for passing term papers, essays and other purposes. What is a flash drive? Only the lazy can not answer this question.
The modern market is literally flooded with the most different models. Many companies can offer original designs as well as smaller versions of flash drives. And so much so that you involuntarily wonder if this is really a flash drive or something else?
What is a flash drive?
Many people know that with a small device you can transfer a variety of text files from one computer to another. electronic documents, music compositions and video files. But not everyone clearly understands what it is.
The flash drive is removable device to transfer or store information. Tellingly, there are no moving parts inside the USB flash drive, which provides it high level reliability. To record data for further distribution or storage, a file system is used (usually FAT32 or NTFS).
In this case, it is more correct to pronounce not a flash drive, but a USB flash drive. What are her (or his) virtues? More on this below.
Obvious benefits
- Easy operation. It is much easier to transfer any information to a USB flash drive than to a CD. To record it, one cannot do without the help of a specialized software. In addition, you do not need a floppy drive to open the flash drive.
- Unlike the floppy disks discussed above, as well as disks, USB flash drives are more reliable.
- Reusable use. It doesn't matter how many GB a flash drive has, there can be several thousand rewrite cycles, which is not so bad.
- Price. It is worth noting that the prices for flash drives are only decreasing every year due to updating models and increasing volume. And now the simplest USB flash drive costs less than $5.
- Compact size: USB sticks are manufactured in a small size and light weight.
- Appearance. Many manufacturers are trying to surprise users by giving USB drives an original design.
Among other things, modern flash drives are a pleasure to work with, as they are characterized by high write speeds, unlike optical discs - up to 20 megabytes per second, or even more.
Due to this, the entire process of copying to a USB drive takes several minutes, depending on the amount of information.
Some disadvantages
Parsing the question of what a flash drive is, do not bypass the existing shortcomings. For some, some of them may seem insignificant. But among all the significant disadvantage is the service life. The number of entries and deletions is not infinite. But in the end, it may well be enough for a period of 5 to 10 years. In this case, the recording speed will gradually decrease.
A flash drive cannot work wet. Although this drawback is no longer significant, since it means connecting it after taking a shower. But if you let it dry well before that, the device will be able to work properly.
Usually USB drives are sold with a protective cap, which is often lost. Of course, this cannot be attributed to serious shortcomings, and it's all about inattention on the part of users. Nevertheless, the sediment remains, because you can come up with some kind of chain. Although miniature models are also easy to lose, and this is already serious, especially if they are not cheap. It's not up to parsing what a flash drive is.
A wide range of
The modern market can offer a great variety of flash drives from the most different manufacturers. In this case, the case of information carriers can be made of different materials:
- plastic;
- rubber;
- metal.
Metal drives are more expensive, but at the same time, unlike plastic counterparts, they are highly reliable. To damage the body, you need to try hard.
Rubber sticks might be to your liking active users. Such devices are characterized by high shock-resistant and waterproof properties. Plastic drives can be a wonderful gift for any celebration - birthday, New Year and other good things.
The use of flash drives
Any user who knows what a flash drive is will not be surprised by the fact that with the advent of CD, DVD and Blu-ray discs, floppy disks have lost their relevance, although not completely. But despite their decline, they have not yet completely gone out of use, and to this day several million copies are sold every year. According to most analysts, these media will be used for several more years. At least until the cost of flash drives and floppy disks is equal.
It does not threaten USB drives! And it's not that every computer or any other similar device there is a corresponding connector. A flash drive can be used for more than just transferring or storing various files, it is easy to use for other purposes. For example, it can be used to set operating system. How to do this will be discussed.
What is bootable media?
What is a USB flash drive is known, but what is a bootable flash drive? There are times when you need to install an operating system, but there is no drive at all (this applies to many netbooks) or it does not work. Then a special bootable USB device will come in handy. This is a kind of "lifeline" for any user.
Bootable media can come in handy in cases where the system has crashed or the computer has stopped booting. It will allow the system to boot quietly in order to troubleshoot problems. After that, Windows will work properly, as before.
Ways to create a boot device
To decide how to make a USB flash drive bootable, you can use several methods:
- Powered by UltraISO software.
- Using the command line.
- Through Windows utilities 7 USB/DVD Download Tool.
- Through the Rufus utility.
All of these methods are easy to follow. It is only worth clarifying that if the bootable media is made using different utilities, then you will need an image of the operating system, preferably in ISO format. And in order for it to fit on a USB flash drive, its volume must be at least 4 GB.
The image should be prepared in advance using the same program UltraISO or any other appropriate type. Then let it be stored on the hard drive, which will save optical media with an operating system that is prone to scratching with frequent use.
After creation bootable flash drive it is mandatory to set the BIOS to boot from a USB device for the first time.
Using UltraISO
With this program, you can create and edit various images, but in our case, several of its other features will come in handy. The first step is to download the software, preferably from the official website, and install it. You need to run the program with administrator rights, for which you can click on its shortcut right click mouse and select the appropriate item.
The program has a Russian-language menu, which is very convenient. First of all, you need to connect the USB flash drive to the USB connector, and then you can run UltraISO. Then click on "File" and then "Open". Then you need to specify the path where the image of the operating system lies, select it, then click the "Open" button.
Next, go to the "Boot" menu and select "Burn Image hard drive". A window will appear in which you need to check the settings. Under Disk Drive should be selected desired device, where the recording method is, USB-HDD+ must be selected. At the same time, check whether the image is selected to create a bootable USB flash drive.
Now it remains to click on the "Record" button, which will start formatting, and answer in the affirmative to the message that appears. This process deletes all data! At the end, a window will appear with a message about the success of the recording. That's all - the flash drive is ready.
Command line help
You can also prepare a USB flash drive for installing the operating system using the tools of Windows itself. What you need can be run in different ways:
- "Menu" - "Start" - "Programs" - "Accessories" - "Command Prompt".
- Press the key combination Win + R (or "Menu" - "Start" - "Run"), in the empty field of the window, enter cmd.
As a result, a black window will appear, which is what you want. In it you need to type the text diskpart and press Enter. This key is pressed after each command entered. Now, in fact, instructions for creating a bootable USB flash drive:
- Enter list disk - a numbered list of all connected disks to the computer will be displayed.
- Enter select disk X - instead of X, you need to substitute the number that corresponds to the flash drive (2 or 3, or 4, and so on).
- The clean command is entered - the media will be cleaned.
- Now we need another command - create partition primary - a partition is created.
- Enter select partition 1 - the created partition will be selected.
- The following text active activates the selected section.
- After that, you will need to enter format fs = NTFS - the formatting process will start in NTFS system. He takes certain time so you have to be patient.
- You can now exit DiskPart mode by entering the Exit command.
The main part is done, after that you need to copy the Windows files to a USB flash drive, and in the same way as it was on the installation disk.
Windows 7 USB/DVD Download Tool
This utility was created by Microsoft, which is responsible for the release of operating systems Windows families. To create bootable media, it fits perfectly. To get started, you need to download the program from the Microsoft website and install it on your computer.
You also need to run the program with administrator rights (how to do this was described above). After do the following:
- Click Browse, select the desired operating system image and click Next.
- Now you need to select the USB device.
- On this step you will need to select your flash drive from the entire list of devices (usually it should already be selected). Then click Begin copying.
The formatting process will start, after which the necessary files will begin to be copied to the flash drive.
Mobile help represented by Rufus
To install from a flash drive Windows versions The Rufus utility might come in handy. This program does not need to be installed on your computer, it starts working immediately after downloading. Customize with it bootable USB stick It will not be difficult, for which you need to follow these steps:
- Connect the flash drive to the computer, and in the "Device" utility field, it should be selected.
- Pay attention to whether the checkbox "Create a bootable disk" is checked below.
- You can uncheck the checkbox if necessary. Quick Format”, only in this case the process will take some time.
- Click on the floppy disk icon and select the prepared operating system image.
- Press the "Start" button.
Formatting will start, but before that the program will notify that all data will be destroyed. Click OK and wait for the creation of bootable media to complete.
The listed methods on how to install an operating system from a USB flash drive are easy to implement. However, the USB stick needs correct use. Then Windows can be installed, and other files will be safe.
Proper use of flash drives
It is not enough to choose a flash drive, you need to use it correctly. To do this, you should follow the elementary rules:
- It is not recommended to pull out the connected flash drive immediately after copying the files. You need to use safe extraction. Otherwise damage cannot be avoided. file system, which will help fix only the formatting, and this is already a guaranteed deletion of information.
- An infected flash drive must always be treated.
- As experts advise, it is better to change the drive every 2-3 years, since the cost allows this.
- Try to avoid impacts and prevent flash drives from falling, as well as immersing them in water.
If it is impossible to carefully connect a USB flash drive to a computer for various reasons, you should take a closer look at devices in a secure case.
When choosing, do not take into account active advertising, since any quality product does not need it!
In conclusion
So that the choice of a flash drive does not turn into a headache, you need to correctly approach the choice of device. You should not be guided only by the big name of some popular brand. Without a doubt, many firms can offer quality products. But only those manufacturers who have passed the test of time deserve trust. In this case, you can be sure that the purchased drive will last a long time.
It is also worth considering that you can infect your computer through a USB flash drive. And to avoid this, you must use licensed anti-virus software!
Good day everyone!
Today's article will mark the beginning of a new, small series of articles on information storage, different types memory, ways of writing / reading information and everything connected with it 😉 And we will start with the device that is well known to us all Flash-memory.
What is Flash memory anyway? Yes, just an ordinary microcircuit, no outwardly different from any other. Therefore, a reasonable question may arise - what is inside and how do the processes of saving / reading information take place in general.
So, the heart of many memory devices is the floating gate FET. The most ingenious invention of the 70s of the 20th century. Its difference from conventional field-effect transistors lies in the fact that between the gate and the channel, right in the dielectric, there is another conductor - which is called the floating gate. Here's what it all looks like:
In the figure, we see the drain-source-gate familiar to us, as well as an additional conductor located in the dielectric. Let's see how this device works.
Let's create a potential difference between the drain and the source and apply a positive potential to the gate. What will happen then? That's right, through the field-effect transistor, current will flow from the drain to the source. Moreover, the magnitude of the current is large enough to “break through” the dielectric. As a result of this breakdown, some of the electrons will hit the floating gate. A negatively charged floating gate creates an electric field that begins to block the flow of current in the channel, causing the transistor to turn off. And if you turn off the power to the transistor, the electrons from the floating gate will not go anywhere and its charge will remain unchanged for many years.
But, of course, there is a way to discharge the floating shutter. To do this, you just need to apply a voltage of the opposite sign to the “main” gate, which will “drive” all the electrons, as a result of which the floating gate will remain uncharged.
Actually, this is how information is stored - if there is a negative charge on the gate, then this state is considered a logical unit, and if there is no charge, then this is a logical zero.
We figured out the preservation of information, it remains to understand how we can read information from a floating gate transistor. And everything is very simple. When there is a charge on the floating gate, its electric field prevents the drain current from flowing. Suppose, in the absence of a charge, we could apply a voltage of + 5V to the “main” gate, and at the same time, current began to flow in the drain circuit. With the floating gate charged, this voltage cannot force the current to flow, because the electric field of the floating gate will interfere with it. In this case, the current will flow only at a voltage of + 10V (for example =)). Thus, we get two voltage thresholds. And, by applying, for example, + 7.5V, we can, by the presence or absence of the drain current, draw a conclusion about the presence or absence of a charge on the floating gate. This is how the stored information is read.
How does all this relate to Flash memory? And very simply - a floating gate field effect transistor is the minimum memory cell capable of storing one bit of information. And any memory chip consists of a huge number of transistors arranged in a certain way. And now it's time to consider the main types of Flash-memory. Namely, I would like to discuss NOR and NAND memory.
Both of these types of memory are based on floating gate transistors, which we have devoted a lot of time to today) And the fundamental difference is how these transistors are connected.
The NOR design uses a two-dimensional table of conductors. The conductors are called the bit line and the word line. All drains of the transistors are connected to the bit line, and all gates to the word line. Let's look at an example for better understanding.
Suppose we need to read information from a particular cell. This cell, or rather this particular transistor, is gated to one of the word lines and drained to one of the bit lines. Then we simply apply a threshold voltage to the word line corresponding to the gate of our transistor and read its state as in the example that we considered a little higher for one cell.
With NAND, things are somewhat more complicated. Returning to the array analogy, NAND memory cells are a three-dimensional array. That is, not one, but several transistors are connected to each bit line at once, which ultimately leads to a decrease in the number of conductors and an increase in compactness. This is just one of the main advantages of NAND-memory. But how can we calculate the state of a certain transistor with such a structure? To understand the process, consider the diagram:
As you can see from the diagram, one bit line corresponds to several cells. AND important feature is the following: if at least one of the transistors is closed, then the bit line will have high voltage. Look here:
Indeed, a low level on the bit line will be only when the entire transistor chain is open (remember the course on field effect transistors 😉).
With this, it seems to be clear, we return to our question - how to calculate the state of a particular transistor? And for this, it is not enough just to apply a threshold voltage to the word line (to the gate of the transistor) and monitor the signal on the bit line. It is also necessary that all other transistors are in the open state. And this is done as follows - a threshold voltage is applied to the gate of our transistor, the state of which we need to read (as in the case of NOR-memory), and an increased voltage is applied to the gates of all other transistors in this chain, such that, regardless of the state of the floating gate the transistor is open. And then, reading the signal from the bit line, we will find out in what state the transistor of interest to us (after all, all the rest are absolutely definitely open). That's all)
Such an article turned out today) We figured out the principle of operation and the main types of Flash, as well as the device and principle of operation of NAND and NOR-memory. I hope that the article will be useful and understandable, see you soon!
Information on a flash drive is stored in memory cells, each of which can store one bit: 0 or 1. A flash drive consists of billions of such memory cells.
Memory cell
One memory cell is one bit. One letter in the text is 8 bits or 1 byte. This text takes about 6 thousand bytes, that is, to save it to a USB flash drive, 48 thousand memory cells are required. A new episode of House in HD will require approximately 11 billion memory cells. It is hard to imagine that they all fit easily into an area of 1 square centimeter.
The memory cell is a transistor. On both sides, it has two n-type semiconductors, which have many free electrons that can move freely, that is, carry current.
Between these semiconductors is a p-type semiconductor, which, on the contrary, has a lack of electrons. The current is carried there, respectively, by holes from the missing electrons.
Current cannot pass between n-semiconductors, because there is a p-conductor between them, and they have different type conductivity.
But above the p-semiconductor is a control gate. This is an electrode to which a positive or negative voltage can be applied. If a positive voltage is applied to it, then it will move the holes in the p-semiconductor and attract electrons, since opposite charges attract.
The floating gate is surrounded by a dielectric so that the electronics do not escape from it. Theoretically, a memory cell can store its value indefinitely, well, or at least for decades.
You get the so-called n-junction, through which electricity can pass from one n-type semiconductor to another and the transistor can conduct current.
Between the control gate and the p-semiconductor there is a metal plate - this is a floating gate. If it is charged negatively, then it will interfere with the operation of the control gate, and the transistor will not conduct current, regardless of whether there is a positive voltage on the control gate or not.
How data is read
To check what is written in the memory cell, zero or one, voltage is applied to the control gate and it is checked whether current can flow through the transistor:
- - If there is an excess of electrons on the control gate, then the current will not flow, so this is one.
- - If there is no excess of electrons on the control gate, then the current will flow, which means it is zero.
How are they recorded
To write a unit to a memory cell, it is necessary to throw electrons onto the floating gate. But this is not so easy to do, because the floating gate is surrounded by a dielectric, which, as you know, does not conduct current.
The tunnel effect is a phenomenon that is only possible in quantum mechanics, when, due to its wave properties, an electron jumps from one place to another. That is, it turns out to be on the other side of the dielectric, without passing through it. In classical mechanics, this is impossible.
In order to put electrons into the floating gate, a positive voltage is applied to the control gate - much higher than when reading. Some of the passing electrons jump onto the floating gate due to the tunnel effect.
Data erasure occurs in exactly the same way, only instead of a positive voltage, a negative voltage is applied to the control gate, and the electrons jump off the floating gate.
You can read about what a flash drive is on many sites. You will also be told in detail what not to do with it. But how do you know what to do with it? How about a lesson with a visual demonstration on all points (from A to Z) about working with a flash drive? Let's say that you want to transfer text from one computer to another (let the second computer be not connected to the Internet).
And in the second case, a cartoon, in the third case, both. What is most important in the lesson is ALL sequential transfer actions.
Original requirement? But after all, this is the only way to show, explain, save a dunno (a pebble in the garden of beginners, not to cope with a flash drive) from unnecessary and unnecessary actions!
There is a lot of information about the flash drive, but there is no specific step-by-step “instruction” for working with the flash drive! But in vain! I am sure that many people have such “difficulties”, but write about them. So keep the lesson about working with a flash drive.
This is what a regular flash drive looks like.
Step 1. Insert it intoUSB port(see picture).
Next to this port are usually the headphone and microphone jacks.
Here they are next to green and pink.
Step 2 Now press "Start". Then "My Computer". Among the pictures you will see a picture of a removable disk. She can have any name.
The main thing is its visual image in the picture.
For example, "KINGSTON (F:)". In this case, "KINGSTON" means the name of the manufacturer of the flash drive, and (F:) is the name of the disk.
Step 3. Write information to a flash drive possible in at least 2 ways. Let's consider both.
1 way. Let's continue where we left off.
1. Click on the image of the flash drive with the left mouse button. As a result, you will see its contents.
2. Select the desired file on the desktop or in any other folder ( Text Document, music, video, whatever) that you want to copy to a flash drive.
3. Now grab it with the left mouse button and drag it to the flash drive folder. Let go.
All. You have copied the file to the flash drive!
2. way.
1.Select the file you need to copy to a USB flash drive.
2. Click on it with the right mouse button.
3. Select "Submit"
4. Then select the item with the image of the flash drive. In our example, "KINGSTON (F:)".
5. That's it, the file has been sent to the USB flash drive. You can check its availability on the flash drive.
Step 4 The information you wrote down . Now you need to safely remove the flash drive from the computer. To do this, do the following.
That's all. Now you have mastered the work with a flash drive. And we are ready to conquer new computer horizons! Good luck with this!
We will talk about the principle of operation of flash drives. The topic is becoming increasingly relevant: "flash drives"are in your pocketeveryone, in mobile phones and tablets inner memory works on the same principle, and even the latest generation of ultraportable laptops refuse to use the usual hard drives in favor of SSDs. They run faster, consume less power (which is very important for laptops), they are quiet, cool and shock resistant. How does it work?
To begin with, flash memory is a non-volatile and rewritable memory based on the special properties of semiconductors. The first term in her description refers to the simple fact that she does not need access to electricity to store information. In order for information to be stored on such drives, they do not need power supply, and for reading a flash drive, no moving systems are needed. In the HDD, this is a disk rotating at high speed, a spindle and a head. This is very good: a flash drive is not so easy to damage, it usually has a long service life, it quickly exchanges data with a computer. These drives are light, simple, and will soon be cheap. So far, they are more expensive than hard drives and are bad because if the number of reads from an SSD is not limited, then the number of rewrite cycles is still not infinite. As a rule, the same memory cells can be overwritten up to ten thousand times.
Each flash memory cell does not contain capacitors - conductors that take up a lot of space and have a complex structure. This is just one transistor of a special architecture that can store electrons, i.e. information.
In addition, flash memory cells are highly scalable: they can be made incredibly small, which means that a lot of data is written to a small medium. With the current level of computerization and development of technology, transistors can be made extremely small. This means only one thing: flash memory takes up extremely little space. Soon we will be able to fit terabytes of information on a regular flash drive.
A typical memory map is a field of columns and columns, in the intersection area of \u200b\u200bwhich there are always two transistors. They are separated by a special insulating layer.
As you probably know, all digital information is stored in megabytes. One megabyte is 1024 kilobytes. There are 1024 bytes in one kilobyte. One byte is 8 bits.
Our computers only understand the binary (binary system). That is, one bit of information is either zero or one.
Bit(English) bi nary digi t; also play on words: engl. bit - a little) (one binary digit in binary system calculus) is one of the most famous units of measurement of information.
A bit occupies one location in flash memory. The main thing in this mechanism is an electron. When you turn on a flash drive in a computer, electricity runs through it, running into all the cells. Each cell is made up of source And channel. Current flows from the source to the channel only if controller with the help of the same electricity, it will charge the electron, and, as if on a bridge, the current will run further along the electron.
If electricity has run, then the cell is zero, if it has not run, then it is one. The value of a cell, that is, a bit, depends on whether there is an electron there or not. When we write information to a flash drive, millions of controllers charge and discharge millions of electrons.
All the described processes take place on the memory chip. But a typical flash drive consists of more than just it. It also has a slot USB type"dad". Another device in a flash drive is a controller that provides mutual understanding between the drive and the computer - for this it has a small processor and a tiny amount of RAM. The latter is such a "buffer" for transferring information.
Imagine that you and your friends are unloading a carload of sugar. The wagon itself is a memory chip. The processor is the senior in the group who manages the process. A RAM on a flash drive - this is a place, a kind of sump, where the bags are thrown off directly near the car - before another loader transfers them to the warehouse (computer).
On the flash drive there is also an oscillator - a controller that sets the frequency of the system. This, one might say, is your employer, whose task is to ensure, on the one hand, top speed unloading the car and safety for the health of workers - on the other hand. Led indicator activity is needed directly for users: so that they know whether the drive is active or not. There is also a switch on flash drives that puts the media in write-protect mode. That, in fact, is all.
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