How does a hard drive work? | One awesome engineering | Clarification

Many people wonder how the music of hundreds of CDs can fit into a memory card equal to a little half an inch. Again a memory card is nothing compared to a hard drive. A hard drive is an efficient computer memory device that can store large amounts of data using simple magnetism. The microprocessor on your computer completes all the processes and tasks of the computer — but the hard drive is the device that allows you to store a large amount of data, music, digital photos, text documents, etc. It was a remarkable invention that originated in the 1950's, and surprisingly, its early form was in the form of cassette tapes

How is it possible to store data with magnetism?

The science behind magnetism is complex. But what happens if you bring a magnet to a piece of iron — you must know that technology বিজ্ঞান the science of magnets is complex but its simple application is much easier. A piece of iron does not have magnetism in the first place, but if you repeat a piece of iron with a magnet, that iron will also become a magnet at some point, and the chip will stick to the other magnet. In addition, magnets have many practical uses, such as the use of electromagnets (which can be turned on or off using an artificial magnet or electricity) to remove debris, and to remove large metal pipes or broken cars.

In addition to garbage disposal, there are other important uses of magnets. Suppose you want to send a message to your friend, but you have a magnet iron and another non-magnet iron to send the message. Now remember, your message is very simple, meaning whether you can meet him, just want to massage yes or no. So if you send a piece of iron to someone at your friend's house, he will attach the piece to his paper clip, if it attracts the paper clip, it is magnetized iron, which means you are coming to see, and if you don't, you can't see. I know, it turned out to be a weird example of sending a message — but think about it, one thing came to the fore as a result of this example, and that is what information that magnet can store.

If you have a 20 gigabyte (GB) hard drive on your computer, think of it as a box containing 160,000 million microscopic magnetized iron pieces, each containing a tiny fraction or bit of your data. I've given a lot of ideas about bits in previous posts, it's basically binary digits where only 1 or 0 is a number. In computers, no number is in the form of decimal or decimal (0-10), but in the pattern of binary numbers. For example, the decimal number 362 is in binary form 101111110 — thus any letters are also in binary form. For example, computer English capital letters "A" whose decimal number "65" is saved as binary number "10000001". Now suppose you want to save the number "10000001" on your computer hard drive, where you have to do it with the help of a magnet. But there you have to find a sari where there are 8 pieces of unused iron together. Now you magnetized the first piece (which saved 1) and left the next 5 pieces magnetized (which saved 5 0), and magnetized the last one (which saved 1). This way you can easily save the data.

How does a hard drive or hard disk work?

Your computer hard drive doesn't actually have any pieces of iron, it just has a glossy round magnetic metal plate called a "plater" —in billions of tiny areas. Each of these areas can acquire magnetism independently (by preserving 1) and can also be non-magnetic (by preserving 0). The problem with computer flash memory is that when it is switched off, it forgets all the data (e.g. RAM), so magnet power is used on the hard drive to store the data, so that it can hold the data even when the computer is off.

The platter is one of the most important part of a hard drive. As the name implies, it is a disk made of solid glass or aluminum, coated with a thin layer of metal that can be magnetized or non-magnetized at any time. Smaller hard drives have only one platter, both sides of which are coated with magnetic metal. Larger hard drives have a series of platters, which can rotate up to 10,000 times per minute (called RPM) so that the data read-right head can access any part at any moment.

Each platter has two read-write heads, one reads the surface and the other reads the bottom — that is, a hard drive that has five plates must have ten heads. The header can move to any position on the platter at any time, but the header and the plater never get too worn out, there is no liquid or air between them.

Data read and write

The best thing about a computer hard drive is not only that it can store some data, but you can also access that data later. Computer hard drives do not have any separate magnetic iron, they all come together. Each bit of information is arranged in a specific pattern, and these patterns form a circular path called a track. Each track has a smaller part, called a sector. The hard drive has a map to determine which sectors have been used and which are still blank. On Windows computers this map is called File Allocation Table or FAT.

When your computer wants to store new information, it looks for empty sectors on the map. The data in that sector is then delivered to the read-write head, and the command to write is given. In order to read the data, the reverse process of writing is done. Hard drives are truly remarkable engineering for their ability to hold such a large amount of data in such a small space. It also allows you to store hundreds of CDs of music in one small box at a time, but it also has some drawbacks. For example, even if a small grain of sand falls on its plate, it can become useless. Moreover, since it is a mechanical device, its head can become useless for any reason while running, this is called disk crash or head crash, and as a result you can lose all the data on the hard drive. No problem, I have a detailed post on how to recover lost data.

However, to avoid data loss from hard drive crashes, important data needs to be backed up to another hard drive or compact disc CD or DVD. I will write a detailed post about how a CD or DVD works.

Working hours

So when you open a file or do any work on the computer, the hard drive finds every data repeatedly. Remember. Once you open an image on the computer, your CPU will tell the hard drive exactly where or in which sector to look for it, the hard drive's platter will start spinning hard and find the image and send it to the CPU in about nanoseconds. And the same is called data reading. The CPU will receive the image and process it to display it on your screen.

Now think about editing the image. When you open an image in an image editing software, it is already saved on the hard drive, but when you edit the image and save it again, the read-right head will go to the previous image and overwrite the data of the new image on it. Is a data write process.