How does a hard drive store data?

Today's hard drives, whether IDE or SCSI, are used"Winchester's technology has the following characteristics:1. Magnetic head, disc and kinematic mechanism sealed.

2。The surface of the plated disc plate, which is fixed and rotated at high speed, is flat and smooth. 3。

The head moves radially along the platter. 4。The magnetic head starts and stops in contact with the platter, but it is in flight and does not have direct contact with the platter when working.

Platter: A hard disk platter is a magnetic particle attached to the surface of an aluminum alloy (glass is also used for new materials). These magnetic particles are divided into concentric circles called tracks, and on the tracks of each concentric circle there are as if there are countless small magnets of any arrangement, which represent states of 0 and 1, respectively.

When these small magnets are subjected to a magnetic force from the head, the direction of their alignment changes. The magnetic force of the head is used to control the direction of a number of small magnets so that each small magnet can be used to store information.

Disk: The disk body of a hard disk is composed of multiple platters, which are stacked together in a sealed box, and they are driven by the spindle motor to rotate at a very high speed, and its speed per minute reaches 3600, 4500, 5400, 7200 or even more.

Head: The head of the hard disk is used to read or modify the state of the magnetic material on the platter, generally speaking, each magnetic surface will have a head, starting from the top, numbered from 0. When the head stops working, it is in contact with the disk, but it is in flight when it is working.

The head takes the contact start and stop method in the landing area of the platter, and the landing area does not store any data, and the head starts and stops in this area, and there is no problem of damaging any data. When the data is read, the platter rotates at high speed, and the head is in a "flying state" at a micron height from the data area of the disc due to the ingenious aerodynamic design for the head movement. It does not cause wear and tear in contact with the disc surface, and the data can be read reliably.

Motor: The motors in the hard disk are all brushless motors, which have little mechanical wear and tear under the support of high-speed bearings, and can work continuously for a long time. The high-speed rotation of the disc body produces an obvious gyroscopic effect, so the working hard disk should not be moved, otherwise it will increase the working load of the bearing.

The seek feeding motor of the hard disk head mostly adopts voice coil rotation or linear motion stepper motor, which accurately tracks the track of the platter under the adjustment of feeding clothing tracking, so there should be no impact collision when the hard disk is working, and it should be handled carefully when moving.

Hard disk storage data] Hard disk is a thin layer of ferromagnetic material coated on a hard platter (usually aluminum alloy, IBM has also tried to use glass before). The principle of storing data on a hard disk is similar to that of a cassette tape, except that the data stored on the cassette is in analog format**, while the hard disk is stored in digital format. When writing, an electric force is applied to the head coil, which generates a magnetic field around it and magnetizes the magnetic material underneath; The direction of the current is different, so the direction of the magnetic field is also different, which can represent the difference between 0 and 1.

When reading, the magnetic head coil cuts the magnetic field line and generates an induced current, and the direction of the magnetic field of the magnetic material is different, so the direction of the induced current generated is also different.

No matter what computer file it is, songs, **, **, documents, etc., all exist in a binary sequence, that is, there are many"10010001110011..."For such a thing, the files stored on the hard drive are actually storing these sequences of 0s and 1s. The head of the hard disk can read the signal at the corresponding position according to the instructions, and can change the direction of the magnetic field at the specified position, which is the reading and writing of data.

It's so powerful, it's good to be in front of you, and I've learned.

I knew this thing was complicated before, but I looked at it today.

Still somewhat scared, it's amazing!

1. The storage principle is as follows: the hard disk is a kind of data storage device using magnetic medium, and the data is stored on a number of disk pieces sealed in the inner cavity of the clean hard disk drive; The traditional hard disk reads and writes are based on the cylindrical surface, the head, and the sector are used as the auspicious address mode, the hard disk maintains high-speed rotation after powering on, and the magnetic head located on the head arm is suspended on the surface of the disk, and moves between different cylinders through the stepper motor to read and write different cylinders; Therefore, if the hard disk is violently shaken during power-up, the disk surface will be easily scratched, and the head will be easily damaged, resulting in irreparable errors in the data.

2. Hard disk storage refers to the storage method of using hard disk as the storage medium.

3. Hard disk storage capacity: Mobile hard disk uses hard disk as the storage medium, and its storage capacity is the storage capacity of its internal hard disk. The storage capacity of a portable hard drive determines its ability to store data.