A hard-disk Drive, or hard-disk Drive, is a major computer storage medium consisting of one or more disks made of aluminum or glass. These discs are coated with a ferromagnetic material. Most hard disks are fixed, permanently sealed and fixed to the hard drive. Now the removable hard disk is more and more popular, more and more kinds.
Chinese name
Hard drive
Foreign names
Hard-Disk Drive
Jane said
The hard disk
Belongs to the discipline
The computer
directory
1 overview
2. Components
3 Working principle
4 The world's first hard disk
5 Precautions
An overview of the
A hard disk drive (HDD) is a device in a personal computer that controls the addressing of the hard disk and the access to data. A hard drive is the only way a computer can store data. Although hard drives and hard disks are two different concepts, because they are usually packaged together, either a hard disk or a hard disk drive usually refers to a device that combines the two.
composition
Mechanical hard disk is mainly composed of magnetic head and disk, the magnetic head is the key part of the mechanical hard disk to read and write data. When a mechanical hard disk is working, the magnetic head writes track data or reads existing data as the disk rotates.
The working principle of
Early desktop computers used hard disk IDE interface, IDE interface hard disk is cheap, but low cost performance; Most personal computers use SATA or SCSI interfaces. The advantage of SCSI-interface hard drives is that up to seven different devices can be connected to the same controller panel. Because the hard disk rotates at a constant and high speed of 3,000 to 15,000 revolutions per minute, it only takes a short time to read data from the hard disk.
The world's first hard disk
The first hard disk was IBM's System 305, produced in 1956, which was used for RAMAC random computing and controlled access to store data. The entire hard drive requires 50 disks with a diameter of 24 inches coated with slurry. The capacity of this hard drive is only 5MB.
Matters needing attention
If the SSD is powered down, it may cause the current to disrupt the master, causing the master to go down. So SSD users, please do not casually power off. Although solid-state drives are orders of magnitude less likely to fail than mechanical hard drives in principle, they are still vulnerable to human failure