Computer memory devices

HDD

• Hard disk (HDD - Hard Disk Drive) refers to non-removable magnetic disk drives. The first hard drive was developed by IBM in 1973 and had a capacity of 16 KB.
• Hard magnetic disks are one or more disks covered with a layer of ferromagnetic material, placed on one axis, enclosed in a metal case and rotating at high angular velocity. Due to the many tracks on each side of the disks and the large number of disks, the information capacity of hard disks can be tens of thousands of times larger than the information capacity of floppy disks and reach hundreds of GB. The speed of writing and reading information from hard disks is quite high (about 300 MB / s) due to the fast rotation of the disks (7200 rpm).