In 1956, the first hard drive to be sold commercially was invented by IBM. This hard drive, shipped with the RAMAC 305 system, was the size of two refrigerators and weighed about a ton. It held 5MB of data at the cost of $10,000 per megabyte.
In 1961, the IBM 1301 Disk Storage Unit was released, utilizing heads that floated on a thin layer of air. This advance meant that the heads could be kept closer to the platters, increasing storage density.
The first removable hard drive was created in 1963. The IBM 1311 contained six disks and could hold 2.6MB of data.
In 1964, the IBM 2311 was the first standardized disk drive, which could be used across multiple versions of the System/360 computer.
Memorex was the first company separate from IBM to produce an IBM-compatible disk drive in 1968.
Western Digital (first named General Digital Corporation) was founded in California in 1970. 1970 was also the first year that error correction was built into hard drives.
In 1973 the IBM Winchester Drive was introduced with three removable, sealed data modules.
The Seagate company was founded in 1979, and IBM introduced its "Piccolo" drive, storing 64MB over eight disks. Also, this year, IBM released the 3370 model, which was the first to use thin-film heads.