In 1980, Alan Shugart’s Seagate Technology shipped the first hard disk drive designed for microcomputers, a $1,500 unit that stored 5 MB of data. Roughly a dozen companies came out with their own hard disks over the next year. It was not until 1984, however, when IBM shipped the PC-AT with a 20 MB hard disk that the storage devices started to gain wider acceptance in the PC market.
By 1988, the typical business PC shipped with a 40 MB hard disk. If this doesn’t sound like much of an improvement over the 20 MB standard of four years earlier, it’s important to consider the limitations imposed by the operating systems of the time. The first release of MS-DOS (or PC-DOS) in 1981 had no support of any kind for hard disks. When DOS 2.0 released in March 1983, it could only support a single 10 MB hard disk. DOS 3.0, released in August 1984, made it possible to support multiple hard disks, but each was limited to a single 32 MB partition.