IBM PC DOS is a DOS system for the IBM Personal Computer and compatibles, manufactured and sold by IBM from the 1980s to the 2000s.

PC DOS 5.0 was released in May 1991. The major new features of the release was ability to run DOS in HMA and addition of the 122-key keyboard support. PC DOS 5.0 required at least 256 kB RAM.

In June 1993 IBM released new verion of its operation system - PC DOS 6.0, which was introduced as PC DOS 6.1.