Topic summary
PC DOS 1.1
Extracted from the Wikipedia article IBM PC DOS.
PC DOS 1.x
At Microsoft in late 1981, Paterson began writing PC DOS 1.10. It debuted in May 1982 along with the Revision B IBM PC. Support for the new double-sided drives was added, allowing 320 KB per disk. A number of bugs were fixed, and error messages and prompts were made less cryptic. The DEBUG.EXE was now able to load files greater than 64 KB in size.