PC-DOS 1.x

IBM PC-DOS was an IBM branded version of MS-DOS licensed from Microsoft for use on the IBM PC system. Versions of PC-DOS paralleled that of MS-DOS up until version 6.1, where PC-DOS was independently maintained by IBM up until 7.1, the last version. Although not the only OS available for the IBM PC when it came out, it quickly became popular due to its low cost in comparison to the others. Its direct competitors on the PC at the time were CP/M-86 and UCSD p-System. The major differences between PC-DOS and MS-DOS were only in terms of driver support and built in programs until version 6.1 where development diverged.

For Microsoft and other OEM DOS releases, please see the MS-DOS product page.

The first version of PC-DOS was released in August 1981 with the IBM PC. The last version released by IBM was PC-DOS 7.1, which had updates all the way up until 2003. This last version of DOS is still in use by some hardware developers usually embedded into recovery tools and BIOS flashers.

This OS does not have a GUI. It uses a command line interface, however PC-DOS 4 and later, like MS-DOS, also included the optional graphical DOSShell program. Like other DOSes, third party GUIs can be installed.

Release notes

IBM PC-DOS 1.0 was a port of 86-DOS purchased by Microsoft in 1981 for use on the IBM PC. This version of DOS resembles that of CP/M at the time. 1.0 only supports single sided 8-sector 160k 5.25 inch floppy disks. 1.1 adds support for double sided 320k disks. Directory support did not exist with this version of DOS.

Installation instructions

PC-DOS 1.x was a floppy-only version of DOS. It cannot be installed to a harddrive.

Emulation instructions: We recommend PCE or MESS. Others may work, but they must support 160k and 320k disk images. Some emulators (and real hardware) may require a "55 AA" boot signature to be added at the end of the floppy boot sector.

Product type
Release date
End of life date
Minimum CPU
Intel 8088 @ 4.77MHz
Minimum RAM
Minimum free disk space
User interface
Download count
180 (21 for release)


Download name Version Language Architecture File size Downloads
IBM PC-DOS 0.90 (6-5-1981) (1.00 Beta) (5.25-160k) 1.00 Beta Prerelease English 172.95KB 1
IBM PC-DOS 1.00 (5.25-160k) 1.00 English 3.24MB 8
IBM PC-DOS 1.00 Manual Aug81 1.00 English 52.95MB 2
IBM PC-DOS 1.00 Manual Jan82 1.00 English 6.71MB 1
IBM PC-DOS 1.10 (5.25-160k) 1.10 English 2.93MB 8
IBM PC-DOS 1.10 Manual May82 1.10 English 7.82MB 1


Comments by