A number of years ago, an 8″ disk containing Seattle Computer Products (SCP) 86-DOS 1.0 was successfully imaged. The newest files on the disk are dated April 30, 1981, making the disk the oldest complete release of what was soon to be known as PC DOS and MS-DOS, about a month older than a pre-release of PC DOS from early June 1981.
While it is possible to run the 8″ disk image with 86-DOS version 1.00 under an emulator, it of course doesn’t run on a PC or any PC emulator/virtualizer. That’s a shame because most of the utilities included with SCP’s 86-DOS run under DOS just fine. In theory, it should be possible to provide a PC compatible “BIOS” component (IBMBIO.COM or IO.SYS equivalent) and run the rest of the system more or less unmodified on a PC.
In practice, it can in fact be done. Behold PC-86-DOS 1.00, running from this disk image.
In case you don’t know or remember, Seattle Computer Products was the company Microsoft bought the rights to DOS from, making SCP’s versions of DOS some of the oldest in existence. Getting these old versions archived and running on modern emulators is critically important for the field of computer archeology.