You could say: "Xenix is a very very old version of Unix for PC's,
based [maybe?] on AT+T System III Unix. Xenix had a lot of influence
on System V developments."
> DOS is a family of single-user operating systems for PCs.
> 86-DOS was a CP/M-like operating system written by Tim Paterson.
> Microsoft bought it, renamed it to MS-DOS 1.0 and sold it to IBM to be
I thought MS-DOS 1.0 was originally named QDOS (Quick and Dirty OS)?
> delivered together with the first IBM PCs (1981).
> MS-DOS 2.0 (1983) was rather different, and designed to be somewhat
> UNIX-like. It supported a hard disk (up to 32MB).
> Version 3.3+ added support for disks up to 2GB.
> Clones exist: DR-DOS, PC-DOS, ...
> See comp.os.msdos.*.
> 7 OS/2 HPFS or QNX2 or Advanced UNIX
Not long ago I ran fdisk on a disk with an NTFS partition, and it claimed
it was OS/2 HPFS.
ben