The
Atari series used this
naming convention. They even used a
disk operating system called (surprise!)
DOS.
I used to believe that they had it before
Microsoft did. That Atari, in fact, had invented it. Of course, this was because
I happened to have an Atari before ever hearing of
Microsoft. Now there's an example of
Post Hoc ergo Propter Hoc reasoning.
I also thought that the 8.3 filename was the best thing about MS-DOS.
So much for pathos.