hmm, `SputnikOS' version GammaElKaramba in 1956 when I was the head researcher in Mother russa...........
j/kes apart, my first OS would be dos in 1993-4 (dun rem which version)
my first encounter with the DoS: i see the command prompt:
c:\>
i walked up to the keyboard and typed in record speed:
c:\> 1 + 2 = _
and pressed enter, to be greeted with my first error message:
Bad command or file name
And here I am, 12 years later, nerd to the core