You and me both. I ran OS-9 on my CoCo 1 in 64Kb RAM... sometime in '84 - '85. Could not do a lot, but it gave me a bit of grounding when I was dropped into SCO Unix in the late 80's.
Oh right, there was OS-9 Level I which ran on the CoCo 1 and 2, but with the max of 64K it was fairly limited in practice, although still a great learning platform.
Later there was OS-9 Level II on the CoCo3 which was much more usable as a daily driver OS.
Later there was OS-9 Level II on the CoCo3 which was much more usable as a daily driver OS.