MCP 3.5 (or III.5 as we would have written it then) ca. 1985 sounds
about right to me for COMS and MARC. It couldn't have been much earlier
than that. I'm not sure that SDF was available with the initial release
of COMS, but came soon later if not.
As I recall, HMP 1.0 came out much later -- in conjunction with the
NX-series machines in 1996.
Paul