The Spaceman and King Arthur (Unidentified Flying Oddball) (1979)

A NASA spacecraft proves Einstein right when, traveling faster than light, it ends up near King Arthur's Camelot. On board are big-hearted Tom Trimble and Hermes, the look-alike robot he built. Tom immediately makes friends with pretty Alisande while becoming enemies with the evil knight Sir Mordred. It seems Mordred has joined up with the Sorcerer Merlin and they are both up to no good. It is now up to Tom to try and use 20th century technology to foil their plans.