I'm trying to remember the name of an old animated movie. Description will be a bit vague but here goes:
It's a cross between Treasure Planet and Sword in the Stone. (it's not Star Chaser). It's a family animated movie about a blonde boy. He finds a sword with an invisible blade, the blade materializes when he uses it. He is on board a talking spaceship - the spaceship has a little rectangular head that pops out when he talks to the boy.
At one point the boy asks the ship to do something and strikes the console. I think he was searching for a treasure or something. The movie is not set in space exclusively, they travel around on a planet. I don't remember other characters.
I don't remember the period - 80's possibly very early 90's
Sorry, I know its vague but that's all I can remember and I'm desperately trying to find it.
Thanks in advance!