I thought the Academy was an electric model, but then again it sometimes seems that Royal was coming up with new models names on a monthly basis during the '60s. Is there any chance that the number has one too many digits in it? Or that the first digit is an S instead of a 5?

Okay, now that I know we're talking about the electric, I'm fairly certain it was made by Nakajima for Royal, which means that you're dealing with a Nakajima and not a Royal serial number. That being the case, based on the serial number I would speculate that your machine's manufacture year was 1985. I'm basing this on the '83 Nakajima electric I have that uses the same serial number format.

I tried looking for information on this model myself, since I got one for free today. A Craigslist posting -- the owner was going to throw it out and offered it for free.  She left it for me to pick up. She said it powered up, and yes, it does that, but that's all. So I'm ticked -- I wondered whether a belt slipped or something, but I can't see how to get inside. Frustrating. So I guess I'll be the one pitching it out -- unless somebody has an idea?

The local typewriter repair shop was able to make a belt to get it working.  Yes, it was a belt issue.

Fleetwing wrote:

That's encouraging -- I can't see how to remove the case to get at the motor and belt, though. There are four screws at the corners on the bottom, and screws holding the feet on, all of which I've unscrewed but with no results.

Usually, I have found that after you get out all the bottom screws you find, you still have to go around the machine where the top meets the bottom with a screw driver or a table knife and go along the edges.  These typewriters with the plastic cases are snapped together in addition to the screws that hold them in place.