Help identify this scifi novel...

Does anybody know the name of this novel? I read it a few years ago. It was set on a space station in the distant future. The main character was a man encased in a shell since birth to serve as a human computer to run the station. He was assigned a new “brawn” a woman. There was also an orphan tomboy named JOAT (Jack/Jill of all trades). They were attacked by space pirates and had to pretent he didn’t exist.

Could it be this?

The City and the Ship

Sample chapters on-line:

http://www.baen.com/chapters/W200403/074347189X_toc.htm

Thanks, that’s it. I had no idea there was a sequel.

There’s a whole series of Ship novels by Anne McCaffrey. Those are just the two most recent.