Disklavier

Here's how I answered Mel...

My understanding is that on a Pro model you should be able to replace 
your control unit and, by doing so, get the latest features.  The 
Pros already came with the latest level of solenoids (mechanicals) as 
the Mark III pianos.

Your current control unit should be a DKC500RW.  You should be able 
to unplug the 15-wire cable in the back, and replace it with the 
latest control unit, the DKC55RCD (which you should be able to buy 
from your dealer).  This should give you CD playback and access to 
the PianoSmart recordings.

Note an unexpected limitation of the DKC55RCD (if you're computer 
literate): the CD player cannot play MIDI files – so don't expect
to download a bunch of MIDI files from the Internet, cut them onto a 
CD-R on your computer, and carry them to the piano.  You'll still
need the diskette drive to play and record MIDI files.

– John Q. Walker