the big secret is revealed at last, thanks Bill. As I thought you would have had no intention of restricting your recollections on the forum and we understand exactly why it was not posted, since you were actually asked to write it specifically for a reason.
To put things in perspective the 8 MB card will hold around 16 retail type technote floppy disks with new styles and song sequences, or more style and setup disks if you selectively save. Or 2 or 3 mp3 songs to play along with, slightly more if you encode at a lower quality. The average owner with a small collection of disks may find the supplied card fine. Others of us may need to buy more or bigger cards. Or you can just overwrite the card as many times as you like from your archive on the laptop or pc with the card reader or software direct link.
If I may just be allowed to add, I think the training programs are built into the PR804 piano. The 7000 should be able to load future release scores type software into the screen, but maybe not with the bouncing ball feature on the 804.