Roland XP Series

Not being able to find my manual this is doing my head in, hence the post.

Anyone know how to turn on and off the data wheel (for patch selection for
example).  Mines not responding, but all other features/buttons of the
workstation are fine.  I can select programs by typing the number in or
using the inc/dec buttons, but thats no good for browsing patches!

Thanks in advance

Please reply in group(s) my email is a spam trap.