Rhodes Chroma Polaris

Hello All:

Like many others I have a Polaris with a semi-functioning control panel.  All the sliders work 
but over half of the membrance switches are out.  I would like to find a MIDI Editor (Mac) that 
I can use to control the Polaris.  I am completly new to the world of MIDI and I am not really 
sure how to go about doing so.

I read through the posts on this site and saw that sounddiver was the most popular way to 
control the Polaris using a computer.  Is this still what people are using?  I downloaded the 
public version of sounddiver but it didnt work because I have no XSKey.  How do I get one?  Is 
purchasing Logic the only way to get an XSKey?  Is there really no way to control a Polaris 
using the Mac other than by purchasing a $1000 piece of software?

I really am new to this world so please forgive me if this is a really basic question.  I have 
been trying to figure this out for a while and I am at a loss.

Thanks!