Korg DW8000, Mono/Poly, MS-20...

I have a Polykorg 61.  The manual tells of saving program data. The 
question I have is when this is done,(havn't attemped it yet) is all of 
the data on board saved or just a single program?  The reason I ask is: 
On Ebay(item 130182657747) there is a fellow selling rescue tapes.  The 
claim is that it will restore all the original factory presets after 
the battery dies.  My battery is still working, so I'd like to make my 
own 'Rescue' tape(saving of $20.00) before I attemt to change out the 
battery, which is another question I have. Hope you all can help.   
Thanks in advance for any responses.   Mike