Patches and discussion for Ensoniq VFX family

This may seem like a strange question but since I wasnt too keyboard 
savy when I bought my Ensoniq ten years ago, I was a bit confused 
about the model. On the keyboard it says VFX SD with the white and 
green logo just to the left of the volume slider. The guy that sold 
me the keyboard said that it was upgraded to an SD-1. To confirm 
this, when trhe keyboard starts up right after its calibration 
message it says Ensoniq SD-1 Music Production Synthesizer. Here is 
my question: It appears I need a new floppy disk drive for this 
keyboard. When ordering, should I request an Ensoniq VFX SD disk 
drive or a SD-1 disk drive? SInce I have never even seen an SD-1, 
what are the  major differences outside the internal system that is 
obviously the same as the one I own?
Thanks.