Fairlight-CMI

My recently purchased IIx came with OS Rev. 19.  Can someone tell me 
the difference between Revs. 19 and 20?  Is it possible for someone 
with Rev 20 to copy it for me?  I can provide whatever disks are 
required.  

Also,  it seems that I have most of the original library, but going 
by the track listing for Pro-Rec's Fairlight IIx sample CD, my 
library is a bit different. For example, I have a disk 
called "Choral" which seems to have many of the Arr1 type sounds, 
but i don't have two discs called "Humans 1 and 2". My string disks 
are called "Strings1," "Strings2," etc.  I also have a disk 
called "Plucked Strings."  Is Pro-Rec's listing of the sample 
library definitive?  Is that the actual library?  I also don't have 
Discs A, B and C (Additionals, Machines and Goodies) or Fairlight 
Sounds (Disk 34 according to Pro-Rec).  Can anyone clear up the 
discrepancies?  


Regards,
Kyle