Int 7F Fn 06  - Alloy Ntnx (slave) - Allocate Free Cluster On Shared Driv  [N]

   AH = 06h
   DL = drive number (1=A:,2=B:,etc)
   CX = number of clusters to allocate

Return: AH = status
       00h successful
       CX = number of clusters still free
       10h invalid shared drive request
       CL = first and second shared drives
       11h invalid cluster count (must be 01h-FFh)