Int 2F Fn 1001  U - Dr-dos 6.0 Share Internal - Set ???                    [d]

   AX = 1001h
   DX:BX -> ???function

Note:  this function is also supported by SuperStor, a disk-compression
     program by Addstor which is bundled with DR-DOS 6.0

See Also: AX=1000h,X=F800h