Int 2F Fn AF1A  - Windos V2.11 - Search For Non-fragmented Disk Area       [O]

   AX = AF1Ah
   BL = drive (00h = current, 01h = A:, etc.)
   CX = number of clusters desired

Return: CF clear if successful
       DI = first free cluster on logical drive
       BP = first cluster of contiguous free area
       AX destroyed
   CF set on error
       AX = DOS error code (see #1366 at INT 21/AH=59h/BX=0000h)
Desc:  attempt to find an area of the disk containing the specified number
     of contiguous unallocated clusters

See Also: AX=AF00h"WinDOS"