Int 13 Fn EF  - Ontrack Drive Rocket - Set Cylinder Offset                 [c]

   AH = EFh
   CX = cylinder offset for next INT 13 call
   DL = drive number (80h, 81h)

Return: CF clear
       AH = 00h
Program: Drive Rocket is a drive accelerator by Ontrack Computer Systems for
     IDE drives supporting the read multiple and write multiple commands
Desc:  the following INT 13 call will add the number given by this call to
     the specified cylinder to get the actual cylinder number, then reset
     the offset to zero

Note:  this function is also supported by the NOW! disk cache, and presumably
     newer versions of SWBIOS and Disk Manager
   for software which supports this call, AH=EEh is equivalent to calling
     this function with CX=0400h
   the cylinder offset is reset to 0 by all INT 13 called except AH=EEh
     and AH=EFh

See Also: AX=7B00h