Int 2F Fn 1509  - Cd-rom - Absolute Disk Write                             [d]

   AX = 1509h
   ES:BX -> buffer
   CX = drive number (0=A:)
   SI:DI = starting sector number
   DX = number of sectors to write

Note:  corresponds to INT 26h and is currently reserved and nonfunctional

See Also: AX=1508h