Int 2F Fn 150D  - Cd-rom V2.00+ - Get Cd-rom Drive Letters                 [d]

   AX = 150Dh
   ES:BX -> buffer for drive letter list (1 byte per drive)

Return: buffer filled with drive numbers (0=A:).  Each byte corresponds
   to the drive in the same position for function 1501h

See Also: AX=150Bh