Int 2F Fn 1501  - Cd-rom - Get Drive Device List                           [d]

   AX = 1501h
   ES:BX -> buffer to hold drive letter list (5 bytes per drive letter)

Return: buffer filled, for each drive letter
     BYTE  subunit number in driver
     DWORD address of device driver header (see #1332)

Note:  reportedly returns AX=0000h and an invalid address under Windows95;
     other reports say it works fine

See Also: AX=1510h