INT 21,44,8 / IOCTL,8 - Device Removable Query
AH = 44h AL = 08 BL = drive number (0=default, 1=A:, 2=B:, 3=C:, ...) on return CF = 0 if successful = 1 if error AX = 00 removable media = 01 non-removable media = error code if CF set (see DOS ERROR CODES) - used to determine if a device supports removable media - RAM disks are not considered removable media - device drivers compatible with DOS 2.0 do not always respond correctly to this query - implemented from DOS 3.0; for earlier DOS versions drive A: and B: are removable media since DRIVER.SYS/SUBST are DOS 3.0+ only