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