Get Extended Disk Change Status

Entry:
    AH = 49h
    DL = Drive number
Exit:
    if change-line inactive (media has not been changed)
        carry clear
            AH = 0
    if change-line active (media may have been changed)
        carry set
            AH = 06h

This function returns disk change status of a specified drive.

If this function returns with carry flag set, the media has not necessarily been changed; the change line can be activated by simply unlocking and locking the drive door without removing the media.

This function corresponds to INT 13h Function 16h, but explicitly allows any drive number to be passed in. If a fixed disk supports the Removable Drive Control API subset, then this function always returns with carry clear and (AH) = 0.