Compatibility: 4.0 only  Undoc 
Expects: AX    440dH
BX    drive (0=default, 1=A, 2=B, etc.)
CL    67H
CH    08H (device category: block device)
DS:DX addr of a 16-bit buffer to receive information
                                                                  
Returns: AX    error code  if CF is set to CY
DS:DX buffer contains returned data:
DS:[DX+0]  always 0
DS:[DX+1]  00H=drive is NOT locked
01H=drive is locked; access is denied
                                                                  
Info: Obtains the current setting of the disk access flag.  The driver
may disable all disk access, for instance, when it detects
unformatted media or an invalid boot record.

Note: This function is not documented in official MS-DOS references.

See Also: Fn 44H (IOCTL)
Fn 440dH (generic IOCTL for block devices)
Fn 440dH 47H (set access flag)
- -

DOS Fn 440dH CL=67H: IOCTL Query Access Flag