DOS Fn 4409H (is drive remote) returns this layout in DX.

IoctlDriveInfoRec     layout when describing a local drive
1 1 1 1 1 1
 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 
 s i f 0 r 0 l 0 q g 0 0 0 0 0 a 
                                  bit  mask
                                  0: 0001H uses 32-bit addressing
                                  6: 0040H suprts generic Blk IOCTL  440dH
                                           and get logical drive map 440eH
                                           and set logical drive map 440fH
                                  7: 0080H suprts query IOCTL suprt  4411H
                                  9: 0100H this local drive is shared
                                 11: 0800H supports Is Media Rmvbl   4408H
                                 13: 2000H Needs FAT with BPB     DvRq 02H
                                 14: 4000H supports IOCTL Read       4404H
                                           and IOCTL Write           4405H
                                 15: 8000H 1=this is a Subst drive

See Also: fn 4409H (IOCTL is drive remote)
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IoctlDriveInfoRec