Msdos hidden files viewable from linux?

Mike Bilow mikebw at bilow.bilow.uu.ids.net
Thu Oct 26 12:16:00 EDT 1995



Mark J. Dulcey wrote in a message to Mike Bilow:

 MJD> Actually, the DOS system files are no longer
 MJD> position-sensitive in DOS 5  and later.  The only thing
 MJD> special about IO.SYS and MSDOS.SYS is that  they must be the
 MJD> first two files listed in the root directory; they can  be
 MJD> stored anywhere on the disk.

IO.SYS must start in the first cluster of the data area, but it can be
fragmented thereafter.

 MJD> DBLSPACE.BIN has no special requirements  at all.

I forgot about DBLSPACE.BIN.  It is not position-sensitive, but it has the
"system" bit set.

 MJD> If you restore IO.SYS and MSDOS.SYS to a completely empty
 MJD> disk, they will  automatically go into the required places
 MJD> in the directory.  Otherwise,  you need low-level access to
 MJD> put them back.

While it is true that restoring in this case would likely result in a bootable
disk, it is important to note that the files may not be restored to the same
place they came from.  Also, by "completely empty," there must not be even a
volume label on the partition before IO.SYS and MSDOS.SYS are restored.

 MJD> It's simpler to just put  them back with the SYS command from a 
 MJD> DOS floppy if needed.

SYS.COM is actually fairly intelligent.

 MJD> 386SPART.PAR (Windows permanent swap file) IS
 MJD> position-sensitive; it  must be in the place that
 MJD> /WINDOWS/SPART.PAR says it is supposed to be,  or you get a
 MJD> "corrupt swap file" message when you start Windows.  
 MJD> 386SPART.PAR also must be in contiguous disk sectors; it
 MJD> can't be broken  up by other files or bad sectors.

No one should use a permanent Windows swap file anyway, but there is no point
to backing up a swap file at all.  Delete it and let Windows create a new one.
 
-- Mike




More information about the Discuss mailing list