home *** CD-ROM | disk | FTP | other *** search
- DDU (Dangerous Disk Utility) provides many uncommon features such as showing
- the clusters assigned to files, listing allocated, bad and free clusters and
- more.
-
- Syntax:
-
- The syntax for DDU depends on the function you wish to perform. More than one
- function may be requested with a single execution of the program
-
- General Syntax:
-
- DDU param-1 param-2 param-3 ... param-x
-
- Specific Syntax:
-
- DDU [d:][path\]filename.ext Show clusters assigned to the specified file
- DDU [d:]/A Show allocated cluster numbers
- DDU [d:]/B Show bad cluster numbers
- DDU [d:]/F Show free cluster numbers
- DDU [d:]cluster/M* Mark specified cluster as bad
- DDU [d:]cluster/O Show name of file that contains this cluster
- DDU [d:]/P Show parameters for specified drive
- DDU [d:]cluster/U* Unmark specified cluster as free
- DDU [d:]/V* Verify specified disk and mark all bad clusters
-
- Note that all options marked with a trailing asterisk (*) rewrite the disk's
- file allocation table. These options are the ones that may be "dangerous".
-
- Requirements:
-
- DOS 2.0 or greater. I believe that with a slight change, this could be
- overcome but I don't have a DOS 1.XX operating system to test with. The
- problem is that DOS 1 does not support directories or the DOS function call
- that returns the current directory.
-
- Standard disk formats. The program has tables for 160K, 180K, 320K, 360K and
- 1.2 meg 5.25 inch disks with no boot record. It should be able to support
- other formats provided with a properly formatted boot record. I have a
- modified VDISK.SYS device driver installed with which it also works.
-
- 25 lines per screen. If you have (for whatever reason) a smaller screen, you
- may loose information. The best example of this is seen with the /P option
- which currently displays about 17 lines.)
-
- Notes:
-
- As always, I have included the source code. As mentioned there, this program
- was derived directly from three other programs: CHAIN.ASM, MARK.ASM, and
- OWNER.ASM. All of which were written by Steven M. Georgiaids. His original
- code was (and is) extensively commented. My changes, on the other hand, are
- not. Aside from reworking the OWNER (/O) algorythm, no really drastic changes
- were made that affected the documentation he provided in the source code.
- Though the code for the /A, /B, /F, and /P options was entirely written by me,
- it does not really use much general code that is not seen in his source code.
- I have elected to leave his original copyright notice in the source code as
- an acknowledgement for his very worthwhile efforts.
- When you use the /P option, there are two things you should be aware of:
- 1. The disk parameters are listed in the same order as they occur in a boot
- sector.
- 2. Calculated values are shown in parentheses
-
- When you use the /V option, you should be prepared for a long wait (10 to 15
- minutes for verifying a hard disk. If all goes well, you should see no
- messages until DDU finishes verifying the media. If DDU discovers bad sectors
- in the system area of the disk, (boot sector, FAT sectors or root directory
- sectors) it will terminate immediately with an error message. If errors are
- found in the data area of the disk, it will attempt to mark the cluster
- containing the bad sectors. If the cluster is in use by another file or is
- already marked as bad or reserved, a message to that effect will be displayed
- and the program will continue. Otherwise, the offending cluster will be marked
- bad.
-
- Note that any drive specification remains in effect until another parameter on
- the same command line containing a drive spec is supplied. If no drive is
- specified with the first parameter the current (default) drive will be used.
- The path specification is not retained from one parameter to the next. If it
- is not given, it is always assumed that the current directory for that drive
- is to be used.
-
- Be careful! Enjoy! and hopefully find this program useful.
-
- Bruce E. Noblick
- 185 Crestview Road,
- Columbus, ohio 43202
-
- (614) 262-4564 evenings and weekends (eastern time).
- seful.
-
- Bruce E. Noblick
- 185 Crestview Road,
- Columbus, ohio 43202
-
- (614) 262-4564 evenings and weekends (eastern t