SHOWFAT Version 2.50 - Copyright (c) 1987-1993 D.J. Murdoch
This program is shareware. See the license discussion below.
SHOWFAT graphically displays the physical layout of the
files on your disk. I use it for several things. First and
foremost, it's a tool that lets me look at my disk and satisfy my
curiosity about what's going on in there. It's easy to see when
the disk is getting badly fragmented and needs to be run through an
optimizer; it's also handy in a multitasker like Desqview, to watch
the results of programs that are writing long output files but
haven't closed them; it's sometimes helpful when automatic unerase
utilities can't successfully retrieve a lost file. Version 2.41
does a CHKDSK-style integrity check on the disk, and reports errors
in a slightly more friendly format.
Unless it needs to use a disk for virtual memory (in which case it
uses the disk it was started from), SHOWFAT never writes to disk.
It should be a perfectly safe and non-destructive way to explore
Run it by typing "SHOWFAT drive". Once running, use the arrow keys
to move the pointer around and get information about any cluster on
the disk. Symbols used include:
- file complete in 1 cluster
- multi-cluster contiguous file
(arrows) - indicate fragmented files
- start of erased file
- cluster not in use
B - bad cluster
The top line gives the cluster number, the first sector number
and, if the cluster is in use, the path to the owner.
The arrow keys (and Home, End, PgUp, and PgDn) cause physical
moves when used plain. When shifted or Alt'd, or when the
corresponding number key is pressed, logical moves according to the
directory structure are made:
Shifted Key Number Action
Left 4 Previous cluster in file
Right 6 Next cluster in file
Up 8 Previous file in directory
Down 2 Next file in directory
Home 7 First cluster in file
End 1 Last cluster in file
PgUp 9 Parent directory
PgDn 3 First file in subdirectory
The following keys are used for commands:
F1 - Help. This re-displays the introductory help screen and disk
A - Toggle Ascii window. This window shows the contents of the
current cluster on the disk. The offset (in bytes, printed in
decimal) from the start of the file to the start of this cluster
shown. Note that the windows are "tiled", not "layered", so none
of the FAT window will be hidden.
Tab - Toggle cursor window. If you have the Ascii or Hex window
open, this toggles between having the cursor move in units of
clusters in the FAT window and moving in units of bytes in the
F - Find file. You'll be prompted to enter a filename, and the
cursor will be moved to the start of that file. Don't use a
drive designator (e.g. A:), since only files on the currently
displayed drive are going to be shown. You can skip the path,
and SHOWFAT will find the file in its version of the "current
directory", which varies slightly from DOS's. If no filename is
displayed at the top of the screen (because your cursor is on a
cluster that's not in any file) then it'll use DOS's current
directory. If it's pointing at a file or an empty subdirectory,
it'll use the parent directory. If it's pointing at any other
subdirectory, that's the current directory. (It's easier to use
than to describe.)
H - Toggle Hex window. This window shows the contents of the current
cluster in hex bytes. Again, the offset is shown.
N - Go to start of next file fragment
P - Go to start of previous file fragment - Go forward to next free cluster
- Go backward to previous free cluster
ESC - Exit the program.
If you don't like my choice of colour scheme, you'll have to
patch the executable to change it. Here are the relevant
declarations from the source:
patch_pointer : string = 'Patch colour bytes here ->';
Standard: byte = Green;
Reverse : byte = 112;
Bright : byte = Yellow;
Search for the patch_pointer contents, and modify the next three
bytes to your heart's content.
IBM compatible computer with DOS 2+
about 70K bytes for the program
about 7 bytes per cluster
about 23 bytes per file, subdirectory, or erased file
Note: Showfat will use EMS memory if available, and if things are really
tight, will also attempt to swap all but 1 byte/cluster to disk
into files called SHOWFAT.$$?. If it can't create the swap file,
it will abort.
2.50 (May 18, 1993) - Fixed bugs that only showed up in DOS 6.0
DBLSPACE drive, and added help screen.
2.41 (December 24, 1990) - Fixed bugs with disk read errors, full
directories, 12 bit FATs, non-standard boot sectors,
unusual sector sizes. Added CHKDSK-style integrity checks.
Thanks to T. Salmi for his tests!
2.36 (November 1, 1990) - Improved speed and memory use, cleaned
it up, and fixed lots of bugs with large disks.
2.23 (May 9, 1990) - Extended DOS 4 support to pseudo-4 versions:
Compaq 3.31 and Zenith 3.30 Plus
2.20 (April 2, 1990) - Minor revision. Added DOS 4 support.
2.10 (April 29, 1988) - Major revision. Translated 2.01 from v. 3 of
Turbo Pascal to v. 4 and fixed bugs (using TDebug - great
program!), added F and D commands and generally cleaned
house. Dropped DISKMON, since it was too slow.
2.01 (not released) - Major revision to add Ascii and Hex windows.
Full of bugs.
1.11 (October 20, 1987) - Bug fix for non-standard cluster size
Minor changes to documentation
1.10 (October 17, 1987) - Added support for DISKMON
1.05 (March 27, 1987) - Overflow in memory check fixed
The screen handling procedures in SHOWFAT are slightly modified
versions of the excellent BOOSTERS routines by George F. Smith.
Low level disk handling and memory management is done by routines
from the Object Professional library by TurboPower software. The
rest is written by me. You may use the program for free for a
month, but a registration fee of $20 (Canadian or U.S.) is
required if you continue to use it after that. Users who pay the
registration fee will receive one free update on disk; please
state which version you're using. I'm also willing to give free
registrations to people who help me fix bugs in it, and I give
discounts for non-profit or educational organizations.
Suggestions for improvements would also be welcome. Messages can
be sent to me (DJ MURDOCH) via Fidomail, at node 1:249/99.5 of
Fidonet, on Compuserve, at address 71631,122, or by Internet to
337 Willingdon Ave.