I have included three programs useful for recovering lost files,
such as ones that are mistakenly deleted, or a patching up an
incorrect FAT. The three programs are PFAT, FAT, and TOSECT. When
used together with DEBUG, it is possible to correct both of the above
situations with some time and patience. I am writing a more complete
DOC file explaining the mysteries of how this is done for DOS non-experts.
For now, I am afraid the best I can do is to refer you to Appendix C
of the PC-DOS manual for more information. It should be available in a
couple of weeks.
These programs probably only work with DOS 2.0 and later and only on
DSDD floppies. They should work on an MS-DOS or PC-DOS system, however,
since I restricted myself to DOS function calls.
This program allows simple modification of the FAT table. The
two copies of the FAT table are read from drive B and compared
to make sure they are consistent. The program will respond with
a FAT> prompt. Responding with a hexadecimal cluster number will
display the hexadecimal contents of the FAT table corresponding to
that cluster. By typing a new hex value, that location can be
modified and the next location is opened. To exit the program,
type ^Z (control Z) after the FAT> prompt. The new FAT table
will be copied to the diskette in drive 2 at this point. If you
don't want the table to be modified, exit the program by typing
The FAT table is printed out in hex on the console. The output
can be redirected to the printer where it will be easier to read.
It is about 100 characters wide.
This utility program converts the cluster number in the FAT table
to a logical sector number (as used by DEBUG).
Questions or problems??? Contact Steve Turley
30539 Canwood St.
Agoura Hills, CA 91301
I am especially anxious to hear how this works with systems other
than my Compaq.