Contents of the MAPDISK.DOC file
Copyright (c) 1987 by M. T. Callahan -- All rights reserved
Purpose This program maps all allocated, and unallocated, extents
for a disk (either floppy or hard). The resulting report
shows ownership of each extent and its starting and ending
position on the disk. The report is written to a user
where d: is the drive to be mapped; there is no
default for drive
and is a file specification for the
output report; default is MAPDSK_d, where
d is the drive being mapped.
This program is intended to be run on an IBM (or very near
clone) PC. To date it has been tested on the IBM XT, AT,
and PS/2 model 60. It has been tested using both PC-DOS
2.x and 3.x operating systems (including 3.3). It has
performed without problem in each of these environments.
It can map both floppy disks and hard disks equally well,
however, it is most useful for mapping hard disks.
Like DOS this program is constrained to disks of 32 Megs
or less since it reads disk parameter information from the
boot record and from the disk parameter block.
Maximum number of files and directories ... 5000
Maximum number of FAT extents ............. 8192
Maximum number of file/extent connections 10000
These maximums were chosen such that most users
would never approach them. However, if your
requirements are unusual, contact me, and I will
see what can be done to accomodate your requirements.
140K + D + F + E + C
D is Directory buffers
- must be large enough to hold all
directories in longest path
- each 512 directory entries requires
16K of memory
- minimum directory size is one
F is 29K per 1000 files
E is 9K per 1000 extents
C is 11K per 1000 file/extent connections
Disk statistics for files and directories will differ from
those returned by CHKDSK in the following ways:
- MAPDISK does not consider the Volume id to be a
file since it only uses a directory entry and not
- The number of directories reported by MAPDISK will
usually be one more than CHKDSK since MAPDISK
reports the root directory as a directory, CHKDSK
- MAPDISK reports all files (SYSTEM, HIDDEN, etc)
in one category, CHKDSK differentiates between
Hidden and non-Hidden files.
This program is supplied AS IS. The author does not
warranty that the program will work as designed on your
particular system. The author will not be liable for any
damages of any kind sustained though the use of this
program on your system. Your use of this program
constitues acceptance of these terms.
This program is intended for the user's personal use,
commercial use is prohibited without payment of a license
You may make copies of the program and documentation
for yourself and others, provided no fee is charged.
An exception is made for PC USER'S GROUPS which may
charge a small amount (not to exceed $6) for handling
Although, the author does allow the user to copy this
program and documentation to pass on to others. It is
hoped, that if the user does find this program usefull,
the user will be willing to send the author $10 for the
program. Commercial users must pay license fee of $10
per copy used.
Comments and suggestions are always welcome.
M. T. Callahan
1565 Holly Ave
Rohnert Park, Ca 94928
1.0 1 Oct 1987 - Internal version - proof of concepts
2.0 20 Dec 1987 - First version released to users