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Disk eXPress
for Creating
Diskette Images
DXP
Version 2.10a
02/12/93
TABLE OF CONTENTS
_________________________________________________________________
1.0. INTRODUCTION TO Disk eXPress ........................3
1.1. What is Disk eXPress? ..........................3
1.2. Features of Disk eXPress .......................3
1.3. New features in Disk eXPress Version 2 .........4
1.4. New Disk eXPress companion program: Xtract .....4
1.5. What's new in Version 2.10a ....................5
2.0. SYSTEM REQUIREMENTS .................................5
3.0. COPYRIGHT NOTICE ....................................5
4.0. WARRANTY ............................................6
5.0. COST OF Disk eXPress ................................6
6.0. CONTENTS OF THIS PACKAGE ............................6
7.0. SYNTAX ..............................................7
7.1. Quick start ....................................7
7.2. Disk eXPress help screens ......................9
8.0. COMMAND LINE SWITCHES DESCRIPTION ...................11
8.1. Regular mode ...................................11
8.2. Extract mode ...................................12
8.3. Batch mode support .............................13
8.4. Disk eXPress real-time bar graph display .......14
9.0. EXAMPLES ............................................15
9.1. Example 1 ......................................15
9.2. Example 2 ......................................16
9.3. Example 3 ......................................16
9.4. Example 4 ......................................17
9.5. Example 5 ......................................17
9.6. Example 6 ......................................18
9.7. Example 7 ......................................18
9.8. Example 8 ......................................19
10.0. ERROR MESSAGES .....................................20
11.0. LIMITATIONS ........................................22
2
1.0. INTRODUCTION TO Disk eXPress
_________________________________________________________________
1.1. What is Disk eXPress?
Disk eXPress (DXP) allows a diskette image to be created for
electronic transmission. Think of it as a way for preparing a
diskette to be FAXed like a regular document. Once the diskette
image is created, it can be transmitted with the use of a modem
on a regular phone line, or any other electronic networks.
One area of use is to archive diskette images on hard drives or
tapes. This can be useful for companies maintaining an
electronic bulletin board service for clients, in which diskette
images for the latest hardware drivers, or fixes are available
for download. This guarantees the contents of the diskette to be
the same as the original -- including all directory structures,
date and time stamps of all the files and directories, and the
location of any hidden information.
For simple file archival purpose, the use of Disk eXPress should
be avoided. The user is encouraged to use one of the many fine
archive programs available on the market. Disk eXPress is useful
for archiving bootable diskettes, diskettes containing hidden
information, or files and directory entries containing characters
unrecognizable by the usual file system functions. Unlike a file
archive program, Disk eXPress requires a diskette drive and a
diskette in order to restore any information stored in an image.
1.2. Features of Disk eXPress
- Disk eXPress recognizes all standard DOS formatted diskettes,
this includes 160K, 180K, 320K, 360K, 720K, 1.2M, 1.44M, and
the latest 2.88M diskettes. Any internal or external diskette
drives connected via DOS or OS/2 block device drivers are
recognized (ie: diskette drives accessed via DRIVER.SYS,
$FDD5.SYS, etc.) All information on the diskette is saved to
a file for electronic transmission, no information is lost!
(see /a switch for detail).
- Disk eXPress can be used for diskette conversion. For
example, a 360K diskette image can be restored onto a 720K,
1.44M, or 2.88M diskette. If someone sends you a bootable
360K diskette image, you can restore it onto a 720K diskette,
and the resulting diskette will be bootable.
- Advanced virus protection. Disk eXPress detects illegal
program modifications whether it's by virus, or bad electronic
transmissions.
- Multiple 32-bit CRC data protection. The image is protected
by several 32-bit CRCs. In some cases, if a non-critical part
of the image is modified, the resulting diskette will still be
usable.
3
- Upgradability of the self-extract code. Disk eXPress provides
a means to upgrade the self-extract code within the image file
for bug fixes, and future code enhancements upgrade.
1.3. New features in Disk eXPress Version 2
- Disk eXPress is now a dual mode executable file. It runs
under both OS/2 and DOS. There is only one version of the
executable as opposed to two in the previous release.
- Disk eXPress exploits the multi-threading capability when it
is run under OS/2. It performs simultaneous disk I/O and data
compression. This typically gives 10 to 50% speed up compare
to running it under DOS.
- Disk eXPress supports long filename for diskette images
created under OS/2 with HPFS (High Performance File System)
disk partition.
- New data compression algorithm based on a modified Lempel-Ziv-
Huffman method. Disk eXPress now compresses smaller than
version 1, and is also 2 to 3 times faster. The compression
rate is comparable to most file archive programs. Compression
is dynamic -- non-compressible data is simply stored.
- Real-time bar graph display showing current compression rate,
disk read/write and compression activities (this capability is
limited under DOS).
- Self-extracting diskette image is also a dual mode executable.
/DOS and /OS2 switches are no longer required (please refer to
version 1 documentation). All the extra functions are
removed, and are now built-into the extract mode of Disk
eXPress itself.
- Disk eXPress can now create non-self-extract image (pure image
data). This is useful for diskette archival purpose on hard
drive or tape.
- Diskette decompression code is now built-into Disk eXPress.
This can be used to decompress version 2 pure diskette image
or Disk eXPress version 1 and 2 self-extract images. It has
the full set of options, including diskette formatting,
conversion, and verification. The decompressor is also fully
multi-threaded under OS/2 to yield the fastest diskette
extraction time.
- The /t switch is added to all the decompressors so that the
integrity of the image can be tested before committing the
lengthy diskette write process.
1.4. New Disk eXPress companion program: Xtract
- Xtract is a dual mode executable. It features all the
decompression capability of Disk eXPress, including multi-
threading under OS/2.
- It is used for distributing pure diskette images in which
unlimited distribution right is granted for Xtract after
purchasing a licensed copy of Disk eXPress.
4
- Xtract is included in the licensed version of Disk eXPress
(not included in the shareware version).
1.5. What's new in Version 2.10a
- New /q switch for QuickFormatting diskette.
- New /DOS switch to create self-extract images that run under
DOS and OS/2 DOS box ONLY. Reduction of 13K overhead in self-
extract code.
- New /s switch in self-extract image to bypass warning prompt.
- Code and compiler optimizations to reduce self-extract code
size by 2K and at the same time, achieve a 10% overall speed
up.
- Description can now be entered via environment variables
(DXPDESC1 to DXPDESC5).
- Low level diskette access code has been completely rewritten
for the DOS side to allow full functionality of Disk eXPress
under OS/2 DOS box.
- Prompt for additional selections ("Format once" and "Format
all") when a diskette write error is encountered. This allows
formatting of just the current track or all subsequent tracks
before diskette writes.
- For a list of bug fixes, please refer to the history file
(DXP.HST).
2.0. SYSTEM REQUIREMENTS
_________________________________________________________________
IBM PC, PC-AT, PS/1, PS/2 and 100% compatibles. Minimum 256K
conventional memory. MS-DOS or PC-DOS version 3.20 or above;
OS/2 1.2 or above, including OS/2 Version 2.x, is required. Hard
disk is required for storing large image file. User must also
provide the necessary program(s) for sending diskette image files
through telephone network with the use of a modem, and whatever
is necessary with any other electronic networks.
3.0. COPYRIGHT NOTICE
_________________________________________________________________
DXP (Disk eXPress) Version 2.10a 02/12/93
XTRACT (Xtract) Version 2.10a 02/12/93
Copyright (c) 1991-93 by
Albert J. Shan
All Rights Reserved. No part of this program may be
disassembled, modified or altered by any means.
5
4.0. WARRANTY
_________________________________________________________________
I, Albert J. Shan, make no warranties, expressed or implied,
including, but not limited to, merchantability or fitness for any
particular purpose. In no event shall Albert J. Shan be liable
for indirect or consequential damages arising from the use of the
software program.
You are free to redistribute this shareware package in its
entirety. No part of this package may be included as part of a
commercial package. If you have any questions about commercial
distribution of Disk eXPress, I can be contacted at:
Albert J. Shan
866 Citadel Drive
Port Coquitlam, British Columbia
CANADA V3C 5Y1
or via CompuServe, ID 70730,401
5.0. COST OF Disk eXPress
_________________________________________________________________
Disk eXPress Version 1 was labeled as "beggarware" in which user
is not required to pay a fee. Due to all the effort and time I
put in for Version 2, it is now marketed as shareware. The user
is granted a 30 days trial period, after which he or she is
required to register the product. The cost of a single machine
license is $24 Canadian. Unlimited distribution right of Xtract
is granted upon licensing Disk eXPress. Please refer to the file
ORDER.FRM for details.
6.0. CONTENTS OF THIS PACKAGE
_________________________________________________________________
The following files are included in this package:
DXP.EXE - Disk eXPress executable
DXP.DOC - This documentation
DXP.HST - History file
ORDER.FRM - Order form
6
7.0. SYNTAX
_________________________________________________________________
7.1. Quick start
The syntax of Disk eXPress is very similar to the COPY command.
To create a diskette image, type:
dxp drive: filename
To create a diskette from an image file, type:
dxp filename drive:
For example, to create a diskette image from your drive B:,
simply type:
dxp b: my_image
The file "my_image.exe" will be created when Disk eXPress
finsihes.
To create the diskette from the self-extract file created above,
you type:
my_image b:
OR
dxp my_image.exe b:
Disk eXPress allows command switches to be specified anywhere on
the command line. Spaces between command line switches are not
required. By default, the file extension is ".EXE" regardless of
what user specifies. When creating a pure diskette image with
the /i switch, user is free to choose the file extension. For
consistency, the recommended file extension to use is ".DXP".
For example, under OS/2 with HPFS drive, a pure diskette image
can be created as follows:
dxp a: "This is diskette 3 of 5.DXP" /i
To create the diskette from the image:
dxp "This is diskette 3 of 5.DXP" a: /f /v
The /f switch tells Disk eXPress to format the diskette a track
at a time just before each track write.
The /v switch tells Disk eXPress to verify the diskette write
after the track is written.
7
Note: When using quotes for HPFS filenames, make sure the quotes
are in front and after if you are specifying a full path:
INCORRECT:
dxp c:\"Disk Image 1.dxp" a:
c:\images\"Disk Image 2" a:
CORRECT:
dxp "c:\Disk Image 1.dxp" a:
"c:\images\Disk Image 2" a:
To QuickFormat a diskette in drive A:, type:
dxp a: /q
The /s switch may be used to bypass the QuickFormat warning
prompt.
You may stop Disk eXPress at any time by pressing Ctrl-C or Ctrl-
Break. The BREAK ON/OFF setting under DOS is ignored.
If Disk eXPress encounters any cluster marked as bad in the File
Allocation Table, you may receive a warning:
X bad cluster(s) detected.
Bad clusters may not be reliably read by Disk eXPress!
However, if you do not encounter any 'Abort/Retry?'
message during read, the image should be fine.
Note:
Disk eXPress will not detect bad clusters in advance if you by-
pass File Allocation Table (FAT) scanning by specifying the /a
switch.
Disk eXPress or Xtract cannnot restore a diskette image onto a
diskette that contains physically bad sectors.
8
7.2. Disk eXPress help screens
Type DXP at the OS/2 or DOS prompt to receive this help screen:
Disk eXPress (OS/2 and DOS) Version 2.10a 02/12/93
Created by Albert J. Shan Copyright (c) 1991-93 SHAREWARE VERSION
Regular mode: DXP [options] [drive:] [d:][path]filename
[options] /? Display extract mode help screen
/a Read the entire disk (all sectors)
/d Input diskette image description (5 lines max.)
/DOS Output DOS only self-extract executable
/i Output just the diskette image
/n Disable data compression
/s Suppress overwrite prompt and self-check message
drive Drive letter of a valid diskette drive
filename Name of output file
Valid options with only filename specified:
/d Display description in image file
/e Edit description in image file
/r Replace or add extract code to image file
Note: Items enclosed in [] are optional.
Diskette must not contain any unreadable sectors.
Supported formats: 160K, 180K, 320K, 360K, 1.2M, 720K,
1.44M and 2.88M DOS diskettes.
9
Type DXP /?, and you'll get the help screen for the extract mode:
Disk eXPress (OS/2 and DOS) Version 2.10a 02/12/93
*** Type DXP by itself to see the regular mode help screen ***
Extract mode: DXP [options] [d:][path]filename [drive:]
[options] /t Test image integrity only
/d Display description in image file
/f Format destination diskette
/s Suppress overwrite prompt and self-check message
/v Verify ON (system verify plus read and compare)
/c Convert image onto a higher density diskette
(Target diskette must be pre-formatted, and
of different form factor. It also overrides /f)
filename Name of input file
drive Drive letter of a valid floppy drive
Valid option with only drive specified:
/q QuickFormat destination diskette
Note: Items enclosed in [] are optional.
The target diskette must be free of defects (no bad sectors).
Supported formats: 160K, 180K, 320K, 360K, 1.2M, 720K,
1.44M and 2.88M DOS diskettes.
10
8.0. COMMAND LINE SWITCHES DESCRIPTION
_________________________________________________________________
When Disk eXPress is used under regular mode for making diskette
images, the following switches are available:
8.1. Regular mode
/a By default, Disk eXPress reads up to the last allocated
sector, according to the information it finds in the File
Allocation Table (FAT) in order to reduce the size of the
image file. However, if there is any deleted files at the
end of FAT that you may want to recover later, the default
action will prevent you from a successful file recovery.
Use /a to tell Disk eXPress to create an exact duplicate of
the original diskette by saving ALL disk sectors to the
image file.
/d Prompt user to input description for the diskette image. A
maximum of 5 lines of 40 characters each can be stored.
Disk eXPress bypasses user input, and reads the description
from the environment variables DXPDESC1 to DXPDESC5, if
there is at least one defined.
/DOS By default, Disk eXPress creates self-extract images that
can be run under OS/2 and DOS. By specifying this switch, a
DOS only self-extract image is created. The DOS code has
been written so that it will run under OS/2 DOS box with
almost no speed penality. This cuts self-extract code
overhead by about 13K.
/i Create a pure diskette image file. The self-extract code
will not be bundled with the resulting file. Disk eXPress
does not enforce any file extension for pure diskette image.
For consistency, it is recommended to use ".DXP" as file
extension. Without specifying this switch, the default file
extension will be ".EXE".
/n Disable compression. If the contents of the diskette is
highly compressed, Disk eXPress may not succeed in
compressing the data any further. This can be visually
inspected when Disk eXPress is run the first time without
the /n switch. If the real-time compression rate is very
low (close to 0%), disabling compression is recommended.
/s Disable any overwrite (y/N) prompt and Disk eXPress self-
check messages.
Three switches are available when no drive letter is specified in
regular mode:
11
/d Display the description of the image file. The full path to
the diskette image must be specified.
/e Edit the description stored in an image file. This is used
to correct the description later instead of having to redo
the entire image from scratch.
/r Replace or add extract code to image file. Full path and
complete filename must be specified. If /r is used against
a self-extract diskette image, the self-extract code will be
replaced with the one stored with Disk eXPress. No backup
file is created if the operation is successful. If used
against a pure image file, the self-extract code will be
added, and a new file with ".EXE" extension will be created.
The ".EXE" file created by this switch is stored in the same
location of the original image file. The /DOS and /s switch
can be used together with this switch.
Note: The file extension replacement algorithm simply
removes any file extension starting after the last '.' and
then appending "EXE". Since it is possible to use multiple
'.' under HPFS, the text after the last '.' is discarded.
It is advisable to avoid using multiple '.' with HPFS
filename, and use a space instead.
8.2. Extract mode
Disk eXPress can decode and extract 3 types of images: type 0
(non-compressed), type 1 (Version 1 compression), and type 2
(Version 2 compression). When Disk eXPress is used for
extracting an image file, the image file can be a pure image
file, or a self-extracting executable. The full path to the
image file must be specified. Wild cards are not allowed. All
the switches available in the extract mode of Disk eXPress are
identical to the standalone Xtract program.
/t Test the integrity of the image only. Disk eXPress performs
data decompression (if necessary) and runs through a 32-bit
CRC computation on the data stored in the image. It reports
the stored and computed CRC values. If these values do not
match, the image will be bad. It overrides the
specification of a drive letter, /f, /s, /v, and the /c
switch.
/d Display the description of the image file. The full path to
the diskette image must be specified.
/f Format the destination diskette. Only standard DOS formats
are supported.
/s Disable any overwrite (y/N) prompt and Disk eXPress self-
check messages.
12
/v Verify on. It performs a track verify via operating system
call, follows by a track read, and a byte-by-byte comparison
with the original data. The byte-by-byte comparison is
added as an extra protection should the CRC test of track
verify failed to pick up an error. If disk cache is used
under DOS, the byte comparison test may not be valid due to
the fact that the cache is supplying the data with no actual
read performed on the diskette. Disk eXPress bypasses disk
cache when it is run under OS/2.
/c Convert the image onto a higher density diskette. The
target diskette must be of different form factor (3.5" to
5.25" and vice versa, but not 3.5" 720K to 3.5" 1.44M due to
hardware limitations). It requires a formatted diskette,
and will automatically overrides the /f switch.
Here is a list of all the diskette conversion possibilities:
160K/180K/320K/360K to 720K/1.44M/2.88M
720K to 1.2M
1.2M to 1.44M/2.88M
/q QuickFormat of diskette in drive. This is useful for
quickly erasing all files on an already formatted diskette.
The File Allocation Table (FAT) and all directory entries
are erased to zero. Bad sectors and volume serial are
preserved after QuickFormatting.
8.3. Batch mode support
You can use Disk eXPress, Xtract, and self-extract images in a
batch file (.CMD file under OS/2 and .BAT file under DOS). The
return code returned by these programs are currently limited to
either a 0 or 1. A return code of 0 indicates operation is
successful. All display output is sent to standard out (stdout),
and can be redirected to a file. Errors and warning messages are
sent to standard error (stderr). You can discard all Disk
eXPress output by redirecting both stdout and stderr to NUL (ie:
DXP A: MyDisk >& NUL).
In addition to entering diskette image description via the /d
switch, you can also enter the description from within a batch
file as shown below:
SET DXPDESC1=Disk eXPress
SET DXPDESC2=Version 2.10a
SET DXPDESC4=Copyright (c) 1991-93
dxp a: MyDisk /d
SET DXPDESC1=
SET DXPDESC2=
SET DXPDESC4=
13
Line 3 and 5 are treated as blanks since DXPDESC3 and DXPDESC5
are not specified. Batch mode description editing (/e) is also
supported.
8.4. Disk eXPress real-time bar graph display
One of the new features of Disk eXPress Version 2 is the use of a
real-time bar graph display. Disk eXPress and Xtract will
exercise the multi-threading capability under OS/2, and you'll
see a display similar to the following:
3% 25% 50% 75% 100%
Action Rate Track Head ├────────┼─────────┼─────────┼─────────┤
COMPRESS 52% 37 1 █████████████████▓▓▓▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒▒
The above bar graph depicts 3 concurrent threads:
▒ Read thread. Performs continuous reading of diskette (or
disk file if it is in extract mode), and releases the
diskette drive (or disk file) for use by another process
when reading is finished.
▓ Compression/decompression thread. Compression/decompression
is performed as soon as data is available from the read
thread.
█ Write thread. Compressed data is written to a disk file (or
decompressed data written to diskette in extract mode).
This can be another diskette drive or any block device.
The description under "Action" shows which thread has just
started executing.
The number under "Rate" shows the current compression rate. It
is the percentage reduction with respect to the size of the
original data.
The numbers under "Track" and "Head" show the current disk track
and head where operation is being performed.
Since DOS has only one thread of execution, only one bar is
updated at any time. Read/Compress/Decompress/Write occurs
sequentially.
14
9.0. EXAMPLES
_________________________________________________________________
9.1. Example 1
To pack a 360K diskette in drive B: onto a file called 'disk1'
for modem transmission, you type:
dxp b: e:\upload\disk1
By default, Disk eXPress will automatically append ".EXE" onto
the output file name. If you specify something else as file
extension, it will be removed before appending. If the command
line syntax is correct, Disk eXPress will first run a self-check
for virus/modification, then it will proceed to create the
diskette image. You'll receive a screen similar to the following
after Disk eXPress is finished:
Checking Disk eXPress for modifications ... OK.
360K diskette found in drive B:
File Allocation Table statistics:
Track 33 head 1 contains the last allocated sector, sector 609.
3% 25% 50% 75% 100%
Action Rate Track Head ├────────┼─────────┼─────────┼─────────┤
STORE 28% 33 1 ████████████████████████████████████████
32-bit CRC of diskette image is DB49A615
By default, Disk eXPress will analyze the FAT and save up to the
last sector used on the diskette. In the above example, it stops
at track 33, head 1, because sector 609 is the last allocated
sector. If you have a fragmented diskette, you might receive a
screen similar to the following when you run Disk eXPress:
Checking Disk eXPress for modifications ... OK.
1.44M diskette found in drive A:
File Allocation Table statistics:
Track 36 head 1 contains the last allocated sector, sector 1319.
Disk fragmentation detected:
814 unallocated sectors will be saved in image
(61% of total used sectors).
The diskette requires compression for maximum storage efficiency.
3% 25% 50% 75% 100%
Action Rate Track Head ├────────┼─────────┼─────────┼─────────┤
COMPRESS 48% 16 0 ██████▓▓▒▒▒▒▒▒▒
15
etc.
Running a disk optimization utility on the diskette will help
packing files tightly together for maximum storage efficiency.
Alternatively, you can copy all the files to another freshly
formatted diskette so that the files are packed next to each
other.
9.2. Example 2
To save the entire diskette from drive A: (including all the
unused sectors) onto the image with compression turned off, you
type:
dxp /a /n a: e:\upload\disk1
You will see this warning if the file exists:
Checking Disk eXPress for modifications ... OK.
E:\UPLOAD\DISK1.EXE exists, overwrite? (y/N):
Default action is 'No' for pressing the 'Enter' key. Type 'y'
then 'Enter' to overwrite.
To suppress the warning, specify /s on the command line:
dxp /a /n a: e:\upload\disk1 /s
Notice that you can specify switches anywhere you want on the
command line, Disk eXPress will sort them out for you.
9.3. Example 3
To enter a description when creating an image, you type:
dxp b: test15 /s /d
You'll see:
Checking Disk eXPress for modifications ... OK.
Please enter diskette description: (5 lines max.)
┌────────────────────────────────────────┐
1:
You're then prompted to enter a maximum of five lines of
description (40 characters for each line). To enter a blank
line, just press Enter.
To continue our example, type in the following:
16
Please enter diskette description: (5 lines max.)
┌────────────────────────────────────────┐
1: Joe,
2: This is the latest beta release of Space
3: Commander. Try it out without a joy
4: stick and let me know how it goes.
5: Regards, John
360K diskette found in drive B:
File Allocation Table statistics:
Track 33 head 1 contains the last allocated sector, sector 609.
3% 25% 50% 75% 100%
Action Rate Track Head ├────────┼─────────┼─────────┼─────────┤
STORE 28% 16 1 ███████████████████▓▓▒▒▒▒▒▒▒
etc.
9.4. Example 4
To change the description of the diskette image created in the
last example, type:
dxp e:\upload\test15.exe /e
The /e switch allows description in the image file to be edited.
Note: The /r switch (self-extract code replacement) can also be
specified together with the /e switch.
9.5. Example 5
Now that you have the self-extract image, what are you going to
do with it? Simply run it! To unpack the disk image created in
example 3, type 'test15' to see the help screen:
Disk eXPress Self-Extract Diskette Image (OS/2 and DOS)
Version 2.10a 02/12/93 Copyright (c) 1991-93
Usage: TEST15 [/s] [/t] [drive:]
/s Suppress overwrite prompt
/t Test image integrity only
drive Drive letter of a valid floppy disk drive
Note: The target diskette must be formatted and must not
have any bad sectors.
To finish our example, now type:
17
test15 b:
You'll see:
┌────── Diskette Image Description ──────┐
Joe,
This is the latest beta release of Space
Commander. Try it out without a joy
stick and let me know how it goes.
Regards, John
└────────────────────────────────────────┘
360K diskette image stored in file.
Diskette in drive B: is about to be overwritten
with new information. Do you wish to continue? (y/N)
Default action is 'No' for pressing the 'Enter' key. Press 'y'
then 'Enter' to start diskette image extraction. The /s switch
can be specified to bypass the prompt.
9.6. Example 6
To test the integrity of the diskette image without writing out
to the diskette, simply type:
test15 /t
And you'll see:
┌────── Diskette Image Description ──────┐
Joe,
This is the latest beta release of Space
Commander. Try it out without a joy
stick and let me know how it goes.
Regards, John
└────────────────────────────────────────┘
360K diskette image stored in file.
100% Read
32-bit CRC stored: DB49A615
32-bit CRC computed: DB49A615
Note: /t overrides drive letter specified on the command line.
9.7. Example 7
Now that Joe got the diskette image. He doesn't have a 360K or
1.2M drive (5.25" drive). All he has is a 1.44M 3.5" drive. He
also happens to have a spare 720K (low-density) diskette he can
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use. What can he do? He can use the /c switch in the extract
mode of Disk eXPress or Xtract. The /c switch can be used to
convert the diskette image from 360K to 720K, and all the data
will still be intact, and usable. The diskette used for
conversion must be pre-formatted. So, Joe went ahead and
formatted the diskette as a 720K diskette, and he types:
dxp test15.exe a: /c
And receives the following screen (answer y at the prompt):
Checking Disk eXPress for modifications ... OK.
Checking test15.EXE for modifications ... OK.
360K diskette image (Disk eXPress type 2)
Diskette in drive A: is about to be overwritten
with new information. Do you wish to continue? (y/N) y
720K diskette found in drive A:
Converting 360K image onto 720K diskette ...
3% 25% 50% 75% 100%
Action Track Head ├────────┼─────────┼─────────┼─────────┤
DECOMPRESS 20 0 █████████▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
etc.
9.8. Example 8
To QuickFormat a diskette, type:
dxp a: /q
OR
xtract a: /q
And you'll see:
Drive A: is about to be QuickFormatted.
Do you wish to continue? (y/N)
The default action is 'No' for pressing the Enter key. The /s
switch can be used to bypass the warning prompt.
Type 'y' and press Enter and you'll see:
QuickFormatting 1.44M diskette ... Done.
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10.0. ERROR MESSAGES
_________________________________________________________________
Disk eXPress incorporates 32-bit CRC checking for itself and the
image it creates. In the event of a virus infection or other
means of modifications (such as errors in electronic
transmissions), the program will abort, and the following message
is displayed:
*** File has been modified or not a valid image file.
Here is a run down of major error messages produced by Disk
eXPress, Xtract and self-extract images: (usually a beep followed
by one of the following messages)
- For bad or not properly formatted diskette during read, write,
format or verify (no beep for any Abort, Retry messages):
Read Error: Abort, Retry? (a/R):
Write Error: Abort, Retry? (a/R):
Write Error: Abort, Retry, Format once, Format all? (a/R/o/f):
Format Error: Abort, Retry? (a/R):
Verify Error: Abort, Retry? (a/R):
*** Bad CRC.
*** Sector not found.
*** General failure reading drive X:
*** Unknown media/inconsistent boot record.
- When disk is full during image creation (output will be
deleted):
*** Error writing disk or disk full.
- With a write protected diskette during diskette write:
*** Diskette is write protected.
- When replacing self-extract code in images with a lower
revision level of Disk eXPress:
*** Image was created by Disk eXPress x.xx
which is of higher revision level.
- When diskette drive is not ready:
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*** Drive X: not ready.
- When drive specified is not available or not a diskette drive:
*** Invalid drive/path specified.
*** Drive X: is not a floppy drive.
- When attempting to replace a version 1 self-extract header with
version 2 by the /r switch:
*** filename is not a type 2 image.
- When Disk eXPress or Xtract is asked to extract an unrecognized
image file:
*** Diskette image header corrupted!
- When Disk eXPress or Xtract is asked to convert a diskette
image to the same form factor diskette:
*** Conversion not supported on target diskette.
- Some error messages returned by Disk eXPress are displayed as:
*** Error n, Drive X:
In such event, please document the procedure on how to get to the
above error, and contact me as soon as possible.
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11.0. LIMITATIONS
_________________________________________________________________
Diskette images created by Disk eXPress version 2 are not
compatible with version 1 images. Replacement of version 1 self-
extracting code with the /r switch is not allowed.
When Disk eXPress is used to create a self-extract diskette
image, the extract code is bundled as an overhead for each image
created. The overhead is currently at 24K (10.4K for DOS only
image). This is acceptable, considering the size of any non-
trivial diskette image is usually quite large (in the order of
several hundred kilo bytes or even mega bytes). 24K should
require no more than two minutes for a 2400 baud modem to
transfer, and with a 14.4K V.32bis modem, the overhead is less
than 16 seconds.
Other limitations include the inability to read a diskette drive
over the LAN (limitation of the network driver), and Disk eXPress
over any copy protected programs. Another limitation is its
inability to read over physically bad sectors.
Any suggestions and comments are welcome. Suggestions for new
features may eventually be incorporated into a future release.
Currently on the drawing board includes a 32-bit version for OS/2
2.0, and the possibility of making it into a multi-threaded PM
application with the use of System Object Model (SOM).
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