    xDMS  version 1.21    Released in 16-Jan-2001


Firstly see xdms120.txt for details.

I made a little modifications in viewing for use as a MultiArc plug-in for
Total Commander. You can use it as good for ordinary command-line use but I tested
only commands suitable for MultiArc plug-in. Included .exe is Win32 PE.

Vladimir Pilny (Vladimir.Pilny@email.cz)
Location of xDMS - my homepage, or http://atrey.karlin.mff.cuni.cz/~vlada/multiarc/



Version 1.21 :  16-Jan-2001
    Modifications for use as a Total Commander (http://www.ghisler.com)
MultiArc plug-in (Siarzhuk Zharski - http://www.crosswinds.net/~zharik/) by
Vladimir Pilny





    xDMS  version 1.2    Released in 1-Mar-98


Introduction:
-------------

    Some time ago I started using UAE and Fellow Amiga emulators in the PC,
while  still  using  my Amiga.  Both emulators are very nice, and I started
testing  some  of my old games and demos on it.  But a thing annoyed me.  I
have  a  number of CDs with demos and other software, with hundreds of disk
images  compressed  with DMS.  DMS was always the Amiga 'de facto' standard
for  storing copies of non-dos disks, as used by most games and demos.  But
the  emulators required the Amiga software to be in uncompressed disk image
format  (now  known as .ADF) or disk images compressed with gzip (ADZ).  To
use  my  DMS  archives  in  the emulators I had to uncompress them with DMS
inside  the  emulation,  saving  it as an uncompressed disk image in the PC
hard  disk.   It  was  very  boring, and also a waste of time and hard disk
space,  since  I  could  not  leave the files in the CDs.  I thought a much
better  solution  would  be  to  add  direct  support  for DMS files in the
emulators itselves, in the same way as they support gzip compressed images.
But  as  DMS  uses  a proprietary format, I thought DMS support in the near
future would be unlikely.  So I decided to do something myself and began to
study  the  inner workings of DMS.  After some days of hard work, I wrote a
portable  DMS  unpacker,  xDMS.   xDMS  is  more  useful for users of Amiga
emulators, but can also be useful for actual Amiga users too.  In fact, the
extract command of xDMS can be very useful to actual Amiga users, just need
an update of readdisk.



xDMS Features:
--------------

  Supports   decompression   of   files  compressed  using  all  known  DMS
compression  modes,  including  old  and  obsolete ones, and also encrypted
files, for 100% compatibility.
  Can  test  DMS  files integrity, view file informations and show attached
Banners and FILEID.DIZ .
  Can generate standard disk images and compressed disk images, using gzip,
if you want to store your files in ADF or ADZ formats.
  Can  extract  the  files  contained  inside  the  DMS  archives,  if  the
compressed disk is an AmigaDOS disk, using readdisk made by Bernd Schmidt.
  Can  process  multiple files in batch with a single command, and also use
stdin and stdout for input and output of data.



Instalation:
------------

  xDMS  was  written  in  ANSI  C  and  should work with most ANSI C or C++
compilers  and  platforms  with  minor  or no changes.  It was tested under
Linux  with  GCC,  MS-DOS  with DJGPP and Amiga with SAS/C and worked well,
0without  warnings.   To compile it with GCC or DJGPP you can just use make
with  the supplied Makefile.  For other compilers you may have to modify it
slightly.   A  smakefile  for  SAS/C  is also supplied.  After a successful
compilation  you  can  install  the  generated executable somewhere in your
path.  You also need to install gzip and readdisk if you want to be able to
create  gzip  compressed  disk  images and extract files from DMS.  gzip is
available  in  most public domain software libraries.  Readdisk is supplied
with  UAE.   You  probably  already  have  both.  Also, as I'm sendind this
program  to  UAE  and  Fellow authors and allowing them (or anyone else) to
include  it with their programs and change it in any way, perhaps xDMS just
came  together  with  your emulator, and was installed with it and directly
supported.  In this case you have nothing to worry.



Usage:
------

  xDMS  is  a  shell  utility program.  When executed without arguments, it
shows an usage screen.  The template of xDMS is the following:

    xdms [options] <command> {<dms_file[.dms]> [+output]}

Arguments inside [] are optional. Arguments inside <> are required.
Arguments inside {} can be used one or several times.

A command is indicated by a letter and can be one of the following:

     t : Test DMS archives
     u : Unpack DMS archives to disk images
     z : Unpack to disk images and compress it with gzip
     x : Extract files inside DMS archives using readdisk
     v : View DMS archives information
     f : View full information
     d : Show attached FILEID.DIZ
     b : Show attached Banner


  If  the  supplied  input  DMS  file  name  doesn't  have  a  .DMS or .dms
extension, a default .dms will be appended to it.
  The  output argument is optional and specifies a file name or a directory
for  each  unpacked  file.   If  the output filename is not supplied, it is
generated  from  the  input  filename.  If the generated file is a standard
disk  image  it  will have the .adf extension.  If it is a compressed image
the  extension  will  be  .adz  .   If  you  supply an output file name, no
extension  will  be  added.   By default, files are unpacked to the current
directory,  unless  you specify another directory with the output file name
or use the -d option.
  Commands  z  and  x  respectively  need gzip and readdisk instaled in the
current path, or it will fail.
  When  extracting files with x option, xDMS will call readdisk and it will
reconstruct  the  tree  of  files  and directories contained inside the DMS
compressed  disk  image,  starting in a directory with the same name as the
volume  name  of  the  disk in the DMS file.  This command can fail if xDMS
can't  execute  readdisk,  or if the dms compressed disk is not an AmigaDOS
disk.  The current version of readdisk supplied with UAE 0.69 only supports
old  OFS Kickstart 1.x compatible disks, reporting any of the newer formats
introduced  with AmigaOS 2.0 or newer as non-dos disks, while they actually
are.
  The  v  commands  show  some  information  contained in DMS files, as the
version  of  DMS  that  created it, the type of the disk, date of creation,
number  of  tracks,  etc.   The  f  command  also  shows  additional tracks
informations.
  The  b command shows the banner, if the file contains one.  A banner is a
text  that  is  displayed  when  DMS  unpacks  a  file and usually contains
informations about the group/BBS/person that made it.
  The  f  command  shows the FILEID.DIZ, if found in the DMS.  It is a text
that identifies what the DMS file contains.
  You can also supply as input filename stdin and/or +stdout as output.  in
this case xDMS will read the data from the standard input and/or send it to
the standard output.
  You  can  supply  multiple  input  and optional output files and use wild
cards.   When  using  wildcards,  the +output argument will affect only the
last  file name expanded from the wildcard.  To supply a global destination
directory  you  must  use  the -d option.  All commands and options are not
case sensitive.

You can also supply one or more (or none) of the following options:

    -q : Quiet
    -v : Verbose
    -d <destdir>  : Set destination directory
    -p <password> : Decrypt encrypted archives using password


  When  more than one option is supplied they must be separated.  You can't
use something like -qd dir .
  The  quiet  option  suppresses  all  messages  usually  emited  by  xDMS,
including error messages.  It is mostly to be used when xDMS is called from
inside  emulators  or  some type of front-end.  The program that calls xDMS
can  verify  if  the  operation  was successful checking the return code of
xDMS.   It  will be 0 if the operation was successful or not 0 if it failed
for one or more files.
  The verbose option makes xDMS display more messages than it usually does,
including  a  progress  indicator  when unpacking files.  This indicator is
only useful if you have a very slow computer.
  The  -d  option specifies a global destination directory.  This directory
name  is  added  before  the  name  of  any output file or output directory
supplied with +output in the command line.
  The  -p  option  uses  a  password  to  decrypt the dms files if they are
encrypted.   DMS uses a very lame encryption algorithm that could be easyly
cracked.  In fact, if the file is encrypted, and contains a banner, you can
unpack it with any password.


Some examples:

    xdms u foo.dms

This  will  unpack the file foo.dms in the current directory and save it as
foo.adf, also in the current directory.


    xdms -v -d /tmp/tst u foo +bar.dsk

This  will  unpack the file foo.dms in the current directory and save it as
/tmp/tst/bar.dsk  .   Aditional  messages  and a progress indicator will be
displayed.

    xdms f ram:Hardwired1.dms   (in the Amiga or inside Amiga emu)

This  will  show  informations about the file Hardwired1.dms in Amiga's Ram
Disk, including tracks information.

    xdms -p treva u tst1 tst2 +tstdir/ttt tst3.DMS +stdout >tora

This  will (try to) unpack the files tst1.dms, tst2.dms and tst3.DMS in the
current directory.  If any of them is encrypted xDMS will try to decrypt it
using  the  password  "treva".   tst1.dms  will  be  unpacked  as tst1.adf,
tst2.dms  as  tstdir/ttt  and  tst3.DMS  will be unpacked to stdout that is
redirected to file tora.

    xdms -d /home/apele/uae/demos z /mnt/cdrom/*.dms       (under Unix)

    xdms -d c:\emul\fellow\demos z f:\*.dms              (under MS-DOS)

This  will unpack all files with the dms extension in the root directory of
a  CDROM  disk,  pack it again using gzip and save it in another directory.
The generated files will have the .adz extension.


    xdms -q x tst

This  will  (try  to)  extract the files contained inside the tst.dms file.
The  files  and  directories  will  be extracted to a directory with a name
equal  to  the  volume  name  of  the  disk  contained in the dms file.  No
messages will be displayed.


    xdms -d stdout u *.dms >bigfile

This  will  unpack all the dms files in the current directory and save them
all to a single file.


    xdms -d /home u apele +apele/yourfile.adf trevor +trevor/yourfile.adf

This will unpack the file apele.dms in the current directory and save it as
/home/apele/yourfile.adf  .   Will  also  unpack  the  file  trevor.dms  as
/home/trevor/yourfile.adf .


    cat tst.dms | xdms u stdin +stdout | strings | more

This  will display the ascii strings inside the unpacked dms file.  In this
case, xDMS is used as a filter.




Known problems:
---------------
  If  you  try  to extract the files (using the x command) of a DMS archive
that  contains  a  disk  in one of the disk formats introduced with AmigaOS
version  2  or  newer, it will fail.  Also, if you try to extract the files
under  MS-DOS  it will almost always fail.  It's not a problem in xDMS.  It
is  a  problem  in  the  current  version of readdisk.  It only suports OFS
disks.   Another  problem  of readdisk is that it fails when executed under
MS-DOS  and  the  DMS  archive  contains files with names invalid to MS-DOS
rules.   If  your  Amiga disk compressed in the DMS archive contains a file
named as Amazing_Amiga.txt.info, it will fail.  It works under Unix.  Under
MS-DOS  readdisk  also  changes  the  current  working  directory after its
execution,  if  you specify an output directory to it.  This can cause some
problems  too.   I was thinking about adding internal support to extraction
of  files to xDMS, with support to all Amiga native filesystems, or write a
replacement to readdisk, but now I think I will just wait for Bernd Schmidt
or someone else to update readdisk.
  xDMS  doesn't  perform  internal  expansion of wildcards, but expects the
shell  (or the compiler) to do it.  It is the usual under unix.  But if you
use  it in a system where the shell does not perform wildcard expansion and
your  compiler  also  does  not generate code to perform it, then wildcards
will not work.  This is the case, for example when using xDMS in the Amiga,
under  the  standard  Amiga Shell, when compiled with SAS/C.  I think Amiga
GCC  adds  wildcard expansion to the program it compiles.  The same applies
to  xDMS compiled with compilers like TurboC under MS-DOS.  DJGPP for MSDOS
generate code to expand wildcards.



Acknowledgements:
-----------------

xDMS  uses  source code fragments or informations from the following public
domain or freeware programs:

Unix  LHA  by Masaru Oki :  xDMS Heavy mode decrunch functions are based in
lha  static  lzh  functions.   DMS used parts of LHA and LZHUF in the first
place.

LZHUF  by Haruyasu Yoshizaki :  xDMS Deep mode decrunch functions are based
in LZHUF.

testdms  by  Bjorn Stenberg :  I got some initial information about the DMS
headers with testdms, and also the CRC calculation function.


xDMS  also  calls,  if  available,  gzip  made  by  Jean-loup Gailly / Free
Software    Foundation,    and    readdisk    made    by    Bernd   Schmidt
<crux@pool.informatik.rwth-aachen.de>



Last comments:
--------------
  I hope you find xDMS useful, be you using it with an actual Amiga or with
an  emulator  to  remember the golden days of the Amiga.  I wrote it mostly
because  I  thought  it  would take ages for DMS support to be added in the
Amiga emulators as its authors were busy with other issues.  I also thought
nobody else would do it.  Later, when xDMS was almost ready, I discovered I
was  completely wrong.  David Tritscher was doing the same thing I was, and
released  a  portable DMS decruncher in Aminet called undms (also spread by
some users as dms2adf).  I tried his program and it appears to work nicely.
But xDMS has far more features ;)
  Also,  xDMS should not be cofused with xdm, the XWindows Display Manager,
or with some of type of database management software package.



Copyright:
----------

  xDMS is released as public domain software.  You can spread it, modify it
and use it in any way you like.  You can do anything with it without asking
me first.  But I would like to know if you do something cool with it.



How to contact the author:
--------------------------

  If  you  have some problem, you can contact me by e-mail.  But first make
sure  you have read all this documentation, to not waste my time with silly
questions.   If you have found a bug in xDMS please contact me.  If the bug
is in readdisk, contact Bernd Schmidt.




                                    Andre' R. de la Rocha

                                    e-mail address : adlroc@usa.net




History:
--------

Version 1.0 :  17-Feb-98
    First release

Version 1.1 :  18-Feb-98
    Reading/writing  to  stdin/stdout  under  MS-DOS didn't work correctly.
    Fixed.

Version 1.2 :  1-Mar-98
    Corrected  a  small  and  harmless  bug.  When using the z command, the
temporary  file  name was saved in the gzip compressed file.  So if someone
tried to unpack it with gzip with the -N option, gzip would generate a file
with a very strange name.  Fixed.

---------------------------------------------------------------------------

