
                   ACB Ver.1.26a (Shareware Version)

          ARCHIVER FOR COMMUNICATION PURPOSES -"TAUGHT CHANNEL"

  ACB Ver.1.26a - is designed for preliminary information compression for
                  communication purposes.

The use of the ACB algorithm gives the best compression coefficient.
The associative coding algorithm puts higher demands towards equipment.
Sizes of archives are decreased by 10-60% compared to ARJ,PKZIP,RAR,UC2. This
justifies to the most extent increased expenses on data compression in
telecommunication tasks.

---------------------- TECHNICAL REQUIREMENTS: ------------------------------

For the work of ACB the following hardware is necessary:
- recommended  - Pentium-133 RAM 16 Mb (512 Kb cache);
- minimum      - i486SX-33   RAM 16 Mb;
- Operational systems are: MS-DOS 6.0+, DOS session in WINDOWS_95 & OS/2 Warp.

- For running ACB under WINDOWS_95 & OS/2_Warp it is necessary to set:
  - minimum size of swapping 8 Mb;    maximum not less than 16 Mb;
  - size DPMI must be 16 Mb (sometimes it is sufficient to have 15 Mb)

Note:
- Usage of archives in the background mode under WINDOWS is effective.
  It can be recommended for computers with 20 Mb RAM and more.
- For the ACB-algorithm it is necessary to have 15450000 bytes of FREE RAM
  (Cnv+Ext),  or if free memory is less, the program can be executed under
  WINDOWS_95, as the program uses its swapping, that results in dramatic
  slower packing/unpacking in big sizes of data (with 3Mb free RAM, slowing
  down takes place with 100 Kb (or more) of nonpacked data).
-----------------------------------------------------------------------------

---------------------------- OVER-ALL INFO: ---------------------------------
Usage:
 ACB <command> <[path\]archive_name>["context_name] [<[path\]mask>] [...]

Commands:
   b       - Backup files to archive with recurse subdirectories
Note: command "b" has 3 modifications : "B" FAST, "b" NORMAL, "u" MAX.
   bf      - Backup only files to archive without recurse subdirectories
bN | bfN   - Where N is size (Kb) of Volumes (enable multiple Volumes)
   r[PSW]  - Restore files from archive 
   l[PSW]  - List archive contents
   p[PSW]  - Error Protection
   c[PSW]  - Error Correction
   d[PSW]  - Deprotection of archive

Note: PSW - password (len<17) can be absent
      After r-operation  *.acp->*.acb  or  *.??p->*.??b (for multiple Volumes)

                       EXAMPLES:

ACB b win c:\win        -packing of the catalogue WIN with subdirectories
ACB B360 d:\awin c:\win\*.*  -FAST packing in multivolume archive (360 Kb.)
ACB r d:\awin e:\win3   -in catalogue WIN3 copy c:\win\*.* with subdirectories
ACB uf53pKUK wrc c:\win\*.rc -MAX. packing of only files *.rc from catalogue
                              WIN in multivolume archive (53Kb) with setting
                              of protection mode with password=KUK
ACB lKUK  wrc  -contents of wrc.??p
ACB rKUK  wrc  -restore all data from wrc.??p in the current catalogue
ACB pALmA wrc  -setting of protection mode with password=ALmA wrc.??b->wrc.??p
ACB cALmA wrc  -testing and correcting of archive wrc.??p
ACB dALmA wrc  -deprotected wrc.??p->wrc.??b

Commands: l,p,c,d can be used in the "Taught Channel"-mode (see below)

                 ----  "TAUGHT CHANNEL" - MODE: ----

"Taught Channel" - compression of another portion of information taking into
account all earlier compressed information -context. For example: you transmit
by modem a corrected version of the text transmitted yesterday. In this case
it's possible to expect 100-time compression, in other words, only the latest
information was transmitted. Besides, there's a possibility to maximize
compression of the data of a certain type. For example, create a context from
the files *.txt and use this txt-context to compress txt-files. In addition,
such an approach ensures additional data protection against non-authorised
access -it's impossible in principle without knowledge of the whole background
data being decoded. In unpacking the context should be the same as in packing.
The context file is renewed each time it is used. For example: you packed the
text of an agreement using the context, the context file was renewed and can't
be used to unpack the received archive but the receiving party (in our example
"office") has a yesterday's context identical to yours up to the latest
packing, that is why the transmitted archive in the office will be unpacked
and the context file will be renewed and identical to yours. If you want to
ban renewal of the context file set it in Read_Only.

Note: the size of a context file grows proportionally to the length of the
      channel background. When the length of the channel background reaches
      1671 Kb, the size of the context file stabilizes and can vary within
      the range: 1.5 .... 1.9 Mb.

                        EXAMPLE:

ACB b john"office.jon john.txt - John transmitted to the office a renewed text,
ACB r john"john.ofs            - the office unpacked the transmitted text.

In the given example the name of the context file is convenient to be
interpreted as address, for John it has the name "office.jon" and in the
office the name "john.ofs".

OR:  ACB Bf3pFANTOMAS john"office.jon john.txt
     ACB rFANTOMAS john"john.ofs c:\john\let

The same but in the multivolume_FAST_mode and with the use of the EP_mode.

       --- UPGRATE OF SOFTWARE BY "TAUGHT CHANNEL" - MODE: ---

"TAUGHT CHANNEL" - MODE can be used in replacing old versions of software by
new versions. General idea: User has an old version of your software. The
difference of a new version from an old version is not more than 10% of code
and 10% of documentation. If you organize your distribution by modules with the
size not more than 1.2 Mb of initial data, "TAUGHT CHANNEL"-MODE can be used
to update the software of your users. The size of the ACB-archives containing
a new version of your software will be 4-8 times less compared to compression
without the use of the "TAUGHT CHANNEL" - MODE.

                        EXAMPLE:

You have the version ACB_1.23c. In order to give you
the new version ACB_1.26a I create the ACB-archive with the use
of the "TAUGHT CHANNEL" - MODE:

---- Create.bat ----
rem ACB.EXE - ACB_v1.23c
ACB u tmp"acb.ctx acb.exe
del tmp.acb
rem acb126a.exe - ACB_v1.26a
ACB u acb126a"acb.ctx acb126a.exe
del acb.ctx
--------------------

As a result we receive the following:

----------------------------
acb126a.acb <12292 bytes> against <35675 bytes>
----------------------------

Now you can unpack and will have the new version ACB_1.26a:

---- Restore.bat ----
rem ACB.EXE - ACB_v1.23c
ACB u tmp"acb.ctx acb.exe
del tmp.acb
ACB r acb126a"acb.ctx
del acb.ctx

------------------------- AGREEMENTS: ---------------------------------------

ACB - does not have a possibility to add/take out one or several files
      in/out of the archive - only all the data.
- files with attributes: hidden, system, read_only are placed to archive too
- sizes of the compressed data are not limited, but the maximum separate file
  size is 64 Mb.
- maximum number of files in the archive is 4096.
- maximum size of the title is 256 Kb (PATH(s)\NAME(s).EXT(s)\ATTRIBUTE(s)).
- Commands: l,p,c,d can be used in the "Taught Channel"-mode
- In using FAST-mode (command "B") the speed of compression/decompression
  increases twice but the sizes of the archives increase by 2-4%.
- In using MAX.-mode (command "u") the speed of compression/decompression
  decreases by 1.5 times and the sizes of the archives decrease by 0.5...1.2%.
- In using EP-mode (command "p") the sizes of the archives increase by 3.2 %.
- formats of previous versions are not supported (see below)
  Creating a multivolume archive the following agreements are observed:
- 1Kb == 1024 bytes
- name of the first volume *.00b...second *.01b...eleventh *.0ab...last *.acb
- unpacking begins with *.00b
- if there is not enough disk space multivolume archive is created
  automatically!
- for EP-mode (Errors Protection) names *.??b are renamed *.??p
- for EP-mode always "multivolume archive" mode is set (by default 
  size of volume is 13 Mb, if nothing else or more than 13 Mb is set)

-------------------------- CONTENTS: ---------------------------------------
ACB.EXE     ACB-compressor v.1.26a (Shareware Version)
ACB123C.EXE ACB_v1.23c: necessary for ACB2ACB.BAT
ZIP2ACB.BAT convertor *.ZIP --> *.ACB
ACB2ACB.BAT convertor *.ACB (1.23) --> *.ACB (1.26)
README.TXT  text of this file
TECHNIQ.TXT overview of ACB,LZ,PPM,DMC technique.
----------------------------------------------------------------------------

                 Terms of using ACB.EXE Ver.1.26a

The Registered Version of this program can be purchased and received
immediately on the Internet at Albert's Ambry.  Registration at Albert's
also eliminates shipping and handling costs.  Please go to:

      http://www.alberts.com

  Search on: acb_126a.zip

  Click on the "Buy It" Hotlink to register this software.

  Thank you for registering this program.

======================================================================

George Buyanovsky
Internet E-mail:  new < acb@online.ru > , old < george@acb.alma-ata.su >
