ARC Introduction and short docs.



          ARC (short for archive) is a file library and compression

          utility.  It may be thought of as an improved version

          of LU and SQUEEZE all rolled into one program.



          ARC analyzes each file to see which of a number of

          compression techniques will generate the smallest code.

          The following estimates give the user a general idea of

          how much compression may be gained by using ARC.



                ARC Text -            45-55% reduction from original

                SQUEEZED Text -       30-40% reduction



                ARC Programs -        25-30% reduction

                SQUEEZED Programs -   15-20% reduction



                ARC Pictures -        45-55% reduction

                SQUEEZED Pictures -   40-50% reduction

                TINY Pictures -       40-50% reduction



          The user should see that compressing files with ARC

          will allow easier telecommunications by combining files

          and shortening their transfer time.



     Usage from TOS

          - double-click-left on ARC.TTP icon

          - observe OPEN APPLICATION menu for ARC.TTP parameters

          - enter switch, archive name and file template

            (ex: lh arc.arc *.*)

          - hit return or click-left on OK box to begin execution

          - "press any key to continue" after completion



     History

          ARC has been in use in the CP/M and MS-DOS world for many

          years.  Thom Henderson developed the version which I

          converted for use on the Atari ST.  I am not sure but he

          may also be the original author.



          It is important to note that no matter who developed this

          program, ARC is based on the file compression theories

          developed by Huffman, Welch, Knott, Knuth, and many other

          scientists.



     Bug Reports

          Since I developed this version of ARC, I will be responsible

          for any erroneous features.  Please relay any problems with

          a written discription of what happened and the .ARC file

          which caused the problem to:



                        Harvey Johnson

                        2398 Oaklyn St NE

                        Palm Bay, FL 32907



                             - or -



                      QUILL BBS 305-724-2303





     Future Products

          It would be nice to have a version of ARC written to utilize

          GEM.  I would also like to write a picture display feature

          that will show compressed pictures directly to the screen.

          This will be useful in that ARC squeezes file 5 to 10% smaller

          than TINY format.  If anyone has the C source to dump NEO,

          Degas, or other pictures to the screen please upload a copy

          to QUILL BBS.



          If you have any ideas for additional capabilities, then send

          them to me with a detailed explanation.  All thoughts are

          welcome.



     Donations

          It would be nice to be supported if you think that ARC

          is any good.  Make no mistake, I did NOT write the original

          version of ARC, but I have spent all my extra time for

          two months making it a reality on the Atari ST.



          As I do recieve contributions, I will consider improvements

          more seriously.  Any donations may be sent to address

          specified in Bug Report section.



          Thank you one and all in advance for considering this

          request, but if you are like me (lazy) then I don't

          really expect to ever see a single dime.



ARCHIVE (ARC.TTP)



     Usage

          arc {amdxelvth} <filename.ARC> [<filename> ...]



               a   = add files to archive

               m   = move files to archive

               d   = delete files in archive

               x,e = extract files from archive

               l   = list files in archive

               v   = verbose listing of files in archive

               t   = test archive integrity

               h   = hold screen before returning to Desktop



     Description

          This program is a general archive utility, and is

          used to maintain an archive of files.  An "archive"

          is a single file that combines many files, reducing

          storage space and allowing multiple files to be

          handled as one.



     Switches



          a - add files to archive.  This switch will force update

              or addition the indicated reguardless of creation

              time and date.



          m - move files to archive.  Same as "a" switch except

              that the files are deleted from the directory as

              they are moved to the archive.



          d - delete files in archive.  The files are lost forever

              and the archive is recompacted to remove the data

              for these files.



          x,e - extract files from archive.  A copy of the files

              in the archive are created in the current directory

              in an uncompacted state.



          l - list files in archive.  Limited information listing

              of files contained in an archive.  Displays only the

              filename.



          v - verbose listing of files in archive.  Complete

              information listing of files contained in an archive.

              Displays the filename, original length, storage method,

              storage factor (% savings), compacted size, date, time,

              and CRC.



          t - test archive integrity.  Check the archive to make sure

              it does not have any bad files contained.



          h - hold screen before returning to Desktop.  This switch

              should be used whenever ARC is executed from the

              Desktop, except in conjunction with file redirection.



     Examples when executed from GEM Desktop:



     ah FILES.ARC *.PRG      Creates a new archive file called FILES.ARC

                             and puts all files ending in .PRG inside.



     xh FILES.ARC *.*        Extracts all files from FILES.ARC.

     xh FILES.ARC            ""

     xh FILES                ""



     xh FILES.ARC *.DOC      Extracts all files ending in .DOC.



     In each case, the 'h' holds the display instead of immediately returning

     to the GEM Desktop so you can view filenames, messages, etc.  More

     complete docs are in the ARC.ARC archive file.  These are just to help

     you get started.  ARC seems to be the most reliable of the 'masher'

     programs and has the best overall size reduction.

