
DE.ARC2GS v1.2                                                       10/6/87
The original ARC is (c) Copyrighted 1985 by: Thom Henderson of
                                             System Enhancements Associates

The modifications to his program to make it work on the Apple //GS are
(c) Copyrighted 1987 by Tim Swihart, P. O.Box 26303, Fort Worth, TX 76121

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        WHAT'S NEW IN VERSION 1.2?????

     All previous version of this program were unable to extract files that had been 'squeezed'.  I fixed one of the three bugs preventing unsqueezing in version 1.1 (last month), but there were two more bugs waiting to be discovered and eliminated.  As far as I know, this version will handle all types of ARC'd files that were created using a standard version of ARC.  There is a new type of compression out called 'squashing' that I have not seen the source code for.  If I can get the source code (LEGALLY), then I will try to include it in a future version.

     If I understand the original source code for this program correctly, then it will abort if it reads a file header that contains an unknown compression method.  I have added a couple of lines that should tell you the number that describes that compression.  If you encounter this sort of a problem, then send me a letter with that number (a copy of the file would be VERY helpful also) and I'll see what I can do.

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     This program will allow you to extract archived files that were compressed by a program known as 'ARC'.  There are versions of 'ARC' that run on the IBM PC, the AMIGA, the ATARI ST, the 8-bit ATARI's (800xl, etc), and many other personal computers.  'ARC' has been widely accepted by those 'other' users as a standard for compressing files that will be uploaded and downloaded.  These compressed file therefore contain a wealth of source code for programmers, a multitude of computer art, etc.

     Prior to the release of this program, the only way an APPLE II user could utilize the contents of an ARC'd file was to get someone with another brand of computer to de-ARC it for them.  While many of us probably did that (that's how I got some of the source code used to write this program), it was slow and inconvient.

     Now, thanks to yours truly (me), APPLE //GS users can de-ARC those files themselves.  This program will only run on either a //GS or a //E that has had its motherboard upgraded to that of a //GS.  I will attempt to create a version of this program that will work on the 8-bit //E's, //C's, II+'s, etc in the future.

     To use this program, simply copy it to the directory that contains the ARC'd file and double click on its icon.  You will be presented with a menu that contains four options.  The menu is presented here to make this discussion easier for both of us:

                  [L]ist contents of an archive
                  [E]xtract contents of an archive
                  [S]et name of archive to work with
                  [Q]uit this program

     The choice is yours =>

     It will be easier to start from the bottom ([Q]uit) of the list.  To select any of these options, simply type the letter that is within the square brackets and press the RETURN key.  If you want to quit, the type the letter 'Q' (upper or lower case, it doesn't matter) and press RETURN.  The "[Q]uit" option allows you to leave this program and return to the Finder (or where ever else you launched this program from).

     "[S]et name of archive to work with" allows you to change the archive you will be listing or extracting from.  This allows you to extract files from several different archives without having to re-start this program for each archive.  To select this option, simply type 'S' (upper or lower case, it doesn't matter) and press RETURN.  You will be prompted to enter a file name. Make sure you spell the file name correctly.  After having set a file name, you will see it listed on the line under the "[S]et name of archive to work with" option.  If you want to list or extract from another archive or you want to correct the file's spelling, simply re-select this option.

     You are allowed up to fifty characters when you type in the file's name. Obviously this is well in excess of PRODOS' limit of fifteen.  However, you can use the remaining thirty-five characters for a partial or full pathname for the target file.  This is handy if you want to place the extracted files into a directory OTHER than the one your ARC'd file is in.  To do this, simply copy this program into the directory that you want the EXTRACTED files to be in, launch the program, and type the full pathname of the target file.

     "[E]xtract contents of archive" option will allow you to extract either some or all of the files that are contained in the archive you are currently working with.  If you have not yet set a file name to work with, you will automatically be prompted for one.

     Next, you will be asked if you want to extract some or all of the files. If you only want some of them, simply type an 'S' (upper or lower case, it doesn't matter) and press RETURN.  You will then be prompted BEFORE each file is extracted.  If you want to skip a file, then simply type 'N' or just press RETURN (the default is 'NO').  If you want to extract it, then type 'Y' and press RETURN.

     If you want to extract all of the files in an archive, then either answer 'A' or just press RETURN (the default is 'ALL') when asked whether you want to extract all or some of the files.

     "[L]ist contents of an archive" option allows you to see the names of the files that are contained in the archive, how much room they will take up when extracted, the compression method used to pack them, and some other information as well.  Please note that the names presented to you when 'L'isted may contain characters that PRODOS considers illegal for file names (things like '&' and '_').  Do not let this concern you.  The program is smart enough to detect garbage like this and, when extracting those files, will change all illegal characters to periods.

     Also, some files may start with a number.  If this is detected, then the number will be changed to a 'Z'.  This substitution will ONLY take place if the FIRST character in the file name is a number.

     After each option is completed, you will be asked to press RETURN to continue.  This was added so that any error messages you may have received will still be visible before the screen is cleared.  Simply press the RETURN key and the program will continue.

     This program is intended to be used from the GS's FINDER or the older Mousedesk v1.1.  However, for those of you who would prefer to use it from a shell (such as APW, ORCA/M GS, or ECP16), all you have to do is change the file type from $B3 to $B5.  Then just treat it the same as you would any other shell command.

     If you are using APW or ORCA/M GS, then you should note that you can no longer pass the file's name from the command line.  This was done to make way for the menu.  Future items intended for inclusion in this program include true directory "walking", the ability to catalog the current prefix, and, one of these days, a desktop (super hi-res) mouse-based user interface.

     You can find ARC'd files to download in the ATARI ST, IBM, and AMIGA Round Tables of GEnie, or from local BBS's that cater to those computers. To use de-ARC'd ATARI pictures, you will need a special program that can handle them.  I recommend Jason Harper's program known as:  SHRconvert.  It can be found in the GEnie downloads as file #1766.

     If you have any problems using this program then contact me at:

     Tim Swihart
     GEnie address:  TSWIHART
     or
     P. O. Box 26303
     Fort Worth, TX  76121

    This program is considered FREEWARE, however, if you feel like sending me money for it, I will gladly accept it.  I intend to make some revisions to this program in the future so that it will be easier to use, have more features, and keep me busy.  If you would like to receive those updates directly, then send $15 to me at the address listed above.

     Thank you very much.

     Tim Swihart
