This is a document about ARC.

I have been thinking for some time that we should ARC  (compress) 
our PD's: then nearly 500KBs could be put on a single sided disk, 
instead of only 330 or so. Here is a version of ARC which is very 
small and easy to use. 

ARC compresses  and decompresses files;  it goes through  a  file, 
finds  all the strings and lines which are similar,  and  replaces 
them with a single character. This makes the file shorter, so that 
it takes up less space on disk or on the telephone.  An ARC  file 
is  something like a folder:  it contains a whole bunch of  other 
files.  To this ARC "folder",  you can add new files,  or you can 
take  out single files,  or you can open the whole  ARC  "folder" 
(take out everything and decompress the whole folder). 

There are several versions of ARC:
     1)   ARCX.TTP is a decompressor-only. A copy of this will be 
          on every PD from now on. Use this to decompress a file.
     2)   ARC.TTP  is  the  full  version.  It  does  everything. 
          Compresses,  decompresses,  makes lists, tests compres-
          sion, and encrypts / decrypts. 
     3)   ARCSHEL2.PRG is a shell for ARC.TTP; instead of using a 
          whole  list of commands,  ARCSHEL2.PRG lets you  merely 
          click  on the screen.  ARCSHEL2.PRG also allows you  to 
          work within folders. ARCSHEL2.PRG needs to have ARC.TTP 
          along with it on disk. ARCSHEL.PRG, an earlier version, 
          should not be used; it crashes very often.

Here  are  the instructions for using ARCX.TTP.  If  you  want  to 
compress, then get a copy of ARC.TTP along with ARCSHEL2.PRG. That 
contains full instructions. 

Let  us  assume you wish to decompress a  file  called  TEST.ARC. 
Start  ARCX.TTP  by double clicking on ARCX.TTP  (or  click  OPEN 
FILE).  A window appears which has space for you to write a line. 
Type in that line 
 
TEST.ARC

(in small or large letters, it doesn't matter). TEST.ARC specifies 
the name of the ARC file which will be decompressed.  You may also 
just  write TEST;  if TEST.ARC is the only thing in the folder  or 
disk,  then write *.*,  which means ANYTHING.ANY ENDING;  ARCX.TTP 
will de-arc anything that has an ARC ending. 

It is best to do this on a new disk; if there is not enough space, 
then the program will abort.  Simply copy the ARC file onto a  new 
disk,  along with ARCX.TTP. You should calculate with an ARC file 
to  expand  about twice its size:  ARCX.TTP will  decompress  the 
program and then save it to disk. If the ARC file is 55KBs large, 
then it will usually become about 110-120KBs large.

The  very  easiest way is to do all this on a  RAM  disk.  Make  a 
ramdisk  which  is about 80% of your available RAM,  put  all  the 
ARC files and ARCX.TTP on it,  and work from there.  It goes  MUCH 
faster. 
                               ----
If  you have comments or suggestions to this  text,  please  send 
them in and we will add it to future versions.



Andreas Ramos
Midtjyllands 68000 User Group
J‘gerg†rdsgade 142.2 th
8000 Aarhus C / Danmark