koreth@ssyx.ucsc.edu (Steven Grimm) (03/22/88)
Submitted-by: wisner@eddie.MIT.EDU (Bill Wisner)
Posting-number: Volume 1, Issue 3
Archive-name: arcdoc
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.
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.