Category : Databases and related files
Archive   : SPLUS300.ZIP
Filename : ARCA.DOC

Output of file : ARCA.DOC contained in archive : SPLUS300.ZIP

ARCA Command Version 1.29
------------ Dec 9, 1987

Purpose: To create or add files to an ARC archive file.

Format: ARCA [drive:][path]arcname.ext [filespecs...] [/d] [/m]

Remarks: The drive and path names are optional. If omitted, the
current drive and path name are used.

The 'arcname' file name must be supplied. The extension
defaults to ARC. All files matching the supplied filespecs are
processed. The input 'filespecs' may contain the * and ?
wildcard characters.

If an existing archive file is used, the specified input
files are added to the end of it. There is no checking
for duplicate filenames and existing archive member files
are not replaced. ARCA is best used when creating a brand-new

The /D option specifies that all input files be deleted. The
files are deleted after successful processing of all of the
input files.

Invoking ARCA with no arguments yields a terse summary of
the needed parameters, along with a version header.

ARCA uses only 2 compression techniques: a modified LZW
compression algorithm and repeated-string compression
("packing"). The LZW algorithm is the same as the one used by
ARC, but modifications have been made to improve its compression
performance, especially when dealing with files containing
more "random" data such as executable files, though compression
performance for files containing less random data such as
textual files suffers a bit, but not much. ARCA generally
performs better than ARC does -- it's significantly faster than
ARC while yielding smaller archives (hard to imagine getting
the best of two worlds!)

Experiments have shown that the modified LZW compression algorithm
generally compresses binary files better than the Huffman algorithm
("squeezing") can, Huffman compression is not used at all. If the
LZW compression fails to yield a smaller file, then packing is used
instead. There are cases where a packed file is larger than the
original file, but these cases don't happen often enough for ARCA to
handle, for example, by copying the unchanged file to the archive.

Though ARCA uses an improved LZW algorithm, its output is TOTALLY
compatible with the one used by System Enhancements Associates'
(21 New Street, Wayne NJ 07470) ARC program, which means that ARCs
created by ARCA can be processed by ARC, or by ARCE and ARCV
(companion extraction & table-of-contents lister programs also
written by Vernon Buerg and Wayne Chin).

ARCA 1.29, Copyright (c) 1986,1987, Wayne Chin and Vernon D. Buerg.

ARCA Command Version 1.29
------------ Dec 9, 1987


o Create an archive file called TEST.ARC, and place all
files from the current directory into it:


o Create an archive called SOURCE.ARC in the subdirectory
\SAVE on drive B, and place all files with an extension
of ASM into to:


o Add files to the archive on drive A called PROGA.ARC all
files in subdirectory \TEST on drive C, all files with a
filename beginning with NE, and all file from the subdirectory
\OLD on drive B:


ARCA Command Version 1.29
------------ Dec 9, 1987

Error Messages

ARCA: filename, analyzing, compressed.
This message is issued for each 'filename' added to
the archive file using LZW data compression. The program

ARCA: filename, analyzing, packed.
This message is issued for each 'filename' added to
the archive file using repeated-string compression. The
program continues.

ARCA: No matching files!
No files were found that matched one of the 'filespecs'
in the command line. The program terminates.

ARCA: You must use DOS version 2.0 or higher.
DOS version 2.0 or higher is required. The program terminates.

ARCA: Insufficient memory.
A minimum of 34k is required. The program terminates.

ARCA: Shrink failed.
This error should not occur. If it does, there is a problem
with DOS. The program terminates.

ARCA: Can't create archive file.
There is no room in the target directory to create the
specified archive file, or the target disk has become full.

ARCA: Write error -- no more disk space? Don't trust this archive!
ARCA has encountered a problem writing to the target disk. Check
if there's sufficient room on the target disk to contain the full
archive or delete unneeded files to free up some space. ARCA
terminates leaving behind an archive that may not be usable --
check it carefully if you still want to use it (check the archive
by using ARCV or ARCE).

ARCA Command Version 1.29
------------ Dec 9, 1987

Version history

1.07 - 4/21/86, initial release
1.08 to 1.13, internal versions
1.14 - 08/07/86
add logic to sort input files using binary tree;
modify filtering of ARC name when adding to ARC;
modify processing of "/D" switch;
do packing of file if LZW compression does no good;
add optional code for 286 processor
1.15, August 08, 1986
more 286-specific instructions
1.16, August 09, 1986
more 286-specific instructions in compression code
1.17, August 10, 1986
speed improvements in compression code
1.17a, August 10, 1986
bug fix for the case of "arca x d:*.*", where d is not
the current drive
1.18, August 11, 1986
further speed tweaking in compression code; save a few
more nanoseconds
1.19 to 1.21
internal versions not released for general consumption
1.22, Sept 13, 1986
improve error handling
improve speed performance roughly 9%
very modest compression perfomance improvement
modify this document accordingly

1.23, Feb 24, 1987
add start-up banner
omit "deleted" messages
add 'copying' method

1.27, May 30, 1987
correct problem reverting to pack method (file size wrong)
revert to copying if packing results in a larger file

1.28, Oct 4, 1987
correction for zero-byte files

| 1.29, Dec 9, 1987
| add /M option to add modified files only
| correction for zero-byte files, again

ARCA Command Version 1.29
------------ Dec 9, 1987

As mentioned, ARCA is intended to be used to create a NEW archive,
not for appending or updating an existing archive, though ARCA does
not prevent you from doing so -- ARCA simply appends new files to the
named archive without deleting existing entries. To properly append
or to update, you should use ARC instead.

There may be two COM files. The ARCA286.COM file is for 80286 based
systems only.


ARCA 1.29, Copyright (c) Wayne Chin and Vernon Buerg 1986,1987.

ARCA is free, but it is a copyrighted work and may be distributed only
pursuant to this license.

Permission is hereby granted to reproduce and disseminate ARCA so long

(1) No remuneration of any kind is received in exchange; and

(2) Distribution is without ANY modification to the contents of
ARCA.COM and all accompanying documentation and/or support
files, including the copyright notice and this license.

No copy of ARCA may be distributed without including a copy of this

Any other use is prohibited without express, written permission in


Vernon D. Buerg
456 Lakeshire Drive
Daly City, CA 94015
CompuServe: 70007,1212
Data/BBS: 415-994-2944

  3 Responses to “Category : Databases and related files
Archive   : SPLUS300.ZIP
Filename : ARCA.DOC

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: