        ABOUT ARCHIVES, LIBRARIES, ZOOS and SQUEEZED FILES

Some of the files in the IBM Software Libraries have been
transformed by using one or another of the standard public domain
utilities that either SQueezes, LiBRaries, ARChives, or ZOOs files. 
This is done to compress the files to minimize download time, and/or
combine several related files into a single easily-managed file.  You
cannot run any of these files without first transforming them back
to their original state.
 
These processed files are specially named with a filetype (the last 3 letters
of a filename after the '.') that signifies the transformation. These are:
 
              .ARC   for files archived with ARC.EXE,
              .ZOO   for files archived with ZOO.EXE,
              .LBR   for files libraried with LU.EXE, and
              .?Q?   for squeezed files (middle letter is a Q).
 
NUSQ.COM is used to unsqueeze, or expand files that have a "Q" as the
middle letter of the filetype.  Such files have been squeezed, or
compressed with SQPC.COM or something similar.  These programs use
Huffman Encoding to reduce the size of the target file.  Depending on
the distribution of data in a file it can be reduced in size by 5% to
60% by squeezing it. If you download a file with a filetype indicating
that it is squeezed, you will need file #43 NUSQ110.COM to expand it
before you can use it.  The syntax to unsqueeze a file would be:
               "A>nusq110 file.tqt" 
where file.tqt was the file you wanted to unsqueeze.  You must supply
the full filename and type.
 
Arc is used to create and maintain file archives.  An archive is a 
group of files collected together into one file in such a way that the 
individual files may be recovered intact.  ARC will automatically
compress member files when adding them to the archive, and will expand
them upon extraction.  For files with the .ARC extension, you must have
a copy of file #427 ARC51.COM (when you run this program, it will
produces ARC.EXE and related documentation) to extract the component
files.  An example of using ARC.EXE to unpack an ARChive file is:
                "A>arc e file"
You do not need to supply the ARC filetype when specifying "file."
 
ZOO.EXE is a newer archiving program that is similar to ARC, but non -
compatible.  It sometimes produces smaller archives than ARC-type
programs, and it is faster than ARC.EXE, although about the same speed
as ARCE.COM and PKXARC.COM.  (These are other ARC-type utilities).  If
you want to take apart a ZOO archive, you will need a copy of ZOO.EXE. 
Since it is a program in development, it's hard to say what it's file
number will be when you read this, but searching the library for the
'ZOO' keyword should turn up the correct file.  The zoo syntax is
similar to that of arc:       "A>zoo e file"

LU and its relatives (LUP, LUU, LUE, LUT, LU86, LAR etc.), maintain
libraries of files.  Most LU-type programs do not perform any
compression.  Because of this, most people will squeeze files before
adding them to a library if they want to save space.  If you want to
remove the component files from an .LBR file, you should have a copy of
file #960 LUE220.COM.  This will break up the library into its component
parts, and optionally unsqueeze any .?Q? files at the same time.  The
syntax for LUE would be:
                         "A>lue220 file"
where file was really FILE.LBR.
 
LUU.COM will create a .LBR file.
 

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