LZW Data Compression Library
                       For Turbo Pascal

                           (LZW4P)

                          Version 1.3

                         Sept 10, 1993


               This software is provided as-is.
        There are no warranties, expressed or implied.


                     Copyright (C) 1993
                     All rights reserved

                     MarshallSoft Computing, Inc.
                     Post Office Box 4543
                     Huntsville AL 35815

                     205-881-4630  Voice / FAX
                     205-880-9748  Support BBS


1.0 Introduction


LZW4P  consists  of a variable code size implementation of the LZW
(Lempel-Ziv-Welch) algorithm  for  compressing  and  decompressing
data.   LZW does particularly well on text files, achieving better
than a 50 % compression ratio for many files.

The  LZW  algorithm  is  considered  to be one of the best general
purpose algorithms available today.  The  new  high  speed  modems
that  employ  on-the-fly  data  compression (such as MNP 5.0 & the
V.42 bis international standard) use the LZW  algorithm,  as  well
as such well known utility programs such as PKZIP.

The  LZW4P  library  is  designed  to be used in a wide variety of
situations. Some of the possible uses include:

 1) Compression and expanding files on disk.
 2) Compressing files "on the fly" before  sending  over  a  modem,
    and then expanding on the receiving end.
 3) Compression of data files used by your application program such
    as help files, graphics screens, etc. The compressed data files
    are then expanded as they are loaded by the application.


1.1 Distribution Files

The distribution files are as follows:


  1) LZW4P.DOC    -- This documentation file.
  2) LZW4P.INV    -- Invoice file.
  3) COMPRESS.PAS -- Data compression example program.
  4) EXPAND.PAS   -- Data expansion example program.
  5) LZW4P.PAS    -- Library unit interface.
  6) TEST_LZW.PAS -- LZW test driver program.
  7) MK_ARC.PAS   -- File archiving program.
  8) UN_ARC.PAS   -- File un-archiving program.
  9) RW_IO.PAS    -- Reader/Writer I/O source file.
 10) DIR_IO.PAS   -- Directory I/O source file.
 11) LZW_ERR.PAS  -- Displays text error messages.
 12) MEMORY.PAS   -- Memory allocation functions.
 13) HEX_IO.PAS   -- Procedure to read & write hexidecimal.
 14) LZW4PLIB.OBJ -- Library object file.

Registered users also receive:

 1) LZW4PLIB.ASM -- Library source file.
 2) MAKETPU.BAT  -- Makes library object from source.