LHWARP 1.40

                           A disk tracker for the Amiga

                            Written by Jonathan Forbes
                       Copyright © Xenomiga Technology, 1990


20-Dec-89 V1.00: Initial release (small extended data bug.)
20-Dec-89 V1.01: Fixed extended data bug.
22-Dec-89 V1.02: 32-bit checksum implemented.
28-Dec-89 V1.03: More CHIP memory efficient, and stack size 50k -> 3k.
01-Jan-90 V1.10: 32-bit CRC, compression routines now in assembly language.
                 16k file i/o buffer, stack size 3k -> 10k.  Bitmap used for
                 skipping unused sectors.
02-Jan-90 V1.11: Another speed increase.  Sectors are displayed as they are
                 archived.
06-Jan-90 V1.20: Squeezing and Vaporising implemented.  Viewing implemented.
08-Jan-90 V1.21: Corrected text file bug in version 1.20.
19-Feb-90 V1.30: Removed track corrupting bug.  Other devices supported.
                 Output file length included within output file.
27-Feb-90 V1.31: Removed bug which prevented Lhwarp from uncompressing files
                 produced by earlier versions.  Memory leak corrected.  Removed
                 bug involving output track data being longer than input track
                 data.
12-Apr-90 V1.40: Incredible speed increases all around.  Compression 25%
                 faster, decompression 60% faster (freezing.)  Asynchrous disk
                 i/o.  Tracks now stored if they cannot be compressed.
                 Corrected bug causing viewing to crash.  Added "no prompts"
                 option.


   Version 1.40 - 12th April, 1990

   I moved the assembly language routines from Lhunarc 0.96 (written by me)
into Lhwarp, which resulted in some incredible speed increases!  Lhwarp also
uses asynchrous disk i/o; what this means, is that Lhwarp continues to
compress/decompress while the disk is being accessed; thus, Lhwarp no longer
has to wait for tracks to be read or written.

   Nobody ever accused Lhwarp of being fast, but it can certainly no longer be
called slow, especially when compared to the other disk compressors available.

   NewTek DYNAMIC HI-RES Demo Disk:

                     Compress    Decompress
                     ---------   ----------
      Version 1.31 | 19:00 min |  12:40 min
      Version 1.40 | 14:50 min |   5:24 min
      Warp 1.1z    | 16:53 min |   1:16 min (Unwarp 1.00)

   If no space is gained by compressing a track, that track is now stored (no
compression) instead.  Vaporising and Squeezing will now produce smaller
files.  In addition, the -q (quick intelligent compression) option has now been
revised, and no longer functions in the same way as before.  Please refer to
the updated documentation for more details.

   The -n option has been added, signifying "no prompts"; Lhwarp won't ask you
to hit return if this option is specified.

   A small bug causing the -v option to crash upon abort has now been fixed.

   Because of the way in which Lhwarp handles version updates, any files
Lhwarp'd with version 1.40 will appear to have been Lhwarp'd with version 1.39
(which doesn't exist.)  This is because Lhwarp assumes that a change in the
10^-1 digit of the version number constitutes a change in the output file
format, which has been true up to now, but not for this version.

   I suppose I could have called this version 1.32, but 1.32 gives the
impression of a minor update; 1.40 is more ostentatious.  In any case, this
small workaround will not affect you in any way.