HP/HPRT Demo Files
22-May-94


This archive contains some files that were compressed with
HardPressed's LZSS module.  I'm making this available so that people
who have downloaded HPRT (HardPressed RunTime, a freely distributable
subset of HardPressed) can experiment with some compressed files, and
see how fast and transparent HardPressed really is.

You should download and install HPRT before trying to look at these
files.  They will appear as type "LBR" (Archive Library) if HPRT is
inactive or not installed.

Before compression, we have the following:

Name            Type  Blocks
FillMaze        S16       41      Application (maze demo)
FILLMAZE.DOC    TXT       30      Plain ASCII documentation
POLYGONIA.I     S16       54      Application (3D demo)
ABOUT.POLYGONIA TXT       24      Plain ASCII documentation
POLYGONIA.ICON  ICN        3      Icon
MORIA.DOC       TXT      129      Plain ASCII documentation
YAHTZEE         S16      119      Application (Yahtzee game; fun)
                         ---
                Total:   400

After compression:

Name            Type  Blocks      Compression       GSHK Compression
FillMaze        S16       23      46%               37%
FILLMAZE.DOC    TXT       17      47%               46%
POLYGONIA.I     S16       28      50%               46%
ABOUT.POLYGONIA TXT       13      46%               47%
POLYGONIA.ICON  ICN        1      36%               64%
MORIA.DOC       TXT       59      55%               50%
YAHTZEE         S16       62      48%               39%
                         ---
                Total:   203

(Compression percentage is % reduced, so 0% compression would be no
compression at all, while 100% compression would be really amazing.
Note that GSHK expresses compression percentages as % of original
size, so values shown above are (100 - %) from what GSHK displays.
The total size of the GSHK archive was 223 blocks.)

As you can see, in most cases LZSS did as well or better than
GS/ShrinkIt's LZW compression algorithm (which, incidentally, is also
supplied with HardPressed).  LZSS also uncompresses in a fraction of
the time that GSHK takes, as you can verify for yourself with HPRT.

You can compare launch and load times for the various documents by
copying them to another directory with HPRT active.  Because HPRT
can't compress files, it will expand them into their original form as
it copies them.  You can then do timing comparisons between the
compressed versions and the originals.

Have fun.  If you decide that HardPressed would be a worthwile
addition to your system, you can contact:

    WestCode Software, Inc.
    15050 Avenue of Science, Suite 112
    San Diego, CA  92128
    (619) 487-9200

This information is also listed in the HPRT ReadMe file.