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1995-03-09
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MASH
Another LZRW based compression algorithm
Version 1.16 (20 aug 1994)
Copyright 1994 Zdenek Kabelac
License/Disclaimer
------------------
xpkMASH is (C) Copyright 1994 by Zdenek Kabelac.
This package may be freely distributed, as long as it is kept in its
original, complete, and unmodified form. It may not be distributed by itself
or in a commercial package of any kind without my written permission.
xpkFAST is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Installation
------------
Make sure the directory libs:compressors does exist and then just copy
xpkFAST.library to libs:compressors. You also need to have the XPK package
installed, it is available from several sources including Fish disks.
Description
-----------
xpkMASH is an XPK compression sublibrary whose main purpose is to be fast
in decrunch and have excelent crunch factor. The sublib is using LZ77
compression, but uses special method in writing matches... Also have very nice
feature - hashing uses a lot of memory - 128KB, but when the memory is low it
will reduce size down upto 4KB, but it will be very very slow. Buffer size is
32KB. Default chunk size is 64KB. Decompresion is very very fast. Also uses
lazy eval method in searching matches - look in the source if you'd like to
know what this means, also if you want to know more about this program - it
slowed everything down, but only in compression.
Sublibrary has several modes:
Mode Strings to be searched
------ ------------------------
0- 9 1 ;for OnTheFly compres (but rake is better)
10-19 2 ;fast but not excelent CF
20-29 4
30-39 8
40-49 16
50-59 32 ;good speed, good results
60-69 64
70-79 128
80-89 256 ;usualy good enough
90-99 512
100 1024 ;the best, the slowest
The second colums shows how many matches should be compared
- the more searched strings - the better results you will get
Last words: I've been using this version 1.16 for two months and no errors
has occured.
And if you want to improve it - send me copy of your work.
History
-------
unreleased
V0.5 Many errors, the biggest problem was bad writing of bits string.
V0.7 Most of errors has been debuged
V0.8 Last byte has not been saved
V0.9 On the first look normaly working version of the sublibrary with
fixed hash table - size 64KB
V1.0 The big improvement in memory allocating
memory is allocated before each chunk compresion and deallocated
after this chunk is compressed (usefull if you have installed
statram.device)
V1.01 Hash size was increased from 64KB to 128KB (16 bits)
V1.05 Hash is allocated dynamicaly - when is large memory free - large hash
is used. Starting with 128KB, 64KB, 32KB, .... ,512 bytes
V1.15 Seems to work perfectly for me
V1.16 I suppose last bug has been removed - value of register D4
was not saved on return. Also most of long word instruction has
been rewritten to word oriented instructions (useful for MC68000)
first public release:
Thanks must go to:
--------------------
Rudolf Kudla <kudlar@risc.upol.cz>
for testing new versions.
Contact Address
---------------
Zdenek Kabelac
Policna 135
Valasske Mezirici
757 01 Czech republic
"kabi/informatics.muni.cz"