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Turnbull China Bikeride
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Turnbull China Bikeride - Disc 2.iso
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!ReadMe
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1998-03-16
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What's going on here?
~~~~~~~~~~~~~~~~~~~~~
This is the second release of bzip2 version 0.1 patch level 2 for RISC
OS. bzip2 is a lossless compression program in the same style as gzip.
It requires a lot of memory to run but typically achieves considerably
better compression ratios than gzip. It is becoming increasingly
popular in the Unix community. bzip2 is distributed under the terms of
the GNU General Public Licence, see the file `Copying' for details.
How do I use it?
~~~~~~~~~~~~~~~~
There is currently no wimp front end for bzip2. There is also no
sprite file available. To install bzip2, if you have an Acorn-style
boot sequence, you may simply run the !Install script. If not, then
copy `bzip2' to somewhere on your Run$Path, and ensure that the lines
in `RunMe' are executed at boot time.
To decompress files, simply doubleclick on them. Note that it spawns
a taskwindow to do this so you can continue to do other things while
it decompresses. To compress files, you will have to invoke bzip2
from the command line, until I have a front end.
There are a few differences from the Unix version, which is documented
in the `Docs' file. Instead of giving compressed files the same name
plus a `.bz2' extension, they have filetype &16E. Decompressed files
all have filetype Data (&FFD) since the file format does not permit me
to store the original filetype within the compressed file. I'm
currently negotiating with the author to work out a scheme that would
permit this.
Technical notes
~~~~~~~~~~~~~~~
As distributed, it runs in `small' mode which reduces the memory
requirement to 2428k but makes decompression slower. If you have a RiscPC,
it will use a dynamic area to store its data, which improves speed
somewhat. If you prefer speed to memory usage, then you may wish to remove
the `-s' option which will cause it to use twice as much memory.
When (de)compressing, it uses a temporary file in the same directory as the
file which you are (de)compressing, then deletes the original, renames the
new file and sets the file type appropriately. This can fail if you have
a read-only filesystem or the directory is full. You may wish to use the
`-c' option to bzip2 and redirect the output to a different file. Also,
the `-k' option will leave you with the original file untouched and a new
file `bzXXXXXX' where the X's are replaced with digits. This is the best
solution I can think of; if anyone has any better ideas, let me know.
The original source code is available from
http://www.muraroa.demon.co.uk/. The Patch file contains a unified
diff format patch from the pl2 source which is currently available on
the source website. I think this discharges my legal & moral
obligations under the GPL.
May the entropy of your files be maximised.
Matthew Wilcox <willy@bofh.ai>, 16th March 1998