1lbrate 1.1 - extract/decompress CP/M LBR archives.
2Copyright (C) 2001 Russell Marks.
3
4This program is free software; you can redistribute it and/or modify
5it under the terms of the GNU General Public License as published by
6the Free Software Foundation; either version 2 of the License, or (at
7your option) any later version.
8
9This program is distributed in the hope that it will be useful, but
10WITHOUT ANY WARRANTY; without even the implied warranty of
11MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12General Public License for more details.
13
14You should have received a copy of the GNU General Public License
15along with this program; if not, write to the Free Software
16Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17
18
19Description
20-----------
21
22lbrate extracts/decompresses files from the CP/M LBR format. (It can
23also list and test such archives.) It does this in an `unzip'-like
24manner, mostly hiding the details of individually compressed and
25renamed files, and transparently deals with the required
26decompression/renaming.
27
28(It can also work on CP/M-ish compressed files (`squeezed', etc.)
29outside of such archives, treating them as if they were really
30single-member LBRs.)
31
32For more on how lbrate works and how to use it, do `man lbrate' once
33it's installed. You might also want to check the "FILENAME ISSUES"
34section if the description sounded a bit confusing... :-)
35
36
37Installation
38------------
39
40Check the Makefile is ok (it should be), then do `make' and (as root)
41`make install'.
42
43
44Why not just use `lar', `xusq', and `uncr'?
45-------------------------------------------
46
47Firstly, all previous decompressors that I'm aware of for the CP/M
48"Q", "Z", and "Y" compression types (including both the original CP/M
49tools and `xusq'/`uncr') have been non-Free. This is less than ideal
50IMHO.
51
52That apart, here are some practical reasons:
53
54- lbrate does the whole process in one. Admittedly you could script up
55  something similar which used lar/xusq/uncr (I used to use something
56  like this myself), but it wouldn't really work as well.
57
58- lbrate can extract "Y" type (LZH) compressed files, both 1.x and 2.x
59  versions. I believe it's the first non-CP/M program to support this
60  format.
61
62- lbrate supports extracting version 1.x crunched files, which `uncr'
63  doesn't.
64
65- lar doesn't check LBR CRCs, and therefore can't test the integrity
66  of LBRs.
67
68
69Who uses LBR files, anyway?
70---------------------------
71
72Even if no-one were ever to create a new LBR file, there's still a
73*lot* of existing CP/M software that is only available in this format.
74If you're going to use CP/M stuff, you pretty much have to be able to
75read LBRs (and .arc/.ark files, which are extractable with `nomarch').
76For example, the Walnut Creek CP/M CD contains well over 4000 LBR
77archives.
78
79
80What about Unisys?
81------------------
82
83lbrate is capable of reading LZW-compressed files (`crunched' files
84use LZW), so it has the same legal status as a GIF decoder. Even in
85their current set-lawyers-to-kill state, I don't think Unisys have a
86problem with programs which only *read* LZW. Their patent expires soon
87anyway, and once that happens we can all just point at them and laugh.
88I know I will. :-)
89
90As for other patents, LZH compression is covered by US patent no.
914,906,991 (which seems to claim all tree-using LZ77), but the patent
92does not claim any form of decompression. Since lbrate only
93decompresses, it should be ok.
94
95
96Is readlzh.c really GPL?
97------------------------
98
99Yes - the original author gave explicit permission for me to do this.
100For the background, read the comment at the top of readlzh.c, and see
101lzhuf-post.txt.
102
103
104Contacting me
105-------------
106
107You can email me at rus@svgalib.org.
108
109
110Share and enjoy!
111
112-Rus.
113