Path: gmdzi!unido!mcsun!uunet!mailrus!umich!ox.com!time
From: t...@ox.com (Tim Endres)
Newsgroups: comp.mail.uucp,comp.sources.d
Subject: WANTED: News compression information...
Message-ID: <1990May29.202056.26271@ox.com>
Date: 29 May 90 20:20:56 GMT
Organization: Ocwen Trading, Inc.
Lines: 20
Posted: Tue May 29 21:20:56 1990
I am working on an implementation of News for the lowly Macintosh.
I have had many requests to support compressed/batched news.
I have easily added the support for batched news, but have found
the support of compressed news to be a dilemma.
Most people have indicated that "compress", the PD version, is what
is normally used for news compression. This would *seem* fine, but
the darn thing requires 500K RAM just to uncompress. This not only
seems extraordinary, but I can not see how implementations on a PC
limited to 640K could even work.
QUESTIONS:
Is "compress" the common news compression algorithm?
Do all news feeds compress at 16 bits or 12 bits?
What are the implications of using compress in commercial sw?
Are there any other, more miserly, compress programs available?
Thanks, tim.
t...@ox.com
Path: gmdzi!unido!mcsun!ukc!mucs!liv-cs!liv!sa44
From: S...@LIVERPOOL.AC.UK (Kevin Maguire)
Newsgroups: comp.mail.uucp,comp.sources.d,news.software.b
Subject: Re: WANTED: News compression information...
Message-ID: <90151.173150SA44@LIVERPOOL.AC.UK>
Date: 31 May 90 16:31:50 GMT
References: <1990May29.202056.26271@ox.com>
Organization: University of Liverpool
Lines: 29
Posted: Thu May 31 17:31:50 1990
In article <1990May29.202056.26...@ox.com>, t...@ox.com (Tim Endres) says:
>I am working on an implementation of News for the lowly Macintosh.
>I have had many requests to support compressed/batched news.
>Most people have indicated that "compress", the PD version, is what
>is normally used for news compression. This would *seem* fine, but
>the darn thing requires 500K RAM just to uncompress. This not only
>seems extraordinary, but I can not see how implementations on a PC
>limited to 640K could even work.
I had a look at the compress.c (comp.c ??) file in C news and it does
indeed seem to be the standard UN*X compress(1) command incognito.
It depends which defines you choose when compiling this file whether
you get 16bit/12bit/whatever compression. Yes 16 bit does need ~400K
to compress in but uncompressing with even 16bit need much less ~70K (?)
So just get this file (compress.c) and compile in 16bit mode. Once compiled
compress automatically determines the compression mode a file was compressed
in so on your Mac you can compress your batches in 13 bit mode and send
them out and uncompress incoming 16bit batches as well. The commandline
option is "compress -b13" for thirteen bits.
This way you'll only need about 70K of work space to send out 13bit
batches (which any compress should automatically handle) and uncompress
16bits batches. Alternatively, ask your feed site to use 13bit (or 12)
compression on your batch (don't think either C news or B news automatically
allow this however :-()
Kevin Maguire
Nsfnet : sa44%liv.ac...@nsfnet-relay.ac.uk
Uucp : ...!mcsun!ukc!liv-ib!sa44
Path: gmdzi!unido!mcsun!uunet!aplcen!uakari.primate.wisc.edu!
zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!tut.cis.ohio-state.edu!
mstar!mstar.morningstar.com!bob
From: b...@MorningStar.Com (Bob Sutterfield)
Newsgroups: comp.mail.uucp,comp.sources.d
Subject: Re: WANTED: News compression information...
Message-ID: <BOB.90May31152322@volitans.MorningStar.Com>
Date: 31 May 90 19:23:43 GMT
References: <1990May29.202056.26271@ox.com>
Sender: n...@MorningStar.COM (USENET Administrator)
Reply-To: b...@MorningStar.Com (Bob Sutterfield)
Organization: Morning Star Technologies
Lines: 21
Posted: Thu May 31 20:23:43 1990
In-Reply-To: time@ox.com's message of 29 May 90 20:20:56 GMT
In article <1990May29.202056.26...@ox.com> t...@ox.com (Tim Endres) writes:
Is "compress" the common news compression algorithm?
Yes.
Do all news feeds compress at 16 bits or 12 bits?
Hard to say, but I don't know of any doing 12-bit compression. But
then, I don't run in those circles.
What are the implications of using compress in commercial sw?
Ask your lawyer. Net advice is worth exactly what you pay for it :-)
Are there any other, more miserly, compress programs available?
Some years ago, someone posted a micro-zcat to net.sources. It
performed the uncompress-in-a-pipe function in about two dozen lines
of C, really pretty elegantly. Of course, I can't dredge it up any
more. Perhaps your friendly neighborhood source archive site would
have a copy?
Path: gmdzi!unido!mcsun!uunet!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!
uwm.edu!bionet!ames!eos!shelby!riacs!jaw
From: j...@riacs.edu (James A. Woods)
Newsgroups: comp.mail.uucp,comp.sources.d
Subject: Re: WANTED: News compression information...
Message-ID: <1990May31.233233.6352@riacs.edu>
Date: 31 May 90 23:32:33 GMT
References: <1990May29.202056.26271@ox.com>
<BOB.90May31152322@volitans.MorningStar.Com>
Sender: n...@riacs.edu (James A. Woods)
Organization: RIACS, NASA Ames Research Center
Lines: 29
Posted: Fri Jun 1 00:32:33 1990
# "don't compress that dwarf, hand me the pliers." -- after firesign theatre
> What are the implications of using compress in commercial sw?
since 'compress' is a component of s5r4 unix, it's been done very publicly.
you, too, can appropriate it in much the same manner as has at&t.
> Are there any other, more miserly, compress programs available?
>>Some years ago, someone posted a micro-zcat to net.sources. It
>>performed the uncompress-in-a-pipe function in about two dozen lines
>>of C, really pretty elegantly. Of course, I can't dredge it up any
>>more. Perhaps your friendly neighborhood source archive site would
>>have a copy?
the first micro-zcat was done in 1987 by karl f. fox of morningstar
technologies. since then, it's become both more (and less),
as discussed under the rubric of other cult postings which
never were directed to an official public archive.
please excuse the ellipticity here, but since mr. fox, myself,
and paul eggert of twinsun.com have a closely-related official
entry in chongo's 7th intl. obfuscated C contest, we ask you *not*
to dredge up the old code for publicity here.
after mid-june, when the judges have pronounced, you'll come to
know more than you'd ever wanted to about this twisted effort.
ames!jaw
Path: gmdzi!unido!mcsun!uunet!mailrus!cs.utexas.edu!news-server.csri.toronto.edu!
utgpu!utzoo!henry
From: he...@utzoo.uucp (Henry Spencer)
Newsgroups: comp.mail.uucp,comp.sources.d,news.software.b
Subject: Re: WANTED: News compression information...
Message-ID: <1990Jun2.224714.5516@utzoo.uucp>
Date: 2 Jun 90 22:47:14 GMT
References: <1990May29.202056.26271@ox.com> <90151.173150SA44@LIVERPOOL.AC.UK>
Organization: U of Toronto Zoology
Lines: 19
Posted: Sat Jun 2 23:47:14 1990
In article <90151.173150S...@LIVERPOOL.AC.UK> S...@LIVERPOOL.AC.UK (Kevin Maguire)
writes:
>I had a look at the compress.c (comp.c ??) file in C news and it does
>indeed seem to be the standard UN*X compress(1) command incognito.
Actually, the C News distribution as shipped from here doesn't include
a compressor at all; we simply assumed that everyone had compress.
(We realize this isn't a safe assumption, but we have to cut things off
somewhere.)
>... Alternatively, ask your feed site to use 13bit (or 12)
>compression on your batch (don't think either C news or B news automatically
>allow this however :-()
C News defaults to 12-bit compression, precisely to be compatible with
small machines. In fact, you have to go in and work at it to get 16-bit
compression. (That probably should be made easier.)
--
As a user I'll take speed over| Henry Spencer at U of Toronto Zoology
features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry he...@zoo.toronto.edu