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From: dankg@sandstorm.Berkeley.EDU (Dan KoGai)
Newsgroups: comp.sys.mac,comp.sys.mac.programmer,comp.sys.ibm.pc,comp.sys.ibm.pc.programmer
Subject: Re: Mac/IBM text compression?
Keywords: Mac,IBM,text,compression
Message-ID: <1990Jun11.224021.23941@agate.berkeley.edu>
Date: 11 Jun 90 22:40:21 GMT
References: <41855@apple.Apple.COM>
Sender: usenet@agate.berkeley.edu (USENET Administrator;;;;ZU44)
Reply-To: dankg@sandstorm.Berkeley.EDU (Dan KoGai)
Organization: ucb
Lines: 54

In article <41855@apple.Apple.COM> anderson@Apple.COM (Clark Anderson) writes:

>I have been given the task of finding a way to transmit
>compressed data to some of our vendors via modem. The
>vendors are all using PC's/ compatibles. (We have all our data
>on Macs). The data we are sending is pure ASCII. The vendors have
>no problem reading uncompressed text, but the transmission times
>are a bit long (1-2 hours).
>
>My question is...is there an application for the Mac that can
>compress text files into a format that is easily de-compressed
>by a PC? (.ARC format?) I know nothing about PCs, so I have
>no idea what's available to them.

	There's unsit.exe for PC also.  And Stuffit Deluxe allows
compression|decompression by ARC and ZOO.  And there are a lot of
other shareware products availabe for archiving.  Let me list what
I know:

Format:		Product			A(archving)|D(earchiving) capability

ARC		MacArc			D	
		Stuffit Deluxe		A|D
ZIP		Unzip			D
ZOO		Stuffit Deluxe		A|D
LHZ		MacLharc0.33		A|D
SIT		Stuffit (of course!)	A|D
		unsit.exe		D
PIT		Stuffit			A|D
		Packit			A|D
		unpit.exe		D
GIF (RLE)	Too many to mention
UNIX Compress	MacCompress		A|D

	And all above formats are available for unix (at least
dearchive basis), All with c sources which you can find format
specs and algorithm.

>As an alternative, is there any documentation available for
>a compressed text-file format for the IBM? If necessary, I can
>write an application that will do the compression, but I'd
>rather not re-invent the screen door, as they say.

	Maybe the best among those are LZH (lharc) format:  It has
the best average compression rate, availablity for Mac, Dos, Unix
and Amiga, and best of all it's all free.  It's originated in Japan
but used widely among europeans (and an Italian programmer ported
it to Amiga).  MacLharc is still too slow and need a lot more polish
but if you want portable and deep compression, there it goes.  LZH
is based on LZW compression method and I found it very efficient
compressing text files (nearly 75% size reduction on average).  I
replaced tar + Z with this.

Dan Kogai (dankg@ocf.berkeley.edu)