anderson@Apple.COM (Clark Anderson) (06/12/90)
Greetings,
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.
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.
Any help would be gratefully appreciated...
--clark
--
-----------------------------------------------------------
Clark Anderson InterNet: anderson@apple.com
CPU Engineering AppleLink: C.ANDERSON
Apple Computer, Inc BellNet: 408-974-4593
"I speak only for myself, much to my employer's relief..."
-------------------------------------------------------------russotto@eng.umd.edu (Matthew T. Russotto) (06/12/90)
In article <41855@apple.Apple.COM> anderson@Apple.COM (Clark Anderson) writes: > >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. I believe the 'Compress' program is available to Macs, PCs, and everything else in the free world... I think the name of the mac program is MacCompress and can be found at info-mac/utils at sumex-aim.stanford.edu. The PC program I'm not sure about (but it's probably compress.exe....) -- Matthew T. Russotto russotto@eng.umd.edu russotto@wam.umd.edu ][, ][+, ///, ///+, //e, //c, IIGS, //c+ --- Any questions?
dankg@sandstorm.Berkeley.EDU (Dan KoGai) (06/12/90)
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)
david_islander_hughes@cup.portal.com (06/15/90)
Arc, zoo, etc. are good, but to really compress times use an MNP 5 or above modem..... and 9600 baud really helps, too
UD069225@NDSUVM1.BITNET (Eric H. Romo) (06/16/90)
At Simtel20.arpa, there is a file that compares(tests) out all the popular compression programs for PCs(ARC, ZOO, ZIP, and more) with different input(GIF, text-only, executables) and ranks them with respect to % compression and speed. Its an arc'd text file, see pd:<msdos.arc-lbr>compres8.arc, which gives the tables of data, and normalized ratings as well. I thought it was known that GIF files are LZW compressed(thats part of the GIF format.), therefore its curious to see that anyone would try compressing a compressed file. I would guess that the only extra compression might be a small amount by doing a huffman encoding on the GIF file, but doing a second pass with LZW would be fruitless(see those tables, none of the compressors even dented a GIF file, some even increased in size after compression.) Eric Romo