Hi, On Wed, Aug 22, 2012 at 11:37 AM, Steve Nickolas <usots...@buric.co> wrote: > On Wed, 22 Aug 2012, Georg Potthast wrote: > >> I observed that 7zip provides a better compression than ZIP. The CD image of >> my Graphical FreeDOS distribution XFDOS "xfdos.iso" is 63.2 MB uncompressed. >> ZIP compresses this to 53.1 MB while 7z compresses it to 27.1 MB, almost >> half of that.
By default (-mx5), 7-Zip (LZMA) uses a 16 MB dictionary (or less if the files don't even total that much). It can go much higher, perhaps up to 1 GB, dunno. Plain old .ZIP and Gzip Deflate is always static 32k dictionary (and barely documented Deflate64 is 64k, not much better, if at all). Not to mention that 7-Zip is (usually) solid compression across all of the archive, unlike .ZIP. EDIT: 7-Zip actually compresses slightly smaller .ZIP and .GZ files than other tools because of its improved Deflate. And it's still compatible to everything I've tested. BTW, I read once that the fastest compression for 7-Zip is "-mx1 -m0=bzip2", but if you really want fast compression, try LZOP. >> See here: >> >> http://code.google.com/p/nanox-microwindows-nxlib-fltk-for-dos/downloads/list >> >> Not all files are compressed that much better with 7zip but this CD image >> does not compress well with ZIP. I used the compression tools on Windows XP. >> >> Georg > > I'm not sure it's worthwhile though unless there's at least a 16-bit > decompressor... I have no problems with 16-bit computers. Compatibility is a nice thing. However, "the world" doesn't care for 16-bit anymore. They only barely care for 32-bit still, now that AMD64 is commonplace. So we're not going to get a lot of sympathy. I don't think 7-Zip (or any of its related tools, e.g. 7zdecode) support 16-bit. You could probably tweak it to work for 286 pmode, but I'm not sure how easy or worthwhile that'd be. Face it, most people use 386+ exclusively. I'm not saying we should throw classic hardware under the bus, I hate that. (Why throw away what still works fine??) But ... it's a lost cause almost. (Like I said, even RAR dropped DOS 32-bit due to lack of Unicode.) Anyways, Georg's XFDOS requires 386+ anyways (FLTK -> DJGPP), so for him it's moot. ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
