Path: utzoo!attcan!uunet!mailrus!umich!umeecs!msi-s0.msi.umn.edu!cs.umn.edu!cybrspc!roy From: cybrspc!roy@cs.umn.edu (Roy M. Silvernail) Newsgroups: comp.binaries.ibm.pc.d Subject: Re: Fastest Modem Transfer Protocal - Opinions Needed Message-ID: Date: 27 Jun 90 19:57:30 GMT References: <26501@netnews.upenn.edu> Organization: Villa CyberSpace, Minneapolis, MN Lines: 41 weisen@eniac.seas.upenn.edu (Neil Weisenfeld) writes: > Thanks goodness someone mentioned this. There was some dispute about > this a while ago. Some people said that Zmodem doesn't do 8th bit quoting > and some said that it does. [...] > Anyway, If someone can truly answer whether or not Zmodem will do it, > and if a version exists for UNIX that will do it, it would be greatly > appreciated. This is from the DSZ.DOC file included with DSZ0411: ------------------------------------- ZMODEM over 7 bit paths: (Not supported in DSZ.COM) A pair of ZMODEM-90 programs with 7-bit support operating over a 7 bit path should detect that fact and switch to one of two 7-bit path compatible encodings. For testing, this can be forced with a "-E" option. Default 7-bit mode is RLE compression and 8th bit quoting similar to Kermit but more efficient because not so many control characters are quoted. Use this default for text files. Rubout and all control characters can be escaped with the -e option. Individual control characters can be escaped with "zmtxesc" and "zmrxesc". Pack-7 instead of quoting is activated with the -P option. (-P has no effect on 8 bit paths.) Pack-7 packs 4 bytes into 5 printing characters. This is more efficient than quoting for files where 25% more 8th bits appear than the number of characters saved by RLE compression. (This statement applies to GIF, ARC, ZOO, and ZIP files. It may or may not apply to other binary file formats, depending on the data.) Pack-7 will match or beat standard Kermit on ZIP files, even when Kermit has use of all 8 bits. ----------------------------------------- The -E option also works with the Unix version (RZSZ0525), in my experience. -- Roy M. Silvernail | 'I don't see why you people | Opinions found now available at: | seem to think this is magic... | herein are mine, cybrspc!roy@cs.umn.edu | Its just this little chromium | but you can rent (cyberspace... be here!)| switch here...[click]' | them.