Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-lcc!pyramid!amdahl!drivax!holloway From: holloway@drivax.UUCP (Bruce Holloway) Newsgroups: comp.unix.questions,comp.sys.ibm.pc,comp.sys.att,comp.sources.wanted,misc.wanted Subject: Re: What is the Diff between Xmodem/Ymodem Message-ID: <770@drivax.UUCP> Date: Wed, 14-Jan-87 12:49:55 EST Article-I.D.: drivax.770 Posted: Wed Jan 14 12:49:55 1987 Date-Received: Thu, 15-Jan-87 04:19:18 EST References: <2374@psuvax1.UUCP> <305@hoqax.UUCP> Reply-To: holloway@drivax.UUCP (Bruce Holloway) Organization: Digital Research, Inc., Monterey Lines: 22 Xref: mnetor comp.unix.questions:659 comp.sys.ibm.pc:988 comp.sys.att:120 comp.sources.wanted:313 misc.wanted:421 In article <305@hoqax.UUCP> twb@hoqax.UUCP (BEATTIE) writes: >> Now, one question for all of you guys who know your communication >> packages. What is the difference between Xmodem/Ymodem/Umodem/Kermit. > >Add rb/sb and zmodem to the list. >What is the difference between all these? XMODEM 128 byte packets, 8 or 16 bit checksum YMODEM 1024 byte packets, 8 or 16 bit checksum ZMODEM 128 byte packets sent four at a time, 8 or 16 bit checksum WMODEM Same as ZMODEM (I think), but for timesharing systems UMODEM ? KERMIT Not related to the above protocols. Kermit can send files to sites when there are severe restrictions that XMODEM et.al. can't handle. Such as 7 bit lines, can only take a line at a time, control characters usually not allowed, etc. Kermit is also a sender driven protocol, unlike the receiver driven XMODEM. Also, Kermit can get directories, type files, etc. on the remote machine. -- ....!ucbvax!hplabs!amdahl!drivax!holloway "What do you mean, 'almost dead'?" "Well, when you stop breathing, and moving around, and seeing things... that kind of almost dead."