Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site bsdpkh.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!whuxl!whuxlm!akgua!akguc!codas!bsdpkh!heffner From: heffner@bsdpkh.UUCP (Paul K Heffner) Newsgroups: net.micro.apple Subject: Re: Data Protocol Question/80-col vid. Message-ID: <130@bsdpkh.UUCP> Date: Thu, 7-Nov-85 23:03:47 EST Article-I.D.: bsdpkh.130 Posted: Thu Nov 7 23:03:47 1985 Date-Received: Sun, 10-Nov-85 07:22:19 EST References: <557@ihlpm.UUCP> <9800016@uiucuxa> Organization: AT&T-IS (SDSS), Orlando Fl. Lines: 35 Benjy Mouse writes: > > Ok, here it is: Ward Christensen wrote the XMODEM protocol with CRC > checking...(Cyclic redundancy check), so that I beleive that all of > the protocols you just mentioned are the same. > > Christiansen=XMODEM=XMODEM/CRC > > How's that? That's pretty close... Actually the baseline Christiansen protocol only checks for transmission errors with a raw checksum. (Add all the characters in the 128 byte buffer up in a 16-bit register tossing out any carries.. the result is your checksum). CRC checking was added sho