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Article #6362crc errors: Death to Checksums!
From: Mark Mendel
Date: Tue, 08 Jul 1986 15:02
Date: Tue, 08 Jul 1986 15:02
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> > Sometimes when I binhex a file that has come over the net I get > a message about a crc error. Can anyone save me a lot of time by explaining I, too, have experienced these errors. I believe they are caused by the file being transferred at some point using a CHECKSUM instead of a CRC. I know of at least one case where this must have been the problem. The BOSTON II font distribution had a CRC error. I looked at the fonts, and LO!, several characters had double bit errors. That is, a localized burst of errors where in nearby bytes the same bit was wrong s.t. a checksum will not detect the error. These are precisely the types of errors that CRCs are designed to catch. I have read articles where people say "checksums have always worked for me...". Well, 99% IS NOT GOOD ENOUGH for a transfer protocol! If you are going to be posting stuff, please try to use an terminal package that supports CRC. -- ------------------------------------------- Mark G. Mendel, Network Systems Corporation ihnp4!umn-cs!hyper!mark
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!caip!meccts!dicome!mmm!umn-cs!hyper!mark From: mark@hyper.UUCP (Mark Mendel) Newsgroups: net.micro.mac Subject: crc errors: Death to Checksums! Message-ID: <66@hyper.UUCP> Date: Tue, 8-Jul-86 11:02:51 EDT Article-I.D.: hyper.66 Posted: Tue Jul 8 11:02:51 1986 Date-Received: Fri, 11-Jul-86 06:27:02 EDT References: <229@ndsuvax.UUCP> Organization: Network Systems Corp., Mpls., Mn. Lines: 20