From owner-freebsd-hackers Thu Jan 23 05:36:19 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id FAA19347 for hackers-outgoing; Thu, 23 Jan 1997 05:36:19 -0800 (PST) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id FAA19342 for ; Thu, 23 Jan 1997 05:36:17 -0800 (PST) Received: (from msmith@localhost) by genesis.atrad.adelaide.edu.au (8.8.2/8.7.3) id AAA21608; Fri, 24 Jan 1997 00:06:09 +1030 (CST) From: Michael Smith Message-Id: <199701231336.AAA21608@genesis.atrad.adelaide.edu.au> Subject: Re: CRC-16 algorithms? In-Reply-To: from "Ron G. Minnich" at "Jan 23, 97 08:19:36 am" To: rminnich@Sarnoff.COM (Ron G. Minnich) Date: Fri, 24 Jan 1997 00:06:08 +1030 (CST) Cc: msmith@atrad.adelaide.edu.au, hackers@freebsd.org X-Mailer: ELM [version 2.4ME+ PL28 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Ron G. Minnich stands accused of saying: > If anyone out there can get me the coefficients, I can deliver a program > that will do the crc-16. But working out the polynomial minus the > coefficients, well, I'll go with Barbie on this one: "Math is hard, let's > go shopping" Well, I tried the Xmodem CRC-16 algorithm, and that came up with the wrong result (0x1911), so I'm stumped 8( > Not impossible: assuming this crc is accumulated 16 bits at a time, there > are only 2^16 possible polynomials, after all ... at least it's not some > crc-32! Hmm, I was actually assuming that it was accumulated 8 bits at a time; the RAM is normally accessed in 8-bit lots, and there's an odd number of bytes involved... > michael let me know if you don't get anywhere. Ta! > Ron Minnich |"Failure is not an option" -- Gene Kranz -- ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[ ]] Genesis Software genesis@gsoft.com.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control. (ph) +61-8-8267-3493 [[ ]] Unix hardware collector. "Where are your PEZ?" The Tick [[