Den mån 27 jan. 2020 kl 02:07 skrev Chuck Guzis via cctalk < [email protected]>:
> On 1/26/20 3:12 PM, Bob Smith via cctalk wrote: > > I ma rusty on this, been almost 50 years since I worked on the DP8EP > > aka the KG83. then the KG11, and the Autodin 2 CRC32 designs in > > hardware. > > I don't recall whether bisync, aka bsc used LRC8, 12, 16, or crc16 as > > the error detection algorithm. > > I don't think it used VRC. I did find a refresher that might help, but > > I don't think the polynomial you have for crc 16 has enough terms. > > BUT I could be misremembering. > > If you've got the message and the checksum, however computed, there are > free tools to grind through the usual suspects. I've used it on alien > disk formats very successfully. > > Yes, there are the crc reveng for example. But I cannot get it to generate the CRC digits that matches. Neither does it give me anything when I ask it to search for algorithm used. Of course it is probably just me that don't understand it well enough. It is slightly worrying though that I cannot recreate known examples that I find online using crc reveng: https://stackoverflow.com/questions/23638939/crc-16-ibm-reverse-lookup-in-c The first answer by Mark Adler involves a pretty simple CRC algorithm that given the data buffer and initiial crc value in the Maxim example generates the mentioned output. But I cannot gat the same output using crc reveng. So I just have to do something wrong when using it. But cannot figure out what. /Mattis > --Chuck > >
