Funny how apparently Trimble were involved in the wk860 problem, I thought they famously used their leap second based rollover protection: http://www.google.co.uk/patents/US5923618 :) Maybe that algorithm isn't that smart after all.
Thanks, Wojciech Original Message From:[email protected] Sent:29 February 2016 11:02 am To:[email protected] Reply to:[email protected] Cc:[email protected] Subject:Re: [time-nuts] GPS Outage Hal, Hal Murray wrote: > > [email protected] said: >>> Strange that at least 3 independant firmware trees/development teams should >>> chose the same magic wk860. > >> I don't find it strange. If the next firmware version is based on the >> previous version and none of the developers has stumbled across this >> potential problem earlier ... > > That sounds like poor software engineering. Or poor engineering management. > > The wk860 is supposed to represent the build time of the software ... Do you *know* this, or are you just *assuming* this? ;-) > so it will > work for 20 years from when it was built rather than 20 years from when the > 10 bit week counter last rolled over or 20 years from when the constant was > last updated. There are also approaches where the proper extension of a week number doesn't just work within a single 1024 week cycle with some hardcoded limit, like this simple example: if ( wn < 860 ) wn += 1024; There may always be pieces of code which generate a faulty result under certain conditions, and no stumbles across this even in reviews until it really happens. I'm not aware of *any* project where each single line of code is checked once again whenever a new release is rolled out. Martin _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
