[time-nuts] GPS Outage

[Magnus Danielson]

Hi,

On 02/26/2016 02:39 PM, jimlux wrote:
> On 2/26/16 3:34 AM, Björn wrote:
>> "The product will not report the correct extended GPS week number
>> after the Feb,13th 2016.
>> After the rollover to week #860, the thunderbolt will not make
>> position for 2 hours, because the Ephemeris data on the GPS receiver
>> being consider incorrect.
>> The module will work fine after this 2 hours."
>>
>> Have the Motorola Oncore/Navman/Jupiter receivers also been checked
>> for this condition?
>>
>> Strange that at least 3 independant firmware trees/development teams
>> should chose the same magic wk860.
>
> Actually not that weird.
> They might all have inherited a published code snippet.  There's a
> little table driven chunk of code to compute CRCs that pretty much
> everybody uses, and it derives from some article published in the 70s or
> early 80s for an 8 bit micro.

Indeed. I know of at least one GPS chip vendor that with their developer 
kit provided code. Some code inheritance might be proper, but some might 
be unintentional or not even valid license-wise. Very nice way to 
inherit bugs, as we know what they are... eventually.

Would still love to see some of that code. Somebody got a copy of the 
Marconi/Zarlink code?

Cheers,
Magnus