[time-nuts] Motorola GPS Z3801A

Rex rexa at sonic.net
Wed Jun 2 00:28:20 UTC 2010

Robert Benward wrote:
> Hi,
> Does anyone have the pinouts for the Motorola GPS within the Z3801A?  It's a 
> ten pin header and I would like to intercept the data stream to see if it's 
> working.  Also, I read about some of the Motorolas putting out binary data, 
> not NEMA protocol.
> Thanks,
> Bob
The Oncore interface diagram on Didier's page should be enough to see 
which pins are which:

For the details, here's a link to a nice clean Oncore manual:

Chapter 6 of that manual is a description of the Oncore commands that 
are used by these receivers. Yes, it is a mixture of ASCII commands with 
binary data.

I forget which receiver(s) the Z3801A used. My Z3816a has a UT+ but it 
is a little more recent than the 3801's. Someone here, no doubt, remembers.

A few years back there were a bunch of posts to this list with reference 
documents for the various Oncores that HP or Symmetricom used in the 
timing receivers. Lots of detail of firmware versions and differences 
between the Oncore receivers. I don't have a link now. Maybe others do.

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