[francis_t_catte]

I have a Symmetricom ExacTime ET6000 that had a Motorola Oncore M12+ mounted to an ACE-III interposer made by Synergy systems that hadn't suffered from a rollover yet, but instead had a 3 month leap second induced offset. I went the (mildly easier) route with a Furuno GT-8736D, then modifying the interposer with a level shifter for the serial lines as the ET6000 uses 5v TTL logic, and the Furuno chipset is only rated for 3.6v maximum (and so was the M12+, for that matter!).

[tverbeure]

My first board rev had level shifters too, but they weren’t needed in the end.