On Tue, Aug 6, 2013 at 4:07 PM, Mark C. Stephens <[email protected]>wrote:
> However if you are hell bent on generating PPS in software somehow (please > let me know you plan? - curious) > FWIW: Over in the hobby-CNC world where it is common to use the parallel port for driving machine tools (mills, lathes, 3d printers) pulses with good timing are output by LinuxCNC which sits on top of a real-time kernel (RTAI, Xenomai, or RT-Preempt). With a well-behaving bios/cpu/motherboard combination it is possible to achieve around 10-20 us maximum jitter - in good cases down to 5 us. The same program run on a non-realtime kernel will easily show 3-5 milliseconds or more of jitter. This is relative to a clock that the real-time kernel uses for internal timing - I am not sure if that clock can be NTP-disciplined. Anders _______________________________________________ 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.
