In message <200703161159.51966.bsdfun@comcast.net>,
Video Mike writes:

>Dear NetBSD,
>
>I am using NetBSD for an automation system for a radio
>station and neither DSL nor broadband is available where
>the system is at so I discovered while reading the man
>page for options(4) that I can lock the real time clock
>onto an external source by using the kernel's "options
>PPS_SYNC".  This involves the DCD line I believe on one
>of the COM ports.
>
>Question is does this work on V4 Beta 
>
I can't say for sure, but I should expect so.

>and am I correct
>to assume that it requires a 1 pulse per second clock
>from an accurate frequency reference?  

Yes. The intent is to use the PPS-API to pass an NTP daemon an
accurate idea of exactly _when_ the second epoch falls. But to run
NTP, you'll also need time information telling you _which_ second
epoch is indicated by each PPS edge.  Typical usage is a GPS device
running in clock mode, emitting a ASCII timestamp burst of about 20
characters.  The ASCII timestamp burst tells you *which* second is
ticking, and the PPS edge tells you *when* during (or near) the burst
that particular epoch happened.


>If so, then I
>can design a nice clock generator that has an RS-232
>output drive to do this.

Hope the above helps.