This is a simple daemon for a computer running Linux to decode the DCF77,
MSF or WWVB time signal from a receiver which pulls the DCD, CTS or DSR pin of
the serial port high and low in correspondence with the radio signal.

Installation should be a dodle type 'make' to build the program. Provided
you have the necessary permissions on the serial port you can then test
it out. You can install the program with 'make install'. By default the
program and manual page are installed in /usr/local. This can be changed
by editing the make file.

For more details on the command line arguments to the program please consult
the manual page, and check the web page

    http://www.buzzard.org.uk/jonathan/radioclock.html

If you have problems getting the software to work using interrupts the
following, command is known to resolve the problem in many instances.

     stty crtscts < /dev/ttyS0

where ttyS0 is the serial port the receiver is connected to. You may also want
to try running

     watch -n 1 cat /proc/interrupts.

If the number of interrupts on the serial port is not steadily increasing then
there is a problem with the serial port detecting interrupts. As a last resort
you may specify a -p command line option to either program, in which case the
programs will poll the serial port every 5ms. This uses slightly more CPU time

If you are have to compile ntp yourself to include the SHM reference clock
driver then you probably want to replace refclock_shm.c in the ntp
distribution with the once included here. On the replacement version
you can set flag3 to 1 and the reference clock will no longer log the
fact that a new time stamp has not been found in the shared memory segment.


JAB.

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Jonathan A. Buzzard                 Email: jonathan@buzzard.org.uk
Northumberland, United Kingdom.       Tel: +44 1661-832195
