Power up the C-10 (12vdc)

Plug a serial cable into the C-10 serial port (DB-9 to DB-9) You may
need a NULL Modem too

Any "terminal" (e.g. hyperterm on Windows) program should see the
NEMA data. I don't have my manual handy but I think the serial
configuration is 4800,8,N,1

If it is not streaming, try 9600 baud with/without the NULL modem.

It is a pretty simple device so it usually "just works". Old versions
of GLideNav II work well with it.