"Jack Erbes" wrote in message
...
Meindert will be along shortly and I'll bet he has all the answers.

Yo ;-)

To combine two NMEA streams you must indeed use a multiplexer. But I get the
feeling that the OP wants to use two combine two streams, one from the GPS
and one from the AIS receivesr. And at the same time he wants to run two
programs, one common nagivation program and one self written AIS program.
For the last trick, you need indeed software that can accept an NMEA stream
from one port and send it to multiple virtual ports, where each program can
open it's own port. We have VirtualPlex for that.

Meindert
www.shipmodul.com