Yes, you want an NMEA multiplexer:
, and others make some good ones.
You will then use a serial / USB adaptor, or a direct USB input into the computer. The USB connection creates "virtual" COM ports that the computer can use.
Some multiplexers can deliver the combined NMEA signals as an ethernet or bluetooth connection. Bluetooth usually looks like another serial port, but with the ethernet link you will need software that can use a network connection. Some software (such as NavMonPc
, which I wrote and give away) can bridge or route
the serial and network connections, delivering them as serial and / or network ports.
All the above is assuming NMEA-0183 data protocol. There is the newer NMEA-2000 standard that is another kettle of fish
When it comes to overlaying the display from a 1980-era radar, I think that's not going to happen.