GpsMap 276C VHF/DSC Setup

Now, that the problem with the NMEA interface of GpsMap 276C with my
autopilot is practically solved with the 3.21 upgrade, I would like
to rise again the issue about the DSC, making the following questions,
which I tried to made to Garmin, but has not received a consistent
answer:

a) As I already have the Map276C sending NMEA messages to the autopilot
and to the PC chart plotter software, and I am receiving NMEA messages
from the depth sounder, all this working fine using the Map276C COM1 at
4800 bps, would be possible to make a interface with a VHF/DSC radio
in order to use the new DSC function of Map276C?
b) Knowing that the gps allows sending NMEA messages up to 3 devices,
and I am using only 2, can I use the COM1 to send NMEA to my VHF/DSC?
c) But, as I am receiving NMEA from the depth sounder, could I mix
this info with the NMEA from my VHF radio in the COM1 to receive the
"Position Reports", assuming that my new radio has NMEA in/out?
d) If the answer is NOT, than I ask: can I use the second serial port
COM2 of GpsMap276C to make this connection?
e) But how I can do this, if the GpsMap276C does not allow me to set
BOTH serial ports to NMEA?
f) And, If I could use the 2 serial ports set to NMEA, how I can setup
the COM2 to 9600 bps, which is the speed that DSC needs, if the actual
software of GpsMap276C does not allows me to make this change?
g) Concluding: has anybody successful tested the DSC function of
GpsMap276C, including the reception of "Position Reports"?
h) If yes, could he please, explain to me how this is done?

Thanks

Pascal

Thanks Peter,

I really do not know if DSC is 9600 or 4800. By the way, as You are the
"pope" on NMEA, can You explain to us the format and meaning of the
DSC/DSCE and the AIVDM messages?

Thanks again


Pascal