Garmin TD 50 Benutzerhandbuch Seite 18

Software Update
You may need to update the device software when you install
the device or add an accessory to the device.
The software update requires either a Garmin memory card
reader accessory or another Garmin chartplotter connected
over the Garmin Marine Network.
See your Garmin chartplotter owner's manual for the full
software-update instructions.
4 Support and Updates