Furuno CU-300 Operator's Manual page 20

Two memory card interface units
1
NavNet VX2-BB
Processor unit
3
NavNet VX2-BB
Processor unit
Unit and available chart card and memory card locations
The numbers in the table refer to the corresponding units in the figure
above.
Available chart card
Unit (priority)
1 1 2 3 4
3 1 2 3 4
2
HUB
4
*: For the second CU-300, DIP switch setting is necessary.
Available memory card
locations
2
2
11
CU-300
CU-300*
location