On Mac OSX Mavericks, why does Arduino Uno uses serial port named
/dev/cu.usbmodemfa131 while Arduino Nano uses
Are they using different FTDI drivers?
It's really down to the manufacturer and what they identify their USB side as. I have found that Arduino(tm) provide a more meaningful (to me) identifier, eg
/dev/cu.usbmodemfa131 Whilst the boards that use the FTDI chip have the more serialised numbers
The Uno is not using FTDI drivers at all, since it does USB through an ATmega16u2, not an FTDI chip.