I am starting to compile information about how to work with the unit from a computer. This page lists the low-level commands available through the unit's serial port while it's not running as a TNC. There are commands to read and set the radio's settings- the frequencies, transmitting offsets, and PL/CTCSS tones, as well as reading and setting the frequency memories and the power-on "Hello" message.
I am thinking about writing an open-source program to save and restore the memories in the unit- at first it would be a command-line program, but it may eventually turn into a GUI application with more functions depending on what's available through the command set.