Viperdoc wrote:
The exact response depends on the autopilot system Some digital autopilots
(I think like the KFC 225 or KAP 150) will respond to the course changes
provided by the Garmin flight plan, do hold entries, etc.

On the other hand, the analog systems (Like the KFC200) require either roll
steering, or manual input of either the heading in heading mode (via the
heading bug), or course input via the course indicator (in nav mode).

I have an analog system, and am thinking about adding roll steering, which
would be particularly useful in flying DME arcs and holds, etc, and
especially in tracking the 90 degree turn in GPS approaches (which NAV mode
doesn't do every well).

Roll steering is a method of control. It is built into the digital
autopilot but it is still roll steering.

Your analog autopilot has CDI steering. With the interface you will be
adding roll steering.