Roll-based AP of same functionality as STEC-30

Matt Barrow wrote:

The King KFC-200 and KAP 200 have been very reliable autopilots.

The cited article speaks of these connected to a vacuum-driven AI. Is that
a requirement, or might these be connected to an electric/electronic AI.

I think that this is really more of a generic question too. My [meager]
understanding was that there are "protocols", and as long as an AI and AP
shared at least one in common, they could be used together. Are the
avionics and AP more tightly coupled than I'd thought?

- Andrew