Royal Expert
Multiplex Royal Expert c. 1987 (not sure of the exact date).
All of the trim pots, dip switches etc. are permanently on the encoder board. For different applications you change an EEprom. Then the trim pots would change function according to the EEprom installed.
One transmitter could do gliders, aerobatic aircrafts, and helicopters. With the Royal Expert shown here, there were a lot of different EEproms availlable even a Nautical one. Way ahead of its time - when all others merely had end point adjust and servo reverse.
Encoder Board
Here is the encoder board. On some of them, you had memory so that when you went back to a certain aircraft or helicopter, all you had to do is recall the memory in that particular EEprom.
1989 catalogue page (courtesy A. Bricteux)