as one who lived thru the time line, it went

single button, escapement type radios

mulitple switches, reeds- right bank of controls, and left bank of controls, you could only use one control function from a bank at a time. this is the origin of mode 1 and mode 2

propo 2 stick
what we have now without the puters

propo single stick

then single stick stuff got too expensive, so the mfgrs droped it.

puterised propo

along in there about the time of prop appearance, we had galoping ghost, a mix of escapement and propo. lotta fun actually