Hi Ian ,
great topic.

I was a lousy piano piano player, at least with an arranger keyboard, the tunes I play are sort of recognizable . haahaa

My first arranger keyboard was a Yammie also. Can't remember the model, (mid 80's?)
It read some sort of a card with sheet music printed on it.
My next one was the KN800 ( approx 1988?) From memory, I think I actually managed to midi it to my Yamaha Disklavier piano.

It was great when Roland & Korg eventually brought out arranger modules. Hubby was happy not to have keyboards taking over our living room.
They were moved to a spare room, the module stayed with the piano.
Really miss having arranger modules, even though my beautiful piano's are long gone.

best wishes
Rikki