I bet it was the Roland setup. I forget the model, but it uses individual pickups for each string and some huge 9 conductor cable to go to a decoding box. I still have one somewhere. The latency was terrible, and more than one note at a time was a gamble, but it was fun for string sounds with a slow attack. Some guitars in the 90s even had the setup built in.

To go back even further, check ot the original, the VOX Guitar Organ. Lots of vids on youtube.