I'm pretty sure it was a CS80. A friend of mine had one, and may still. The oscillators drifted on that machine. Actually, the oscillators drifted on almost all the machines up until the Oberheim and Prophet. If you listen to the Bruce recording you can hear some drifting goin' on which although unintended, adds to the width. I know the CS80 went the path of the dodo bird many years ago but honestly, I don't know if I've ever heard anything quite like that keyboard before or since. The Oberheims and Prophets that followed sounded wonderful, were far more stable, far, far, far less weighty, and way more roadworthy. But for fat analog string, pads, and synth basses, the CS80 was a beast.I think it is a CS80 string pad though some say it was an oberheim...If you read the Wiki on it, the version we hear was the original demo that Bruce did in his home studio all by himself...