I’m not entirely sure when I bought this keyboard, but I have it on photographs taken in 1988/1989. I remember that there was also a WK50 available, but that was a more expensive 5-octave model.
But this keyboard is really what “started it all”. It was my very first MIDI keyboard that I could hook up to my Atari ST and use multiple MIDI channel on to make compositions! If I remember correctly, I had something like 7 channels to play with or something like that. Might not be that spectacular today, but we’re talking end-80s here. There were no soft-synths, no VST or stuff like that. Everything was done using hardware and MIDI cables.
Unfortunately the quality of the demo is extremely bad. I don’t even remember how I got a hold of it.