The CASIO VL-Tone was my first real electronic instrument (Bontempi organs powered by electric turbines are not really electronic, not really instruments), the one by which everything happened, the reason why today I'm spending so much time on Ableton, an old TR-505 and my QY70.
I think I got it around 1981, from a TANDY (Radio Shack) store in Nivelles. As soon as I touched it, I realised how much this machine was great. Can you imagine, not only can you choose from 5 different instruments (piano, fantasy, guitar, violin, flute and guitar) but you can also design your own sounds, by entering the parameters in the calculator's memory. That's the reason why I think the VL-Tone is a crossover between a calculator (a computer) and a synth. That is probably the first computer based instrument, that was affordable, and that you can take with you anywhere. For the same (low) price you get a built-in sequencer. My first sequencer. Just play a melody and it's recorded into the memory. Play it again, and add a second track live !