This OP-1 reminds me of the Casio VL-1 [1], made famous (in Germany at least) by the pop band Trio in their NDW (Neue Deutsche Welle) song Da Da Da [2] [3].

I wonder whether that's accidental, or an homage.

[1] https://en.wikipedia.org/wiki/Casio_VL-1

[2] https://en.wikipedia.org/wiki/Da_Da_Da

[3] for example about 1:25 into this video: https://www.youtube.com/watch?v=lNYcviXK4rg