One of the first three portable keyboards that Yamaha produced for the home market in 1980, the PS-1 was the most compact, with only 4 voices and 4 rhythms to work with.
All sounds you hear in the track were made using the PS-1 and run through various single effects pedals (TC Electronic Sub Up octaver for bass notes and for a floaty lead part, the very synth-friendly Yamaha SDS CH-10MII chorus pedal, and the Vestax DDX vintage digital delay). .
This tune was my first (or was it second?) attempt at writing something on the PS-1, before scrapping it in favour of Lens Flare.