I bought myself a Yamaha QY10 off eBay for less than £30 and was quite pleased with that. Once I’d got it I switched it on to see what it sounded like, and I am quite impressed with the quality of the sound for a device that hasn’t been made since the 1990’s
There’s some interesting stuff on wikipedia about the QY10:
“Released by Yamaha in 1990, the QY10 was the first device offering the facilities of a music workstation in a portable package. In response to its design, the music technology press coined the term “walkstation”, a pun on the words “walkman” and “workstation”. The QY10 sold well, indicating that there was a market for these devices, so Yamaha followed it up in 1992 with the more powerful QY20 and QY22. Subsequently, both Yamaha (most Yamaha QY sequencers) and Roland (the Roland PMA-5) have produced walkstations, although neither officially use the term for their products.”
I’m planning to connect it to my SG20 and use it with my TRGPro using miniMusic software. I’ll let you know how it goes.