Next to the "established" brand devices by Casio and Yamaha, there was also a whole row of good "no name" devices on the keyboard market.
But also brand manufacturers that aren't really connected to home keyboards, produced some interesting products. For example the organ and accordion manufacturer "Hohner", who helped develop several keyboards under Casio's licence in the eighties and released them on the market under other names and with different casings. The video and hifi manufacturer "JVC" also produced a very good keyboard series in the mid-eighties.
I modified some of these devices: