Books on mini home keyboards?

Hey I have a question? Are there any books on those mini home keyboards of the 1980's? The one's made by Casio and Yamaha? I recnetly bought a Yamaha PSS-130, for $9.00.

Paul

I know it is Old but: http://www.manualslib.com/download/196845/Yamaha-Portasound-Pss-130.html<

Rejjieb

Thanks so much. I downloaded it and will add it to the Synth Zone archive.