The Roland P-330 digital piano module was released in the late '80s shortly before the U-110. The U-110's accurate acoustic piano samples might explain why the P-330 wasn't very popular, but it might also be due to the flood of MKS-20s on the market after the U-110 was released. The P-330 attempts to do all the MKS-20 digital piano module can do, and more, all in a light weight one rack space package.