The Roland D-50 is a digital synthesizer used by Prince in the late 1980s and early 1990s. It was acquired by Prince in 1987 and went on to become the main keyboard on Lovesexy. Songs that use sounds from the D-50 include Positivity (DigitalNativeDance), Eye No (Sountrack) and Anna Stesia (Piano-Fifty). Prince also used the D-50 on Batman and Graffiti Bridge. It may have been in use in the studio as late as 1992.
The D-50 was also used live by Dr Fink, Boni Boyer and Rosie Gaines. Dr Fink also used a Roland D-550, which is a rack version of the D-50. He layered the two units to create a bigger sound.
It's pretty much the same keyboard setup Prince records with, but I'll try to enhance the sounds. Instead of having one D-50 per patch, I’ll stack another one on there to fatten it up. I have three [Roland] D-550s in my rack, and a couple of Emax IIs; I'll do all kinds of different things with them.
He still uses a lot of Fairlight samples that he created. I know that for the Batman album and for Graffiti Bridge, he pretty much used a [Roland] D-50 and the old Emax 12-bit CD-ROM library for a lot of sounds.