HI JOAN,
You don't say how old this organ is but I might have some info of interest that could help answer your question.
I bought a digital Piano from Technics when they first brought them out, about 1987 or thereabouts. it came with a little card that you could save half a dozen songs on.
There was a floppy disc accesory that was also sold but because it was over 700.00 USD at that time, I declined to buy it. I also recall there was not any info in the PR90 piano manual about the floppy disc other then a reference to it as an available accesory.
Best to you,
Bebop