Oddly, hardware synth manufacturers have been reluctant to port their sound designs to software plugins. Roland doesn't do it. Yamaha doesn't do it. Aside from Korg, every software emulation I know of has been the work of third parties. It makes sense that a hardware vendor doesn't want to compete with their own products, but you'd think that wouldn't be an issue with discontinued products.
If you really, really want that patch in your computer, it can be done. Not easily or without cost, but it can be done. I have ported some of my favorite patches from my Yamaha MO8 over to Kontakt. It was time-consuming and I sure wouldn't want to port the entire soundset, but it's been very handy to have some of my most-used patches on disk.