Akai S900 OS 4.0 where can I get one? Mine got corrupt.

Made lots of beats with the OS 4.0 and my disk is now corrupt.. Can't load anything without it. Don't have a old PC to make a new one myself. Where can I buy? Or who will sell me a few copies on disk? Or has anyone successfully made one with a newer macbook and a usb floppy drive?

I have an original OS 4.0 disk, never tried to use it though, so no idea if it still functions or not, or if it was functioning when I bought it second hand.

If there was a way to make a copy, I could give it a go.

It seems that OmniFlop might do it on a PC, but seems to need a built-in floppy drive, which I don't have anymore.

http://www.shlock.co.uk/Utils/OmniFlop/OmniFlop.htm

Would be interested to know if there are any other options, and if there is anything to do it on a Mac, as well.