Believe it or not, I allready did the floppy drive sound thing with an older release of WinUAE, you can grab it
here, as I say, it's an older version, without any off the new stuff from the last few releases (i must get the latest sources and update it at some point) You can turn the effect on and off from the floppy tab. The effect is ... different ...
but there you go
enjoy.