In Toast 6, when you create a data disk, you choose either "Mac only" or "Windows and Mac" . If you choose "windows and Mac" when you create the disk you should be able to read it on both platforms. If you just want to read the current disk, I tried an eval of a product called MacDrive (
http://www.mediafour.com/products/macdrive6 ) and it seemed to work OK, however it cost more than it was worth to me ($50 US).
Hope this helps
Dave