Odd question: I have mac snow leopard on the main drive. I have Mavericks on an external. I'd like to be able to drag stuff between them but the drive for whichever is not booted (both are bootable) shows everything locked. Both drives are set to share in general. Is there anyway to set up a folder to let them 'talk' to each other? The external with Mavericks is smaller so I can't just install everything over there. The point of having both is that I know, for certain, somethings I need and can't replace would break on update. This is one way of testing which, assuming I can figure out how to get them over onto the other drive. Is there anyway to do this?