Hi guys, got my new rMBP yesterday and loving it so far. Today I want to set up the time machine back up utility whilst I've got the time. Heres what my situation is; In my possession is 500gb USB 3.0 drive. I used this drive with my old windows PC and I have about 150gb of files that I want to keep on there. How do I setup time machine to partition this drive so that i can keep the backup of my mac and keep all my files on there as well? cheers.