Asus a7v333 Promise harddrive boot-up

[cg]

Hi, I just purchase this new MB, and it uses the Promise raid, I am used to the highpoint. I have 2 hard drives connected to the 2 raid controller. Is they an option for me to chose which harddrive to boot up with. Because I have 2 operating system on each of those harddrive. They was an option like this in the highpoint bios, is they one also in the promise? I try searching for it but have no luck. Do I need to do it through the asus bios? Or will I have to physically disconnect the harddrive and just connect the ide to raid controller 1 or 2, everytime I want it to boot from a certain harddrive. Thanks