For some background information: I had a ps3 that got ylod, and apparently it couldn't be fixed, so I bought a friends ps3, so now I have 2 ps3 hard drives. (even though I can just use any laptop hard drive for the ps3)

Currently the hard drive from my ps3 (the one with ylod) is in the ps3 I bought.

Now onto the questions:
If I switch the hard drive's out (take out my first ps3's hard drive, and switch it with the other one), and then switch it out again, would I need to format my hard drive? or would the ps3 know that it is a hard drive that was curently in it.

Question 2:
If I switch hard drives, is the firmware on the hard drive, or is it not? (sounds like a stupid question, but I am seriously not sure)

Thanks