One of the interesting classes I took at common was on ptf's and about how important it is to do a perm apply so that the A side gets updated. Also discussed about downloading ptf's from the web onto the box, etc. (which I do). And something I guess I didn't know after you perm apply the ptf's, and re-ipl, the machine will come up on the A side. I just always thought you would come back to the b side.
Of course today ptf's are so much easier than when they were on diskette or on a cassette.