AP off, flight director off. Then it is all the same, verbatim. I have transferred to the bus 3 months ago and the difference is such:
on a 737 you disconnect the autothrotle and fly away from the flight directors to respect RA commands keeping manual control of the thrust/energy. When clear, you have the flight director to help you regain previous trajectory, if desired.
on a bus, you want to keep the autothrust to simplify the manouevre. So you deselect the flight director which trips the A/THR to a basic mode for energy control. When clear, you fly the aircraft manually where you want it and then rengage the automation.
However, I find the 737 classic RA command display (read area shown over attitude indicator) superior over the VSI command on the 320. Because what you do, is fly the aircraft on pitch reference so you want a pitch command. To me this feels more pilot minded compared to the VSI displays that stem from the way TCAS actually works and calculates - comparing relative velocities.
Mind you, this is not a B. vs. A. issue, the more advanced Boeing models have TCAS command presentation similar. It seems that someone was trying hard how to put the TCAS display into 737 class. cockpit with least hardware re-arrangements and happened to hit the sweet spot.
I wonder what the TCAS diplay is in a NG fitted with PFD/ND. I understand they have altitude tape and VSI pointer. Do you guys have it 777 like or the old style?
FD.
(the un-real)