Why do you think he was told to look at software as it is not in the dialogue?
Huh? I don't. I just ruled out one thing that the display might be about.
I see. I wasn't sure why you brought it up since I did not.
It's not about the abstractions of navigation - it's about the practical means of pointing the ship's bow in a desired direction.
If that were so, then why were they disrupting the "automatic helm and navigation
control"? A ship also needs to have sensors to understand if it's course correction inputs are having the desired effect.
If it was as simple as cutting power to one nacelle to skid steer the ship we would have plenty of examples - but we don't.
Actually, when looking at the argument of how tightly coupled helm control is to the engines it would appear that they are treated as two separate systems which undercuts your argument that helm and navigational control circuits would be present on that diagram.
"The Naked Time"
Captain's Log, stardate 1704.4. Ship out of control, spiraling down towards planet Psi 2000. We have nineteen minutes of life left without engine power or helm control.Kirk calls out "helm control" and "engine power" as distinct entities.
and in the same episode, Scotty jury-rigs "something" to give power to helm control to stabilize the descent.
SCOTT: Engineering to Bridge. Try your helm. You'll have enough power to keep her stabilised. Here, let's have a look at that.But hey wait a minute, helm control is controlling the ship with the warp engines and impulse engines off? That does not sound like they are tied directly to the warp engines.
and "The Ultimate Computer"
KIRK: Lieutenant, get Daystrom up here. Disengaging M-5 unit. Cut speed to warp one. Navigator, go to course one one three mark seven. I want that ship given a wide berth.Kirk addresses two DIFFERENT functions, engine speed and helm control/navigation. Sulu's "helm control" cannot turn her around. So Kirk goes to "engine control" or Scotty to slow the ship down with engines. Notice he doesn't tell Scotty to slow one engine down to turn the ship.
SULU: She won't respond, sir. She's maintaining course.
CHEKOV: Going to warp four, sir.
KIRK: Scotty, reverse engines. Slow us down.
SCOTT: Reverse thrusts will not engage, sir. Manual override isn't working either.
If we were to think about how helm control (or steering) works it would be independent of acceleration and braking controls (or engines).
Yes, Helm control does send throttle settings to the active engine systems (warp or impulse or both) to accelerate and decelerate but turning is NOT reliant on them in a direct sense since we've seen it operate with engines down. If you're wondering what does the actual turning, in TOS it is left vague. However in various later series and the movies they point strongly to "thrusters" and "stabilizing gyros". Especially "For the Uniform" where the control systems are disabled and the crew has to manually trigger the thrusters for helm control.
So if that diagram was related to autopilot helm control, it would be the computer leads to the banks of sensors (to confirm that they are actually changing directions), gyros, thrusters and throttle control to the warp and impulse engines (but not necessarily detailed down to the reactors and crystal assemblies).
Also another factor against that diagram having the helm and navigational control circuits in them is that it shows up in many episodes on that panel. It would be foolhardy to argue that every time that diagram shows up the ship's automatic helm and navigational controls have been re-routed and the normal circuits are dead
BUT - if you've stayed reading this far, I'm happy to agree that the diagram could be about the power generation and/or propulsion system.
Chekov clearly looks down at the buttons and makes a determination that the circuits are dead after fiddling with it. He NEVER looked back up to that diagram to confirm the circuits were dead when he goes to tell Spock indicating that the diagram had nothing directly to do with the helm and navigational control circuit