Additional information for the video above:
The firing commands are hard to understand in the video so here's how it should go as I remember it. These commands may have changed in the last 40 years.
Commander - driver! move out. (tells the driver to go from turret down position to hull down position.
Commander - gunner! SABOT! moving tank! Alerts the gunner to look for a moving enemy tank. Also alerts the loader as to the type of ammunition he wants loaded.
Gunner - Identified! Lasing! The gunner sees the enemy tank and is using the tank's lasers to compute the distance to the target. The tanks computer is factoring in weather, wind speed and speed of the tank.
Loader - UP! This means the loader has loaded the SABOT round into the breach and locked it. He is out of the way and the gun is ready to fire.
Commander - FIRE! This let's the gunner know to pull the trigger when he's locked on and ready.
Gunner - On the way! The gunner let's the crew know he is firing the main gun.
Commander - Target destroyed! Driver reverse! The enemy tank is knocked out. The driver should move the tank back to the turret down position to make it less of a target in case there is another unseen enemy tank in the area.