The command computer was the interface between the bridge and the engineering section of Federation starships in 2364. The computer was positioned to the left of the chief engineer's console on Galaxy-class starships.
The bridge of a starship would issue a command to the engineering section for an event to occur, for example, to go to warp 3. A command computer would receive the order and pass the order to the engineering computers. The engineering computers in turn would then initialize the warp engines. The rate of communication was measured in milliseconds.
Isolinear optical chips were integral to the functioning of the command computer. The chips for the command computer were marked by a blue strip. As the engineering computers were dependent on the command computer for commands, if the chips were removed, the ship wouldn't be able to move.
In 2364, aboard the USS Enterprise-D, Assistant Chief Engineer Jim Shimoda, suffering from polywater intoxication, had pulled out all the command computer chips. As it would take a Human many hours to restore the chips to their rightful places, Lieutenant Commander Data was called upon to restore the command computer. The android accomplished the task in minutes. With the command computer fully restored, the Enterprise warped out of the path of the stellar core fragment. (TNG: "The Naked Now")