The original Harrier sim at Wittering comprised 3 horizontal scenes with a 3 axis cockpit in a separate room. The particular board in use was lit with hundreds of flourescent tubes to give the right sort of lighting for the moveable cameras. The resultant heat required a rather large air conditioning room which, of course, was also needed for cooling the room (a large room) which contained all the reel-to-reel computer cabinets.
The result of all this was quite a large building.
In my war role my senior flt sgt was also the i/c flt sim in his day job. One Christmas I managed to win an Atari 64K computer thingy in the Christmas draw. The flt sgt told me that the computing power in that thing outstripped the computer power in his entire flt sim!