There was never any focus on graphics in airliner simulators, The focus was on replicating the cockpit environment to be an exact duplicate of the actual aircraft that the pilot was training on. The seat material, the tactile feel of the switches in the cockpit and pressure required to activate them, the sounds, the motion if it was a level D sim, everything had to be exactly right. The flight dynamics in the sim are created by data taken from test flights at the aircraft manufacturer, like Boeing. They look at the data during actual flight conditions, and pick the data from the average aircraft , out of all the samples they have, and that becomes the physics of the particular simulator they are programming. That is how they can program a scenario into the simulator, of an emergency, and the sim will react exactly as the real aircraft would in the exact same situation.
The computer that runs the motion part of the simulator, which costs about 1 1/2 million dollars by itself, has to be controlled by some of the main sim computers which are contained in several cabinets in back of the simulator cockpit which are about 6 feet high, by 3 feet wide and deep. It's motion has to create the illusion of acceleration, pitch ,climbing, descending, yaw, and roll and all combinations of these conditions of flight, so that the pilot is totally immersed in the sensation of flying the actual aircraft. When you apply takeoff thrust, you will be pushed back into your seat as you would in the real aircraft. If you abort the takeoff, and you don't have your seatbelt on, your will be thrown out of your seat and hurled against the front of the instrument panel, which you don't want to have happen. As you taxi to the active runway, you can even feel the bumps in the taxiway which are programmed into the sim software.
I flew a Delta 767-400 ER sim in Atlanta, and the graphics showed the airport, the interstates that go by the airport, the Marta Train, that runs into the airport, and the ramps and taxiways. There is no scenery as you would see in Trainz or FSX, because that is not important to the training pilot. What is important is the cockpit environment, the avionics, the behavior of the aircraft, the navaids, the lighting, especially the approach lights in instrument approaches, as well as weather generation. When you land one of the sims in a 200 foot ceiling with 1/4 mile visibility, it must be exactly as you would see out of the windscreen in a real aircraft making the same approach at the same airport under the same conditions.
When the airline receives this simulator from a company like CAE, which makes about 90% of the airline sims in the world, it has to go though an acceptance flight by the FAA just as a real aircraft would. If the FAA examiner feels that there is something not quite right with the sim he is checking out, he will not sign off on it, and the Airline will not give the sim company a payment for the sim. Without FAA acceptance, it is a 20 million dollar Nintendo game, as far as the airline is concerned. All of the training the pilot gets before he or she carries passengers is done in these simulators, all of it.
This is what it is like if you would like to learn something about this type of sim, which is made by CAE.
http://www.youtube.com/watch?v=L8JUWUKXV08
The idea of doing this type of simulation using a PC, is just ludicrous.
If we do need to cite information, which I tend to do on occasions, put in a URL, or other source of information. It does back up the validity of a point.