Remember the 60's and the really poor television we had back then? We had no LED screens, hell, we had no LEDs.
We didn't have large flat screen TV's that you could see across a room. NASA, along with Philco Ford, had several screens in front of them filled with maps, real time data, astronaut physiology data, projected flight paths, and even a crappy black and white TV.
Here is how they did it and it is ingenious! So ingenious, they were using the same system through the shuttle missions because they couldn't find a better substitute.