I understood that. I'm old enough to remember VCR's / game consoles required you to turn to channel 3 or 4. But what were the older, non-personal terminals usin

I understood that. I'm old enough to remember VCR's / game consoles required you to turn to channel 3 or 4. But what were the older, non-personal terminals using? Was there some sort of RF modulated raster pattern optimized for displaying text? Were they drawing everything as vectors? Did they use off the shelf CRT's?