One picture over multiple CRT monitors

Hi Guys,
I’m not asking how to do it, I understand enough to know I’m not up to that,
It was a respectable idea and implementation at the time for whomever did it first.

I would like to know the name of the commercial device that did the upscaling of each quadrant,
and added the new horiz & vertical sync for each monitor of a multiple monitor array to show one
coherent video signal. I’m talking about analogue sources before the bigger display methods were happening.
Cheers, Art.