Linearity of the scope amplifiers was a big issue. Back when this was a thing there was a big difference in image quality between a Tektronix or HP oscope vs s

Linearity of the scope amplifiers was a big issue. Back when this was a thing there was a big difference in image quality between a Tektronix or HP oscope vs some no name scope. For probably 40 years people have been hooking up 8 bit microprocessors and DACs to a scope and trying to display a clock or something and getting a perfectly round clock dial with a cheap scope is not easy.