A "cga" video card drives a standard (NTSC-style) color monitor, I believe.
The "40 column" mode of cga video was designed for using the PC with an
RF modulator and a standard TV.

I don't recall for sure whether the connector actually had standard video
signals, or whether it was a combination of RGBI signals and such, but the
relevant scan rates were "standard video."

BillW, keeper of ancient knowlege.