If all you're looking at is text, hook up a serial line, run a terminal program on your other system, type PR#[serial card slot], and voila! Graphics, no way.
There were various 3rd party video cards and Apple's genlock cards which put out honest-to-gosh NTSC properly timed broadcast-able video. Otherwise, it was usual to aim a TV camera at the Apple's monitor. There are a few TBCs which will accept Apple's funny video and correct it.
80 column text requires about 7 or 8 MHz video response, and that's beyond NTSC color composite compatibility, though RS170 monochrome video is compatible. For 80 columns, you need a monochrome or an RGB monitor.
@Osgeld, think about interlace. One field starts at the upper left margin of the screen and ends at the lower right. The next field starts in the top middle of the screen and ends in the bottom middle. So there is a half-line of nothing at the start and end of the second field in each frame. So you could say 525 lines is made up of a 262 line field + a 263 line field, or two 262.5 line fields. Or whatever. Yes, the half-line time is also vertical retrace time. No wonder video engineers called it "Never Twice Same Color" and other less printable names. Apple video is shorter than standard (longer front & back porches) because it is designed to be in the visible part of a TV screen, whereas broadcast video is normally overscanned (extends past the visible area on both sides).
Other systems like Atari and Commodore used custom 4-bit DAC / timing chips to generate video, which produced a more standard video signal, but still usually not broadcast-able, because they also used 262p video to avoid flicker from interlace. Don't know if that makes the subject any clearer. . . :-/