[jeff_tyrrill]

Watch a broadcast TV signal on an old CRT: The scanlines appear to roll up (or down, depending on how you are trying to perceive them).

Hook up an NES to an old CRT and look closely at the screen: The scanlines are absolutely still. (This is also the case with the full-screen menus of VCRs, with the white text on blue background.)

The NES most definitely outputs progressive-scan video at 240p, with all 240 lines drawn 60 times per second.