> Naturally, there are downsides: having to mess with the CRTC every couple of scanlines is quite taxing for the poor 4.77MHz 8088, so there's not much you can do with this other than static pictures. The 512-color variant, using only ASCII 0x55 and 0x13, doesn't suffer from this – it's basically "set and forget", requiring no more CPU intervention than any 80-column text mode (the familiar overhead of avoiding snow).
> Then, there's that other problem which plagues 80-column CGA on composite displays... the hardware bug that leads to bad hsync timing and missing color burst. There are ways to compensate for that, but none that reliably works with every monitor and capture device out there. This proved to be an enduring headache in calibrating, determining the actual colors, and obtaining a passable video capture of the entire demo... but that's all covered elsewhere.
> Naturally, there are downsides: having to mess with the CRTC every couple of scanlines is quite taxing for the poor 4.77MHz 8088, so there's not much you can do with this other than static pictures. The 512-color variant, using only ASCII 0x55 and 0x13, doesn't suffer from this – it's basically "set and forget", requiring no more CPU intervention than any 80-column text mode (the familiar overhead of avoiding snow).
> Then, there's that other problem which plagues 80-column CGA on composite displays... the hardware bug that leads to bad hsync timing and missing color burst. There are ways to compensate for that, but none that reliably works with every monitor and capture device out there. This proved to be an enduring headache in calibrating, determining the actual colors, and obtaining a passable video capture of the entire demo... but that's all covered elsewhere.