GoKawiilThe Nintendo Entertainment System. Is it the platonic ideal of an 8-bit video game system? Well, only because it’s so prominent and successful– it’s actually kind of an oddball in its expandability and design. But there’s something else about it. The picture is a bit… wobbly. Well, over composite video anyway. Let’s dig in and learn a little big more about the nitty-gritty of composite video.
This whole blog post is only going to talk about NTSC encoding and timing. PAL encoding is its own thing, and the signal timings on 50Hz are different in significant ways. I don't have many consoles that output PAL and I'm less familiar with it.
Not so mighty now, are you
You don't have a video tag support or something? So you can't see this footage of the *Mighty Bomb Jack* title screen? Ah too bad.
Mighty Bomb Jack, the most iconic bomb-collection platform taking place in a pyramid for the Nintendo Entertainment System. The title screen here, like a lot of title screens, is entirely static. But here, I’m using my composite-modded system, which just amplifies the video signal coming right off of the PPU, and the picture is wobbly.
And you might be tempted to say, now wait a second Nicole, this is composite video. You wrote a whole post on it! Composite video is inferior to other signals because it’s basically a form of video signal compression. And that’s true; but there’s no reason a composite frame should differ from frame to frame, is there? Here’s my beautiful Apple ][ running Shanghai (as referenced in a recent post).
You don't have a video tag support or something? So you can't see this footage of the *Shanghai* title screen? Ah too bad.
That’s incredibly static!
Explanation Attempt 1: Interference
Interference isn’t actually as big of a problem as you’d expect. It’s probably something you’re thinking about, but interference would generally present as a random pattern, not the cyclic noise seen on the NES screenshot. In fact, the Apple video was captured using a much longer cable, being strewn over my desk where several electronics were running, and you can actually see some noise in the white parts of the image. But it’s noise; it’s uncorrelated to the input signal.
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