I guess I just hadn't noticed this til I started writing my own programs for the NES, but on a real TV when you look at the side of a vertical edge of an object such as a wall or block, I notice the scanlines sort of alternate..they aren't perfectly lined up vertically. I assume that is just a consequence of how old TVs work...anyone know why this is?
*edit* I notice this effect is softened in games that use black outlines for objects, such as SMB3. SMB1 has the effect very noticably..scanlines sort of "bleed" into one another as it were.
This would be caused by either RF or composite output noise, or possibly by NTSC or PAL "fun".
If the bricks of SMB1 1-2 look really jagged, you're seeing the chroma bleeding into the luma. The
NES PPU's NTSC video encoder takes some shortcuts to save die size (and therefore cost), and they cause the luma and chroma to bleed into each other.
^^would there be a way to "Fix" this (probably some kinda filter to filter the two signals)
There are two ways to fix this:
- Play on a system with an RGB PPU, such as the PlayChoice or the Famicom Titler. This is doable, though it might be hard to find.
- Make an FPGA-based device that samples the PPU's output pin at 43 MHz to reconstruct the intended luma and the amplitude and phase of the chroma. This is still an exercise for the reader.
Ok i'll take that as a no. (well the rgb ppu thing is ok but problem is that that they dont do all the colours correct ect.)
Here's a more "visual" description of what NES graphics look like when displayed natively through composite video:
http://www.disgruntleddesigner.com/chri ... shots.html
Is anyone aware of any differences in video circuitry between the US front-loader and the AV Famicom? The picture my Fami puts out is a hell of a lot sharper and cleaner than any of my front-loaders. I'll have to try and get some decent pictures...
^^gonna have to say I agree on that. Not sure if its because of the slightly darker picture or something but it just seems......sharper.