nesdev.org

Palette color 0x0D is called blacker than black.

I was using it as my background color. Which was a mistake at least when playing on a real system depending on the TV.

What are the consequences of doing this on a real system?
Are there any other colors that are "wrong" to use?

On a TV that reacts to that color (like re-triggering vblank), can it cause damage to the TV or the NES?

Al

The game genie used that color as the background. I think it did weird temporary things to some TVs, nothing permanent.

Dwedit is right. If a TV loses track of horizontal and vertical sync, it might cause the picture to roll or the character generator[1] to turn the screen a solid color. But TVs should be robust against malformed composite video signals, if only because they have to be robust against distorted signals received by the RF tuner.

[1] All American TVs have a character generator to display captions. Most run their menus through the same character generator.

On one old TV, the Game Genie code screen displayed improperly, with the image flickering badly and the screen contents not being at the correct position on the screen. As I recall, the screen was still visible enough to enter code letters (though it wasn't pretty), and once you got past that screen everything was fine. I've used the NES and Game Genie with several different TVs, and that TV was the only one that exhibited problems (and it was an old model).

From what I understand about how the PPU outputs composite video, color $0D is the only one that needs to be avoided (not sure if color emphasis changes this or not).

I've only used my Game Genie once (damned Zelda II exp system started to really piss me off so I did the 256 exp code to level me to 8-8-8 ), & of that one time, I noticed about 2/3sec of a solid color. I figured it was just a long init time, but come to think of it, it did seem the same color as the character generator.

Can someone help me out on this?

I was able to see the problem on my LCD TV. By changing my palette from 0x0D to 0x0F, the problem went away. It was pretty freaky.

Al

So, what is the correct black to use again? $0F?

I think 0F is good. Its what I changed mine to and my problems went away. if anyone else has opinions, let me know.

Al

I'd just like to point out as an example that SMB1 uses $0f for black. It doesn't necessarily mean that they couldn't use $0e, just that $0f was probably the one recommended color setting for black.