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Green outlines on sprites?

Green outlines on sprites?
by on (#193026)
I just got a used NES but when I boot it up I noticed that there were green outlines everywhere and a green bar across the middle of the screen. Has anyone ever seen this?
Re: Green outlines on sprites?
by on (#193028)
Pictures please.
Re: Green outlines on sprites?
by on (#193033)
Sorry for the late reply, here are the pictures
Re: Green outlines on sprites?
by on (#193034)
That green bar has been seen before, some kind of shadow image of horizontal blanking. I can't remember if there was a solution for this, but there was definitely a thread about it before (but I can't find it at the moment).

As for outlines on Mario I'm not sure what that's a picture of but it's normal/standard for the NES to have colour errors at the edges of shapes due to how it generates its NTSC signal (example).
Re: Green outlines on sprites?
by on (#193035)
I noticed that when I do anything it gets mirrored on the other side of the screen in that same green
Re: Green outlines on sprites?
by on (#193036)
Would the horizontal blanking interval be due to the up scaling? Could it be due to the TV itself? I am using an adapter to convert it to HDMI but it works perfectly on the ATARI.
Re: Green outlines on sprites?
by on (#193037)
As you can see the blocks are being mirrored to the left, thi bugs me the most
Re: Green outlines on sprites?
by on (#193039)
Interesting. It looks like those are off by 128 pixels. Maybe some counter in the PPU's 8th bit is broken, and something funny inside there is actually affecting tile fetching. That is going out on a limb considerably, though.

Do you have another TV to try?
Re: Green outlines on sprites?
by on (#193040)
Jackknife18846 wrote:
As you can see the blocks are being mirrored to the left, thi bugs me the most

Oh wow, maybe that's not the problem I'm thinking off.

mikejmoffitt wrote:
Interesting. It looks like those are off by 128 pixels. Maybe some counter in the PPU's 8th bit is broken, and something funny inside there is actually affecting tile fetching. That is going out on a limb considerably, though.

I would guess this is some sort of analog signal delay, not any kind of logical failure in the PPU. I think a logic problem would have much stronger consequences than an afterimage kinda thing like this.
Re: Green outlines on sprites?
by on (#193041)
Jackknife18846 wrote:
I am using an adapter to convert it to HDMI but it works perfectly on the ATARI.


Does it do anything like this without the upscaler? If not, whatever adapter you're using should be the prime suspect.
Re: Green outlines on sprites?
by on (#193042)
I have a portable sreen to try acually but not a CRT or anything
Re: Green outlines on sprites?
by on (#193044)
I just replaced the TV with AV support before I got the NES, I can only try it with the adapter
Re: Green outlines on sprites?
by on (#193045)
You appear to have a "reflection" in the video output. The easiest things to try first depend on how you're connecting to the TV right now: if you're using the RF output, try another RF switch; If the RCA output, try another (different length) RCA cable.

The green vertical bar is how the TV signal specifies the hue of the color information on screen, repeated somewhere around 1/3 to 1/2 of a scanline (≈20 to 30µs) later. This can be caused by the TV lacking the correct input impedance, the NES having the wrong output impedance, or the cable being damaged.

(I wouldn't be the least bit surprised if a cheap composite-to-HDMI converter had the wrong input impedance)
Re: Green outlines on sprites?
by on (#193047)
I'm pretty sure the adapter is the problem. It does work on my ATARI though.
Re: Green outlines on sprites?
by on (#193048)
The adapter needs to be plugged in but I haven't tried it unplugged. I'll see if that fixes it.
Re: Green outlines on sprites?
by on (#193050)
rainwarrior wrote:
That green bar has been seen before, some kind of shadow image of horizontal blanking. I can't remember if there was a solution for this, but there was definitely a thread about it before (but I can't find it at the moment).

viewtopic.php?f=5&t=12052
Re: Green outlines on sprites?
by on (#193051)
DRW: That's about CRT. This appears to be a modern TV whose deinterlacer is doing this because it expects a frame that's 262.5 lines long instead of 262.

Retro consoles produce an NTSC-compatible signal with slightly nonstandard scanline length and field length. The size of the field incluing blanking varies from one picture generator to another. Measured in color subcarrier cycles, the field sizes are as follows:

  • Atari 2600, Atari 7800, Apple II, Master System, and Genesis: 228x262. Color artifacts line up vertically.
  • NES and Super NES: 227.333x262. Color artifacts line up diagonally.
  • Neo Geo: 227.5x262. Static dot pattern.
  • Fifth generation consoles (PlayStation, N64): Haven't tested
  • Sixth generation (Dreamcast and later): 227.5x262.5. This timing follows the NTSC standard.

Does the problem happen when you connect the same NES Control Deck to a traditional CRT SDTV?
Re: Green outlines on sprites?
by on (#193116)
I only have an LCD, if I had a CRT I would use the NES on it.
Re: Green outlines on sprites?
by on (#193117)
You said you "The adapter needs to be plugged in but I haven't tried it unplugged". How did that go?

Does the HDMI adapter have an RF or A/V input? Do you have another cable for whichever connection you're using? Have you tried it?

Does the HDMI adapter have an S-video input?