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Messages - immrbig

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EverDrive N8 / Re: Everdrive N8 random white artifacts on screen?
« on: September 09, 2016, 03:00 PM »
I was seeing graphical glitches in smb real cart and everdrive so I went on a hunt for info, I have come upon this.

http://forums.nesdev.com/viewtopic.php?f=2&t=13046 - short version of the info
http://forums.nesdev.com/viewtopic.php?f=2&t=10104 - original post

I think this issue was discussed on nes dev, this happens on stock nes NTSC / j NTSC Famicom with original carts about 1/4 every time you boot certain games with coding that causes this bug.

I'm not knowledgeable about this stuff but if its a different graphical glich sorry for wasting your time lol.

This is a different issue, specific to SMB (don't personally know about other games), and unrelated to EDN8.  Even authentic cartridges on original NES hardware do this.

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EverDrive N8 / Re: Everdrive N8 random white artifacts on screen?
« on: September 06, 2016, 07:56 AM »
I am using a custom AC/DC converter circuit, but I have completely ruled this circuit out as a source of interference.

I have Rev G NTSC CPU/PPUs, and my motherboard is stamped -09.

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EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 29, 2016, 04:37 AM »
Copper tape, in combination with the 100 ohm resistor AND a capacitor (I used a 47 pF ceramic cap, because that's what I have on hand)  seemed to have fixed my NES ED N8 crashes on my Famicom AV.

However, I was getting some noise in my picture because of insufficient grounding for the copper tape. In addition to the via in the video, I also grounded the tape to pin 72 on the NES side and pin 16 on the Famicom side. I only noticed marginal improvement after grounding to the Famicom side, but grounding the tape to pin 72 on the NES side made a big difference.

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EverDrive N8 / Re: Everdrive N8 random white artifacts on screen?
« on: August 24, 2016, 03:48 AM »
I Kirby I only see the noise on the pause screen. My front-loader is RGB modded, but I still see the noise if I disable the mod and go back to regular composite output.

I was playing around with different filtering capacitors last week, and when had the top RF shield off I noticed that the noise got worse in SMB3. I started seeing it at the black end-of-level screen instead of only on the scrolling secret cloud areas (W1L3, for example).

It appears that the N8 is generating noise, which is getting radiated/leaked back into somewhere that causes the white lines on the screen. I tried shielding the N8 itself, but that didn't have an effect.

There have been other cases where NES systems generated noise only when an N8 was present. See this thread, for example: http://shmups.system11.org/viewtopic.php?f=6&t=50313

I removed that transistor on my machine but didn't notice any difference.

Unfortunately, I don't have any equipment that would let me properly diagnose this issue. I suspect that some extra shielding or a strategically placed bypass cap would fix this.

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EverDrive N8 / Re: Everdrive N8 random white artifacts on screen?
« on: August 22, 2016, 11:32 AM »
I have had something similar come up in a few games.

Are there sometimes many of these artifacts on the screen? I saw these in Metroid, Kirby, SMB3, and Punch-out! in addition to Tetris.


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EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 22, 2016, 10:05 AM »
I am using a Famicom AV.

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EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 20, 2016, 01:11 PM »
I did two things - Firstly I lifted the M2 line on the 72 pin connector - so the pin from the 72 pin socket is not connected to the PCB, but I also made a very small cut in the trace (right next to the via on the 60 pin side), then used a wire from the M2 pin on the 72 pin connector, through a 100 ohm resistor and the other end goes to the M2 pin on the 60 pin side.   If you don't cut the trace leading to the 60 pin M2, then the trace runs in parallel with the wire and its the trace that's part of the problem.   So in summary you end up with a wire for the M2 line, running through a 100ohm resistor, and the original PCB trace should not be connected at all.  I've not been able to create any glitches or crashes / lockups since doing this.  Only time will tell whether its a perfect fix but it does seem to be working for me with my 72 pin N8 on the Famicom here.   There are so many variables and really it needs someone more experienced to take a look I think, but it does seem to have solved my problems with my Famicom.

I tried your modification today, and I *think* it is working okay. Thank you! Would you mind, however, checking Metroid on your end? That was one of the games I was having trouble with, and I seem to still be getting some strange graphical anomalies and random resets.

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EverDrive N8 / Re: Nes (72-pin) to Famicom (60-pin) converter mod
« on: August 17, 2016, 09:36 AM »
Just wanted to say thanks for posting this guide!  I did this today, but also added a 68pF cap to the M2 pin, which solved instabilities with my Famicom.  I was having hanging / lockups with games, and resets etc when using an N8.

https://www.youtube.com/watch?v=buLuvjwwI3s

I saw on your YouTube video comments that you are now trying a 100 ohm resistor in series with M2. How did you make this connection? The via for this line is in an awkward spot--very far away from the NES connector and almost too close to the FC connector.

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