krzys cart?? mine failed

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nesoldskool
Posts: 5
Joined: Sat Feb 19, 2022 7:24 am

krzys cart?? mine failed

Post by nesoldskool »

Just thought i would ask if anyone else has tried the krzys flash cart before. i got one to test my hack on a real nes. it worked, well kinda, a few times. every game i tried has some type of minor graphical error. then it just doesnt work anymore. just get the typical blank nes screen of a certain color. I contacted the seller but have not heard back yet. just thought i would ask if anyone has had similar issues.
Fiskbit
Posts: 891
Joined: Sat Nov 18, 2017 9:15 pm

Re: krzys cart?? mine failed

Post by Fiskbit »

The graphical errors you're seeing may be the result of an NES hardware issue discovered somewhat recently where some kind of analog effect (maybe signal reflections) on the CPU data lines causes corruption of the sprite RAM in the PPU, similar to DRAM decay. The presence of this issue and severity differ across consoles, but it seems to be much more common with modern cartridge hardware, with the PowerPak being the earliest example I've heard of. The FDS RAM adapter is the only contemporary cartridge I'm aware of that can trigger this [Edit: Looks like Goose2k also reported it on Mighty Final Fight on his extremely sensitive console]. (For more information, you can find research on the problem starting at this post: Re: Graphical glitches on the Everdrive)

Assuming you're seeing sprite corruption as described above, that can be fixed by putting 100 ohm resistors in series on the 8 CPU data lines (or using a different, unaffected console). These resistors were added on the PowerPak at some point and are present in the Everdrive N8 Pro, though the original Everdrive N8 and krzysiobal's cart don't have them, I believe.

I can't make a guess about the cart not working anymore, though.
nesoldskool
Posts: 5
Joined: Sat Feb 19, 2022 7:24 am

Re: krzys cart?? mine failed

Post by nesoldskool »

awesome. thank you. I will look into this deeper. About it not working, hopefully the seller can help me out. He is the maker of krzy carts.
Last edited by nesoldskool on Tue Mar 01, 2022 8:56 pm, edited 1 time in total.
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