Author Topic: Everdrive N8 Pro 72-pin version: Problems in NES Front-Loader "European Version"  (Read 484 times)

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Offline NewRisingSun

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I have received the 72-pin version of the Everdrive N8 Pro, and have the following problem when using it in my front-loading Nintendo Entertainment System "European Version" (i.e. PAL-B), as seen in the first attached picture: During gameplay, there are graphical glitches on the left side of the screen. The glitches do not occur in the N8 Pro menu, and nor do they occur when running normal cartridges in the console, so I don't think the console is bad.

The N8 Pro Diagnostic's RAM checks show no errors. Running Nintendo's original NTF2 test cartridge from the Everdrive N8 Pro shows that "VRAM" (i.e. nametable memory, PPU address $2xxx) seems to be the culprit, as seen in the second attached picture. This happens with two OS versions that I have tried, 2.10 and 2.08.

Is my N8 Pro broken? Then why do the glitches not occur in Everdrive N8 Pro's menus, and why does the diagnostic check not detect the problem? Yes, I have cleaned the pins just to be sure.

Also a background question: does the N8 Pro during gameplay use the console's 2 KiB of nametable memory, like a normal NES cartridge, or does it always map its own memory into the PPU $2000-$2FFF address range, even with the vast majority of games that do not use 4-screen mirroring?
« Last Edit: November 26, 2020, 11:28 PM by NewRisingSun »

Offline NewRisingSun

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I obtained a 72-to-60 pin converter and tried that Everdrive N8 Pro in my Sharp Turbo Twin Famicom (AN-505BK). It worked flawlessly there. This means that the N8 Pro itself is not broken, but that it is incompatible with the licensed PAL NES console. In particular, there seems to be a problem with CIRAM /CE timing.

Because there are some games that are exclusive to licensed PAL NES consoles, such as Astérix and Die Schöne und das Biest -- exclusive in the sense that they will not work on NTSC and Dendy consoles -- this is an issue that should be resolved in a future firmware version.
« Last Edit: December 10, 2020, 05:19 PM by NewRisingSun »