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PPU of E revision has a bug with reading palette, so using it with Everdrive leads to incorrect restoring of save states in games.

All UMC CPUs are quite pickie to clock signal. So you can play around with capacitor between generator and cpu.

Depending on what's available to you, it might be preferable to use famiclone parts (e.g. UA6527, UA6528) instead of a real famicom, and/or to use the real famicom as a famicom. It is hard to find working ones. So buying a famicom is preferable. Also better to use processors with G or H revision, s...

I described my modification of mmc3 board in this post viewtopic.php?f=2&t=12421&start=15#p247101

You should use deprotected ROM (you need to apply patch that I posted in this thread earlier)

I don't have clear final picture.

Is the shaking graphics on mmc3 the result of ppu a12 glitch? Just remember such problem with the game "8-bit Adv Stains Gate" on hardware.

I'm pretty sure that it has the same pinout.
I've checked several pins an they are match.

I've never seen these games. Actually nj-1b and nj-1c for Final Fantasy VII. I made Diablo II from one of them.
Nj-1 for Pokemon Yellow.

When I tried to make Pokemon Yellow from FF VII board then it has freezed when screen is scrolled outside a home. So I have to bought original Pokemon Yellow cart.
By the way, I have several design of pcb with mapper 163.
NJ-1, NJ-1B, NJ-1C

Clone on 1818p is quite common in Russia because first models of "Dendy" have this chip. You wont rid off jailbars completely, even if you build external video amplifier. You can try this scheme to fix sound: uGuFedOhVEg.jpg * Remove components marked with grey. "мкф" is uF https://youtu.be/VUQ7KATQ...

I thought that scheme for 3th and 4th controller is popular https://forums.nesdev.com/viewtopic.php?t=18066#p229366 In all japanese games where only 1 or 2 players available 3th and 4th will work like 1st and 2nd. More interesting how japanese 4-player adapter works. It uses a way from NES four scor...

What happens when cartridges try to disable the internal CIRAM in clones where it's permanently enabled? I hear people saying that "games don't work", but what exactly is the visual result of trying to use these cartridges? In most cases pin for disabling ciram is used for detecting cartridge prese...

So dev cartridge is needed for testing purposes from time to time. I know that invitenes has some integration with assembler studio to debug in realtime on hardware. But i'm not sure that everdrive has something similar. So for debugging you don't have good alternatives to emulators. Topic starter h...

Nowadays for retro gamedev you can use emulator. The only reason of using dev cartridge is unique hardware.
Also everdrive clone doesn't have much difference from original, so it can be used in the same way.

Dwedit wrote: ↑

Tue May 26, 2020 5:00 pm

Two bad CPUs sounds unlikely

It is quite real situation. I have repaired famicom where both cpu are gone due to short circuit in cartridge.

But it is better to buy replacement famicom board on ebay than buy chinese cpu. It is really high chance to get faulty cpu from aliexpess.