phases $x2/$x6/$xA should be delayed because the same node in the chroma generator has to drive extra long traces for emphasis even when emphasis isn't being used Specifically, it's because the chip is NMOS and those nodes have to be pulled up to +5V via resistors on the die, and those pull-up resi...

I am looking at this finally in FCEUx. For me, I get to a black screen directly after "Licensed by Nintendo of America, Inc." I attached the 4-score and it still crashes the same. Is this what you are seeing in an emulator? I see the exact same thing in Nintendulator, and it's plainly obv...

If your data is written to $2007 in this manner: ;each write to $2007 with a data ;(separated here with commas): A, B, C, D, E, F, G, H, I and bit2 of $2000 has already been set to 0 (enabling PPU to display tiles horizontally) in a vblank period, then your screen should display: ABCDEFGHI OR, if t...

Dwedit wrote: ↑Fri Jul 22, 2022 6:14 pm If it's MMC1, there shouldn't be any bus conflicts?

As noted above, rather than switching from UNROM to MMC1, the poster has decided to instead switch to UOROM (which obviously still suffers from bus conflicts),

About my code, what way should I write it then? By using LDX and STX instead of setting stuff into the accumulator? I am new at creating templates of code lines so I do not know what difference there is by using the accumulator instead of the X register. You're presumably replacing code from the or...

Hello. I have slowly learning to program my own custom codes for my Megaman 1 hack, focusing on attack patterns and movement patterns for bosses and normal enemies. However, one of my codes (one that makes the boss stay still for a determinated time before jumping to the next action) is showing a g...

Running the patch on a NES triggers the shot when the trigger is halfway pushed on the Zapper, works as it should. But it seems with the revolver, it seems it shots when the trigger is released. As stated on the wiki : The official Zapper's trigger returns 0 while the trigger is fully open, 1 while...

1) How should I know that FF in the program does not stand for ISC {ABX} ? (illegal opcode) It's not an instruction until the program counter ends up pointing at it. If your emulator somehow is trying to execute that block of 0xFFs as code, then you're doing something wrong. 2) If the FF really is ...

I see an obvious solder bridge connecting two pins on the back there? (For those somehow unable to see it, it's the right hand chip, lower left area) The SMB1 cartridge doesn't have any bridges in that area: https://nescartdb.com/images/700/6d26509249f161184d69d98ece2cba53.jpg (I assume it's okay t...

s the ROM chip bigger than the original, and if so, did you repeat the data to fill the whole chip? Yes, I used 2 ST 27c512 (64kb) and so the PRG is repeated 4 times and the chr 8 times. The rom is pin compatible since is 28pins and I already used in an NROM (actualy another soccer game with the sa...

This might be totally unrelated, but there used to be a common problem in emulators where the Super Mario Bros title screen would be missing. Anyone remember why that was or if it could be related? I'm pretty sure that was because of ROM images that had been extracted from multicarts whose contents...

On the C64, a very easy way to "profile" code is to change the border color at the start and end of different sections of code. That way, you can see how many scanlines your code is taking in real time. Is there a similar trick available on the NES? Near as I can see, there are no registe...

I did some tests. nmi brk fail? 287481621_381695023819153_4877789103913901460_n.jpg Those results suggest that NMI never triggered at all, which might explain the problems you're seeing elsewhere - double-check that PPU pin 19 connects to CPU pin 33 and that there's a suitable pull-up resistor at e...

dot: (am unsure) ….oooh, maybe a pixel on the screen? The "PPU Scrolling" page mentions things happening on certain "dots", and in this case it's referring to PPU cycle numbers within a given scanline (of which the first 256 directly correspond to rendered pixels and the remaini...

Rather than attaching an Excel spreadsheet (that some of us might not be willing or able to open), could you post a screenshot?