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@Quietust https://github.com/christopherpow/nes-test-roms/blob/master/other/nestest.log I'll need to contact the owner of that repository, then - the log there is quite old and has at least one error in it (specifically, the indirect JMP test at $DBB5 suggests that it's going to jump to $A900 when ...

I'm testing my 6502 implementation with "nestest" rom and comparing my emulator behavior with "nestest" logs, but there is a strange fragment in tthis "nestest" logs: C836 A9 04 LDA #$04 A:FF X:00 Y:00 P:EF SP:FB CYC:146 SL:243 C838 48 PHA A:04 X:00 Y:00 P:6D SP:FB CYC:152 SL:243 C839 28 PLP A:04 X...

What's new for version 5.66 (04/09/2021) ... [general] - Removed value $40 ORed at every joypad read. ... I hope this means it's being handled by general Open Bus emulation (i.e. setting the upper 3 bits according to the last value that the CPU successfully read) rather than a hardcoded special cas...

You're supposed to set the scroll *after* all VRAM updates. The usage of PPUADDR and PPUDATA messes up the scroll, so every time you use them you corrupt the scroll and the screen "jumps" for a frame. Move your PPUSCROLL and PPUCTRL writes so they happen after the VRAM updates, so that the scroll i...

I get no readings off of any the address or data lines of the S-CPU. Not even a little. When you say "no readings", do you mean that they're outputting a constant value that never changes, or do you mean that they're not outputting any values at all (i.e. they're high impedance)? If the former, hav...

So, in summary, the problem was that you were trying to write to VRAM while rendering was enabled and your code was taking longer than 1 VBLANK to run, and you fixed it by turning off rendering beforehand.

M2m wrote: ↑

Sun Apr 04, 2021 12:59 am

On the Gameboy I think fixed cats are better then floating cats - at least faster !

But floating cats are more amusing, and much easier to transform into lolcats.

VGdevOnSNES wrote: ↑

Sun Apr 04, 2021 2:52 am

After looking for the problem, i managed to fix it.

Could you go into more detail? Other people might run into similar problems in the future and want to know how to fix the problem, and finding a thread that just ends with "I fixed it" tends to be frustrating.

I use FCEUX, and what it does when running the program is (what it's supposed to do) writing on PPU addresses $2000-$20FF, but for some reason, when it reaches $207A, it jumps back to $2000 and writes over my characters i've already written. NMI is enabled, but it does nothing except incrementing a...

i made a code to write a "Hello, world!" message on the Nametable. for some reason, when the PPU address reaches $207A, it jumps back to $2000 and writes over the characters i've already written. if you want to see the code, here it is: Load_page1_message_loop: LDA PAGE1_MESSAGE,X STA PPU_DATA ; Wr...

I was reading there's a flag that makes it so that it increments to nametable address can be either +1 or +32. So, if your ROM has vertical mirroring, is it better to use the +32 increment and write in columns? And if so, if your map is RLE compressed, does that mean that you have to decompress the...

I'm pretty sure one of them has been here before, too, since I clearly remember seeing a "where did my first post go?" question a few weeks ago (before it got deleted).

Hello everyone I am newbie here and yesterday I have submitted my first post on this forum and it successfully post on the forum but now when I login into my account it doesn't appear on the forum section where I have submitted my post please help me to fix it because I think there is a bug. :? You...

Well, my emulator generates raw unsigned samples. I do what Anes wrote, the resample method is adding around 40 samples, then DIV by approx 40. There's a formula to convert to signed samples, working like a charm... but it's a second step though. I prefer to work with integer numbers for speed. I w...

When the screen loads up (e.g. after the map is just loaded), this is how I can get the bytes I need to display 1) I have to figure out what's the address of the byte on the top left tile within the camera, something like first_byte = start + (cameray * map_width) + camerax 2) Then, I'd have to loo...