nesdev.org

Thanks clueless, no problem, I'm glad you understand.

Do you have a download available? I'll try your emu with my homebrew game. I notice in your screen-shot that you have a "debug" menu. I'm curious what debug features you have. The debug menu just contains a memory viewer whereyou can view the CPU and PPU memory, which looks like this. htt...

I have fixed many erros since I posted this thread, games like Super mario now work almost flawlessly (graphics wise). The main problem that was causing this was the SBC instruction, in which I was not calculating the borrow correctly. I have also renamed my "Nes emu" to something more int...

Sorry for the awkward question and change of subject, but it's all in the same boat, my awful PPU emulation haha. If you stop SMB with a debugger is it looping on reads of $2002? If so then it's either looking for sprite 0 hit ($40) or VBLANK ($80) set. If sprite 0 hit isn't working correctly SMB u...

Cheers Dwedit, that's helpful, I was unsure about how the latched value works exactly. I just thought, since my emulator fails every sprite test in NEStress, it might be a good idea to mention those too. First of all, can anyone tell me what might be the cause of sprites not showing or flickering du...

I'll get down to brass tax here, my emulator sucks and I was thinking about abandoning its development in favour of another emulator I'm working on. However, I feel that the very least I can do is get it to a reasonably decent standard, and since I got Blargs CPU test (nestest.nes) working 100%, I w...

My emu finally passed all the tests :D http://img31.imageshack.us/img31/3746/36322957.png Thanks so much for all the help, this is a major mile stone for me as alot of the games are booting and playing fine, and of course, thanks for writing the nestest Blargg. Now, the other instruction tests are r...

As stated on the Wiki, it's best to get nestest passing first. Yes, I will get the last two tests fixed (hopefully) first before I move on to other test roms. As for my PPU emulation, the only problem (optimistically) is that incorrect data is been written to the nametables. As you said though, i w...

Blargg, I tried your instruction tests as well, but something is going very wrong in my emulator. Here is a screenshot of the rom single "01-implied.nes", rom. (same story for all the rom singles) http://img829.imageshack.us/img829/4381/60638956.png After a short time, I hit an illegal ins...

Hi Blargg Both logs are basically in the exact same format now, and I'm actually making some great progress since my first post, I now pass 10 of the 13 tests and lots of games that didn't boot before are starting to work. http://img822.imageshack.us/img822/7799/39851074.png Something I realised is ...

a u8 - u8 is always >= 0 I beg to differ, in C++ if you to the sum 10 - 15, you will get -5, unless you typecast the result of course. For example, this will evaluate as true. if (10-15 < 0) As for the nestest log, I will show you the first part that isn't the same. (ignoring scanline and small cyc...

Ok, i think i got the CPX flags problem fixed. void NesMainClass::_CMP(u8 cmpReg, u8 toCmp, int cycles) { cpuCycles += cycles; // Is the Negative/Sign bit set? (TestBit(cmpReg-toCmp, 7)) ? SET_N_FLAG : CLR_N_FLAG; // Is the result zero? (cmpReg-toCmp == 0) ? SET_Z_FLAG : CLR_Z_FLAG; // Should we set...

@pdq I have already done this, and I actually have programmed my emulator to output an identicaly formatted log file to the nestest.log file. Although, the contents is different at this point obviously. @James To make things clearer, take this for example (but you're right lol) regs->P = (TestBit(re...

Hi everyone Here is a screenshot of the nestest.nes rom completed in my emulator http://img44.imageshack.us/img44/7392/55517763.png As you can see, many of the tests fail, but the test numbers that are indicated are mostly all just general failiures, such as "SBC # Failiure", so it's diffi...

It's only now that I'm starting to feel confident with writing emulators, and actually making good progress. Emulation is tough, but that's why I love it, it's a challenge.

Anyway, sorry to hijack the thread jonathonrh, but I'm sure you will find your way with emulation, just keep at it