nesdev.org

On the first cycle, the opcode is read, and the program counter is incremented past it. (In an emulator, this will usually take place before the switch statement). Opcode = CPU_Read (CPU_PC.Word++); On the second cycle, the pointer address is read into a temporary register, and the program counter i...

Ah. You're using the sound buffer callback for timing. That makes sense, it's about the easiest way to do it on a Win32 platform. Well, I'm seeing from 90-95fps with throttling disabled. This is on a 1.8 GHz P4 @ 2.4 GHz.

The most accurate NES emulators execute one opcode at a time and also update the PPU/APU/MMC states at each clock cycle. Nintendulator falls into this category. (What, if any, other emulators do so?) I can't determine what Nintendulator's full speed is on my system, since I can't find any option to ...

I'm currently in the process of writing a cycle-based 2A03 CPU core. The ViCE documentation ( http://www.nesdev.com/6502_cpu.txt ) is quite helpful, but the information contained there about branch opcodes is not all that clear. I know that some people here (Quietust and perhaps others) have written...

When using a YIQ-based method to generate a NES palette, like this one by Blargg , what's the most accurate way to do color emphasis? Someone once posted a table of floating point constant factors for each of the 8 color emphasis values, which would be applied to the RGB values to make "emphasi...

In my opinion, until a more coherent NES file format like UNIF is adopted, the best way to handle emulation of mappers is simply to use a big fucking CRC32 database containing data for all known dumps. Quite a few NES emulators already do this. That way, it doesn't matter if the ROM still has "...

Does anyone have a list of other ROMs whose mirroring bits in GoodNES are incorrect? I'm planning on doing a database-based mapper detector in my emulator, and I don't want to run into these issues.

Which emulators display this glitch? Does swapping the mirroring type have any effect (it's a CNROM title, so this should be hard wired).

The existing PPU documentation is excellent, but there are a few minor aspects that I thought were somewhat unclear. (1) If the primary object has an X-coordinate in the range (0...7) and the OBJ clip or background clip features (or both) are enabled, will the primary object collision still take pla...