Emulator warning menu

An idea of emulator is if you want to implement a warning menu that you might enable some warnings (you can select which ones, including to count how often and how many times it occurs, in case someone find it useful) such as:

• Decimal arithmetic
• Unofficial opcodes
• DPCM interference with controller read (not applicable to keyboard)
• Reading or writing with bus conflicts
• OPLL register writing too fast
• OAM DRAM not reloaded correctly
• PPU slave mode is selected
• Attempting to write to CHR ROM
• Attempting to write to PRG ROM (may be useful to warn if making a multigame cartridge containing NROM games)
• JMP indirect wrapping
• Zero-page wrapping
• PPU emphasis bits
• Attempts to advance coin counter without correct timing
• Improper iNES header
• Writing to tape with too low or too high frequency
• Vertical scroll out of range
• PPU is enabled too early
• Attempts to enable AY8930 mode
• (For .NSF only) Read/write to a memory which a .NSF isn't allowed to read/write

Which emulators support these warnings and counting, if any, and can any emulator add such feature?

(If this is in the wrong section, or another thread already exist, you can merge it in the correct thread, please; I don't know if it should but hopefully a moderator should know because that is your job)

NO$GBA supports counting "errors" in the free version and breaking them down by type in the paid version. But some of these can be made as breakpoints in existing NES emulators.

What's wrong with using emphasis bits?

It prevents people who broke a VS system or PC10 in order to get an RGB famicom from playing the game.

Most of the stuff on that list is meaningless. PPU slave mode?

You forgot "access to zero page using absolute addressing".
Also, what is "decimal arithmetic" ?

"Decimal arithmetic" is using ADC or SBC while SED is on. It can break famiclone compatibility.


Defined as writing a value to ROM whose relevant bits don't match those from the ROM, in mappers that don't avoid bus conflicts.


How would this be defined?


This is intentional more likely than not.


By "too early" do you mean less than one full field has elapsed after power-on or reset?


What's this?

a.k.a writing to $2000 with the $40s bit set. Causes the PPU to try to drive pins high that have been tied to ground, possibly damaging the PPU.

Just because you're ignorant doesn't mean it has no meaning.

Using the SED instruction, or doing the equivalent using PHA PLP.

Trying to pretending that the YM2149 in the sunsoft 5b is actually an AY-3-8930. Seems a bit of a stretch.

I don't know if this was widely known before, but only recently I learned that the PPU has 4 pins that can act as either input or output of pixels. When set to input, the pixels coming in from these pins are drawn in place of color 0. Apparently this would allow PPUs to be chained together to generate multiple background layers (plus a layer of background colored sprites!). All consoles have these pins connected to GND, so color 0 always shows up as %0000. Setting the pins for output while they are connected to GND might actually be bad, electronically speaking (or so I heard).

Relax. I've just checked the wiki to find that this appears to be the case. Every other technical document doesn't mention it and even though the wiki does that is a recent appearance. So to be honest most people are ignorant of it. If we are then that's hardly our fault now is it?

I guessed as much, "BCD mode" or "BCD arithmetic" would be clearer.

Yes, or mappers that sometimes have bus conflicts.

I don't know, but because of the way the DRAM works it can cause problems which may not be easy to emulate.

Correct; all of these things need to be options, anyways.[/quote]

Yes, that is what I mean.

Yes, exactly what I mean and the purpose of it.

Yes, although such a warning option would ensure compatibility if you need to make up a Sunsoft 5B cartridge and don't have a YM2149, in case the only chip you have that can imitate it is AY8930 instead (I don't expect this to be particularly common, but maybe it might happen sometimes).