nesdev.org

I'm applying unit automated testing to the 6502 instructions of my NES emu.
I ended up replicating in the tests the same logic that's being tested, so I could be making the same mistake twice, the tests pass and I don't notice it.
So are there already test cases compiled for this from a known working emulator?
Thanks!

Blargg's 6502 tests do a CRC32 checksum of what the results should be after an exhaustive all-possible-inputs test, so it's highly unlikely that they will give a false report.
But finding out what's wrong is the hard part.