The only difference you can rely on between a 6502 and 6510 is the IO ports on the 6510.
Beyond that, the handling of undocumented opcodes can be different between different models.
TXY/TYX is only present on the 16-bit 65C816
Beyond that, the handling of undocumented opcodes can be different between different models.
TXY/TYX is only present on the 16-bit 65C816
[Update] I guess there was an entire set of illegal opcodes on the 6510. Unfortunately, I longer have my source code; that shoebox is long gone.
The one thing I do remember is that it had something to do with registers because it gave my code a computer significant performance boost because I didn't have to go to memory so often.
References:
Yes, but they were the same set of illegal/undocumented opcodes as the 6502.