What a great resource!

I know a lot about these chips and learned something new:

There is a single cycle NOP on the 65C02! Spiffy!

---Excerpt Below---

There aren't really any undocumented instructions on the 65C02--any instructions not listed above are documented as performing no operation.

However, these alternate NOPs are not created equal. Some have one- or two-byte operands (which they don't do anything with), and they take different amounts of time to execute.

Instruction Bytes Cycles

     xxxxxx10	2	2
     xxxxxx11	1	1
     01000100	2	3
     x1x10100	2	4
     01011100	3	8
     11x11100	3	4