[flohofwoe]

Alternatively it's fairly trivial today to run a transistor-level simulation of the 6502 (and a couple of other chips) thanks to the visual6502 reverse engineering effort (the http: link is intended):

http://visual6502.org/

The netlist is available in their Git repo:

https://github.com/trebonian/visual6502

...and there's a C port of the netlist simulation code:

https://github.com/mist64/perfect6502

One advantage of this approach is that you can inspect internal chip state that isn't visible on the output pins, which is very useful for emulator coding.

...and a couple of years ago I glued all those bits and pieces together for a 'remix' of the original visual6502 web application, using WASM + WebGL + Dear Imgui:

https://floooh.github.io/visual6502remix/