That's an impressively detailed simulation. This is tangentially related, but I made an html5 Apple ][+ emulator which, of course, includes a 6502 component. Mine doesn't simulate gates or anything that cool (and isn't even 100% correct yet) but it boots and runs a lot of different software (at full speed): <a href="http://porkrind.org/a2/" rel="nofollow">http://porkrind.org/a2/</a>