This handy guide to the 6502 family of processors makes a great pocket reference for any retro assembly programmer.
Its a reference to the over 250 instructions (ha!) with all cycle times and lengths. Youll never need to open a book again!
Seriously though, programming retro systems is a labor of love and so is this app. Im planning a lot of updates to go well beyond just the processor data. I hope you will give it a try.
IMPORTANT NOTE (2013-08-08) : I will have a new version available shortly that adds CPU filtering. At that time, I will set the price back to free. I like to play with the price. If you want the app for free, check back in a few days. If you cant wait, then by all means feel free to help the cause. Cheers!