I've coded a NES emulator for my C++ programming course (https://github.com/JaCzekanski/AnotherNES) and one of the features is live view of RAM and PPU registers (check out Screenshots at bottom of Readme). As for now only RAM can be changed during game play but I plan to carry on with development and create emulator with ability to change every register of console in realtime (like ICU64 here: https://www.youtube.com/watch?v=tjcvR5McmSg)
