Some videos about Keymmodore and Pimmodore-64.

More features were added after these (like several Compatibility Modes), but you can get the idea. It’s in spanish though, but you can enable subtitles in english.

https://www.youtube.com/watch?v=0yE07ZxENaU&t=254shttps://www.youtube.com/watch?v=aitljqoASrA&t=125shttps://youtu.be/va8B_2cYdTg?t=2635